about:debugging (before Firefox 68) - Firefox Developer Tools
the about:debugging page provides a single place from which you can attach the firefox developer tools to a number of debugging targets. at the moment it supports three main sorts of targets: restartless add-ons, tabs, and workers. opening the about:debugging page there are several different ways to open about:debugging: type "about:debugging" in the firefox url bar. in the tools > web developer menu, click "service workers". select the web developer menu under the hamburger menu (), then select "service workers". when about:debugging opens, on the left-hand side, you'll see a sidebar enabling you to switch between the two main views: one for add-ons and one for workers. ...
...eveloper menu, click "service workers". select the web developer menu under the hamburger menu (), then select "service workers". when about:debugging opens, on the left-hand side, you'll see a sidebar enabling you to switch between the two main views: one for add-ons and one for workers. whether or not system add-ons appear in the list on this page depends on the setting of the devtools.aboutdebugging.showsystemaddons preference. if you need to see system add-ons, navigate to about:config and make sure that this value is set to true. add-ons the add-ons section in about:debugging only supports restartless add-ons, including basic bootstrapped extensions, add-on sdk add-ons, and webextensions. this page enables you to do two things: load an add-on temporarily from disk connect the ...
...owsystemaddons preference. if you need to see system add-ons, navigate to about:config and make sure that this value is set to true. add-ons the add-ons section in about:debugging only supports restartless add-ons, including basic bootstrapped extensions, add-on sdk add-ons, and webextensions. ...
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Debugging a XULRunner Application - Archive of obsolete content
the easiest way to debug a xulrunner application is to get the system to tell you what's wrong! there are two different consoles available and various preferences which will ensure that the information you need to know is displayed on them. see also debugging javascript prefs setting the following prefs will make your debugging life much easier! preferences should be in a .js file in the directory %appname%/defaults/preferences/. it doesn't matter what the file is called (as long as the extension is .js), so debug.js is as good as any! /* debugging prefs */ pref("browser.dom.window.dump.enabled", true); pref("javascript.options.showinconsole", true); pref("javascript.options.strict", true); pref("nglayout.debug.disable_xul_cache", true); pref("nglayout.debug.disable_xul_fastload",...
... see: preference reference for more information about these preferences. console to enable a console on windows, start xulrunner with the -console argument. note that -console goes after the application.ini argument: e.g. ...
...t). jsdump(str) (function defined below) will output str as a "message" with a speech bubble icon next to it: function jsdump(str) { components.classes['@mozilla.org/consoleservice;1'] .getservice(components.interfaces.nsiconsoleservice) .logstringmessage(str); } for more information about the error console see the error console and browser console article. ...
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Debugging
debugging a project as large as mozilla can be a daunting task. fortunately, over the years, mozilla developers have come up with not just technologies and features to help you debug code, but have devised tips and techniques that can help too. also available are assorted tools that you can use when debugging. documentation topics debugging on top of the mozilla platform debugging javascript code how to debug javascript code, with a focus on debugging code in the mozilla project itself. debugging a xulrunner application tips and suggestions that will help you debug your xulrunner based application. debugging update problems learn how to debug update problems in mozilla-based applications. ...
...n top of the mozilla platform debugging javascript code how to debug javascript code, with a focus on debugging code in the mozilla project itself. debugging a xulrunner application tips and suggestions that will help you debug your xulrunner based application. debugging update problems learn how to debug update problems in mozilla-based applications. debugging the mozilla platform using debuggers with mozilla debugging mozilla on windows faq questions (and answers) about debugging mozilla on windows. debugging mozilla on os x questions (and answers) about debugging mozilla on os x. debugging mozilla with gdb gdb is our primary debugger on mac and linux. ...
...ems in mozilla-based applications. debugging the mozilla platform using debuggers with mozilla debugging mozilla on windows faq questions (and answers) about debugging mozilla on windows. debugging mozilla on os x questions (and answers) about debugging mozilla on os x. debugging mozilla with gdb gdb is our primary debugger on mac and linux. debugging mozilla with lldb lldb is the new debugger on mac. advanced debugging techniques understanding crash reports how to read crash reports, which are full of information yet often not easy to interpret and act on. debugging a minidump windows crash reports include a minidump, which contains a lot of information about the application when it crashed. d...
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JavaScript Debugger Service - Archive of obsolete content
obsolete since gecko 33 (firefox 33 / thunderbird 33 / seamonkey 2.30) this feature is obsolete. although it may still work in some browsers, its use is discouraged since it could be removed at any time. try to avoid using it. ...
...k in some browsers, its use is discouraged since it could be removed at any time. try to avoid using it. in firefox versions prior to gecko 33 (firefox 33 / thunderbird 33 / seamonkey 2.30), the javascript debugger service (or simply jsd) used to be an xpcom component that allows the tracking of javascript while it was being executed in the browser. however, jsd has been removed in favor of the debugger api. see the tracking bug bug 800200 for more details. snippets acquiring the service we acquire the service by calling the xpcom object. ...
...next, we add code to the various hooks. ...
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Remotely debugging Firefox for Metro - Archive of obsolete content
this article explains how to use remote debugging to inspect and code running in the new windows 8 ("metro-style") firefox app, using the developer tools in firefox on the desktop. prerequisites you will need: windows 8 (metro-style) firefox running in the touch-friendly "metro" mode on a windows 8 computer. firefox running in classic "desktop" mode on windows, mac os x, or linux, either on a separate computer or in a separate profile on the same computer. ...
...ites you will need: windows 8 (metro-style) firefox running in the touch-friendly "metro" mode on a windows 8 computer. firefox running in classic "desktop" mode on windows, mac os x, or linux, either on a separate computer or in a separate profile on the same computer. ...
... on a windows 8 computer. firefox running in classic "desktop" mode on windows, mac os x, or linux, either on a separate computer or in a separate profile on the same computer. ...
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Debugging JavaScript
this document is intended to help developers writing javascript code in mozilla, mainly for mozilla itself, but it may also be useful for web developers. it should give pointers to tools, aids and tricks which make debugging your code easier. web console this is the first place to go when you're debugging a web page; open the web console using the web console option in the web developer menu. this shows any javascript errors in your app, as well as any logging calls from the console api. ...
... web console option in the web developer menu. this shows any javascript errors in your app, as well as any logging calls from the console api. browser console the browser console lets you see all javascript errors and logging in the browser, including from firefox code. to enable it, go to about:config in the url bar and set devtools.chrome.enabled to true, or set the "enable chrome and add-on debugging" option in the developer tool settings. activate it through with the menu tools > web developer > browser console. you can also start the browser console when you launch firefox, by launching firefox from the command line and passing --jsconsole as a flag: /path/to/firefox --jsconsole log to the browser console using the standard console api after importing console.jsm: let console = (cu.
...-jsconsole as a flag: /path/to/firefox --jsconsole log to the browser console using the standard console api after importing console.jsm: let console = (cu.import("resource://gre/modules/console.jsm", {})).console; console.log("hello from firefox code"); error console this is obsolete and is no longer enabled in firefox by default. use the web console or the browser console instead. browser debugger (built-in) on firefox 19 or later, it's possible to use the built-in js debugger on the browser itself. go to about:config and set the following two prefs: devtools.chrome.enabled: true devtools.debugger.remote-enabled: true after you restart the browser, you can access the browser debugger through tools > web developer > browser toolbox. (note that before firefox 28, this was labeled "bro...
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Debugging OpenGL
for various reasons, debugging opengl related code can be tricky. this article provides suggestions for how to improve your efficiency while debugging opengl code in gecko. opengl debug mode when running a debug build, you can enable the opengl debug mode by defining the environment variable moz_gl_debug. if you start up firefox with this variable defined, the following behavior changes occur: each time you issue an opengl call, a check is performed to ensure that the gl context is current, using a thread-local static variable to keep track of this. if the context isn't current, the call aborts. every time an opengl call completes, glfinish() gets run automatically. this flushes out each call, essentially turning opengl into a synchronous api. ...
...ing behavior changes occur: each time you issue an opengl call, a check is performed to ensure that the gl context is current, using a thread-local static variable to keep track of this. if the context isn't current, the call aborts. every time an opengl call completes, glfinish() gets run automatically. this flushes out each call, essentially turning opengl into a synchronous api. this makes debugging crashes caused by an opengl call much easier, since the stack you see will match where the call was issued, rather than some time in the future when it happens to run and crash. if an opengl error occurred when executing the call, an error message is output. note: you can download debug builds from mozilla taskcluster — click an appropriate platform's debug build on the left, e.g. linux...
...g crashes caused by an opengl call much easier, since the stack you see will match where the call was issued, rather than some time in the future when it happens to run and crash. if an opengl error occurred when executing the call, an error message is output. note: you can download debug builds from mozilla taskcluster — click an appropriate platform's debug build on the left, e.g. ...
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Debugging service workers - Firefox Developer Tools
when you open the application panel’s service workers view on a page that doesn't have a service worker registered, you'll get the following output shown: this gives you some advice on what to do if you don't have a service worker registered, and were perhaps expecting there to be one registered! let's start by troubleshooting this. getting your service worker to register before you can look at your service worker in action in the applications panel, you need to successfully register it. ...
...ator.serviceworker .register('sw.js') .then(function() { console.log('service worker registered'); }); } if you get the path wrong, for example, you'll get an error in the web console giving you a hint as to what's wrong, which depends on what exactly is wrong with the code. ...
....log('service worker registered'); }); } if you get the path wrong, for example, you'll get an error in the web console giving you a hint as to what's wrong, which depends on what exactly is wrong with the code. if this is not enough to help you figure out the problem, you could also try going to the javascript debugger and stepping through your code to pinpoint exactly where it is going wrong. debugging your service worker in any case, when the service worker is successfully registered, you'll see information about it displayed in the application > service workers view (along with any other service workers registered on the same domain): this gives you a variety of information about your service worker: the url that the service worker is registered on. that last time the service work...
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Debugging HTML - Learn web development
ting html is fine, but what if something goes wrong, and you can't work out where the error in the code is? this article will introduce you to some tools that can help you find and fix errors in html. prerequisites: html familiarity, as covered in, for example, getting started with html, html text fundamentals, and creating hyperlinks. objective: learn the basics of using debugging tools to find problems in html. debugging isn't scary when writing code of some kind, everything is usually fine, until that dreaded moment when an error occurs — you've done something wrong, so your code doesn't work — either not at all, or not quite how you wanted it to. for example, the following shows an error reported when trying to compile a simple program written in the rus...
...atively easy to understand — "unterminated double quote string". if you look at the listing, you can probably see how println!(hello, world!"); might logically be missing a double quote. however, error messages can quickly get more complicated and less easy to interpret as programs get bigger, and even simple cases can look a little intimidating to someone who doesn't know anything about rust. debugging doesn't have to be scary though — the key to being comfortable with writing and debugging any programming language or code is familiarity with both the language and the tools. html and debugging html is not as complicated to understand as rust. html is not compiled into a different form before the browser parses it and shows the result (it is interpreted, not compiled). and html's elemen...
...en the web was first created, it was decided that allowing people to get their content published was more important than making sure the syntax was absolutely correct. the web would probably not be as popular as it is today, if it had been more strict from the very beginning. active learning: studying permissive code it's time to study the permissive nature of html code. ...
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Using the Debugger map scopes feature - Firefox Developer Tools
select the "bundle.js" file in the sources panel on the left and then set a breakpoint at line 102 in the increment function. ...
... select the "bundle.js" file in the sources panel on the left and then set a breakpoint at line 102 in the increment function. ...
... select the "bundle.js" file in the sources panel on the left and then set a breakpoint at line 102 in the increment function. ...
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Remote debugging - Archive of obsolete content
this requires quite a bit of trust, in both directions. the developer trusts that his time is not being wasted: the crash is a real bug in firefox. (that is, there's a legitimate reason it happens only on some computers, but that reason just hasn't been discovered.) the crash victim, in turn, trusts the developer with full access to his computer. ...
...s the developer with full access to his computer. a good place to start is a detailed stack (in gdb, use bt followed by bt full). there give more information about the stack than a breakpad crash report: not only the names of the functions on the stack, but also the values they were passed. core dump a core dump includes all of the memory of a crashed program. it allows you to see the crash in a debugger even after the program has long exited. transferring a core dump is tricky, because it is large and can contain private information. core dumps on mac and linux to generate a core dump on mac, type "ulimit -c unlimited", run firefox from the command line, and make firefox crash. when firefox crashes, a core will be placed in /cores. you can then load the core file into gdb (gdb firefox-bin cor...
...ced in /cores. you can then load the core file into gdb (gdb firefox-bin corefile), and it will be as if you caught the crash while running firefox under gdb! when transferring a mac or linux core dump, you'll also have to transfer the firefox executable (and maybe more). core dumps on windows on windows you can produce a "minidump". ...
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Debugging Frame Reflow
create a text file (for instance reflow_rules.txt). ...
...its reflow reflow reason available width, available height computed width, computed height the previous and the next frame in flow and a count number. when the frame's reflow is finished the following information is displayed : reflow metric (desired) width, height max. element width maximum width frame status overflow area getting the log make sure that your build is a debug build (in short you need ac_add_options --enable-debug in your .mozconfig file). create a text file (for instance reflow_rules.txt). enter this line in the text file * 1 this should look like: point the gecko_display_reflow_rules_file environment variable to the path of the reflow_rules.txt file. run the debug build, saving stdout to a file. on mac this is accom...
...ile). create a text file (for instance reflow_rules.txt). enter this line in the text file * 1 this should look like: point the gecko_display_reflow_rules_file environment variable to the path of the reflow_rules.txt file. run the debug build, saving stdout to a file. on mac this is accomplished with: $ env dyld_library_path="`pwd`/obj-ff-dbg/dist/nightlydebug.app/contents/macos" \ ./obj-ff-dbg/dist/nightlydebug.app/contents/macos/firefox-bin > logfile.txt after loading your testcase, the log file will contain the promised information. log file analysis the log file for a simple table like <!doctype html public "-//w3c//dtd html 4.01 transitional//en"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=iso-8...
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Debugging Table Reflow
reflow the most efficient tool to claim that html-table code is the victim and not the source of layout bugs is a frame reflow debug log. look there especially how the maxelementsize (mes) and desired size are propagated. block reflow another way to debug the reflow process is implemented inside nsblockframe.cpp. ...
... reflow the most efficient tool to claim that html-table code is the victim and not the source of layout bugs is a frame reflow debug log. look there especially how the maxelementsize (mes) and desired size are propagated. block reflow another way to debug the reflow process is implemented inside nsblockframe.cpp. ...
...ese options can be combined with a comma separated list messages generated by the reflow switch: block(div)(1)@00be5ac4: reflowing dirty lines computedwidth=9000 computedheight=1500 this message is generated inside of nsresult nsblockframe::reflowdirtylines(nsblockreflowstate& astate) it first shows the block id and address and then the computed width and height from the htmlreflowstate. ...
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Debug.writeln - Archive of obsolete content
the debug.writeln function sends strings to the script debugger, followed by a newline character. syntax debug.writeln([str1 [, str2 [, ... [, strn]]]]) parameters str1, str2, ... , strn optional strings to send to the script debugger. remarks the debug.writeln function sends strings, followed by a newline character, to the immediate window of the microsoft script debugger at run time. if the script is not being debugged, the debug.writeln function has no effect. the debug.writeln function is almost identical to the debug.write function. the only difference is that the debug.write function does not send a newline character after sending the strings. ...
...wed by a newline character, to the immediate window of the microsoft script debugger at run time. if the script is not being debugged, the debug.writeln function has no effect. the debug.writeln function is almost identical to the debug.write function. the only difference is that the debug.write function does not send a newline character after sending the strings. example this example uses the debug.writeln function to display the value of the variable in the immediate window of the microsoft script debugger. note: to run this example, you must have a script debugger installed and the script must run in debug mode. internet explorer 8 includes the javascript debugger. ...
... this example uses the debug.writeln function to display the value of the variable in the immediate window of the microsoft script debugger. note: to run this example, you must have a script debugger installed and the script must run in debug mode. internet explorer 8 includes the javascript debugger. if you are using an earlier version of internet explorer, see how to: enable and start script debugging from internet explorer. var counter = 42; debug.writeln("the value of counter is " + counter); requirements supported in the following document modes: quirks, internet explorer 6 standards, internet explorer 7 standards, internet explorer 8 standards, internet explorer 9 standards, internet explorer 10 standards, internet explorer 11 standards. also supported in store apps (windows 8 an...
...counter = 42; debug.writeln("the value of counter is " + counter); requirements supported in the following document modes: quirks, internet explorer 6 standards, internet explorer 7 standards, internet explorer 8 standards, internet explorer 9 standards, internet explorer 10 standards, internet explorer 11 standards. also supported in store apps (windows 8 and windows phone 8.1). ...

Debugging CSS - Learn web development
previous overview: building blocks next sometimes when writing css you will encounter an issue where your css doesn't seem to be doing what you expect. perhaps you believe that a certain selector should match an element, but nothing happens, or a box is a different size than you expected. this article will give you guidance on how to go about debugging a css problem, and show you how the devtools included in all modern browsers can help you to find out what is going on. prerequisites: basic computer literacy, basic software installed, basic knowledge of working with files, html basics (study introduction to html), and an idea of how css works (study css first steps.) objective: to learn the basics of what browser devtools are, and how to do simple inspe...
... the different longhand properties and their values. you can toggle values in the rules view on and off, when that panel is active — if you hold your mouse over it checkboxes will appear. uncheck a rule's checkbox, for example border-radius, and the css will stop applying. you can use this to do an a/b comparison, deciding if something looks better with a rule applied or not, and also to help debug it — for example if a layout is going wrong and you are trying to work out which property is causing the problem. the following video provides some useful tips on debugging css using the firefox devtools: editing values in addition to turning properties on and off, you can edit their values. perhaps you want to see if another color looks better, or wish to tweak the size of something? devt...
... applies, and also shows you the color property applied to the em crossed out. you can now see that the class is overriding the element selector. find out more about the firefox devtools there is a lot of information about the firefox devtools here on mdn. take a look at the main devtools section, and for more detail on the things we have briefly covered in this lesson see the how to guides. debugging problems in css devtools can be a great help when solving css problems, so when you find yourself in a situation where css isn't behaving as you expect, how should you go about solving it? the following steps should help. take a step back from the problem any coding problem can be frustrating, especially css problems because you often don't get an error message to search for online to help...
...us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

nglayout.debug.disable xul fastload
true xul fastload is disabled. ...
... true xul fastload is disabled. ...
... true xul fastload is disabled. ...
... true xul fastload is disabled. ...

IJSDebugger
js/ductwork/debugger/ijsdebugger.idlscriptable provides the javascript debugger service. you should usually interface with this using the javascript code module instead of directly. see the javascript debugger api guide for details. 1.0 66 introduced gecko 9.0 inherits from: nsisupports last changed in gecko 9.0 (firefox 9.0 / thunderbird 9.0 / seamonkey 2.6) implemented by: @mozilla.org/jsdebugger;1 as a service: var jsdebugger = components.classes["@mozilla.org/jsdebugger;1"] .createinstance(components.interfaces.ijsdebugger); note: you should almost never directly use this service; instead, you should use the javascript code module that does this for you. ...
... 2.6) implemented by: @mozilla.org/jsdebugger;1 as a service: var jsdebugger = components.classes["@mozilla.org/jsdebugger;1"] .createinstance(components.interfaces.ijsdebugger); note: you should almost never directly use this service; instead, you should use the javascript code module that does this for you. the only time you should directly use this interface to create the debugger object is if you need to debug chrome; due to bug 707237, the javascript code module doesn't work in that case. see the javascript debugger api guide for details on using the debugger api. method overview [implicit_jscontext] void addclass(); methods addclass() defines the global debugger constructor. on return, the debugger object has been added to the global context. [im...
...cript code module doesn't work in that case. see the javascript debugger api guide for details on using the debugger api. method overview [implicit_jscontext] void addclass(); methods addclass() defines the global debugger constructor. on return, the debugger object has been added to the global context. [implicit_jscontext] void addclass(); parameters none. ...
...ork in that case. see the javascript debugger api guide for details on using the debugger api. method overview [implicit_jscontext] void addclass(); methods addclass() defines the global debugger constructor. on return, the debugger object has been added to the global context. [implicit_jscontext] void addclass(); parameters none. ...

nsIDebug
xpcom/base/nsidebug.idlscriptable provides debugging support for scripted languages, such as javascript, java, python, perl, and so forth. inherits from: nsisupports last changed in gecko 1.7 note: c/c++ consumers who are planning to use the nsidebug interface with the @mozilla.org/xpcom;1 contract should use ns_debugbreak() from xpcom glue instead, or alternatively the ns_abort, ns_assertion, ns_break, and ns_warning macros, which also call ns_debugbreak() if used in a debugging build. method overview void abort(in string afile, in long aline); void assertion(in string astr, in string aexpr, in string afile, in long aline); void break(in string afile, in long aline); void warning(in string astr, in string afile, in long aline); methods abort() requests the process t...
...ine); void break(in string afile, in long aline); void warning(in string astr, in string afile, in long aline); methods abort() requests the process to trigger a fatal abort. void abort( in string afile, in long aline ); parameters afile file containing abort request. aline line number of abort request. ...
...sed on the xpcom_debug_break environment variable, defaulting to calling break() on windows and os/2 and warning on other platforms. void assertion( in string astr, in string aexpr, in string afile, in long aline ); parameters astr assertion message. aexpr expression that failed. afile file containing assertion. aline line number of assertion. break() requests the software break into a debugger. if no debugger is running then this usually results in a program crash. however, on windows a dialog is first presented giving the user the option of aborting, breaking, or ignoring the request. the dialog can be suppressed by use of the windbgdlg registry key. this allows the debugger to be attached before the software break. void break( in string afile, in long aline ); parameters afi...
... the debugger to be attached before the software break. void break( in string afile, in long aline ); parameters afile file containing break request. aline line number of break request. warning() shows a warning. void warning( in string astr, in string afile, in long aline ); parameters astr warning message. afile file containing warning. aline line number of warning. ...

Debugging Firefox Desktop - Firefox Developer Tools
this guide explains how you can use the firefox developer tools to debug a different instance of desktop firefox running on the same machine. in this guide, the instance of firefox being debugged is called the debuggee, and the instance of firefox doing the debugging is called the debugger. enable remote debugging first, you'll need to ensure that both debugger and debuggee have the "enable browser chrome and add-on debugging toolboxes" and "enable remote debugging" settings checked in the developer tools settings. you only need to do this once: the setting values persist across restarts. start the debugger server next, you need to start the debugger server in the debuggee. ...
... remote debugging first, you'll need to ensure that both debugger and debuggee have the "enable browser chrome and add-on debugging toolboxes" and "enable remote debugging" settings checked in the developer tools settings. you only need to do this once: the setting values persist across restarts. start the debugger server next, you need to start the debugger server in the debuggee. run the debuggee from the command line, passing it the --start-debugger-server option: /path/to/firefox --start-debugger-server passed with no arguments, --start-debugger-server makes the debugger server listen on port 6000. ...
.... start the debugger server next, you need to start the debugger server in the debuggee. run the debuggee from the command line, passing it the --start-debugger-server option: /path/to/firefox --start-debugger-server passed with no arguments, --start-debugger-server makes the debugger server listen on port 6000. to use a different port, pass the desired port number: /path/to/firefox --start-debugger-server 1234 note: in windows, the start-debugger-server call will only have one dash: firefox.exe -start-debugger-server 1234 note: by default, and for security reasons, the devtools.debugger.force-local option is set. ...
... --start-debugger-server makes the debugger server listen on port 6000. to use a different port, pass the desired port number: /path/to/firefox --start-debugger-server 1234 note: in windows, the start-debugger-server call will only have one dash: firefox.exe -start-debugger-server 1234 note: by default, and for security reasons, the devtools.debugger.force-local option is set. if you want to debug a firefox instance from an external machine, you can change this option, but only do this on a trusted network or set a strong firewall rule to lock down which machines can access it. ...

WEBGL_debug_renderer_info - Web APIs
the webglrenderingcontext.getparameter() method can help you to detect which features are supported and the failifmajorperformancecaveat context attribute lets you control if a context should be returned at all, if the performance would be dramatically slow. webgl extensions are available using the webglrenderingcontext.getextension() method. ...
...the webglrenderingcontext.getparameter() method can help you to detect which features are supported and the failifmajorperformancecaveat context attribute lets you control if a context should be returned at all, if the performance would be dramatically slow. webgl extensions are available using the webglrenderingcontext.getextension() method. ...
... at all. in firefox, if privacy.resistfingerprinting is set to true, this extensions is disabled. this extension is available to both, webgl1 and webgl2 contexts. constants ext.unmasked_vendor_webgl vendor string of the graphics driver. ext.unmasked_renderer_webgl renderer string of the graphics driver. ...
...2 contexts. constants ext.unmasked_vendor_webgl vendor string of the graphics driver. ext.unmasked_renderer_webgl renderer string of the graphics driver. examples with the help of this extension, privileged contexts are able to retrieve debugging information about about the user's graphic driver: var canvas = document.getelementbyid('canvas'); var gl = canvas.getcontext('webgl'); var debuginfo = gl.getextension('webgl_debug_renderer_info'); var vendor = gl.getparameter(debuginfo.unmasked_vendor_webgl); var renderer = gl.getparameter(debuginfo.unmasked_renderer_webgl); console.log(vendor); console.log(renderer); specifications specification status comment webgl_debug_renderer_infothe definition of 'webgl_debug_renderer_info' in that specification. reco...

Debug.msTraceAsyncCallbackStarting - Archive of obsolete content
the debug.mstraceasynccallbackstarting function associates the callback stack with a previously specified asynchronous operation. syntax debug.mstraceasynccallbackstarting(asyncoperationid) parameters asyncoperationid the id associated with the asynchronous operation. remarks call this function in the callback function for the asynchronous operation after the call to debug.mstraceasyncoperationcompleted. note: some debugging tools do not display the information sent to the debugger. asyncoperationid must correspond to the operation name previously returned from debug.mstraceasyncoperationstarting. example the following code provides an example of tracing an asynchronous call for a windows 8.x store app. ...
... debug.mstraceasyncoperationcompleted. note: some debugging tools do not display the information sent to the debugger. asyncoperationid must correspond to the operation name previously returned from debug.mstraceasyncoperationstarting. example the following code provides an example of tracing an asynchronous call for a windows 8.x store app. function asyncwrapperfunction() { var opid = debug.mstraceasyncoperationstarting('async trace'); dosomethingasync().then(function (result) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_success); debug.mstraceasynccallbackstarting(opid); // process result of async operation. ...
...call for a windows 8.x store app. function asyncwrapperfunction() { var opid = debug.mstraceasyncoperationstarting('async trace'); dosomethingasync().then(function (result) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_success); debug.mstraceasynccallbackstarting(opid); // process result of async operation. }, function (error) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_error); debug.mstraceasynccallbackstarting(opid); }); debug.mstraceasynccallbackcompleted(); } function dosomethingasync() { return winjs.promise.as(true); } asyncwrapperfunction(); requirements supported in the internet explorer 11 standards document mode. also supported in store apps (windows 8.1 and windows...

Debug.msTraceAsyncCallbackCompleted - Archive of obsolete content
the debug.mstraceasynccallbackcompleted function indicates that an asynchronous operation has completed. syntax debug.mstraceasynccallbackcompleted() parameters asyncoperationid the id associated with the asynchronous operation. status optional the status of the asynchronous operation. if not specified, debug.ms_async_op_status_success is used. remarks call this function when the asynchronous operation completes. asyncoperationid must correspond to the operation id previously returned from debug.mstraceasyncoperationstarting. the possible values for status include: debug.ms_async_op_status_success debug.ms_async_op_status_canceled debug.ms_async_op_status_error note: some debugging tools do not display the information sent to the debugger. example...
...e possible values for status include: debug.ms_async_op_status_success debug.ms_async_op_status_canceled debug.ms_async_op_status_error note: some debugging tools do not display the information sent to the debugger. example the following code provides an example of tracing an asynchronous call for a windows 8.x store app. function asyncwrapperfunction() { var opid = debug.mstraceasyncoperationstarting('async trace'); dosomethingasync().then(function (result) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_success); debug.mstraceasynccallbackstarting(opid); // process result of async operation. ...
...call for a windows 8.x store app. function asyncwrapperfunction() { var opid = debug.mstraceasyncoperationstarting('async trace'); dosomethingasync().then(function (result) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_success); debug.mstraceasynccallbackstarting(opid); // process result of async operation. }, function (error) { debug.mstraceasyncoperationcompleted(opid, debug.ms_async_op_status_error); debug.mstraceasynccallbackstarting(opid); }); debug.mstraceasynccallbackcompleted(); } function dosomethingasync() { return winjs.promise.as(true); } asyncwrapperfunction(); requirements supported in the internet explorer 11 standards document mode. also supported in store apps (windows 8.1 and windows...

Debug.write - Archive of obsolete content
the debug.write function sends strings to the script debugger. syntax debug.write([str1 [, str2 [, ... [, strn]]]]) paramaters str1, str2, ... , strn optional strings to send to the script debugger. remarks the debug.write function sends strings to the immediate window of a script debugger at run time. if the script is not being debugged, the debug.write function has no effect. the debug.write function is almost identical to the debug.writeln function. the only difference is that the debug.writeln function sends a newline character after the strings are sent. example this example uses the debug.write function to display the value of the variable in the immediate window of the script debugger. ...
...function has no effect. the debug.write function is almost identical to the debug.writeln function. the only difference is that the debug.writeln function sends a newline character after the strings are sent. example this example uses the debug.write function to display the value of the variable in the immediate window of the script debugger. note: to run this example, you must have a script debugger installed and the script must run in debug mode. internet explorer 8 includes the javascript debugger. if you are using an earlier version of internet explorer, see how to: enable and start script debugging from internet explorer. ...
...n to display the value of the variable in the immediate window of the script debugger. note: to run this example, you must have a script debugger installed and the script must run in debug mode. internet explorer 8 includes the javascript debugger. if you are using an earlier version of internet explorer, see how to: enable and start script debugging from internet explorer. var counter = 42; debug.write("the value of counter is " + counter); requirements supported in the following document modes: quirks, internet explorer 6 standards, internet explorer 7 standards, internet explorer 8 standards, internet explorer 9 standards, internet explorer 10 standards, internet explorer 11 standards. also supported in store apps (windows 8 and windows phone 8.1). ...

Access debugging in add-ons - Firefox Developer Tools
we are planning to deprecate the use by firefox add-ons of the techniques described in this document. don't write new add-ons that use these techniques. the following items are accessible in the context of chrome://browser/content/debugger.xul (or, in version 23 beta, chrome://browser/content/devtools/debugger.xul): window.addeventlistener("debugger:editorloaded") - called when the read-only script panel loaded. ...
... add-ons of the techniques described in this document. don't write new add-ons that use these techniques. the following items are accessible in the context of chrome://browser/content/debugger.xul (or, in version 23 beta, chrome://browser/content/devtools/debugger.xul): window.addeventlistener("debugger:editorloaded") - called when the read-only script panel loaded. ...
...at use these techniques. the following items are accessible in the context of chrome://browser/content/debugger.xul (or, in version 23 beta, chrome://browser/content/devtools/debugger.xul): window.addeventlistener("debugger:editorloaded") - called when the read-only script panel loaded. window.addeventlistener("debugger:editorunloaded") relevant files: chrome://browser/content/devtools/debugger-controller.js chrome://browser/content/devtools/debugger-toolbar.js chrome://browser/content/devtools/debugger-view.js chrome://browser/content/devtools/debugger-panes.js unfortunately there is not yet any api to evaluate watches/expressions within the debugged scope, or highlight elements on the page that are referenced as variables in the debugged scope. (currently a work in progress, s...

The Firefox JavaScript Debugger - Firefox Developer Tools
the javascript debugger enables you to step through javascript code and examine or modify its state to help track down bugs. you can use it to debug code running locally in firefox or running remotely, for example on an android device running firefox for android. see remote debugging to learn how to connect the debugger to a remote target. to find your way around the debugger, here's a quick tour of the ui. how to to find out what you can do with the debugger, refer to the following how-to guides. open the debugger pretty-print a minified file search use a source map pause execution you probably want to pause the execution of your code, in order to see what is going on at various points. ...
...ind your way around the debugger, here's a quick tour of the ui. how to to find out what you can do with the debugger, refer to the following how-to guides. open the debugger pretty-print a minified file search use a source map pause execution you probably want to pause the execution of your code, in order to see what is going on at various points. ...
... points. there are multiple ways to tell the debugger how and when to pause: set a breakpoint set a conditional breakpoint set an xhr breakpoint set event listener breakpoints break on exceptions use watchpoints for property reads and writes break on dom mutation disable breakpoints control execution what can you do after execution pauses? step through code black box a source debug worker threads debug eval sources look at values you probably want to see the value of variables or expressions, either during execution or when it is paused. set a logpoint set watch expressions reference keyboard shortcuts source map errors ...

Debug.msUpdateAsyncCallbackRelation - Archive of obsolete content
the debug.msupdateasynccallbackrelation function updates the relationship status between a synchronous work item and the associated asynchronous operation. syntax debug.msupdateasynccallbackrelation(relatedasyncoperationid, relationtype) parameters relatedasyncoperationid the id associated with the asynchronous operation. relationtype optional the value that specifies the relationship status. remarks the synchronous work item is typically the callback function for the asynchronous operation. this function may be called when an asynchronous operation is aborted, when a join operation is used, or in other scenarios. ...
...associated with the asynchronous operation. relationtype optional the value that specifies the relationship status. remarks the synchronous work item is typically the callback function for the asynchronous operation. this function may be called when an asynchronous operation is aborted, when a join operation is used, or in other scenarios. the possible values for relationtype include: debug.ms_async_callback_status_assign_delegate debug.ms_async_callback_status_join debug.ms_async_callback_status_chooseany debug.ms_async_callback_status_cancel debug.ms_async_callback_status_error for more information, see debug constants. note: some debugging tools do not display the information sent to the debugger by this function. requirements supported in the i...

Debug.setNonUserCodeExceptions - Archive of obsolete content
the debug.setnonusercodeexceptions property determines whether any try-catch blocks in this scope are to be treated by the debugger as user-unhandled. exceptions can be classified as thrown, user-unhandled or unhandled. syntax debug.setnonusercodeexceptions [= bool]; remarks if this property is set to true within a given scope, the debugger can then choose whether to take some specified action on exceptions thrown inside that scope: for instance, if the developer wishes to break on user-unhandled exceptions. setting this property to false is the same as never having set the property. for more information on debugging, see the active script debugging overview. example the following code shows how to set this property. ...
...n choose whether to take some specified action on exceptions thrown inside that scope: for instance, if the developer wishes to break on user-unhandled exceptions. setting this property to false is the same as never having set the property. for more information on debugging, see the active script debugging overview. example the following code shows how to set this property. (function () { debug.setnonusercodeexceptions = true; try{ var x = null; x.y(); } catch (e) { // catch the exception. } })(); requirements supported in the following document modes: internet explorer 10 standards and internet explorer 11 standards. also supported in store apps (windows 8 and windows phone 8.1). not supported in the following document modes: quirks, internet explorer...

nsIDebug2
xpcom/base/nsidebug2.idlscriptable adds access to additional information in debug builds of mozilla code by expanding upon the features in nsidebug 1.0 66 introduced gecko 1.9.2 inherits from: nsidebug last changed in gecko 1.9.2 (firefox 3.6 / thunderbird 3.1 / fennec 1.0) attributes attribute type description assertioncount long the number of assertions since process start. this is normally zero in release builds, but does include calls to nsidebug.assertion(). read only. isdebugbuild boolean whether xpcom was compiled with debug defined. this often correlates to whether other code (for example, firefox, xulrunner) was compiled with debug defined. read only. ...
... assertioncount long the number of assertions since process start. this is normally zero in release builds, but does include calls to nsidebug.assertion(). read only. isdebugbuild boolean whether xpcom was compiled with debug defined. ...

Debug eval sources - Firefox Developer Tools
you can debug javascript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the function constructor. in the video below, we load a page containing a source like this: var script = `function foo() { console.log('called foo'); } //# sourceurl=my-foo.js`; eval(script); var button = document.getelementbyid("foo"); button.addeventlistener("click", foo, false); the evaluated string is given the name "my-foo.js" using the //# sourceurl directive. this source is then listed in the source list pane, and can be opened and debugged like any other source. the name of the source will also appear in stack traces appearing in the web console. ...
...js`; eval(script); var button = document.getelementbyid("foo"); button.addeventlistener("click", foo, false); the evaluated string is given the name "my-foo.js" using the //# sourceurl directive. this source is then listed in the source list pane, and can be opened and debugged like any other source. the name of the source will also appear in stack traces appearing in the web console. the debugger will also stop at debugger; statements in unnamed eval sources. ...

console.debug() - Web APIs
objn a list of javascript objects to output. the string representations of each of these objects are appended together in the order listed and output to the console. msg a javascript string containing zero or more substitution strings, which are replaced with subst1 through substn in consecutive order. subst1 ... substn javascript objects with which to replace substitution strings within msg. ...
...o replace substitution strings within msg. this gives you additional control over the format of the output. see using string substitutions in console for a description of how substitutions work. see outputting text to the console in the documentation of the console object for details. specifications specification status comment console apithe definition of 'console.debug()' in that specification. living standard initial definition ...

WEBGL_debug_shaders.getTranslatedShaderSource() - Web APIs
return value a string containing the translated shader source. an empty string is returned, if: no source has been defined or, webglrenderingcontext.compileshader() has not yet been called or, the translation for the shader failed. ...
...ringcontext.compileshader() has not yet been called or, the translation for the shader failed. examples var canvas = document.getelementbyid('canvas'); var gl = canvas.getcontext('webgl'); var shader = gl.createshader(gl.fragment_shader); gl.shadersource(shader, 'void main() { gl_fragcolor = vec4(gl_fragcoord.x, 0.0, 0.0, 1.0); }'); gl.compileshader(shader); var src = gl.getextension('webgl_debug_shaders').gettranslatedshadersource(shader); console.log(src); // "void main(){ // (gl_fragcolor = vec4(gl_fragcoord.x, 0.0, 0.0, 1.0)); // }" specifications specification status comment webgl_debug_shadersthe definition of 'webgl_debug_shaders.gettranslatedshadersource' in that specification. recommendation initial definition. ...

WEBGL_debug_shaders - Web APIs
the webgl_debug_shaders extension is part of the webgl api and exposes a method to debug shaders from privileged contexts. this extension is not directly available to web sites as the way of how the shader is translated may uncover personally-identifiable information to the web page about the kind of graphics card in the user's computer. webgl extensions are available using the webglrenderingcontext.getextension() method. for more information, see also using extensions in the webgl tutorial. availability: depending on the privacy settings of the browser, this extension might only be available to privileged contexts. this extension is available to both, webgl1 and webgl2 contexts. methods webgl_debug_shaders.gettranslatedshadersource() returns the translated shader source. specific...
...ions in the webgl tutorial. availability: depending on the privacy settings of the browser, this extension might only be available to privileged contexts. this extension is available to both, webgl1 and webgl2 contexts. methods webgl_debug_shaders.gettranslatedshadersource() returns the translated shader source. specifications specification status comment webgl_debug_shadersthe definition of 'webgl_debug_shaders' in that specification. recommendation initial definition. ...

Automatically Handle Failed Asserts in Debug Builds - Archive of obsolete content
the handler receives the assert string, and sequentially attempts to match each word in the string (left to right) to registry dword names from hklm\software\mozilla.org\windbgdlg and hkcu\software\mozilla.org\windbgdlg. at the first match, it will take the action specified by the dword's value. the valid values are: 0x5 automatically ignore 0x4 automatically retry 0x3 automatically abort note that you can also force windbgdlg to prompt, by setting a value of 0xfffffffe. to "comment out" a value, set its value to 0xffffffff. ...

Running Windows Debug Builds Downloaded From Tinderbox - Archive of obsolete content
you can see this by looking in at firefox.exe with http://www.dependencywalker.com/. unfortunately these dlls are not redistributable. to get these dlls you only have to install the visual c++ compilers from the windows vista sdk. no other packages are necessary. if you are a mozilla employee or contractor, click for more instructions. ...

Debug.msTraceAsyncOperationStarting - Archive of obsolete content
initiates a trace for an asynchronous operation. debug ...

Debugging Internet Explorer
use jrmuizel's script to get started. ...

Debugging Safari
to enable the very useful debug menu in safari use the following: defaults write com.apple.safari includeinternaldebugmenu 1 it is often useful to switch into single process mode by turning off "use multi-process windows" ...

Debugging update problems
you can do this using the live http headers addon to determine the url of the update request. that url might look something like: https://aus3.mozilla.org/update/3/firefox/12.0a1/20120106040225/darwin_x86_64-gcc3-u-i386-x86_64-shark/nightly-profiling/darwin%2010.8.0/default/default/update.xml?force=1 you can then request this url manually to see what's inside. useful preferences enabling the following preferences in about:config can help troubleshoot problems with updates: app.update.log - for application updates; extensions.logging.enabled - for add-on updates. ...

Debugging a hang on OS X (Archived)
when you have the raw sample data, you can't just save that and attach it to a bug, because the format is not very usable (unless the developer is a mac hacker). export it using tools > generate report, and attach this as a text file to the bug report. the final data will show where the application spent all its time when it was hung, and hopefully your bug will be easier to fix now! see also debugging on mac os x ...

Building Firefox with Debug Symbols
by default, a release build of firefox will not generate debug symbols suitable for debugging or post-processing into the breakpad symbol format. use the following mozconfig settings to do a build with symbols: building firefox with symbols there is a single configure option to enable building with symbols on all platforms. this is enabled by default so unless you have explcitly disabled it your build you should include symbols. ac_add_options --enable-debug-symbols this can optionally take an argument for the type of symbols that need to be produced (like "-g3"). by default it uses "-g" on linux and macos. this value takes precedence over the flags set in moz_debug_flags note that this will override the values provided for cflags and cxxflags. breakpad symbol files after the ...

nglayout.debug.disable_xul_cache
of the next time mozilla starts). ...

Debugging out-of-memory problems
a common bug to diagnose with emscripten is where a big game fails due to an out of memory error (oom) somewhere during load time. by the time about:memory is loaded in a new tab and you have clicked the "measure" button to diagnose what's happened, the memory usage causing the spike has gone away, making temporary memory spikes difficult to diagnose. this article explains how to debug such problems. out-of-memory exceptions from js setting memory.dump_reports_on_oom in about:config to true will cause the browser to automatically write about:memory dumps to a temp file printed to the browser console (note: not web console) when an oom crash is encountered. for more information, see bug 969415. out-of-memory crashes in some cases, running out of memory causes the browser to crash. i...

Debug worker threads - Firefox Developer Tools
the debugger shows the source code for all running worker threads — web workers, service workers, etc. — listed in the sources list. you can open the javascript file for the worker process and set breakpoints and logpoints just as you can with javascript code running on the main thread. inspecting worker code for example, see the selected item worker.js below — it is listed in a separate thread in the sources list, but appears in the source pane in the same way as main thread code when selected. setting breakpoints, etc. you can set a breakpoint (or logpoint) on any active worker thread: when execution is paused in a worker thread, the context of the debugger is updated to show the correct breakpoints, call stack, etc., just as you'd expect. ...

Open the debugger - Firefox Developer Tools
there are three ways to open the debugger: select "debugger" from the web developer submenu in the firefox menu (or tools menu if you display the menu bar or are on mac os x) press ctrl + shift + z on windows and linux, or cmd + opt + z on macos (starting in firefox 71; prior to firefox 66, the letter in this shortcut was s). press the menu button ( ), select "developer", then "debugger". ...

Debugger keyboard shortcuts - Firefox Developer Tools
l feature: for example, to change the screen brightness or the volume. see this guide to using these keys as standard function keys. to use a remapped key as a standard function key, hold the function key down as well (so to open the profiler, use shift + function + f5). note: before firefox 66, the combination ctrl + shift + s on windows and linux or cmd + opt + s on macos would open/close the debugger. from firefox 66 and later, this is no longer the case. global shortcuts these shortcuts work in all tools that are hosted in the toolbox. command windows macos linux increase font size ctrl + + cmd + + ctrl + + decrease font size ctrl + - cmd + - ctrl + - reset font size ctrl + 0 cmd + 0 ctrl + 0 ...

Remote Debugging - Firefox Developer Tools
the other browser might be on the same device as the tools themselves or on a different device, such as a phone connected over usb. the detailed instructions for connecting the developer tools are specific to the runtime. you can connect the developer tools to gecko-based runtimes like firefox desktop, firefox for android, and thunderbird. ...

debugger - JavaScript
the debugger statement invokes any available debugging functionality, such as setting a breakpoint. if no debugging functionality is available, this statement has no effect. syntax debugger; examples using the debugger statement the following example shows code where a debugger statement has been inserted, to invoke a debugger (if one exists) when the function is called. function potentiallybuggycode() { debugger; // do potentially buggy stuff to examine, step through, etc. } when the debugger is invoked, execution is paused at the debugger statement. it is like a breakpoint in the script source. specifications specification ecmascript (ecma-262)the definition of 'debugger statement' in that specification. ...

Index - Firefox Developer Tools
found 158 pages: # page tags and summary 1 firefox developer tools developing mozilla, guide, tools, web development, web development:tools, l10n:priority firefox developer tools is a set of web developer tools built into firefox. you can use them to examine, edit, and debug html, css, and javascript. 2 3d view html, tools, web development, web development:tools when you click on the 3d view button, the page goes into 3d view mode; in this mode, you can see your page presented in a 3d view in which nested blocks of html are increasingly "tall," projecting outward from the bottom of the page. this view makes it easy to visualize the nesting of your content. 3 accessibility inspector accessibility, accessibility insp...
...ications, and it's possible to embed it in your own xulrunner app. dom inspector can serve as a sanity check to verify the state of the dom, or it can be used to manipulate the dom by hand, if desired. 10 all keyboard shortcuts tools, l10n:priority this page lists all keyboard shortcuts used by the developer tools built into firefox. ...
...te of the dom, or it can be used to manipulate the dom by hand, if desired. 10 all keyboard shortcuts tools, l10n:priority this page lists all keyboard shortcuts used by the developer tools built into firefox. 11 application application, debugging, devtools, firefox, guide, manifests, service workers the application panel provides tools for inspecting and debugging modern web apps (also known as progressive web apps). this includes inspection of service workers and web app manifests. 12 debugging service workers application, devtools, firefox, guide, service workers in this article we will look at debugging service workers using the firefox devtools application panel. 13 inspecting web app manifests application, devto...
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MCD, Mission Control Desktop, AKA AutoConfig - Archive of obsolete content
create an email account, and configure imap and smtp: [root@calaz /usr/lib/thunderbird] $ cat thunderbird.cfg //put everything in a try/catch try { // 1) env variables if(getenv("user") != "") { // *nix settings var env_user = getenv("user"); var env_home = getenv("home"); } else { // windows settings var env_user = getenv("username"); var env_home = getenv("homepath"); } var env_mozdebug= getenv("mozilla_debug"); // var env_user = prompt("indiquez votre login", toto); // 2) lock general preferences //ldap address book lockpref("ldap_2.prefs_migrated", true); lockpref("ldap_2.servers.ldapint.auth.savepassword", true); lockpref("ldap_2.servers.ldapint.description", "ldap int"); lockpref("ldap_2.servers.ldapint.filename", "abook-1.mab"); lockpref("ldap_2.servers.ldapint.uri", "ldap...
... var cn = getldapvalue(values, "cn"); var mail = getldapvalue(values, "mail"); var url = getldapvalue(values, "labeleduri"); // those ldap variables are only available in this processldapvalues context! // so we set the preferences that need them here. lockpref("mail.identity.id1.useremail", mail); lockpref("mail.server.server2.name", mail); lockpref("mail.identity.id1.fullname", cn); //debug with popup error messages doesn't work anymore :-( !! var env_mozdebug= getenv("mozilla_debug"); if (env_mozdebug) {displayerror("no error, just a debug, cn =" + cn + " and mail = " + mail); } } } // 4) call ldap servers to get ldap attributes (mail & cn), this will finally call processldapvalues, "3)" just above. getldapattributes("ldap2.int-evry.fr","ou=people,dc=int-evry,dc=fr","uid=" ...
...entities", "id1" ); defaultpref("mail.account.account1.server", "server1" ); defaultpref("mail.accountmanager.accounts", "account1" ); defaultpref("mail.accountmanager.defaultaccount", "account1" ); defaultpref("mail.smtp.defaultserver", "smtp1" ); defaultpref("mail.smtpservers", "smtp1" ); // close the try, and call the catch() } catch(e) { displayerror("lockedpref", e); } test autoconfig debug to check that our autoconfig works fine, we just set to env variable to check the read of thunderbird.cfg file: $ export nspr_log_modules=mcd:5 $ export nspr_log_file=/tmp/thunderbird-log.txt when thunderbird has started, you should read: $ cat /tmp/thunderbird-log.txt -1209403040[808a788]: general.config.filename = thunderbird.cfg -1209403040[808a788]: evaluating .cfg file thunderbird.cfg ...
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Web Replay
web replay is no longer developed by mozilla; however, the work continues as a standalone project. learn more web replay allows firefox content processes to record their behavior, replay it later, and rewind to earlier states. replaying processes preserve all the same js behavior, dom structures, graphical updates, and most other behaviors that occurred while recording. devtools' debugger and console can be used to inspect and control the replay. getting started to enable web replay (macos and firefox nightly only), go to devtools settings and select "enable webreplay". web replay's features can only be used in a tab that is recording or replaying. there are a few ways to start recording a tab: record current tab open the developer tools and click the button indicated below.
...ools are not open. open a saved recording in a new tab click the 'tools -> web developer -> web replay -> open new recording tab' menu item to open a new blank tab that is recorded. live rewinding at any time while recording, the tab can be rewound to replay earlier behavior, all the way back to when the tab was opened or to the last time it navigated. an easy way to see this is to open the debugger developer tool, press the pause button and then the rewind button. while replaying old behavior, the tab can't be interacted with. to resume recording and interacting with the tab, press the pause button and then the play button to run forward to the end of the recording. save recording and replay on the same machine clicking the 'tools -> web developer -> web replay -> save recordin...
...rom the one which recorded them. this requires using the same build of firefox and a reasonably similar version of the operating system; otherwise the tab will probably crash. this feature has had little testing or polishing and there is not yet a good definition of 'reasonably similar'. time travel features this section describes extensions to the developer tools that use time travel to help debug a recording/replaying tab. step back when paused, the reverse step button in the debugger developer tool will step to the previous line executed and allow inspecting program state there. it is the opposite of the normal forward step button. rewind to breakpoint when paused, if there are any breakpoints set then the rewind button will run back and stop at the last time a breakpoint was set.
...And 29 more matches

Index - Archive of obsolete content
er and xmlhttprequest, this is a new feature that is not yet supported by all browsers in use in the wild. the code snippets on this page will let your site work until these new features are more widely available. ...
... 375 blackconnect java no summary! 376 blackwood java no summary! 377 bonsai developing mozilla, tools it is a tool that lets you perform queries on the contents of a cvs archive; you can: get a list of c...
...2 other mozilla customization pages administration, configuration management, enterprise no summary! 373 protecting mozilla's registry.dat file administration, configuration management, enterprise no summary! 374 automatically handle failed asserts in debug builds as of 2004-12-8, it is now possible to automatically handle failed asserts in debug builds of mozilla for windows. 375 blackconnect java no summary! 376 blackwood java no summary! 377 bonsai developing mozilla, tools it is a tool that lets you perform queries on the contents of a cvs archive; you can: get a list of checkins, see what checkins have been made by a given person, or on a given cvs branch, or in a particu...
...And 28 more matches

Index - Web APIs
lizes the attributes of a compositionevent object instance. 653 compositionevent.locale api, compositionevent, deprecated, locale, property, reference the locale read-only property of the compositionevent interface returns the locale of current input method (for example, the keyboard layout locale if the composition is associated with ime). 654 console api api, debugging, overview, console, dump, log, output, test the console api provides functionality to allow developers to perform debugging tasks, such as logging messages or the values of variables at set points in your code, or timing how long an operation takes to complete. 655 constantsourcenode api, audio, constantsourcenode, interface, media, reference, web audio api the cons...
...ter the function or program which created it exits and only if the javascript execution stack is empty, but before returning control to the event loop being used by the user agent to drive the script's execution environment. 4257 in depth: microtasks and the javascript runtime environment api, advanced, guide, javascript, microtasks, asynchronous, queuemicrotask, runtime when debugging or, possibly, when trying to decide upon the best approach to solving a problem around timing and scheduling of tasks and microtasks, there are things about how the javascript runtime operates under the hood that may be useful to understand. that's what this section covers 4258 the websocket api (websockets) api, client, communication, overview, server, two-way, websocket, webs...
...sion the webgl_compressed_texture_s3tc extension is part of the webgl api and exposes four s3tc compressed texture formats. 4562 webgl_compressed_texture_s3tc_srgb api, reference, webgl, webgl extension the webgl_compressed_texture_s3tc_srgb extension is part of the webgl api and exposes four s3tc compressed texture formats for the srgb colorspace. ...
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Venkman Introduction - Archive of obsolete content
warning: the content of this article may be out of date. a powerful new tool is available for web developers for use in many mozilla-based products, including firefox, mozilla suite and netscape 7.x. the javascript debugger, also called venkman, has been a part of the mozilla browser and the community of web and script developers there for some time. this article provides an overview and some practical examples of using the javascript debugger in web applications and web page scripting. this introduction is the first in a series of articles on venkman and javascript debugging. even if you are already using venkman, the features, procedures, and tips described here will make you a more confident web developer and debugger. venkman is both a graphic and a console debugger. featur...
...an is both a graphic and a console debugger. features such as breakpoint management, call stack inspection, and variable/object inspection are available from the user interface and from console commands, letting you work in the way you are most accustomed to. the interactive console also allows for execution of arbitrary javascript code. venkman's keyboard shortcuts are the same as leading visual debugging environments, and gdb users should be familiar with venkman's /break, /step, /next, /finish, /frame, and /where commands. on windows, the javascript debugger compares favorably with visual interdev and other large web development tools. on other platforms, including mac os and unix, it is alone in offering this degree of flexibility, depth, and power in a visual debugging environment. start...
...ironments, and gdb users should be familiar with venkman's /break, /step, /next, /finish, /frame, and /where commands. on windows, the javascript debugger compares favorably with visual interdev and other large web development tools. on other platforms, including mac os and unix, it is alone in offering this degree of flexibility, depth, and power in a visual debugging environment. starting the debugger the javascript debugger is automatically pre-installed in mozilla 1.x but must be installed separately in firefox and other gecko-based products, such as thunderbird and netscape 7.x. fortunately, the xpinstall technology makes it possible to install new application modules in firefox by just clicking a hyperlink. if you don't already have venkman or would like to upgrade, you can easily get...
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dev/panel - Archive of obsolete content
this module is new in firefox 34. note that at the moment you can't debug remote targets (for example, firefox os, the firefox os simulator, or firefox for android) using tools developed with this api. we're working on removing this restriction. enables you to extend the firefox developer tools. most of the firefox developer tools are hosted in a ui component called the toolbox. individual built-in tools, such as the javascript debugger or the web console, occupy "panels" in the toolbox. ...
... for a simple walkthrough of using the dev/panel api to add a new tool, see adding a panel to the toolbox. ...
... create your own panels in the toolbox: the panel gets a tab in the toolbox toolbar which enables the user to open it: you specify the panel's content and behavior using html, css, and javascript. when the panel's created, the framework passes it a debuggee: this is a messageport object that you can use to exchange json messages with the browser that the developer tools are currently debugging. the messages follow the remote debugging protocol. for a simple walkthrough of using the dev/panel api to add a new tool, see adding a panel to the toolbox. basic usage defining the panel constructor to add a new tool you first need to define a constructor that inherits from the panel class, and in that constructor you need to supply values for various properties . you can set the const...
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Hacking Tips
this page list a few tips to help you investigate issues related to spidermonkey. all tips listed here are dealing with the javascript shell obtained at the end of the build documentation of spidermonkey. it is separated in 2 parts, one section related to debugging and another section related to drafting optimizations. many of these tips only apply to debug builds of the js shell; they will not function in a release build. debugging tips getting help (from js shell) use the help function to get the list of all primitive functions of the shell with their description. note that some functions have been moved under an 'os' object, and help(os) will give brief help on just the members of that "namespace". getting the bytecode of a function (from js shell) the shell has a small function named ...
... notes: ofs line pc delta desc args ---- ---- ----- ------ -------- ------ 0: 1 0 [ 0] newline 1: 2 0 [ 0] colspan 2 3: 2 2 [ 2] colspan 9 getting the bytecode of a function (from gdb) in jsopcode.cpp, a function named js::disassembleatpc can print the bytecode of a script. some variants of this function such as js::dumpscript etc are convenient for debugging. printing the js stack (from gdb) in jsobj.cpp, a function named js::dumpbacktrace prints a backtrace à la gdb for the js stack. the backtrace contains in the following order, the stack depth, the interpreter frame pointer (see js/src/vm/stack.h, stackframe class) or (nil) if compiled with ionmonkey, the file and line number of the call location and under parentheses, the jsscript pointer...
...e the codegenerator::link lineno instead of the full qualified name to put the breakpoint. let's say that the line number of this function is 4780, for instance: (gdb) b codegenerator.cpp:4780 breakpoint 1 at 0x84cade0: file /home/code/mozilla-central/js/src/ion/codegenerator.cpp, line 4780. (gdb) r starting program: /home/code/mozilla-central/js/src/32-release/js -f /home/code/jaeger.js [thread debugging using libthread_db enabled] using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [new thread 0xf7903b40 (lwp 12563)] [new thread 0xf6bdeb40 (lwp 12564)] run#0 breakpoint 1, js::ion::codegenerator::link (this=0x86badf8) at /home/code/mozilla-central/js/src/ion/codegenerator.cpp:4780 4780 { (gdb) n 4781 jscontext *cx = getioncontext()->cx; (gdb) n 4783 ...
...And 15 more matches

Shell global objects
med by string arguments. filename is relative to the calling script. evaluate(code[, options]) evaluate code as though it were the contents of a file. ...
...evaluate(code[, options]) evaluate code as though it were the contents of a file. ...
... a file. options is an optional object that may have these properties: isrunonce use the isrunonce compiler option (default: false) noscriptrval use the no-script-rval compiler option (default: false) filename filename for error messages and debug info linenumber starting line number for error messages and debug info columnnumber starting column number for error messages and debug info global global in which to execute the code newcontext if true, create and use a new cx (default: false) catchtermination if true, catch termination (failure without an exception value, as for slow scripts or out-of-memory) and return 'terminated' element if present with value v, convert v to an object o and mark the source as being attached to the dom element o. if the proper...
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Tutorial: Set a breakpoint - Firefox Developer Tools
these are located at the bottom right of the options panel; you may need to scroll to see them. ...
...these are located at the bottom right of the options panel; you may need to scroll to see them. ...
...these are located at the bottom right of the options panel; you may need to scroll to see them. ...
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How to get a stacktrace with WinDbg
ll stack) for a crash or hang but breakpad fails because it's a special crasher or a hang. this article describes how to get a stacktrace in those cases with windbg on windows. (to get a stacktrace for thunderbird or some other product, substitute the product name where ever you see firefox in this instructions.) requirements to get such a stacktrace you need to install the following software: debugging tools for windows microsoft distributes the debugging tools for windows for free, those include windbg which you will need here. download it from install debugging tools for windows. (you'll want the 32-bit version, even if you are using a 64-bit version of windows) then install it, the standard settings in the installation process are fine. a firefox nightly or release you need a firefox ...
...ll it, the standard settings in the installation process are fine. a firefox nightly or release you need a firefox version for which symbols are availables from the mozilla symbol server to use with windbg. you can use any official nightly build or released version of firefox from mozilla. you can find the latest trunk nightly builds under http://ftp.mozilla.org/pub/mozilla.o.../latest-trunk/. debugging to begin debugging, ensure that firefox is not already running and open windbg from the start menu. (start->all programs->debugging tools for windows->windbg) next, open the "file" menu and choose "open executable...". in the file chooser window that appears, open the firefox.exe executable in your firefox program folder (c:\program files\mozilla firefox). you should now see a "command" tex...
... tip: all commands must be entered exactly as written, one line at a time, into the bottom of the command box. ...
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Configuring Build Options
objdir name start with obj so that mercurial ignores it. sometimes it can be useful to build multiple versions of the source (such as with and without diagnostic asserts). to avoid the time it takes to do a full rebuild, you can create multiple mozconfig files which specify different objdirs. ...
...s of the source (such as with and without diagnostic asserts). to avoid the time it takes to do a full rebuild, you can create multiple mozconfig files which specify different objdirs. for example, a mozconfig-dbg: mk_add_options moz_objdir=@topsrcdir@/obj-ff-dbg ac_add_options --enable-debug and a mozconfig-rel-opt: mk_add_options moz_objdir=@topsrcdir@/obj-ff-rel-opt ac_add_options --disable-debug ac_add_options --enable-optimize allow for building both versions by specifiying the configuration via the mozconfig environment variable: $ env mozconfig=/path/to/mozconfig-dbg ./mach build $ env mozconfig=/path/to/mozconfig-rel-opt ./mach build don't forget to set the mozconfig environment variable for the mach run command as well. be aware that changing your mozconfig will require the con...
...options --enable-application=suite calendar (lightning extension, uses thunderbird) ac_add_options --enable-application=comm/mail ac_add_options --enable-calendar selecting build options the build options you choose depends on what application you are building and what you will be using the build for. if you want to use the build regularly, you will want a release build without extra debugging information; if you are a developer who wants to hack the source code, you probably want a non-optimized build with extra debugging macros. there are many options recognized by the configure script which are special-purpose options intended for embedders or other special situations, and should not be used to build the full suite/xul applications. the full list of options can be obtained by r...
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WebReplayRoadmap
replay was an early-stage experiment and is no longer part of firefox. this document describes existing, planned, and potential features for the firefox developer tools that are based on web replay, along with their ui. the low level, yet flexible architecture (described here) provides an extremely powerful platform for implementing debugging and analysis features. we would like to use web replay to radically improve not just the debugging experience but the entire web development experience. to that end, this document will be revised over time as we find new and better ways of helping developers. time travel features more features are planned for the timeline, as described below. retroactive console logging console logging is one of the primary tools most developers use to de...
... this is time consuming, especially when the bug only reproduces intermittently. retroactive console logging offers a large improvement to this workflow. ...
...ugger's log points, reloading, and reproducing the bug. this is time consuming, especially when the bug only reproduces intermittently. retroactive console logging offers a large improvement to this workflow. the bug only needs to be reproduced in a recording tab once, and then console logs can be added which apply throughout the entire recording. this is based on the logpoints feature in the debugger, which can be enabled with the devtools.debugger.features.log-points preference. set a breakpoint and right click on it to change it to a log point. in a non-recording tab this will update the console whenever the log point's location executes in the future. in a recording tab, however, this will update the console with messages for every time the location has ever been hit. this requires ...
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UI Tour - Firefox Developer Tools
at the top level sources are organized by origin, and under that they're organized by the directory structure from which they are served. ...
...at the top level sources are organized by origin, and under that they're organized by the directory structure from which they are served. ...
...at the top level sources are organized by origin, and under that they're organized by the directory structure from which they are served. you can search for a file using ctrl + p (cmd + p on a mac). web extensions are listed in the source list pane using the extension's name. ...
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Setting up an extension development environment - Archive of obsolete content
s as of gecko 2 (firefox 4), javascript files are cached ("fastload"). the -purgecaches command-line flag disables this behavior. alternatively, you can set the moz_purge_caches environment variable. see this bug for more information. development preferences there is a set of development preferences that, when enabled, allows you to view more information about application activity, thus making debugging easier. however, these preferences can degrade performance, so you may want to use a separate development profile when you enable these preferences. accessing firefox development preferences to change preference settings in firefox or seamonkey, type about:config in the location bar. you can also use the extension developer's extension, which provides a menu interface for firefox settings.
...rticle on "about:config". tip: you can install either the developer profile or devprefs add-ons to handle setting these preferences automatically, and skip the rest of this section. devprefs can now be found at https://github.com/noitidart/devprefs. maxversion needs to be set in install.rdf javascript.options.showinconsole = true. logs errors in chrome files to the error console. nglayout.debug.disable_xul_cache = true. disables the xul cache so that changes to windows and dialogs do not require a restart. this assumes you're using directories rather than jars. changes to xul overlays will still require reloading of the document overlaid. browser.dom.window.dump.enabled = true. enables the use of the dump() statement to print to the standard console. see window.dump for more info. you ...
...le have this setting turned off when developing, you will see lots of warnings for problems with their code in addition to warnings for your own extension. you can filter those with console2. devtools.chrome.enabled = true. this enables to run javascript code snippets in the chrome context of the scratchpad from the tools menu. don't forget to switch from content to browser as context. ...
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Tamarin build documentation - Archive of obsolete content
tral tips for working with mercurial can be found here. building tamarin building tamarin will create all the libraries for the avmplus and garbage collector (mmgc), and create a standalone executable (shell) for executing files in the abc file format. running the shell without any arguments will list the available options. note that additional command-line arguments are only available in the debug configuration. the tamarin codebase contains a cross-platform build system for mozilla developers. the cross-platform build system is used for daily automated build testing so it is the most reliable system. the tamarin codebase has the ability to build additional code which supports debugging hooks. in the xcode project, this is the debug_debugger and release_debugger configurations. the flash...
...ebase contains a cross-platform build system for mozilla developers. the cross-platform build system is used for daily automated build testing so it is the most reliable system. the tamarin codebase has the ability to build additional code which supports debugging hooks. in the xcode project, this is the debug_debugger and release_debugger configurations. the flash player builds tamarin with the debugging hooks off for codesize reasons, but the mozilla client will build tamarin with the debugging hooks on. cross-platform build (general instructions - non-android) prerequisites: you need python 2.5 or later and gnu make 3.81 or later. (gnu make 3.80 does not work. nor does any other brand of make.) with the right prerequisites, use these commands to build tamarin: $ hg clone http://hg.mozi...
...nu make 3.80 does not work. nor does any other brand of make.) with the right prerequisites, use these commands to build tamarin: $ hg clone http://hg.mozilla.org/tamarin-redux/ $ cd tamarin-redux $ mkdir objdir-release $ cd objdir-release $ python ../configure.py $ make ... $ shell/avmshell shell 1.0 build cyclone ... the avmplus executable is avmshell. optional flags: --enable-debugger - debugger build --enable-debug - debug build for verbose build of tamarin, you can pass cppflags to make. $ make cppflags=-davmplus_verbose additional instructions for non-android cross-platform tamarin-redux build on osx 10.6 (snow leopard) (to build tamarin-central on mac please see previous cross-platform instructions here: https://developer.mozilla.org/index.php?title=en/tamarin/t...
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nsIXPConnect
tobjecttracerptr atracer); native code only! void clearallwrappednativesecuritypolicies(); nsixpconnectjsobjectholder createsandbox(in jscontextptr cx, in nsiprincipal principal); native code only! ...
...ly! void clearallwrappednativesecuritypolicies(); nsixpconnectjsobjectholder createsandbox(in jscontextptr cx, in nsiprincipal principal); native code only! ...
...der createsandbox(in jscontextptr cx, in nsiprincipal principal); native code only! ...
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Mac stub installer - Archive of obsolete content
run the installer from the opt "mozilla installer" folder. alternative to steps 3 and 4 copy the "installer modules" folder from the "mozilla installer" folder into the "macbuild" folder that contains th...
... run the installer from the opt "mozilla installer" folder. alternative to steps 3 and 4 copy the "installer modules" folder from the "mozilla installer" folder into the "macbuild" folder that contains th...
... run the installer from the opt "mozilla installer" folder. alternative to steps 3 and 4 copy the "installer modules" folder from the "mozilla installer" folder into the "macbuild" folder that contains th...
...And 7 more matches

Web Console remoting - Firefox Developer Tools
introduction this document describes the way web console remoting works. the web console is split between a client with its user interface, and the server which has listeners for all the things that happen in the tab. for communication between the server and the client we use the remote debugging protocol. this architecture allows you to connect a web console client instance to a server running on b2g, fennec or some other firefox instance. to better understand the architecture of the web console we recommend learning about the debugger architecture. the remote web console is a feature introduced in firefox 18. this document describes the latest protocol, with changes that have been made since then. the webconsoleactor and the webconsoleclient the webconsoleactor lives in dbg-web...
...t describes the latest protocol, with changes that have been made since then. the webconsoleactor and the webconsoleclient the webconsoleactor lives in dbg-webconsole-actors.js, in the toolkit/devtools/webconsole folder. the webconsoleclient lives in webconsoleclient.jsm (in toolkit/devtools/webconsole) and it is used by the web console when working with the web console actor. to see how the debugger is used in the web console code, look in browser/devtools/webconsole/webconsole.js, and search for webconsoleconnectionproxy. the new web console actors are: the webconsoleactor allows js evaluation, autocomplete, start/stop listeners, etc. the networkeventactor is used for each new network request. the client can request further network event details - like response body or request heade...
...proxy. the new web console actors are: the webconsoleactor allows js evaluation, autocomplete, start/stop listeners, etc. the networkeventactor is used for each new network request. the client can request further network event details - like response body or request headers. to attach to the webconsoleactor, follow these steps: connecttoserver() // the usual listtabs() pickthetabyouwant() debuggerclient.attachconsole(tab.consoleactor, listeners, onattachconsole) the listeners argument is an array which specifies listeners you want to start in the web console. these can be: page errors, window.console api messages, network activity, and file activity. for example: ["pageerror", "consoleapi", "networkactivity", "fileactivity"] the web console actor does not start any listeners by def...
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MMgc - Archive of obsolete content
lasses) must zero themselves out completely upon destruction. asserts enforce this. the reason is that our collector zeroes memory upon free and this was hurting performance. since mmgc must traverse objects to decrement refcounts properly upon destruction, i just made destructors do zeroing too. this mostly applies to non-pointer fields as drcwb smart pointers do this for you. poisoned memory in debug builds, mmgc writes "poison" into deallocated memory as a debugging aid. here's what the different poison values mean: 0xfafafafa uninitialized unmanaged memory 0xedededed unmanaged memory that was freed explicitly 0xbabababa managed memory that was freed by the sweep phase of the garbage collector 0xcacacaca managed memory that was freed by an explicit call to gc::free (including drc re...
...barriers there are some automatic aids in the mmgc library which can help you find missing write barriers. look in mmgc/gc.cpp. ...
.../ check for missing write barriers at every alloc bool gc::incrementalvalidationpedantic = false; if you suspect you have missing write barriers, turn these switches on in a debug build. (the second switch will slow your application down a lot more than the first switch, so you could try the first, then the second.) when a missing write barrier is detected, mmgc will assert and drop you into the debugger, and will print out a message telling you which object contained the missing write barrier, the address of the member variable that needs it, and what object didn't get marked due to the missing write barrier. ...
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Table Layout Regression Tests - Archive of obsolete content
warning: the content of this article may be out of date. while the information on the layout debugger is still useful, the testing information is much less relevant now than it has been, as the "rtest" testing framework described here has been superseded by the reftest framework. it is unclear whether or how well rtest continues to work and whether it is still used or not. subject overview changes in layout, parser and content code can have unintended side effects, also known as regressions. it is good style to check for these unwanted regressions and fixing them before checkin rather than causing bugzilla avalanches. ...
...o work and whether it is still used or not. subject overview changes in layout, parser and content code can have unintended side effects, also known as regressions. it is good style to check for these unwanted regressions and fixing them before checkin rather than causing bugzilla avalanches. prerequisites in order to run these tests, you will need to have: make sure that your build is a debug build (in short you need ac_add_options --enable-debug in your .mozconfig file). to build the layoutdebugger itself, build either all extensions or include layoutdebug in your .mozconfig file. for example ac_add_options --enable-extensions=all. a mozilla tree with the test files at %moz_src%/layout/html/tests, disable_tests should not be defined (so ac_add_options --enable-tests), patience an...
...her all extensions or include layoutdebug in your .mozconfig file. for example ac_add_options --enable-extensions=all. a mozilla tree with the test files at %moz_src%/layout/html/tests, disable_tests should not be defined (so ac_add_options --enable-tests), patience and time. test runs go to the %moz_src%/layout/html/tests/block directory. avoid the nasty assertions to pop up by set xpcom_debug_break=warn, the world would be a much better place if we could first fix those assertions. as you will probably run your normal mozilla in parallel with the testing issue then: set moz_no_remote=1 at the command prompt. start the layout debugger via mozilla -layoutdebug - p foo where foo is just another profile than your main profile. select from the regression-test menu the add new list...ent...
...And 6 more matches

Index - Learn web development
into the world of javascript. we've begun with just theory, to start getting you used to why you'd use javascript and what kind of things you can do with it. along the way, you saw a few code examples and learned how javascript fits in with the rest of the code on your website, amongst other things. 88 what went wrong? troubleshooting javascript article, beginner, codingscripting, debugging, developer tools, error, javascript, learn, tutorial, console.log, l10n:priority so there we have it, the basics of figuring out errors in simple javascript programs. it won't always be that simple to work out what's wrong in your code, but at least this will save you a few hours of sleep and allow you to progress a bit faster when things don't turn out right, especially in the earlier ...
...cript, learn, loops this aim of this skill test is to assess whether you've understood our looping code article. 101 solve common problems in your javascript code beginner, javascript, learn the following links point to solutions to common problems you may encounter when writing javascript. 102 learn to style html using css beginner, css, codingscripting, debugging, landing, style, topic, length, specificity cascading stylesheets — or css — is the first technology you should start learning after html. while html is used to define the structure and semantics of your content, css is used to style it and lay it out. for example, you can use css to alter the font, color, size, and spacing of your content, split it into multiple columns, or add ani...
...ilding blocks beginner, css, learn, building blocks this module carries on where css first steps left off — now you've gained familiarity with the language and its syntax, and got some basic experience with using it, its time to dive a bit deeper. this module looks at the cascade and inheritance, all the selector types we have available, units, sizing, styling backgrounds and borders, debugging, and lots more. 104 a cool-looking box assessment, beginner, css, learn, backgrounds, borders, box, box model, effects in this assessment, you'll get some more practice in creating cool-looking boxes by trying to create an eye-catching box. 105 advanced styling effects article, beginner, blend modes, boxes, css, codingscripting, filters, styling, box shadow...
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Leak-hunting strategies and tips
(or allocations?) all tier 1 platforms build with --enable-trace-malloc leak tools for simple objects and summary statistics tracemalloc all allocations all tier 1 platforms build with --enable-trace-malloc valgrind all allocations mac, linux buil...
...the most common source of hard-to-fix leaks is ownership cycles. if yo...
...e bug 109671 for an example. destructors that should have been virtual: if you expect to override an object's destructor (which includes giving a derived class of it an nscomptr member variable) and delete that object through a pointer to the base class using delete, its destructor better be virtual. (but we have many virtual destructors in the codebase that don't need to be -- don't do that.) debugging leaks that go through xpconnect many large object graphs that leak go through xpconnect. this can mean there will be xpconnect wrapper objects showing up as owning the leaked objects, but it doesn't mean it's xpconnect's fault (although that has been known to happen, it's rare). debugging leaks that go through xpconnect requires a basic understanding of what xpconnect does. xpconnect allows ...
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NSS API Guidelines
hould be followed for naming and identifying new files, functions, and data types. cvs id each file should include a cvs id string for identification. the preferred format is: "@(#) $rcsfile: nss-guidelines.html, v $ $revision: 48936 $ $date: 2009-08-11 07:45:57 -0700 (tue, 11 aug 2009) $ $name$" you can put the string in a comment or in a static char array. ...
...nd identifying new files, functions, and data types. cvs id each file should include a cvs id string for identification. the preferred format is: "@(#) $rcsfile: nss-guidelines.html, v $ $revision: 48936 $ $date: 2009-08-11 07:45:57 -0700 (tue, 11 aug 2009) $ $name$" you can put the string in a comment or in a static char array. use #ifdef debug to include the array in debug builds only. ...
...entification. the preferred format is: "@(#) $rcsfile: nss-guidelines.html, v $ $revision: 48936 $ $date: 2009-08-11 07:45:57 -0700 (tue, 11 aug 2009) $ $name$" you can put the string in a comment or in a static char array. use #ifdef debug to include the array in debug builds only. the advantage of using an array is that you can use strings(1) to pull the id tags out of a (debug) compiled library. you can even put them in header files; the header files are protected from double inclusion. ...
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NSS environment variables
le (see below). makes nsrandfile usable with /dev/urandom. 3.12.3 nsrandfile string (file name) uses this file to seed the pseudo random number generator. before 3.0 nss_allow_weak_signature_alg boolean (any non-empty value to enable) enables the use of md2 and md4 inside signatures. this was allowed by default before nss 3.12.3. 3.12.3 nss_debug_pkcs11_module string (module name) name the pkcs#11 module to be traced. pkcs #11 module logger 3.6 nss_default_db_type string ("dbm", "sql", or "extern") determines the default database type to open if the app does not specify. nss_shared_db 3.12 nss_disable_arena_free_list string (any non-empty value) define this variable to get accurate le...
...-empty value) it is an error to try to use a pkcs#11 crypto module in a process before it has been initialized in that process, even if the module was initialized in the parent process. beginning in nss 3.12.3, softoken will detect this error. this environment variable controls softoken's response to that error. ...
...a pkcs#11 crypto module in a process before it has been initialized in that process, even if the module was initialized in the parent process. beginning in nss 3.12.3, softoken will detect this error. this environment variable controls softoken's response to that error. if set to to "1" or unset, softoken will trigger an assertion failure in debug builds, and will report an error in non-debug builds. ...
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SpiderMonkey Build Documentation
when building a version older than 28, you'll additionally need nspr. and of course, you'll need to get the spidermonkey source code. non-developer (optimized) build use these steps if you want to install spidermonkey for production use or run performance benchmarks. (if you want to use spidermonkey as a library in your c++ application, or work on improving spidermonkey itself, do a developer/debug build instead, as described below.) cd js/src # this name should end with "_opt.obj" to make the version control system ignore it. mkdir build_opt.obj cd build_opt.obj /bin/sh ../configure.in # use "mozmake" on windows make a few notes about this: the most common build problems are dependency problems. see the build prerequisites page for your platform. spidermonkey does not suppo...
...lease/dist/bin. you can test it with dist/bin/js --help, which displays a help page. at this point, you're ready to run and try out the shell. on mac, linux, or unix, you can install spidermonkey on your system with the additional command make install. this installs the shared library to /usr/local/lib, the c header files to /usr/local/include, and the js executable to/usr/local/bin. ...
...ith dist/bin/js --help, which displays a help page. at this point, you're ready to run and try out the shell. on mac, linux, or unix, you can install spidermonkey on your system with the additional command make install. this installs the shared library to /usr/local/lib, the c header files to /usr/local/include, and the js executable to/usr/local/bin. developer (debug) build for developing and debugging spidermonkey itself, it is best to have both a debug build (for everyday debugging) and an optimized build (for performance testing), in separate build directories. thus, in addition to following the steps above, you should also create a debug build using these steps: cd js/src # this name should end with "_dbg.obj" to make the version control system ignore it. mkdir build_dbg.obj cd build_...
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Index
icates and keys in such files. 208 nss tools pk12util-tasks newsgroup: mozilla.dev.tech.crypto 209 nss tools signver-tasks no summary! 210 nss tools sslstrength a simple command-line client which connects to an ssl-server, and reports back the encryption cipher and strength used. 211 nss tools ssltap the ssl debugging tool is an ssl-aware command-line proxy. it watches tcp connections and displays the data going by. if a connection is ssl, the data display includes interpreted ssl records and handshaking. 212 nss tools : cmsutil name cmsutil — performs basic cryptograpic operations, such as encryption and decryption, on cryptographic message syntax (cms) messages. synopsis ...
... the given databases are in the old format. -p prefix specify the prefix used on the certificate and key databases. this option is provided as a special case. changing the names of the certificate and key databases is not recommended. -h tokenname specify the name of the token to import into or export from. -v enable debug logging when importing. -k slotpasswordfile specify the text file containing the slot's password. -k slotpassword specify the slot's password. -w p12filepasswordfile specify the text file containing the pkcs #12 file password. -w p12filepassword specify the pkcs #12 file password. -c keycipher specify the key encrypti...
...n your database. an asterisk appears to the left of the nickname for any certificate that can be used to sign objects with signtool. --leavearc retains the temporary .arc (archive) directories that the -j option creates. these directories are automatically erased by default. retaining the temporary directories can be an aid to debugging. -m metafile specifies the name of a metadata control file. metadata is signed information attached either to the jar archive itself or to files within the archive. this metadata can be any ascii string, but is used mainly for specifying an installer script. the metadata file contains one entry per line, each with three fields: field...
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Using Breakpoints in Venkman - Archive of obsolete content
this article continues a series of articles on venkman that began with venkman introduction. one of the basic tasks of debugging any language is setting breakpoints. breakpoints are places in code where execution is suspended. when you set a breakpoint in a debugging application such as venkman, you can take advantage of the suspension to examine variables, objects, and other featues of the execution. this article describes breakpoints in javascript and how to use venkman to set and examine breakpoints. basic breakpoints the stop button and debugger keyword are useful features of the javascript debugger, but when you are debugging deep in code—especially code you have authored yourself and are responsible for troubleshooting—you're going to need breakpoints. types of breakpoints ven...
...s is to stop in a "top level" script (script that executes outside of any function), or script that executes during the onload event of a page. when a script is loaded that matches the url of a future breakpoint, and has executable code at the specified line, venkman will automatically set a future breakpoint. except for this distinction, breakpoints in venkman work like breakpoints in most other debuggers. the dots you see in the left margin of the source code view indicate which lines contain executable code, places where a hard breakpoint can be set. setting breakpoints clicking on one of these dots in the source code view will set a breapoint at that line. venkman will stop before the line executes. when a breakpoint is set, the margin will change to the letter "b", as in figure 2. if you ...
... in the source code view will set a breapoint at that line. venkman will stop before the line executes. when a breakpoint is set, the margin will change to the letter "b", as in figure 2. if you execute this code again after having set this breakpoint, venkman will stop at line 81. (note: by default, venkman hides files file that appear to be part of the browser core; this includes extensions. to debug an extension, uncheck "exclude browser files" on the debug menu and your installed extension files should appear in the loaded scripts list.) venkman also indicates that one or more breakpoints have been set in the loaded scripts view, where red dots appear next to the files in which breakpoints have been set, along with the line number where the function begins whose code is being stopped. usi...
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Venkman - Archive of obsolete content
venkman is the code name for mozilla's javascript debugger. it aims to provide a powerful javascript debugging environment for mozilla based browsers namely firefox, netscape 7.x/9.x and seamonkey. note that it is not included in the gecko-based browsers such as k-meleon, galeon and netscape 8.x. venkman has been provided as part of the mozilla install distribution since october 2001, as well as an extension package in xpi format. documentation venkman introduction an overview and some practical examples of using the javascript debugger in web development. using breakpoints in venkman this article describes breakpoints in javascript and how to use venkman to set and examine breakpoints. learning the javascrip...
... venkman faq answers to common questions on venkman. ...
...an overview and some practical examples of using the javascript debugger in web development. using breakpoints in venkman this article describes breakpoints in javascript and how to use venkman to set and examine breakpoints. learning the javascript debugger venkman written by svend tofte to the javascript programmers who are not familiar with other debugging tools. venkman faq answers to common questions on venkman. venkman internals notes on venkman source code. venkman development page older news and releases. view all... brief history in 1998, john bandhauer was in charge of creating the netscape 4.x javascript debugger. in order to keep things modular, he...
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Eclipse CDT
red. for this to work reliably though, you still need to build using slow -j1 -w builds, so that make outputs non-interleaved "entering"/"leaving" lines. it also used to be necessary to add the following two lines to your mozconfig to make the compiler output errors all on a single line, but that may not be needed anymore: export cflags="-fmessage-length=0" export cppflags="-fmessage-length=0" debugging to create a debug configuration, open the project properties window, and select "run/debug settings" on the left. click "new", then select "c/c++ application". in the window that opens enter the path to your firefox binary (something like {your-obj-dir}/dist/nightlydebug.app/contents/macos/firefox) and select "disable auto build". select the arguments tab and enter any args you want to pass ...
...profile"). if you're on linux, you may also need to set the "working directory" to {your-obj-dir}/dist/bin, and then select the environment tab and set ld_library_path to ".:./plugins:." and library_path to ".:./components:.". ...
...nvironment tab and set ld_library_path to ".:./plugins:." and library_path to ".:./components:.". (are these variables really necessary? if so, why? isn't library_path for compile time, not runtime, linking?) in the workspace preferences, you may want to go to "c/c++ > debug > gdb" and deselect "stop on startup at", so that eclipse won't automatically break in main() when it launches firefox for debugging. to debug, click the debug button on the toolbar, or select "run > debug" from the menu bar. it's not obvious, but you can get a gdb prompt in the console so that you can type gdb commands directly. after you've finished debugging, you can get back to the c/c++ perspective (i.e. window layout) via the menubar by selecting "window > open perspective > c/c++". upgrading gdb on mac the anci...
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Index
this macro is meant for critical errors; like assertions, ns_errors should not be reachable. 148 ns_if_addref xpcom, xpcom_macros macro 149 ns_if_release xpcom, xpcom_macros macro 150 ns_release xpcom, xpcom_macros macro 151 ns_warning xpcom, xpcom_macros macro 152 standard xpcom co...
...erface reference the iaccessiblevalue interface represents a single numerical value and should be implemented by any class that supports numerical value like progress bars and spin boxes. this interface lets you access the value and its upper and lower bounds. 175 idispatch interfaces, interfaces:scriptable, xpcom, xpcom interface reference no summary! 176 ijsdebugger debugger, interfaces, interfaces:scriptable, xpcom interface reference implemented by: @mozilla.org/jsdebugger;1 as a service: 177 amiinstallcallback interfaces, interfaces:scriptable, xpcom, xpcom interface reference called when an install completes or fails. 178 amiinstalltrigger interfaces, interfaces:scriptable, xpcom, xpcom interface reference...
...ed as errors. makes eval() use the last object on its 'obj' param's scope chain as the ecma 'variables object'. private data for this object is an nsisupports object. attempting to alter this bit will result in an ns_error_illegal_value. opt_* values above, or'd together. last version set on this context. scripts typically select this with the "language" attribute. see the version_* consts on jsdidebuggerservice. unique tag among all valid jsdicontext objects, useful as a hash key. private data for this context, if it is an nsisupports, |null| otherwise. retrieve the underlying context wrapped by this jsdicontext. top of the scope chain for this context. |true| if this context should be allowed to run scripts, |false| otherwise. this attribute is only valid for contexts which implement nsiscrip...
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DevTools API - Firefox Developer Tools
warning: the devtools api is still wip. if you notice any inconsistency, please let the firefox developer tools team know. while this api is currently a work-in-progress, there are usable portions of page inspector and debugger that may be used currently. introduction the devtools api provides a way to register and access developer tools in firefox. in terms of user interface, each registered tool lives in its own tab (we call one tab a panel). these tabs are located in a box we call a toolbox. a toolbox can be hosted within a browser tab (at the bottom or on the side), or in its own window (we say that the toolbox is undocked). a toolbox (and all the tools it contains) is linked to a target, which is the object the tools are debugging. a target is usually a web page (a tab), but can b...
...ion about the theme. unregistertheme(theme) unregisters the given theme. parameters: theme {themedefinition|string} - the theme definition object or the theme identifier. showtoolbox(target [, toolid [, hosttype [, hostoptions]]]) opens a toolbox for given target either by creating a new one or activating an existing one. parameters: target {target} - the target the toolbox will debug. toolid {string} - the tool that should be activated. if unspecified the previously active tool is shown. hosttype {string} - the position the toolbox will be placed. one of bottom, side, window, custom. see hosttype for details. hostoptions {object} - an options object passed to the selected host. see hosttype for details. return value: a promise that is fulfilled with the toolbox instance ...
...dow, custom. see hosttype for details. hostoptions {object} - an options object passed to the selected host. see hosttype for details. return value: a promise that is fulfilled with the toolbox instance once it has been initialized and the selected tool is loaded. gettoolbox(target) fetch the toolbox object for the given target. parameters: target {target} - the target the toolbox is debugging. return value: toolbox object or undefined if there's no toolbox for the given target.. closetoolbox(target) closes the toolbox for given target. parameters: target {target} - the target of the toolbox that should be closed. return value: a promise that is fulfilled once the toolbox has been destroyed. getdefaulttools() returns an array of tooldefinition objects for the ...
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Chapter 5: Let's build a Firefox extension - Archive of obsolete content
an create the dev profile and configure its home-path. change your preferences for more efficient development before you get to work developing your extension, you’ll want to change some of your firefox preferences. this isn’t a requirement for extension development, but i recommend it as a way to work more efficiently. preference description value nglayout.debug.disable_xul_cache (not present in firefox 3.5+) ordinarily, firefox will cache xul documents after they have been read in once, to speed subsequent displays. disabling this cache forces xul documents to be reloaded any every time they are displayed. true browser.dom.window.dump.enabled (not present in firefox 3.5+) enables use of the dump method for debugging. refer...
...t present in firefox 3.5+) ordinarily, firefox will cache xul documents after they have been read in once, to speed subsequent displays. disabling this cache forces xul documents to be reloaded any every time they are displayed. true browser.dom.window.dump.enabled (not present in firefox 3.5+) enables use of the dump method for debugging. refer to the “javascript debugging methods” sidebar. true javascript.options.showinconsole (present in firefox 3.5+) outputs javascript errors to the error console. true javascript.options.strict (present in firefox 3.5+) enforces strict error output from javascript true table 1: preferences to set for developing extensions to make these changes, start your development profil...
... is an extension that lets you examine html and xul dom tree structures, javascript objects and css properties, etc. this is not required for developing extensions, but it is handy to have around. install extensions for firefox from the mozilla add-ons website. optional - install firebug and chromebug chromebug is used by the firebug development team to develop firebug. you can use it to help debug firefox extensions as well as to inspect and learn how the firefox ui (chrome) is constructed. you can learn more about chromebug and download it at http://getfirebug.com/wiki/index.php/chromebug_user_guide you may also find this extension to be valuable: extension developer https://addons.mozilla.org/firefox/addon/7434 developing extensions: what you need to know let’s delve into chrome...
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Appendix D: Loading Scripts - Archive of obsolete content
stand at a glance. speed: script tags may or may not be loaded from pre-compiled bytecode in the fastload cache (gecko 1.x) or startup cache (gecko 2), which means they don't necessarily need to read as source and compiled with each restart. flexibility: script tags provide a means to specify the character set and javascript version of the scripts to be loaded, which many other methods do not. debuggable: development tools support debugging javascript loaded by script tags disadvantages scoping: scripts loaded via script tags share the global scope with all other scripts loaded into the same window. these tags provide no means to load scripts into a private or otherwise specific scope. speed: even if these scripts are loaded from a cache, only read and compile time are reduced. the scr...
...ng: since scripts executed via evalinsandbox run in a defined namespace, global namespace contamination and the resultant extension compatibility issues are not usually a problem. flexibility: the evalinsandbox method accepts several parameters, including the url, line number, and javascript version of the file from which the code being evaluated was extracted. this information is invaluable for debugging, and the flexibility with which it can be specified makes this method useful for extracting javascript from a number of file formats other than raw javascript scripts. additionally, as sandbox objects can be created with an arbitrary prototype object, the evaluated code can be given access to the global properties of any existing scope. security: sandbox objects are initialized with a securi...
... addition to the possible performance concerns, passing data between these compartments is not entirely transparent. some known issues include: e4x xml objects cannot be wrapped for passage between compartments: bug 613142 there are a number of type detection issues, including: string.replace does not recognize regexp objects from foreign compartments: bug 633830 debugging: support for sandbox evaluation in development tools is uneven. chromebug supports firebug based sandboxes. examples the following code will execute a simple script in a sandbox with the privilege level of the current content page. the globals of the current content window will be available in the scripts global scope. in stack traces, the script will appear to have been loaded from the fi...
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Migrate apps from Internet Explorer to Mozilla - Archive of obsolete content
t down). internet explorer is always in quirks mode, as it does not support true xhtml. to make this work in strict mode in mozilla, separate the string into two parts: <!doctype html public "-//w3c//dtd xhtml 1.0 transitional//en" "http://www.w3.org/tr/xhtml1/dtd/xhtml1-transitional.dtd"> ... <script> document.write("<script type='text\/javascript'>alert('hello');</" + "script>") </script> debug javascript mozilla provides several ways to debug javascript-related issues found in applications created for internet explorer. the first tool is the built-in javascript console, shown in figure 1, where errors and warnings are logged. you can access it in mozilla by going to tools -> web development -> javascript console or in firefox (the standalone browser product from mozilla) at tools -> j...
...ned variable called is_ns70. clicking on the link will open mozilla's internal view source window with the offending line highlighted. the console also allows you to evaluate javascript. to evaluate the entered javascript syntax, type in 1+1 into the input field and press evaluate, as figure 2 shows. figure 2. ...
...sole also allows you to evaluate javascript. to evaluate the entered javascript syntax, type in 1+1 into the input field and press evaluate, as figure 2 shows. figure 2. javascript console evaluating mozilla's javascript engine has built-in support for debugging, and thus can provide powerful tools for javascript developers. venkman, shown in figure 3, is a powerful, cross-platform javascript debugger that integrates with mozilla. ...
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Using gdb on wimpy computers - Archive of obsolete content
mozilla uses pthreads for its networking library so you need to be able to work in a threaded environment. the best way to do this is to set a breakpoint in main, let the program run until main and then turn off automatic library loading. ...
...mory, your computer will become unhappy as gdb loads mozilla's shared libraries. the solution to this is to delay loading shared libraries until they are actually needed. however, you need to make sure that the base libraries like libc and pthreads are loaded before you tell gdb to stop loading shared libraries. if you don't allow those libraries to be loaded then gdb will not be able to properly debug threads on linux. mozilla uses pthreads for its networking library so you need to be able to work in a threaded environment. the best way to do this is to set a breakpoint in main, let the program run until main and then turn off automatic library loading. from there you can allow the program to continue running. here's an example: [blizzard@gunhead mozilla]$ cd dist/bin/ [blizzard@gunhead bin]$ ...
...gdb is free software, covered by the gnu general public license, and you are welcome to change it and/or distribute copies of it under certain conditions. type "show copying" to see the conditions. there is absolutely no warranty for gdb. type "show warranty" for det...
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What are browser developer tools? - Learn web development
tor for a start, right-click (ctrl-click) an html element in the dom inspector and look at the context menu. the available menu options vary among browsers, but the important ones are mostly the same: delete node (sometimes delete element). deletes the current element. edit as html (sometimes add attribute/edit text). lets you change the html and see the results on the fly. very useful for debugging and testing. :hover/:active/:focus. forces element states to be toggled on, so you can see what their styling would look like. copy/copy as html. copy the currently selected html. some browsers also have copy css path and copy xpath available, to allow you to copy the css selector or xpath expression that would select the current html element. try editing some of your dom now. double-cli...
...pecting uses css grid, this section allows you to view the grid details. fonts: in firefox, the fonts tab shows the fonts applied to the current element. find out more find more out about the inspector in different browsers: firefox page inspector ie dom explorer chrome dom inspector (opera's inspector works the same as this) safari dom inspector and style explorer the javascript debugger the javascript debugger allows you to watch the value of variables and set breakpoints, places in your code that you want to pause execution and identify the problems that prevent your code from executing properly. to get to the debugger: firefox: select ➤ web developer ➤ debugger or press ctrl + shift + s to open the javascript debugger. if the tools are already displayed, click on ...
... the javascript debugger allows you to watch the value of variables and set breakpoints, places in your code that you want to pause execution and identify the problems that prevent your code from executing properly. to get to the debugger: firefox: select ➤ web developer ➤ debugger or press ctrl + shift + s to open the javascript debugger. if the tools are already displayed, click on the debugger tab. chrome: open the developer tools and then select the sources tab. (opera works the same way.) edge and internet explorer 11: press f12 and then, ctrl + 3, or if the tools are already displayed, click on the debugger tab. safari: open the developer tools and then select the debugger tab. exploring the debugger there are three panes in the javascript debugger on firefox. file list th...
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Capturing a minidump
if the application is hanging (not responding to input, but hasn't crashed) then breakpad is not triggered, and it can be difficult to determine where the problem lies. sometimes a more complete form of minidump is needed to see additional details about a crash, in which case manual capture of a minidump is desired. this page describes how to capture these minidumps on windows, to permit better debugging. privacy and minidumps warning! unlike the minidumps submitted by breakpad, these minidumps contain the complete contents of program memory. they are therefore much more likely to contain private information, if there is any in the browser. for this reason, you may prefer to generate minidumps against a clean profile where possible. capturing a minidump: application crash to capture a ful...
...d, these minidumps contain the complete contents of program memory. they are therefore much more likely to contain private information, if there is any in the browser. for this reason, you may prefer to generate minidumps against a clean profile where possible. capturing a minidump: application crash to capture a full minidump for an application crash, you can use a tool called windbg. install debugging tools for windows microsoft distributes the debugging tools for windows for free, those include windbg which you will need here. download it from install debugging tools for windows. (you'll want the 32-bit version of windbg only if you are using a 32-bit version of firefox) then install it, the standard settings in the installation process are fine. capture a minidump connect firefox...
... next, open the "file" menu and choose "open executable...". in the file chooser window that appears, open the firefox.exe executable in your firefox program folder (c:\program files\mozilla firefox). ...
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Log.jsm
mponents.utils.import("resource://gre/modules/log.jsm"); basic usage components.utils.import("resource://gre/modules/log.jsm"); // get a logger, give it a name unique to this chunk of code. ...
...expect these to be immediately visible on a status console. ...
...expect these to be immediately visible on a status console. error other runtime errors or unexpected conditions. expect these to be immediately visible on a status console. ...
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Profiling with the Firefox Profiler
ols for. (and "symn" if you have an "n" job you want symbols for, i.e. a build job with the "nightly configuration.) profiling firefox mobile firefox 61 for android supports gecko profiler again; see remote profiling on android for details. the following information is old version of firefox for android. for local builds of fennec, you should build with optimization and strip_flags="--strip-debug" but not with --enable-profiling. nightly builds are already built with the appropriate flags. you'll need to have adb and arm-eabi-addr2line (which is part of the android ndk) in your bash path, so use locate arm-eabi-addr2line (on linux) or mdfind name:arm-eabi-addr2line (on os x) and stick an export to its location in ~/.bash_profile. the extension will invoke bash to use adb and addr2line. ...
...our bash path, so use locate arm-eabi-addr2line (on linux) or mdfind name:arm-eabi-addr2line (on os x) and stick an export to its location in ~/.bash_profile. the extension will invoke bash to use adb and addr2line. install the latest pre-release build in your host machine's firefox browser that has your phone reachable via adb. this will add a icon in the top right of the browser. set devtools.debugger.remote-enabled to true in about:config for fennec. select target mobile usb and press connect. the first run will take an additional 1 minute or so to pull in the required system libraries. profiling firefox startup start your firefox with the environment variable moz_profiler_startup=1 set. this way the profiler is started as early as possible during startup. then capture the profile u...
...gs that can be configured with the environment variables moz_profiler_startup_entries, moz_profiler_startup_interval and moz_profiler_startup_filters: if it looks like the buffer is not large enough, you can tweak the buffer size with the env var moz_profiler_startup_entries. this defaults to 1000000, which is 9mb. if you want 90mb use 10000000, and 20000000 for 180mb, which are good values to debug long startups. if you'd like a coarser resolution, you can also choose a different interval using moz_profiler_startup_interval, which defaults to 1 (unit is millisecond). you can't go below 1 ms but you can use e.g. 10 ms. if the default threads to be profiled are insufficient, you can choose which threads to profile using moz_profiler_startup_filters, which is a comma separated list. descri...
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Logging
this chapter describes the global functions you use to perform logging. nspr provides a set of logging functions that conditionally write printf() style strings to the console or to a log file. nspr uses this facility itself for its own development debugging purposes. you can select events to be logged by module or level. a module is a user-defined class of log events. a level is a numeric value that indicates the seriousness of the event to be logged. you can combine module and level criteria to get highly selective logging. nspr also provides "assert"-style macros and functions to aid in application debugging. conditional compilation and execution log types and variables logging functions and macros use example conditional compilation and execution nspr's logging facility is condi...
...set one of the compile-time defines when you build your application. ...
...ogging functions and macros use example conditional compilation and execution nspr's logging facility is conditionally compiled in and enabled for applications using it. these controls are platform dependent. logging is not compiled in for the win16 platform. logging is compiled into the nspr debug builds; logging is not compiled into the nspr optimized builds. the compile time #define values debug or force_pr_log enable nspr logging for application programs. to enable nspr logging and/or the debugging aids in your application, compile using the nspr debug build headers and runtime. set one of the compile-time defines when you build your application. execution-time control of nspr's logging uses two environment variables. these variables control which modules and levels are logged as well...
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Using the Mozilla symbol server
the mozilla project runs a symbol server for trunk firefox nightly and release builds on windows. symbols are available for at least 30 previous days worth of nightly builds, and firefox releases from 2.0.0.4. this allows debugging of those builds without forcing all users to download large debugging files. the server functions like microsoft's symbol server so the documentation there can be useful. note that because mozilla release builds are heavily optimized, debugging is not always easy. the debugger will not be able to show you the content of all variables and the execution path can seem strange because of inlining, tail calls, and other compiler optimizations. the only workaround is to build an unoptimized local build. the official symbol server url for firefox is https://symbol...
...in the examples below, a local cache directory is used to avoid repeatedly fetching the pdb from the server. replace c:\users\bsmedberg\symbols with an appropriate cache directory on your machine. using the symbol server in microsoft visual c++ using the symbol server in windbg the windbg symbol path is configured with a string value delimited with asterisk characters. ...
...the output of...
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Migrating from Firebug - Firefox Developer Tools
switch to another tab, though, they're closed. open the tools firebug can be opened by pressing f12. to open it to inspect an element it is possible to press ctrl+shift+c / cmd+opt+c. the devtools share the same shortcuts, but also provide shortcuts for the different panels. e.g. the network monitor can be opened via ctrl+shift+q / cmd+opt+q, the web console via ctrl+shift+k / cmd+opt+k and the debugger via ctrl+shift+s / cmd+opt+s. web console the web console is the equivalent of firebug's console panel. it shows log information associated with a web page and allows you to execute javascript expressions via its command line. the display between both is somewhat different. this may be changed in bug 1269730. filter log messages firebug offers two ways to filter log messages, via the optio...
...used the change. this feature can globally be enabled via the break on mutate button, or individually for each element and for different types of changes like attribute changes, content changes or element removal. unfortunately, the devtools do not have this feature yet (see bug 1004678). ...
... switch between sources firebug has a script location menu listing all javascript sources related to the website. those sources can be static, i.e. files, or they can be dynamically generated (i.e. ...
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Firefox Developer Tools
if you have any feedback on devtools, or want to contribute to the project, you can join the devtools community. note: if you are just getting started with web development and using developer tools, our learning docs will help you — see getting started with the web and what are browser developer tools? for good starting points. ...
... also includes links to the documentation for firefox web tools and the mozilla community. closes the developer tools page inspector view and edit page content and layout. visualise many aspects of the page including the box model, animations, and grid layouts. web console see messages logged by a web page and interact with the page using javascript. javascript debugger stop, step through, examine, and modify the javascript running in a page. network monitor see the network requests made when a page is loaded. performance tools analyze your site's general responsiveness, javascript, and layout performance. responsive design mode see how your website or app will look and behave on different devices and network types. accessibility i...
...site's general responsiveness, javascript, and layout performance. responsive design mode see how your website or app will look and behave on different devices and network types. accessibility inspector provides a means to access the page's accessibility tree, allowing you to check what's missing or otherwise needs attention. application panel provides tools for inspecting and debugging modern web apps (also known as progressive web apps). this includes inspection of service workers and web app manifests. note: the collective term for the ui inside which the devtools all live is the toolbox. more tools these developer tools are also built into firefox. unlike the "core tools" above, you might not use them every day. memory figure out which objects are keeping mem...
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Chapter 6: Firefox extensions and XUL applications - Archive of obsolete content
summer 2007. matsuzawa-san is a co-author of firefox 3 hacks (o'reilly japan, 2008.) this chapter discusses tools to assist in developing extensions. tools for extension developers fixme: are we sure we'll talking about venkman since it's not well maintained fixme: we maybe should talk about firebug and chromebug fixme: and what about console 2 and docked-js console? venkman, the javascript debugger venkman is a full-fledged javascript debugger that runs inside firefox. it works like typical debuggers, and is useful not only for developing extensions, but also for general web development. also, because it works with the javascript in extensions and firefox itself, the debugger can be a good way to learn about design methods. installing this is bundled with the mozilla suite and the cu...
...nsions and firefox itself, the debugger can be a good way to learn about design methods. installing this is bundled with the mozilla suite and the current version of seamonkey, but it needs to be installed as an extension in firefox. see https://addons.mozilla.org/firefox/216/. install the extension in firefox directly from the above url and relaunch firefox. starting up select “javascript debugger” from the tools menu. targeting javascript for debugging. when venkman first launches, it can only debug the file currently open in your web browser. this is because a lot of javascript files can slow down the browser down if they’re opened for debugging, but you’ll need to lift this restriction in order to develop extensions. uncheck the “exclude browser files” menu item under the...
...install quicknote from the following url and relaunch firefox. https://addons.mozilla.org/firefox/46/. ...
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Running Tamarin acceptance tests - Archive of obsolete content
jdir-release/shell/avmshell $ python runtests.py tamarin tests started: 2010-09-28 10:37:06.410676 current configuration: x64-mac-tvm-release avm version: 5260:6d1899261bac executing 2532 tests against vm: /users/build/hg/builds/5260-6d1899261bac/mac/avmshell_64 2532 running abcasm/abs_helper.as skipping... reason: 2531 running abcasm/adhoc.abs skipping... reason: inconsistencies in different debug output, need to implement regex matching of diffs 2527 running abcasm/branchtocommon.abs 2530 running abcasm/arithmetic.abs 2529 running abcasm/bkpt.abs 2528 running abcasm/bkptline.abs 2526 running abcasm/bug_476556.abs 2524 running abcasm/bug_491056.abs ... test run passed! tests complete at 2010-09-28 10:39:26.751797 start date: 2010-09-28 10:38:07.221457 end date : 2010-09-28 10:39:26.7...
...you should set environment variables as described above except for avm, which should be: $ export avm=$tamarin_build_top/platform/android/android_shell.py where $tamarin_build_top is your main tamarin repo folder. note that avm needs to point to android_shell...
.... the latest asc.jar can be downloaded from from ftp://ftp.mozilla.org/pub/js/tamarin...latest/asc.jar. also the source to asc.jar may be downloaded and rebuilt from http://opensource.adobe.com/wiki/display/flexsdk/flex+sdk. - set the asc environment variable, as described above. - set the shellabc environment variable to the path of the generated/shell_toplevel.abc. adb 'adb' stands for android debug bridge. adb is used to access your android device and can run both direct and shell-type commands. if you've correctly edited and run the android-vars.sh script mentioned on the tamarin build documentation page you should already be pathed to the adb executable in the public sdk/ndk, but if not it exists at /android-public/android-sdk-mac_86/platform-tools. adb supports ssh-like commands to an an...
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Ember resources and troubleshooting - Learn web development
mber.js guides tutorial: super rentals ember.js api documentation ember.js discord server — a forum/chat server where you can meet the ember community, ask for help, and help others! general troubleshooting, gotchas, and misconceptions this is nowhere near an extensive list, but it is a list of things that came up around the time of writing (latest update, may 2020). ...
...up around the time of writing (latest update, may 2020). how do i debug what's going on in the framework? ...
...may 2020). how do i debug what's going on in the framework? ...
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Handling common JavaScript problems - Learn web development
o automate testing tools in a later article.) see eslint integrations for eslint options; jshint is supported out of the box by grunt, and also has other integrations available, e.g. jshint loader for webpack. note: eslint takes a bit more setup and configuration than jshint, but it is more powerful too. browser developer tools browser developer tools have many useful features for helping to debug javascript. for a start, the javascript console will report errors in your code. make a local copy of our broken-ajax.html example (see the source code also). if you look at the console, you'll see the error message "uncaught typeerror: can't access property "length", heroes is undefined", and the referenced line number is 49. if we look at the source code, the relevant code section is this: f...
...); showheroes(superheroes); to the following: request.onload = function() { let superheroes = request.response; populateheader(superheroes); showheroes(superheroes); } to summarize, anytime something is not working and a value does not appear to be what it is meant to be at some point in your code, you can use console.log() to print it out and see what is happening. ...
...ime something is not working and a value does not appear to be what it is meant to be at some point in your code, you can use console.log() to print it out and see what is happening. using the javascript debugger unfortunately, we still have the same error — the problem has not gone away. let's investigate this now, using a more sophisticated feature of browser developer tools: the javascript debugger as it is called in firefox. note: similar tools are available in other browsers; the sources tab in chrome, debugger in safari (see safari web development tools), etc. in firefox, the debugger tab looks as follows: on the left, you can select the script you want to debug (in this case we have only one). the center panel shows the code in the selected script. the right-hand panel sho...
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HTTP logging
this saves a log of http-related information from your browser run into a file that you can examine (or upload to bugzilla if a developer has asked you for a log). note: the web console also offers the ability to peek at http transactions within firefox. http logging generally provides more detailed logging. using about:networking this is available starting with firefox 52. this is the best and easiest way to do http logging. at any point during while your browser is running, you can turn logging on and off. this allows you to capture only the "interesting" part of the browser's behavior (i.e. ...
...multiple processes, and each process gets its own log file. for many bugs, the "log.txt-main" file is the only thing you need to upload as a file attachment to your bugzilla bug (this is assuming you're logging to help a mozilla developer). other bugs may require all the logs to be uploaded--ask the developer if you're not sure. pat yourself on the back--a job well done! thanks for helping us debug firefox. logging http activity by manually setting environment variables sometimes the about:networking approach won't work, for instance if your bug occurs during startup, or you're running on mobile, etc. in that case you can set environment variables *before* you launch firefox. note that this approach winds up logging the whole browser history, so files can get rather large (they compres...
...if it's running. open a new shell. the commands listed here assume a bash-compatible shell. copy and paste the following commands into the shell one at a time. make sure to hit enter after each line. export moz_log=timestamp,rotate:200,nshttp:5,cache2:5,nssockettransport:5,nshostresolver:5,cookie:5 export moz_log_file=/tmp/log.txt cd /path/to/firefox ./firefox reproduce the problem you're debugging. when the problem has been reproduced, exit firefox and look for the generated log files, which you can find at /tmp/log.txt. mac os x these instructions show how to log http traffic in firefox on mac os x. quit firefox is if it's currently running, by using the quit option in the file menu. keep in mind that simply closing all windows does not quit firefox on mac os x (this is standar...
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Eclipse CDT Manual Setup
utocomplete suggestion., so as soon as you type any alphabetical character that may begin with a symbol name like there is in other ides.) select "c/c++ > editor > save actions" and deselect "ensure newline at the end of file". select "c/c++ > editor > scalability" and set "enable scalability mode when the number of lines in the file is more than:" to something larger, like 100000. select "run/debug > console" and deselect "limit console output". if you want to increase the text size in the editor, select "general > appearance > colors and fonts", select "basic > text font", and edit the font size. creating an eclipse project to create an eclipse project for your mozilla source tree, select "file > new > makefile project with existing code". in the "import existing code" window that opens...
... add a recursive, regular expression "exclude all" filter for files with name matching "\.(?:rej|orig|o|pp|swp)$" to exclude .rej, .orig, .pp, .o, and .swp f...
... only/the primary object directory) for the source tree and those directories are inside the source tree (or if you might have such object directories in future), then add an "exclude all", regular expression filter for folders with a project relative path matching "obj(?!-debug(?:$|/)).+". this particular regular expression will exclude all directories beginning with the string "obj" except "obj-debug", so if "obj-debug" is not the name of your main object directory, then adjust the regular expression as necessary. add a recursive, regular expression "exclude all" filter for files with name matching "\.(?:rej|orig|o|pp|swp)$" to exclude .rej, .orig, .pp, .o, and .swp files. add "exclude all" filters for any other non-source directories that you've added to your source tree (e.g., xcode or ms...
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Gecko Logging
the given level enabled. module - the log module to use. level - the output level of the message. log level numeric value purpose mozilla logging levels disabled 0 indicates logging is disabled. this should not be used directly in code. ...
...zilla logging levels disabled 0 indicates logging is disabled. this should not be used directly in code. error 1 an error occurred, generally something you would consider asserting in a debug build. warning 2 a warning often indicates an unexpected state. info 3 an informational message, often indicates the current program state. debug 4 a debug message, useful for debugging but too verbose to be turned on normally. verbose 5 a message that will be printed a lot, useful for debugging program flow and will probably impact performance. example usage code sample #include "mozilla/logging.h" using mozilla::loglevel; static mozilla::lazylogmodule slogger("example_logger"); static void dostuff() { m...
... that will be printed a lot, useful for debugging program flow and will probably impact performance. example usage code sample #include "mozilla/logging.h" using mozilla::loglevel; static mozilla::lazylogmodule slogger("example_logger"); static void dostuff() { moz_log(slogger, loglevel::info, ("doing stuff.")); int i = 0; int start = time::nowms(); moz_log(slogger, loglevel::debug, ("starting loop.")); while (i++ < 10) { moz_log(slogger, loglevel::verbose, ("i = %d", i)); } // only calculate the elapsed time if the warning level is enabled. if (moz_log_test(slogger, loglevel::warning)) { int elapsed = time::nowms() - start; if (elapsed > 1000) { moz_log(slogger, loglevel::warning, ("loop took %dms!", elapsed)); } } if (i != 10) { moz...
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gtstd.html
to run the makefile. on windows nt, use the nmake utility that comes with visual c++. ...
...e makefile. on windows nt, use the nmake utility that comes with visual c++. ...
... you create your own makefiles, be sure to include the libraries in the same order that they are listed in the sample makefiles. ...
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Bytecode Descriptions
sync generators. gen must be the generator object for the current frame. it must not have been previously suspended. the resume point indicated by resumeindex must be the next instruction in the script, which must be afteryield. implements: generatorstart, steps 4-7. format: jof_resumeindex afteryield operands: (uint32_t icindex) bytecode emitted after yield expressions. this is useful for the debugger and abstractgeneratorobject::isafteryieldorawait. it's treated as jump target op so that the baseline interpreter can efficiently restore the frame's interpretericentry when resuming a generator. the preceding instruction in the script must be yield, initialyield, or await. format: jof_icindex finalyieldrval stack: gen ⇒ suspend and close the current generator, async function, or async ge...
... the contiguous chunk of bytecode from the instruction after jsop::pushlexicalenv to jsop::poplexicalenv (inclusive); but if that range contains any instructions on exit slides, after a jsop::poplexicalenv, then those must be correctly noted as outside the scope. format: jof_scope poplexicalenv pop a lexical environment from the environment chain. see jsop::pushlexicalenv for the fine print. debugleavelexicalenv no-op instruction that indicates leaving an optimized lexical scope. if all bindings in a lexical scope are optimized into stack slots, then the runtime environment objects for that scope are optimized away. no jsop::{push,pop}lexicalenv instructions are emitted. however, the debugger still needs to be notified when control exits a scope; that's what this instruction does. the las...
...mechanisms. lineno operands: (uint32_t lineno) no-op instruction emitted immediately after jsop::*eval so that direct eval does not have to do slow pc-to-line mapping. the lineno operand should agree with this script's source notes about the line number of the preceding *eval instruction. nopdestructuring no-op instruction to hint that the top stack value is uninteresting. this affects only debug output and some error messages. in array destructuring, we emit bytecode that is roughly equivalent to result.done ? undefined : result.value. nopdestructuring is emitted after the undefined, so that the expression decompiler and disassembler know to casually ignore the possibility of undefined, and render the result of the conditional expression simply as "result.value". forceinterpreter no-o...
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SpiderMonkey Internals
ide spidermonkey and jsapi callback functions signal errors by calling js_reporterror or one of its variants, or js_setpendingexception, and returning js_false or null. public apis the public c/c++ interface, called the jsapi, is in most places a thin (but source-compatible across versions) layer over the implementation. see the jsapi user guide. there is an additional public api for javascript debuggers, jsdbgapi, but js/jsd/jsdebug.h might be a better api for debuggers. another api, jsxdrapi, provides serialization for javascript scripts. (xul fastload uses this.) just-in-time compiler spidermonkey contains a baseline compiler as first tier. a second tier jit, code-named ionmonkey was enabled in firefox 18. ionmonkey is an optimizing compiler. self-hosting of built-in functions in js st...
...files exist to group struct and scalar typedefs so they can be used everywhere without dragging in struct definitions from n different files. the jspubtd.h file contains public typedefs, and is included automatically when needed. the jsprvtd.h file contains private typedefs and is included by various .h files that need type names, but not type sizes or declarations. jsdbgapi.cpp, jsdbgapi.h the debugging api. provided so far: traps, with which breakpoints, single-stepping, step over, step out, and so on can be implemented. the debugger will have to consult jsopcode.def on its own to figure out where to plant trap instructions to implement functions like step out, but a future jsdbgapi.h will provide convenience interfaces to do these things. at most one trap per bytecode can be set. when a s...
...e to consult jsopcode.def on its own to figure out where to plant trap instructions to implement functions like step out, but a future jsdbgapi.h will provide convenience interfaces to do these things. at most one trap per bytecode can be set. when a script (jsscript) is destroyed, all traps set in its bytecode are cleared. watchpoints, for intercepting set operations on properties and running a debugger-supplied function that receives the old value and a pointer to the new one, which it can use to modify the new value being set. line number to pc and back mapping functions. the line-to-pc direction "rounds" toward the next bytecode generated from a line greater than or equal to the input line, and may return the pc of a for-loop update part, if given the line number of the loop body's closin...
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nsIEventListenerInfo
interface describes how an event listener was added to an event target; these are returned by nsieventlistenerservice.getlistenerinfofor, which provides a list of all the listeners to a given event target. 1.0 66 introduced gecko 1.9.2 inherits from: nsisupports last changed in gecko 1.9.2 (firefox 3.6 / thunderbird 3.1 / fennec 1.0) method overview nsisupports getdebugobject(); astring tosource(); attributes attribute type description allowsuntrusted boolean indicates whether or not the event listener allows untrusted events. read only. capturing boolean indicates whether or not the event listener is in capture mode. read only. insystemeventgroup boolean indicates whether or not the even...
...e event listener allows untrusted events. read only. capturing boolean indicates whether or not the event listener is in capture mode. read only. insystemeventgroup boolean indicates whether or not the event listener is in the system event group. read only. type astring the type of the event for which the listener was added. read only. ...
...trusted events. read only. capturing boolean indicates whether or not the event listener is in capture mode. read only. insystemeventgroup boolean indicates whether or not the event listener is in the system event group. read only. type astring the type of the event for which the listener was added. read only. ...
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Mozilla
ct prior inspecting normal http cache. nsiapplicationcacheservice::chooseapplicationcache is given the url the channel is about to load. it synchronously returns an nsiapplicationcache object representing the most recent cache version from the most recent cache group containing the entry under the url or a matching namespace. benchmarking debug builds (--enable-debug) and non-optimized builds (--disable-optimize) are much slower. any performance metrics gathered by such builds are largely unrelated to what would be found in a release browser. browser chrome tests the browser chrome test suite is an automated testing framework designed to allow testing of application chrome windows using jav...
... produce the same bitmap. creating sandboxed http connections starting with gecko 1.8.1 (firefox 2), it is possible to create sandboxed http connections which don't affect the user's cookies. this article will cover the basics of doing http connections from xpcom javascript, and should easily translate to c++ xpcom. debugging debugging a project as large as mozilla can be a daunting task. fortunately, over the years, mozilla developers have come up with not just technologies and features to help you debug code, but have devised tips and techniques that can help too. also available are assorted tools that you can use when debugging. developer guide ...
.../release, pushstate/popstate) must be paired. using tab-modal prompts note: this part of the documentation is outdated. the updated prompt documentation can be found in the firefox source docs. using the mozilla source server using the mozilla source server is now even more feature-packed. the nightly debug builds are now also source indexed so that by following a couple of simple steps you can also have the source code served to you for debugging without a local build using the mozilla symbol server the mozilla project runs a symbol server for trunk firefox nightly and release builds on windows. symbols are available for at least 30 previous day...
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Browser Toolbox - Firefox Developer Tools
the browser toolbox enables you to debug add-ons and the browser's own javascript code rather than just web pages like the normal toolbox. the browser toolbox's context is the whole browser rather than just single page on a single tab. note: if you want to debug a specific add-on that is restartless or sdk-based then try the add-on debugger. use the browser toolbox for add-ons that are neither. enabling the browser toolbox the browser toolbox is not enabled by default. to enable it you need to check the settings "enable chrome and addon debugging" and "enable remote debugging". to do this, open the developer tools settings, go to the section "advanced settings", and check the settings "enable browser chrome and add-on debugging toolboxes" and "enable remote debugging". opening ...
...ome and add-on debugging toolboxes" and "enable remote debugging". opening the browser toolbox open the browser toolbox through the menu button and the menu items "developer" then "browser toolbox". you can also open it with the ctrl + alt +shift + i key combination ( cmd + opt +shift + i on a mac). you will be presented with a dialog like this (it can be removed by setting the devtools.debugger.prompt-connection property to false): click ok, and the browser toolbox will open in its own window: you'll be able to inspect the browser's chrome windows and see, and be able to debug, all the javascript files loaded by the browser itself and by any add-ons that are running. ...
...it can be removed by setting the devtools.debugger.prompt-connection property to false): click ok, and the browser toolbox will open in its own window: you'll be able to inspect the browser's chrome windows and see, and be able to debug, all the javascript files loaded by the browser itself and by any add-ons that are running. altogether you will have access to the following developer tools: debugger (note: if you want to debug a specific add-on that is restartless or sdk-based then try the add-on debugger.) console style editor performance network monitor page inspector accessibility inspector you can debug chrome: and about: pages using the normal debugger, just as if they were ordinary content pages. targeting a document in the normal toolbox, there's a button in the toolbar...
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Set watch expressions - Firefox Developer Tools
each time it does, the box will flash briefly yellow. ...
...each time it does, the box will flash briefly yellow. ...
...each time it does, the box will flash briefly yellow. ...
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Tutorial: Show Allocations Per Call Path - Firefox Developer Tools
tutorial: show allocations per call path this page shows how to use the debugger api to show how many objects a web page allocates, sorted by the function call path that allocated them. visit the url about:config, and set the devtools.chrome.enabled preference to true: setting the 'devtools.chrome.enabled' preference open a developer scratchpad (menu button > developer > scratchpad), and select "browser" from the "environment" menu. (this menu will not be present unless you have changed the preference as explained above.) selecting the 'browser' context in the scratchpad enter the following code in the scratchpad: // this simply defines the 'debugger' constructor in this // scratchpad; it doesn't actually start debugging anything. components.utils.impo...
...rom the "environment" menu. (this menu will not be present unless you have changed the preference as explained above.) selecting the 'browser' context in the scratchpad enter the following code in the scratchpad: // this simply defines the 'debugger' constructor in this // scratchpad; it doesn't actually start debugging anything. components.utils.import('resource://gre/modules/jsdebugger.jsm'); adddebuggertoglobal(window); (function () { // the debugger we'll use to observe a tab's allocation. var dbg; // start measuring the selected tab's main window's memory // consumption. this function is available in the browser // console. window.demotrackallocations = function() { dbg = new debugger; // this makes hacking on the demo *much* more // pleasant. ...
...emotrackallocations = function() { dbg = new debugger; // this makes hacking on the demo *much* more // pleasant. dbg.uncaughtexceptionhook = handleuncaughtexception; // find the current tab's main content window. var w = gbrowser.selectedbrowser.contentwindow; console.log("tracking allocations in page: " + w.location.href); // make that window a debuggee of our debugger. dbg.adddebuggee(w.wrappedjsobject); // enable allocation tracking in dbg's debuggees. dbg.memory.trackingallocationsites = true; } window.demoplotallocations = function() { // grab the allocation log. var log = dbg.memory.drainallocationslog(); // neutralize the debugger, and drop it on the floor // for the gc to collect. console.log("sto...
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Deprecated tools - Firefox Developer Tools
uate the expression using ctrl + enter (cmd + enter on macos). when evaluating, the input isn't cleared, which makes it possible to quickly iterrate over a snippet of code. the results are displayed in the console output, to the right of the input, providing immediate feedback. unlike in scratchpad, errors are properly displayed in the output with an expandable stacktrace, making it easier to debug the code you're currently writing. starting firefox 72, you can import a javascript file content in the console input with ctrl + o (cmd + o on macos), as well as saving the console input content to a file using ctrl + s (cmd + s on macos). webide and connect page webide was deprecated as of firefox 69 disabled as of firefox 70 (bug 1539451). removed as of firefox 71 (bug 1539462). descript...
...using ctrl + s (cmd + s on macos). webide and connect page webide was deprecated as of firefox 69 disabled as of firefox 70 (bug 1539451). removed as of firefox 71 (bug 1539462). description webide allowed you to connect the firefox developer tools to remote browsers, such as firefox for android. it was also intended to support application development for firefox os. ...
...). webide and connect page webide was deprecated as of firefox 69 disabled as of firefox 70 (bug 1539451). removed as of firefox 71 (bug 1539462). description webide allowed you to connect the firefox developer tools to remote browsers, such as firefox for android. it was also intended to support application development for firefox os. alternatives remote debugging is available in about:debugging as of firefox 68. ...
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Examine and edit HTML - Firefox Developer Tools
. now children are indicated in the tree with this icon: at the right side of some nodes there are markers shown indicating different pieces of information related to it: event the element has one or several event listeners attached to it. clicking the marker opens a tooltip listing the event listeners and allows you for each listener to switch to the line of javascript code in the debugger where the listener is defined. scroll the element is a scroll container, i.e. it has overflow: scroll or overflow: auto applied to it, and it has scrollable overflow. grid the element is a grid container, i.e. it has display: grid applied to it. clicking the marker enables the grid highlighter. flex the element is a flex container, i.e. it has display: flex ...
...r display: inline grid applied to it. clicking the marker enables the grid highlighter. inline-flex the element is an inline flex container, i.e. it has display: inline-flex or display: inline flex applied to it. clicking the marker enables the flexbox highlighter. custom… the element is a custom element. clicking the marker switches to the line of javascript code in the debugger where the custom element got defined. note: there are some useful keyboard shortcuts that can be used in the html tree — see the html pane keyboard shortcuts list. ::before and ::after you can inspect pseudo-elements added using ::before and ::after: custom element definition when you open the inspector on a page that includes custom elements, you can view the class definition...
...t defined. note: there are some useful keyboard shortcuts that can be used in the html tree — see the html pane keyboard shortcuts list. ::before and ::after you can inspect pseudo-elements added using ::before and ::after: custom element definition when you open the inspector on a page that includes custom elements, you can view the class definition for the custom element in the debugger: inspect the element click on the word custom the source for the element's class will be displayed in the debugger. whitespace-only text nodes web developers don’t write all their code in just one line of text. they use white space such as spaces, returns, or tabs between their html elements because it makes markup more readable. usually this white space seems to have no effect ...
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console - Archive of obsolete content
logged using log(), info(), trace(), or warn() won't be logged in these situations. console methods all console methods except exception() and trace() accept one or more javascript objects as arguments and log them to the console. depending on the console's underlying implementation and user interface, you may be able to examine the properties of non-primitive objects that are logged. console.debug(...) deprecated, you should use console.log() instead. console.error(object[, object, ...]) logs the arguments to the console, preceded by "error:" and the name of your add-on: console.error("this is an error message"); error: my-addon: this is an error message console.exception(exception) logs the given exception instance as an error, outputting information about the exception's stack t...
...unction is called. console.warn(object[, object, ...]) logs the arguments to the console, preceded by "warn:" and the name of your add-on: console.warn("this is a warning message"); warn: my-addon: this is a warning message logging levels logging's useful, of course, especially during development. but the more logging there is, the more noise you see in the console output. especially when debug logging shows up in a production environment, the noise can make it harder, not easier, to debug issues. this is the problem that logging levels are designed to fix. the console defines a number of logging levels, from "more verbose" to "less verbose", and a number of different logging functions that correspond to these levels, which are arranged in order of "severity" from informational message...
...means that the same code can be more verbose in a development environment than in a production environment - you just need to arrange for the appropriate logging level to be set. the complete set of logging levels is given in the table below, along with the set of functions that will result in output at each level: level will log calls to: all any console method debug debug(), error(), exception(), info(), log(), time(), timeend(), trace(), warn() info error(), exception(), info(), log(), time(), timeend(), trace(), warn() warn error(), exception(), warn() error error(), exception() off nothing setting the logging level the logging level defaults to "error". there are two system preferences that can b...
...-on using jpm run (without --profile set) or jpm test, the global extensions.sdk.console.loglevel preference is automatically set to "info". this means that calls to console.log() will appear in the console output. when you install an add-on into firefox, the logging level will be "error" by default (that is, unless you have set one of the two preferences). this means that messages written using debug(), log(), info(), trace(), and warn() will not appear in the console. this includes add-ons being developed using the extension auto-installer. ...

Setting Up a Development Environment - Archive of obsolete content
roject). if you don't see this textbox, click on the "more" button. you also have the option to save the command, by clicking on the "add to toolbox" checkbox. to see the toolbox, click on view > tabs > toolbox, from the main menu. with that, you should now have a very easy way to build your xpi, by just double clicking on the created commands. we can make it even better. once you're testing and debugging your code, you'll find that constantly building and installing an xpi can be very tedious. this is the reason why we introduced "make install". this only works if your extension is already installed in a firefox profile. just like in the provided project, you need the add-on id and profile location set in the file makefile. we use this information to locate the installation path of the extens...
... to get started using it. the dom inspector is particularly useful in finding out how to overlay a window, and how to replace default css style rules. you can see the names of the files involved, which gives you a good starting point when looking into the mozilla source. you can even change styles, attributes and execute javascript code in it, although that's not completely reliable. javascript debugger the name says it all. the venkman javascript debugger is a great way to trace execution of your javascript code. to debug extension and browser code, right-click on the loaded scripts panel and uncheck exclude browser files. the list of loaded scripts will grow long to include all of the scripts in firefox. having our file naming conventions prove very useful in this case. you can set breakp...
...ile naming conventions prove very useful in this case. you can set breakpoints, step in and out of methods, and even get profiling information from javascript execution. you can inspect variables, keep track of watch expressions, and evaluate arbitrary js at any point in execution. this extension has seen little maintenance in quite some time, so it is very buggy. it is specially unreliable when debugging code in javascript xpcom and xbl files. nevertheless, it is a valuable tool when trying to figure out why a certain function is misbehaving. tamper data tamper data intercepts http requests and their responses. it allows you to cancel them and even replace payload data before it is sent. there are several similar extensions, such as live http headers, but tamper data is the one that we use ...
...bl files. nevertheless, it is a valuable tool when trying to figure out why a certain function is misbehaving. tamper data tamper data intercepts http requests and their responses. it allows you to cancel them and even replace payload data before it is sent. there are several similar extensions, such as live http headers, but tamper data is the one that we use the most. we'll cover more on http debugging later on. firebug the firebug extension includes pretty much all tools mentioned so far, but it's mostly focused on web development. the chromebug extension helps in making firebug more useful for extension development, but it may still not be powerful enough to replace all of the previously mentioned add-ons. on the other hand, firebug has a very friendly, integrated user interface, and s...

Index of archived content - Archive of obsolete content
ution dialogs and prompts downloading files drag & drop embedding svg examples and demos from articles file i/o finding window handles forms related code snippets html in xul for rich tooltips html to dom isdefaultnamespace js xpcom javascript debugger service javascript timers javascript daemons management label and description lookupnamespaceuri lookupprefix miscellaneous modules on page load page loading post data to window preferences progr...
...rs how mozilla finds its configuration files how thunderbird and firefox find their configuration files introduction kill the xul.mfl file for good locked config settings other mozilla customization pages protecting mozilla's registry.dat file automatically handle failed asserts in debug builds blackconnect blackwood bonsai bookmark keywords build building transformiix standalone chromeless compiling the npruntime sample plugin in visual studio creating a firefox sidebar extension creating a microsummary creating a mozilla extension add...
...gposts build bundlelibrary bundles configuration extensions faq hostwindow installer scripting styling proxy ui pydom rdf api rdf datasource how-to reading textual data remote xul remote debugging rsyncing the cvs repository running windows debug builds downloaded from tinderbox sxsw 2007 presentations safe browsing safe browsing: design documentation safely loading uris same origin policy for xbl space manager detailed design space manager high level design standalone xpcom st...
... xulrunner application update article building xulrunner building xulrunner with python commandline components creating xulrunner apps with the mozilla build system creating a windows inno setup installer for xulrunner applications custom app bundles for mac os x debugging a xulrunner application deploying xulrunner dialogs in xulrunner getting started with xulrunner how to enable locale switching in a xulrunner application macfaq make your xulrunner app match the system locale opening a link in the default browser specifying startup chrome window using c...

Unix stub installer - Archive of obsolete content
where does the unix stub installer code reside? the unix stub installer project resides at: <http://lxr.mozilla.org/seamonkey/sou...ard/unix/src2/> how do we get setup to debug the unix stub installer? build the unix installer (debug or non-debug target) by typing "make" in the src2 directory grab a nightly build, say from <http://ftp.mozilla.org/pub/mozilla/n...staller.tar.gz> gunzip and untar the build to some temporary location like /tmp. copy the installer.ini and config.ini files over into the src2 directory. if you don't want the installer to download then grab a nightly "full" installer, say from <ftp://ftp.mozilla.org/pub/mozilla/ni...gnu-sea.tar.gz>. then untar and gunzip this to /tmp. copy the xpi directory into the src2 directory you are debugging from. run the i...
...oad then grab a nightly "full" installer, say from <ftp://ftp.mozilla.org/pub/mozilla/ni...gnu-sea.tar.gz>. then untar and gunzip this to /tmp. copy the xpi directory into the src2 directory you are debugging from. run the installer from the src2 directory by either using the mozilla-installer shell script or the mozilla-installer-bin binary with the appropriate flags. if you need to use gdb to debug the installer run it by typing "gdb mozilla-installer-bin" on the shell prompt. how we get setup to debug the xpinstall engine from the unix stub installer? build your entire mozilla tree (which should build the installer in the src2 directory as well). go to mozilla/xpinstall/packager/unix. on the shell prompt type "perl deliver.pl". now you will find an installer *and* the xpcom.xpi and ...
... you can step into the xpinstall engine through the xpistub once the xpistub dll is loaded. ...
... you can step into the xpinstall engine through the xpistub once the xpistub dll is loaded. ...

Template Logging - Archive of obsolete content
« previous debugging problems with a template can be difficult as many problems are logic errors that are often not possible to determine automatically. for example, if you spell a value wrong, no data may be returned, but the template system won't know that that this was because of a spelling error, or simply that there shouldn't be any data anyway. fortunately, some debugging and logging support is provided with templates that may help. logging template results there are two main ways in which template errors may be detected. the first debugging method involves logging all new results that apply to the template due to the data changing as well as logging results that are changed or removed. in addition, each result generated when the template is first created and initialized i...
...ust be enabled with a flag. <vbox datasources="..." flags="logging"/> the flags attribute on the root element of the template should include the logging flag. if other flags are used as well, separate them with spaces. enabling logging will output details to the error console for each result. the error console can be found on the firefox tools menu. this logging of results can be very useful for debugging, but remember to remove this flag when you have finished and the template works correctly, as the logging can take up extra time that is not necessary when the template is working. each result is logged in a form much like the following: in template with id root using ref http://www.some-fictitious-zoo.com/birds new active result for query 2 matching rule 1: http://www.some-fictitious-zoo.com...
... ?human to match. however, it is important to note that an error will not be printed simply if data didn't exist for a particular result. in the above example, some people may not have names. these people will not match the query but it will not cause an error. thus, if no error is logged, it generally indicates an issue with the data or that the data does not match the query being used. we could debug this by removing parts of the query bottom up, for instance, removing the <triple> element completely and seeing whether any results or content is generated. remember to use the logging flag as described above to see whether any results are being generated. unfortunately, detecting network or parsing errors with the data itself can be difficult. naturally, semantic errors in the data in the datas...
... « previous ...

Getting started with XULRunner - Archive of obsolete content
we also need a simple chrome.manifest in the application root which will include the the manifest in our chrome root. here is the application root chrome.manifest: manifest chrome/chrome.manifest step 6: set up preferences the prefs.js file tells xulrunner the name of the xul file to use as the main window. ...
...ces the prefs.js file tells xulrunner the name of the xul file to use as the main window. here is mine: pref("toolkit.defaultchromeuri", "chrome://myapp/content/main.xul"); /* debugging prefs, disable these before you deploy your application! */ pref("browser.dom.window.dump.enabled", true); pref("javascript.options.showinconsole", true); pref("javascript.options.strict", true); pref("nglayout.debug.disable_xul_cache", true); pref("nglayout.debug.disable_xul_fastload", true); xulrunner specific preferences include: toolkit.defaultchromeuri specifies the default window to open when the application is launched. toolkit.defaultchromefeatures specifies the features passed to window.open() when the main application window is opened. toolkit.singletonwindowtype allows configuring the app...
...s the default window to open when the application is launched. toolkit.defaultchromefeatures specifies the features passed to window.open() when the main application window is opened. toolkit.singletonwindowtype allows configuring the application to allow only one instance at a time. the toolkit preferences are described in further detail in xulrunner:specifying startup chrome window. the debugging preferences are discussed in debugging a xulrunner application step 7: create some xul finally, we need to create a simple xul window, which is described in the file main.xul. nothing fancy here, just the minimum we need to make a window. no menus or anything. main.xul: <?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin/" type="text/css"?> <window id="main" title="my app...
...see xul application packaging for details. mac on the mac, before you can run a xulrunner application with everything intact, you must install it using the --install-app xulrunner commandline flag. installing the application creates an os x application bundle: /library/frameworks/xul.framework/xulrunner-bin --install-app /<path>/<to>/myapp.zip once installed, you can run the applic...

Tools for game development - Game development
asm.js asm.js is a very limited subset of the javascript language, which can be greatly optimized and run in an ahead-of-time (aot) compiling engine for much faster performance than your typical javascript performance. this is, of course, great for games. emscripten an llvm to javascript compiler; with emscripten, you can compile c++ and other languages that can compile to llvm bytecode into high-performance javascript. ...
...lets you profile your code to help figure out where your performance issues are so that you can make your game run at top speed. shumway shumway is a renderer for adobe flash built entirely in javascript, webgl, etc., bridging the gap between flash and web standards. this article shows how to make use of shumway, and how to contribute fixes and bugs to the project. ...
...erformance issues are so that you can make your game run at top speed. shumway shumway is a renderer for adobe flash built entirely in javascript, webgl, etc., bridging the gap between flash and web standards. this article shows how to make use of shumway, and how to contribute fixes and bugs to the project. ...
...e gap between flash and web standards. this article shows how to make use of shumway, and how to contribute fixes and bugs to the project. ...

Command line options
y. other components -chat start with the irc client, chatzilla, if installed. -devtools start with native developer tools opened. -editor url or -edit url start with editor (composer) for the given url (where url is optional). seamonkey only. seamonkey -edit www.mozilla.org -inspector url start with the dom inspector, if installed, and inspect the given url (where url is optional). ...
...if installed. -devtools start with native developer tools opened. -editor url or -edit url start with editor (composer) for the given url (where url is optional). seamonkey only. seamonkey -edit www.mozilla.org -inspector url start with the dom inspector, if installed, and inspect the given url (where url is optional). -jsdebugger start application with browser toolbox (formerly browser debugger). that is different to venkman debugger (see option -venkman). -jsconsole start application with the error console, or, in firefox, the browser console. -purgecaches gecko (layout engine) has a javascript cache, which is not reset on startup, this clears it. -start-debugger-server port firefox only. start the debugger server on port. this will enable another instance of firefox to connec...
...t application with the error console, or, in firefox, the browser console. -purgecaches gecko (layout engine) has a javascript cache, which is not reset on startup, this clears it. -start-debugger-server port firefox only. start the debugger server on port. this will enable another instance of firefox to connect the firefox developer tools to this firefox instance. see the article on remotely debugging firefox desktop. the port argument is optional, and if it is omitted, the server will listen on port 6000. -venkman start with the javascript debugger, venkman, if installed. xulrunner -app /path/to/application.ini start a new process running the xulrunner application at path/to. also works with firefox version 3 and above. --install-app path/to/myapplication.(xpi|xulapp) installs the...
...mote control -remote remote_command this feature was removed in firefox 36.0, restored in 36.0.1 and removed again in 39.0. see bug 1080319. execute the specified remote_command in an already running application process. firefox -remote "openurl(www.mozilla.org, new-tab)" this option is only available on x-windows unix platforms. miscellaneous -attach-console write messages for the debugging console into the window which launched the application instead of opening a new window for the debugging messages. only supported on the windows operating system. -console start application with a debugging console. note: windows only. -h or -help or -? print the list of all available command line options. note that on windows this only works with a redirection such as |more (bug 35588...

PRLogModuleLevel
the enumerated type prlogmodulelevel defines levels of logging available to application programs. ...
... the enumerated type prlogmodulelevel defines levels of logging available to application programs. ...
... the enumerated type prlogmodulelevel defines levels of logging available to application programs. ...
... the enumerated type prlogmodulelevel defines levels of logging available to application programs. ...

NSS_3.12_release_notes.html
.12 requires nspr 4.7.1. see the documentation section for the build instructions. nss 3.12 source and binary distributions are also available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_rtm/src/. binary distributions: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_rtm/. both debug and optimized builds are provided. go to the subdirectory for your platform, dbg (debug) or opt (optimized), to get the tar.gz or zip file. the tar.gz or zip file expands to an nss-3.12 directory containing three subdirectories: include - nss header files lib - nss shared libraries bin - nss tools and test programs you also need to download the nspr 4.7.1 binary distribution...
...th_camellia_256_cbc_sha tls_ecdh_anon_with_null_sha tls_ecdh_anon_with_rc4_128_sha tls_ecdh_anon_with_3des_ede_cbc_sha tls_ecdh_anon_with_aes_128_cbc_sha tls_ecdh_anon_with_aes_256_cbc_sha bugs fixed the following bugs have been fixed in nss 3.12. bug 354403: nsslist_createiterator returns pointer to a freed memory if the function fails to allocate a lock bug 399236: pkix wrapper must print debug output into stderr bug 399300: pkix error results not freed after use. bug 414985: crash in pkix_pl_ocsprequest_destroy bug 421870: strsclnt crashed in pkix tests. bug 429388: vfychain.main leaks memory bug 396044: warning: usage of uninitialized variable in ckfw/object.c(174) bug 396045: warning: usage of uninitialized variable in ckfw/mechanism.c(719) bug 401986: mac os x leopard build failure ...
...bug 420979: vfychain ignores -b time option when -p option is present bug 403563: implement the tls session ti...
...g 341371: certutil lacks a way to request a certificate with an existing key bug 382292: add support for camellia to cmd/symkeyutil bug 385642: add additional cert usage(s) for certutil's -v -u option bug 175741: strict aliasing bugs in mozilla/dbm bug 210584: cert_asciitoname doesn't accept all valid values bug 298540: vfychain usage option should be improved and documented bug 323570: make dbck debug mode work with softoken bug 371470: vfychain needs option to verify for specific date bug 387621: certutil's random noise generator isn't very efficient bug 390185: signtool error message wrongly uses the term database bug 391651: need config.mk file for windows vista bug 396322: fix secutil's code and nss tools that print public keys bug 417641: miscellaneous minor nss bugs bug 334914: hopefully...

NSS Tools ssltap
it watches tcp connections and displays the data going by. if a connection is ssl, the data display includes interpreted ssl records and handshaking. availability this tool is known to build on solaris 2.5.1 (sunos 5.5.1) and windows nt 4.0. description the ssltap command opens a socket on a rendezvous port and waits for an incoming connection from the client side. once this connection arrives, the tool makes another connection to the specified host name and port on the server side. it passes any data sent by the client to the server and vice versa. ...
...ta to the shell window from which it was called. it can do this for plain http connections or any tcp protocol, as well as for ssl streams, as described here. the tool cannot and does not decrypt any encrypted message data. you use the tool to look at the plain text and binary data that are part of the handshake procedure, before the secure connection is established. syntax to run the ssl debugging tool, type this command in a command shell: ssltap [-vhfsxl] [-p port] hostname:port options the command does not require any options other than hostname:port, but you normally use them to control the connection interception and output. the options for the command are the following: -v print a version string for the tool. -h turn on hex/ascii printing. instead of outputting raw d...
...on. -l turn on looping; that is, continue to accept connections rather than stopping after the first connection is complete. -p port change the default rendezvous port (1924) to another port. ...
...119 nntps 563 (nntp over ssl) examples you can use the ssl debugging tool to intercept any connection information. although you can run the tool at its most basic by issuing the ssltap command with no options other than hostname:port, the information you get in this way is not very useful. for example, assume your development machine is called intercept. the simplest way to use the debugging tool is to execute the following command from a command shell: ssltap www.netscape.com:80 the program waits for an incoming connection on the default port 1924. in your browser window, enter the url http://intercept:1924. the browser retrieves the requested page from the server at www.netscape.com, but the page is intercepted and passed on to the browser by the debugging tool on intercept. ...

NSS tools : ssltap
it watches tcp connections and displays the data going by. if a connection is ssl, the data display includes interpreted ssl records and handshaking options -v print a version string for the tool. -h turn on hex/ascii printing. ...
...e. -p port change the default rendezvous port (1924) to another port. ...
...nntp over ssl) usage and examples you can use the ssl debugging tool to intercept any connection information. although you can run the tool at its most basic by issuing the ssltap command with no options other than hostname:port, the information you get in this way is not very useful. for example, assume your development machine is called intercept. the simplest way to use the debugging tool is to execute the following command from a command shell: $ ssltap www.netscape.com the program waits for an incoming connection on the default port 1924. in your browser window, enter the url http://intercept:1924. ...
...on its way to the browser, the data is printed to the command shell from which you issued the command. ...

Index
an get the spidermonkey source code in gzipped form or directly from the mercurial repository. 9 hacking tips spidermonkey this page list a few tips to help you investigate issues related to spidermonkey. all tips listed here are dealing with the javascript shell obtained at the end of the build documentation of spidermonkey. it is separated in 2 parts, one section related to debugging and another section related to drafting optimizations. many of these tips only apply to debug builds of the js shell; they will not function in a release build. 10 how to embed the javascript engine embedding mozilla, javascript, spidermonkey, tutorial see also jsapi user guide. in particular, it has more and better code examples! 11 index index, mdn meta, ...
.... return false on error, as usual for bool result-typed api entry points. 438 js_restoreexceptionstate jsapi reference, spidermonkey this function permits to restore any previously saved exception state which was saved into a jsexceptionstate object created by the js_saveexceptionstate function. 439 js_set_tracing_details jsapi reference, spidermonkey set debugging information about the next thing to be traced by a jstracer. 440 js_samevalue jsapi reference, reference, référence(2), spidermonkey samevalue slightly differs from strict equality (===) in that +0 and -0 are not the same and in that nan is the same as nan. the samevalue algorithm is equivalent to the following javascript: 441 js_saveexceptionstate jsapi ...
...ger types. 517 jsdbgapi javascript, spidermonkey these functions can be used to profile a spidermonkey application using the mac profiler, shark. see profiling javascript with shark. 518 parser api api, guide, javascript, spidermonkey example: 519 profiling spidermonkey guide 1.) get yourself an optimized libxul build of firefox, with debugger info. 520 running automated javascript tests automated testing, build documentation, guide, qa, spidermonkey the jstests shell harness is js/src/tests/jstests.py. basic usage is: 521 running parsemark spidermonkey, tests here's how you get your mitts on it. the test files are not checked into the source tree because they're non-mozilla js code. ...
...ly linked list of stack frames. it represents a javascript call stack at a past moment of execution. younger frames hold a reference to the frames that invoked them. the older tails are shared across many younger frames. 523 setting up cdt to work on spidermonkey developing mozilla, eclipse, ide, spidermonkey, tools for cdt to index all code, spidermonkey has to be built with debug information. the full process of and requisites for doing so are described here. please follow those instructions up until the point of invoking configure. 524 shell global objects javascript, needscontent, spidermonkey these are the global objects that are set up automatically by the spidermonkey js command-line interpreter when you start the program. 525 spidermo...

JS_NewGlobalObject
lags bits set. the caller must ensure that the jsclass remains alive throughout the lifetime of the new object, including the garbage collection cycle that finally frees it. the usual way to do this is to make jsclasses global or static. principals jsprincipals * the security information to associate with this compartment. hookoption js::onnewglobalhookoption see debugger api hook added in spidermonkey 31 options const js::compartmentoptions &amp; the option for new compartment (passed to jscompartment constructor). added in spidermonkey 31 description js_newglobalobject creates a new global object based on the specified class. the new object has no parent. it initially has no prototype either, since it is typically the first object crea...
...s. the new object has no parent. it initially has no prototype either, since it is typically the first object created; call js_initstandardclasses to create all the standard objects, including object.prototype, and set the global object's prototype. the constructor clasp-&gt;construct is not called. on success, js_newglobalobject returns a pointer to the new object. otherwise it returns null. debugger api hook during global creation, we fire notifications to callbacks registered via the debugger api. these callbacks are arbitrary script, and can touch the global in arbitrary ways. when that happens, the global should not be in a half-baked state. but this creates a problem for consumers that need to set slots on the global to put it in a consistent state. this api provides a way for consu...
...it's unfortunately on the clunky side, but that's the way the cookie crumbles. if callers have no additional state on the global to set up, they may pass fireonnewglobalhook to js_newglobalobject, which causes that function to fire the hook as its final act before returning. ...
...globalhook, which means that they are responsible for invoking js_fireonnewglobalobject upon successfully creating the global. if an error occurs and the operation aborts, callers should skip firing the hook. but otherwise, callers must take care to fire the hook exactly once before compiling any script in the global's scope (we have assertions in place to enforce this). this lets us be sure that debugger clients never miss breakpoints. enum onnewglobalhookoption { fireonnewglobalhook, dontfireonnewglobalhook }; see also mxr id search for js_newglobalobject mxr id search for onnewglobalhookoption bug 897322 bug 880917 bug 759585 bug 570040 bug 755186 bug 1239666 - options is no longer optional ...

JS_SetGCZeal
syntax void js_setgczeal(jscontext *cx, uint8_t zeal, uint32_t frequency); name type description cx jscontext * a context. the gc zeal level of the associated jsruntime is set. zeal uint8_t the desired level of garbage collection. frequency uint32_t with some zeal levels, a gc is triggered every frequency allocations. ...
...10 incremental gc in multiple slices. 11 verify post write barriers between instructions. 12 verify post write barriers between paints. 13 check internal hashtables on minor gc. 14 perform a shrinking collection every frequency allocations. ...
... every frequency allocations. with gc zeal enabled, gc-related crashes are much easier to reproduce (they happen more reliably) and debug (they happen sooner, closer to the source of the bug). the drawback is that gc zeal can cause javascript code to run extremely slowly. regularly running your test suite with gc zeal enabled at level 2 is a good practice. this function is available only in debug builds. to enable this function in an optimized build, define the macro js_gc_zeal building spidermonkey. ...
... more reliably) and debug (they happen sooner, closer to the source of the bug). the drawback is that gc zeal can cause javascript code to run extremely slowly. regularly running your test suite with gc zeal enabled at level 2 is a good practice. this function is available only in debug builds. to enable this function in an optimized build, define the macro js_gc_zeal building spidermonkey. ...

TPS Tests
note: if you are updating the tps environment and want to keep your existing config (eg, the existing username and password), you should instead execute: python create_venv.py --keep-config %path% activate the environment source %path%/bin/activate run some tests note that the testfile is not a path, it should only be the filename from services/sync/tests/tps/ runtps --debug --testfile %test_file_name% --binary %firefox_binary_path% additionally, omitting a --testfile parameter will cause it to run all tps tests listed in services/sync/tests/tps/all_tests.json an example on osx, for running just the test_sync.js testfile against a locally built firefox (where the mozconfig set the objdir to obj-ff-artifact): runtps --debug --testfile test_sync.j...
...functions you can also write your own functions to be called as actions. for example, consider the first action in the phase above: [bookmarks.add, bookmarks_initial] you could rewrite this as a custom function so as to add some custom logging: [async () => { logger.loginfo("adding bookmarks_initial"); await bookmarks.add(bookmarks_initial); }] note that this is probably best used for debugging, and new tests that want custom behavior should add it to the tps addon so that other tests can use it. example test here's an example tps test to tie it all together. // phase declarations var phases = { "phase1": "profile1", "phase2": "profile2", "phase3": "profile1" }; // asset list // the initial list of bookmarks to be added to the browser var bookmarks...
... and data is synced from the sync server. the tps extension verifies that the bookmarks in bookmarks_after_first_modify list are present; i.e., all the changes performed in profile2 have successfully been synced to profile1. lastly, firefox closes and the tests ends. (implementation detail) two final cleanup phases are run to wipe the server state and unregister devices. troubleshooting and debugging tips for writing and running tps tests tps evaluates the whole file in every phase, so any syntax error(s) in the file will get reported in phase 1, even though the error may not be in phase 1 itself. inspect tps.log. when a tps test fails, the log is dumped to tps.log in the virtualenv. inspect about:sync-log. every sync should have a log and every item synced should have a record. run...
...riting and running tps tests tps evaluates the whole file in every phase, so any syntax error(s) in the file will get reported in phase 1, even though the error may not be in phase 1 itself. inspect tps.log. when a tps test fails, the log is dumped to tps.log in the virtualenv. inspect about:sync-log. every sync should have a log and every item synced should have a record. run runtps with --debug. this will enable much more verbose logging in all engines. check the tps.log file written out after tps runs. it will include log output written by the python driver, which includes information about where the temporary profiles it uses are stored. run test_sync.js. this test generally validates your tps setup and does a light test of a few engines. comment out the goquitapplication() calls i...

Thread Sanitizer
st one place in our build where # our cflags are not added during linking. # note: the use of this flag causes clang to automatically link the tsan runtime :) export ldflags="-fsanitize=thread -fpic -pie" # these three are required by tsan ac_add_options --disable-jemalloc ac_add_options --disable-crashreporter ac_add_options --disable-elf-hack # keep symbols to symbolize tsan traces export moz_debug_symbols=1 ac_add_options --enable-debug-symbols ac_add_options --disable-install-strip # settings for an opt build ac_add_options --enable-optimize="-o2 -gline-tables-only" ac_add_options --disable-debug starting the build process now you start the build process using the regular make -f client.mk command. starting firefox after the build has completed, you can start firefox from the objdir...
...the default way of symbolizing the traces is much slower than using llvm-symbolizer for that purpose: llvm ships with a symbolizer binary that tsan...
...8 fi using llvm symbolizer for faster/better traces by default, tsan traces are symbolized because otherwise, the runtime suppression list wouldn't work. the default way of symbolizing the traces is much slower than using llvm-symbolizer for that purpose: llvm ships with a symbolizer binary that tsan will readily use to immediately output symbolized traces much faster. furthermore, additional debug information is included in traces when llvm-symbolizer is used. to use it, either make sure the llvm-symbolizer binary is in your path or set the environment variable tsan_options="external_symbolizer_path=/path/to/llvm-symbolizer" before running the process. if you've built tsan as described above, then you will want to set the variable to $llvm_home/build/bin/llvm-symbolizer. ignoring known ra...
...er supports them. compile-time blacklisting is the preferred way of blacklisting, because it does not have a performance impact. still, blacklisting should be done very carefully so we won't miss important bugs. runtime suppressions to prevent races from showing up at runtime, tsan also provides a runtime suppression list. this list is a good tool to temporarily hide some traces, especially for debugging purposes. however, unlike compile-time blacklisting, runtime suppressions do have a performance impact, especially if the race in question keeps showing up a lot. for more information on how to use the runtime suppression list, see the tsan wiki. ...

Reference Manual
r only does exactly the work you would have done, if you always remembered to do the right thing. safety features type safeguards it is an invariant of nscomptr that it holds the xpcom-correct interface pointer for it's underlying type. for example, an nscomptr<nsifoo> will always hold the pointer that would be returned by queryinterface, when querying an xpcom object for its nsifoo interface. in debug builds, if you subvert this invariant with one of the assignment forms that doesn't call queryinterface, nscomptr will assert at runtime in the bad assignment. // given two un-related interfaces |nsifoo| and |nsibar|... nsibar* bar = ...; // ... nscomptr<nsifoo> foo = bar; // ns_assertion: "queryinterface needed" // ...even assuming you can get the line to compile ...
... // old-style c/c++ casts by-pass |nscomptr|s machinery and cause leaks... nsresult rv; nscomptr<nsifoo> foo = ...; // ... rv = getfoo( (nsifoo**)&foo ); rv = getfoo( &(nsifoo*)foo ); // sure, they compile; but now you leak. to help prevent this, we are trying to make the first form, above, illegal by making operator& private. see bug 59414. implementation details and debugging machinery although it is a class, nscomptr has no virtual methods, and therefore, no vtable or vptr. because a few key routines are factored out into a common non-template base class, the actual underlying pointer is stored as an nsisupports* (except in debug builds where nscap_feature_debug_ptr_types is turned on). it is because of these factored routines that nscomptr users must link with t...
..., nscomptr has no virtual methods, and therefore, no vtable or vptr. because a few key routines are factored out into a common non-template base class, the actual underlying pointer is stored as an nsisupports* (except in debug builds where nscap_feature_debug_ptr_types is turned on). it is because of these factored routines that nscomptr users must link with the xpcom library. when nscap_feature_debug_ptr_types is turned on, instead of holding its underlying pointer in a variable of type nsisupports*, the nscomptr holds it in a pointer matching the underlying type. this allows source level debuggers to more easily "follow" the pointer. however, the routines that would normally be factored into a base class now must become template-specific inlines. there is no factored base class. this implies...
...the app will not link. ...

Mailnews and Mail code review requirements
d be filed on the needed test framework. the in-testsuite? flag should be set on the bug until the framework has been completed and the test code is running automatically. certain build-config or tooling bugs which don't affect the actual product cannot be usefully tested. these bugs should have the in-testsuite- flag set. ...
...the in-testsuite? flag should be set on the bug until the framework has been completed and the test code is running automatically. certain build-config or tooling bugs which don't affect the actual product cannot be usefully tested. these bugs should have the in-testsuite- flag set. ...
... flag set. rubber-stamp approvals for intermittently failing ("orange") test fixes/debugging in order to make it easier to debug and fix tests that fail intermittently ("intermittent orange" tests), we have created the following two rubber-stamps based on this proposal on the tb-planning mailing list. the procedure to use these is to be sure to: include "rs=simple-orange-fix" or "rs=orange-debugging" in the first line of the commit message paste a link to the pushed commit with the rubber stamp in the bug make sure you pasted a link to any try-server pushes of the patch in the bug rs=simple-orange-fix requirements: the patch is fixing an intermittent orange test failure. the patch is a change exclusively to test logic. the patch has identified a likely problem and fixes it; no ...
...d on try or has been run locally on the appropriate platform(s). specifically, if the xpcshell test will do different things on windows than it will do on os x or linux, it must be run on windows and one of os x / linux. the author of the patch is the module owner or a peer of the module to which the test corresponds. a bug is still required, even if it is immediately marked fixed. rs=orange-debugging requirements: the patch is trying to fix an intermittent orange test failure. the patch only touches test logic. the patch only adds/modifies logging statements, although the logs can be conditional. the patch must have been run at least once on the try server. (i have done some mozmill orange fixing where the try server would not duplicate the orange failures of the trunk and so in o...

Use a source map - Firefox Developer Tools
ript sources executed by the browser are often transformed in some way from the original sources created by a developer. for example: sources are often combined and minified to make delivering them from the server more efficient. javascript running in a page is often machine-generated, as when compiled from a language like coffeescript or typescript. ...
...hen compiled from a language like coffeescript or typescript. in these situations, it's much easier to debug the original source, rather than the source in the transformed state that the browser has downloaded. a source map is a file that maps from the transformed source to the original source, enabling the browser to reconstruct the original source and present the reconstructed original in the debugger. to enable the debugger to work with a source map, you must: generate the source map include a comment in the transformed file, that points to the source map. the comment's syntax is like this: //# sourcemappingurl=http://example.com/path/to/your/sourcemap.map in the video above we load https://mdn.github.io/devtools-examples/sourcemaps-in-console/index.html. this page loads a source...
... ...
...github.io/devtools-examples/sourcemaps-in-console/index.html. this page loads a source called "main.js" that was originally written in coffeescript and compiled to javascript. the compiled source contains a comment like this, that points to a source map: //# sourcemappingurl=main.js.map in the debugger's source list pane, the original coffeescript source now appears as "main.coffee", and we can debug it just like any other source. ...

How to - Firefox Developer Tools
these articles describe how to use the debugger. ...
... these articles describe how to use the debugger. ...
... these articles describe how to use the debugger. ...
... these articles describe how to use the debugger. ...

URLSearchParams.set() - Web APIs
parameter. params.set('baz', 3); params.tostring(); // "foo=1&bar=2&baz=3" below is a real-life example demonstrating how to create a url and set some search parameters. you can copy and paste the example in a code environment like codepen, jsfiddle, or the multi-line javascript interpreter in firefox. ...
...n, jsfiddle, or the multi-line javascript interpreter in firefox. line #41: comment out this line to stop dumping the search parameters to the console (debug). line #43: dumps the generated object and it's string representation to the console (info). line #44: tries to automatically open a new window/tab with the generated url (when uncommented). ...
...pen a new window/tab with the generated url (when uncommented). ...
...ext, bdebug=false){ let theurl theurl= new url('https://regexr.com') theurl.searchparams.set( 'expression', rexp.tostring() ) theurl.searchparams.set( 'tool', 'replace' ) theurl.searchparams.set( 'input', '\u2911\u20dc' )// ⤑⃜ theurl.searchparams.set( 'text', atext.join('\n') ) if( bdebug ){ // display the key/value pairs for(var pair of theurl.searchparams.entries()) { console.debug(pair[0] + ' = \'' + pair[1] + '\''); } console.debug(theurl) } return theurl } var url = genurl( /(^\s*\/\/|\s*[^:]\/\/).*\s*$|\s*\/\*(.|\n)+?\*\/\s*$/gm // single/multi-line comments // /(^\s*\/\/.*|\s*[^:]\/\/.*)/g // single-line comments ,[ "these should work:", "", "// eslint-disable-next-line no-unused-vars", "lockpref( 'keyword.url',\t\t'https://duckduckgo.com/html/?

cfx - Archive of obsolete content
nary to run. the path may be specified as a full path or may be relative to the current directory. but note that the version must be 4.0b7 or later. cfx run runs the host application with a new profile. you can specify an existing profile using the --profiledir option, and this gives you access to that profile's history, bookmarks, and other add-ons. this enables you to run your add-on alongside debuggers like firebug. see "using --profiledir" for more information. -b binary, --binary=binary use the host application binary specified in binary. binary may be specified as a full path or as a path relative to the current directory. --binary-args=cmdargs pass extra arguments to the binary being executed (for example, firefox). for example, to pass the -jsconsole...
...used to execute the command. for example, if you type: cfx run ---no-run you will see something like: to launch the application, enter the following command: /path/to/firefox/firefox-bin -profile /path/to/profile/tmpjdnlp6.mozrunner -foreground -no-remote this enables you to run the add-on without going through cfx, which might be useful if you want to run it inside a debugger like gdb. -o, --overload-modules in early versions of the sdk, the sdk modules used by an add-on were themselves included in the add-on. the sdk modules now ship as part of firefox. from firefox 21 onwards, sdk add-ons built with sdk 1.14 or higher will use the sdk modules that are built into firefox, even if the add-on includes its own copies of the sdk modules. use ...
...used to execute the command. for example, if you type: cfx run ---no-run you will see something like: to launch the application, enter the following command: /path/to/firefox/firefox-bin -profile /path/to/profile/tmpjdnlp6.mozrunner -foreground -no-remote this enables you to run the add-on without going through cfx, which might be useful if you want to run it inside a debugger like gdb. -o, --overload-modules in early versions of the sdk, the sdk modules used by an add-on were themselves included in the add-on. the sdk modules now ship as part of firefox. from firefox 21 onwards, sdk add-ons built with sdk 1.14 or higher will use the sdk modules that are built into firefox, even if the add-on includes its own copies of the sdk modules. use ...

jpm - Archive of obsolete content
see selecting a browser version. --binary-args cmdargs pass extra arguments to firefox. for example, to pass the -jsconsole argument to firefox and launch the browser console, try the following: jpm run --binary-args -jsconsole to pass multiple arguments, or arguments containing spaces, quote them: jpm run --binary-args '-url mzl.la -jsconsole' --debug run the add-on debugger attached to the add-on. -o --overload path rather than use the sdk modules built into firefox, use the modules found at path. if -o is specified and path is omitted, jpm looks for the jetpack_root environment variable and use its value as the path. see overloading the built-in modules for more information. -p --profile= profile ...
... a browser version. --binary-args cmdargs pass extra arguments to firefox. for example, to pass the -jsconsole argument to firefox, which will launch the browser console, try the following: jpm test --binary-args -jsconsole to pass multiple arguments, or arguments containing spaces, quote them: jpm test --binary-args '-url mzl.la -jsconsole' --debug run the add-on debugger attached to the add-on. -f --filter file[:test] only run tests whose filenames match file and optionally match test, both regexps. jpm test --filter base64:btoa the above command only runs tests in files whose names contain "base64", and in those files only runs tests whose names contain "btoa". -o --overload path rather t...
...ts, so it was not signed. increment the version number in your package.json file and run the command again. under the hood, jpm sign creates an unlisted add-on inside addons.mozilla.org, which means you must distribute the xpi file yourself for your users to install it. if you need to create a listed add-on, just submit it directly to addons.mozilla.org where it is signed automatically. see the debugging section if you are experiencing difficulty installing a signed add-on. jpm sign accepts the following options: --api-key=jwt_issuer api access key (string) generated on the addons.mozilla.org key management page. on the amo key management page, this value is labeled "jwt issuer". --api-secret=jwt_secret api access secret (string) generated on the a...

Developing for Firefox Mobile - Archive of obsolete content
efox mobile, and use jpm-mobile instead of the normal jpm. right now not all modules are fully functional, but we're working on adding support for more modules. the tables at the end of this guide list the modules that are currently supported on firefox mobile. this tutorial explains how to run sdk add-ons on an android device connected via usb to your development machine. we'll use the android debug bridge (adb) to communicate between the add-on sdk and the device. it's possible to use the android emulator to develop add-ons for android without access to a device, but it's slow, so for the time being it's much easier to use the technique described below. setting up the environment first you'll need an android device capable of running the native version of firefox mobile. then: insta...
...use the android emulator to develop add-ons for android without access to a device, but it's slow, so for the time being it's much easier to use the technique described below. setting up the environment first you'll need an android device capable of running the native version of firefox mobile. then: install the nightly build of the native version of firefox mobile on the device. enable usb debugging on the device (step 2 of this link only) on the development machine: install version 1.5 or higher of the add-on sdk install the correct version of the android sdk for your device using the android sdk, install the android platform tools next, attach the device to the development machine via usb. now open up a command shell. android platform tools will have installed adb in the "pla...
...the addon to your device starting: intent { act=android.activity.main cmp=org.mozilla.fennec/.app (has extras) } --------- beginning of /dev/log/main --------- beginning of /dev/log/system could not read chrome manifest 'file:///data/data/org.mozilla.fennec/chrome.manifest'. info: starting info: starting zerdatime 1329258528988 - browser chrome startup finished. this will be followed by lots of debug output. on the device, you should see firefox launch with your add-on installed. console.log() output from your add-on is written to the command shell, just as it is in desktop development. however, because there's a lot of other debug output in the shell, it's not easy to follow. the command adb logcat prints adb's log, so you can filter the debug output after running the add-on. for example, ...

Local Storage - Archive of obsolete content
« previousnext » note: you may rather be looking for dom storage (localstorage, etc.), unless you really are doing xul development. it is very common for an extension to require some kind of local persistent storage. we recommend that you at least keep an error log, so that you can request error data from your users when you encounter problems that are hard to debug. we'll discuss logging in this section, but first let's look at the right (or at least, common and scalable) way of managing local files. it is strongly recommended that you keep your local files inside the firefox profile directory. otherwise you may run into problems if the same extension is installed in multiple profiles. the common practice is to create a directory with the name of your project at the root of the pro...
...lly without deleting it. a good argument can be done for both, so it is up to you to choose what to do in this case. the fuel library has an uninstall event you can use to perform these operations. logging good logging is essential in all kinds of software projects. any extension that is more complex than a hello world needs some way to log errors and trace execution without having to fire up a debugger. it used to be the case that custom logging solutions were necessary, but mozilla labs have come up with a javascript implementation of a logger similar to the log4j logger used in java projects. the logger is called log4moz and it is implemented as a javascript code module, so it only works on firefox 3 and above. to use this logger, you need to copy the log4moz.js file to your modules dire...
... store it in a private variable. and then logging is done with any of the following methods, depending on the kind of message being logged: this._logger.fatal("this is a fatal message."); this._logger.error("this is an error message."); this._logger.warn("this is a warning message."); this._logger.info("this is an info message."); this._logger.config("this is a config message."); this._logger.debug("this is a debug message."); this._logger.trace("this is a trace message."); you can filter the output of the global logger or any specific logger instance by setting the level property. during development you should use the "all" level, but for release versions it's usually better to move the level up to "warn", so that the log is compact and execution is more efficient. note: we recommend th...

Environment variables affecting crash reporting - Archive of obsolete content
don't submit it to the server. ...
...till be moved to the "crash reports/pending" directory. moz_crashreporter_no_report save the minidump file but don't launch the crash reporting ui or send the report to the server. minidumps will be stored in the user's profile directory, in a subdirectory named "minidumps". moz_crashreporter_disable disable breakpad crash reporting completely. you can use this if you would rather use the jit debugger on windows with the symbol server, for example. moz_crashreporter_shutdown save the minidump and then force the application to close. this is useful for content crashes that don't normally close the chrome (main application) processes. this variable would cause the application to close as well. moz_crashreporter the opposite of moz_crashreporter_disable, force crash reporting on even if di...
... save the minidump and then force the application to close. this is useful for content crashes that don't normally close the chrome (main application) processes. this variable would cause the application to close as well. moz_crashreporter the opposite of moz_crashreporter_disable, force crash reporting on even if disabled in application.ini. you must use this to enable crash reporting on linux debug builds. additionally, on mac os x, you can set an application default setting to allow apple's crash reporter tool to run alongside the breakpad crash reporter. run this on the command line: defaults write org.mozilla.firefox oscrashreporter 1 note that you will get two crash dialogs with this setting, one from the os and one from mozilla. ...

Using microformats - Archive of obsolete content
gin the search. if you want to search the entire document, specify content.document. options optional. if provided, this is a javascript object that contains zero or more of the following flags: recurseexternalframes if true, child frames are included in the search. the default is true. showhidden if true, hidden microformats are added; otherwise they're left out. the default is false. debug specify true if debug mode is in use; otherwise, specify false. the default is false. return value an integer value indicating the number of microformats that match the specified criteria. debug() returns a string that describes a microformat object. note: you can simply call debug() on a microformat object: microformatobject.debug() instead of using this method if you prefer. var dumpst...
... return value a string that describes the contents of the specified microformat object. get() returns an array of microformat objects corresponding to the microformats found that match specified criteria. ...
...earch the entire document, specify content.document. options optional. if provided, this is a javascript object that contains zero or more of the following flags: recurseexternalframes if true, child frames that reference external content are included in the search. the default is true. showhidden if true, hidden microformats are added; otherwise they're left out. the default is false. debug specify true if debug mode is in use; otherwise, specify false. the default is false. targetarray optional. if provided, this is an array of microformat objects to which the search results are added. return value a new array of microformat objects matching the search criteria, or the array specified by microformats with the newly found microformat objects added. getnamesfromnode() ret...

Nanojit - Archive of obsolete content
the lir as it passes from the lirbuffer toward the assembler. the result of compilation is a function that the application can call from c via a pointer to the first instruction. example the following code works with spidermonkey's hacked version of nanojit. figuring out how to compile it is left as an exercise for the reader; the following works when run in the object directory of an --enable-debug spidermonkey shell: g++ -ddebug -g3 -wno-invalid-offsetof -fno-rtti -include js-confdefs.h -i dist/include/ -i.. -i ../nanojit -o jittest ../jittest.cpp libjs_static.a note: remove the -ddebug if you have not compiled spidermonkey with --enable-debug, and use whatever you called the sample source file in place of jittest.cpp. #include <stdio.h> #include <stdint.h> #include "jsapi.h" #include ...
...ermonkey with --enable-debug, and use whatever you called the sample source file in place of jittest.cpp. #include <stdio.h> #include <stdint.h> #include "jsapi.h" #include "jstracer.h" #include "nanojit.h" using namespace nanojit; const uint32_t cache_size_log2 = 20; static avmplus::gc gc = avmplus::gc(); static avmplus::avmcore core = avmplus::avmcore(); int main() { logcontrol lc; #ifdef debug lc.lcbits = lc_readlir | lc_assembly; #else lc.lcbits = 0; #endif // set up the basic nanojit objects. allocator *alloc = new vmallocator(); codealloc *codealloc = new codealloc(); assembler *assm = new (&gc) assembler(*codealloc, *alloc, &core, &lc); fragmento *fragmento = new (&gc) fragmento(&core, &lc, cache_size_log2, codealloc); lirbuffer *buf = new (*alloc) lirbuffer(*alloc); #...
...cbits = lc_readlir | lc_assembly; #else lc.lcbits = 0; #endif // set up the basic nanojit objects. allocator *alloc = new vmallocator(); codealloc *codealloc = new codealloc(); assembler *assm = new (&gc) assembler(*codealloc, *alloc, &core, &lc); fragmento *fragmento = new (&gc) fragmento(&core, &lc, cache_size_log2, codealloc); lirbuffer *buf = new (*alloc) lirbuffer(*alloc); #ifdef debug fragmento->labels = new (*alloc) labelmap(*alloc, &lc); buf->names = new (*alloc) lirnamemap(*alloc, fragmento->labels); #endif // create a fragment to hold some native code. fragment *f = fragmento->getanchor((void *)0xdeadbeef); f->lirbuf = buf; f->root = f; // create a lir writer lirbufwriter out(buf); // write a few lir instructions to the buffer: add the first parameter // to t...

Space Manager Detailed Design - Archive of obsolete content
eflow. ...
...tion of float damage during * reflow. */ prbool hasfloatdamage() { return !mfloatdamage.isempty(); } void includeindamage(nscoord aintervalbegin, nscoord aintervalend) { mfloatdamage.includeinterval(aintervalbegin + my, aintervalend + my); } prbool intersectsdamage(nscoord aintervalbegin, nscoord aintervalend) { return mfloatdamage.intersects(aintervalbegin + my, aintervalend + my); } debug only methods /** * dump the state of the spacemanager out to a file */ nsresult list(file* out); void sizeof(nsisizeofhandler* ahandler, pruint32* aresult) const; unused / obsolete methods /* * get the frame that's associated with the space manager. this frame * created the space manager, and the world coordinate space is * relative to this frame. * * you can use queryinterface() on t...
...ist. this algorithm is pretty confusing - basically what needs to happen is that rects and bands need to be divided up so that complicated cases like#2, #4, and #7, are reduced to simpler cases where the rects is totally above,below, or between a band rect. from the current implementation, it might be worth verifying that the final result of the inserts is a correctly ordered list of bandrects (debug mode only). algorithm 3: removeregion when a float is removed, the space manager is notified by a call to removeregion,passing in the frame that is being removed. get the frameinfo for the frame passed in. if not found, an error is returned. if the rect for the frame is not empty, then visit each band in the bandlist: for each rect in the band: if the bandrect is occupied by the frame, ei...

Cmdline tests - Archive of obsolete content
the cmdline testsuite is located in test/cmdline. the testsuite allows more flexibility by coding scripts in python allowing any executable to run, sending commands to stdin, and asserting output using regular expressions. see test/cmdline/readme document for more information. ...
...ending commands to stdin, and asserting output using regular expressions. see test/cmdline/readme document for more information. ...
...output using regular expressions. see test/cmdline/readme document for more information. ...

Windows stub installer - Archive of obsolete content
where does the windows stub installer code reside? the windows stub installer project resides at: <http://lxr.mozilla.org/seamonkey/sou...windows/setup/> how do we get setup to debug the windows stub installer? build your entire mozilla tree, which should build the stub installer in the setup directory as well. (if you need to rebuild stub installer, got to /mozilla/xpinstall/wizard/windows/setup and type "nmake /f makefile.win") go to mozilla/xpinstall/wizard/windows/builder on the shell prompt type "perl build.pl". now you will find an installer *and* the xpcom.xpi and other debug xpis delivered to mozilla/dist/win32_d.obj/install. run the stub installer setup.exe from the install directory. if you need to use vc++ to debug the installer: under project | settings | debug...
...make /f makefile.win") go to mozilla/xpinstall/wizard/windows/builder on the shell prompt type "perl build.pl". now you will find an installer *and* the xpcom.xpi and other debug xpis delivered to mozilla/dist/win32_d.obj/install. run the stub installer setup.exe from the install directory. ...
...st/win32_d.obj/install. run the stub installer setup.exe from the install directory. if you need to use vc++ to debug the installer: under project | settings | debug set "executable for debug session" to be the path to mozilla/dist/win32_d.obj/install/setup.exe set "working directory" to be the path to mozilla/dist/wind32_d.obj/install press f10 to step into the code how we get setup to debug the xpinstall engine from the windows stub installer? this section needs to be added how do i add an installer package to the windows installer? adding a package involves a few steps: add a section named for your <component> to the packages-win manifest that describes which files from dist belong to which module. for example, see the xpcom section that lists all the shared libraries as see...

Creating XULRunner Apps with the Mozilla Build System - Archive of obsolete content
ld process itself will be slightly different. got source? now you need to set up a special .mozconfig file to tell mozilla to build both xulrunner and your application. here's a sample .mozconfig for building xulrunner and mccoy: # options for client.mk. mk_add_options moz_build_projects="xulrunner mccoy" mk_add_options moz_objdir=@topsrcdir@/../mccoybase # global options ac_add_options --enable-debug ac_add_options --disable-optimize # xulrunner options ac_add_app_options xulrunner --enable-application=xulrunner # mccoy options ac_add_app_options mccoy --enable-application=mccoy ac_add_app_options mccoy --with-libxul-sdk=../xulrunner/dist the first section tells mozilla what to build and where to put the resulting object files. in this case, we are building both xulrunner and mccoy and pla...
...ld in the directory mccoybase, located at the same level as the current (i.e. source) directory. to build just one of the projects, remove the name of the other from moz_build_projects. for example, you might want to set it to "xulrunner" now and run make to ensure that everything is set up correctly so far. the second section contains general options for your build. in this case we're creating a debug build, so you'd have to change the relevant options if you want a release build instead. you can find out more about which options to use in configuring build options. the third section contains options for building xulrunner. you shouldn't have to change this. finally, the final section contains options specific to your application. make sure you change the application name (following ac_add_app...
...r the file as is, since once again variables are used for things like the application name and version. but you will have to change the id to something unique to your app. default-prefs.js - these are the default mozilla preferences used by xulrunner when running your app. the important ones are described in xulrunner:specifying startup chrome window. you can add other preferences for things like debugging, as mccoy does (e.g. javascript.options.showinconsole). default.ico and default.xpm - icons for your app on windows and linux. macbuild/ - when steve jobs said "think different", we took that to heart, and not just by rejecting useless adverbial endings. we've included a whole subdirectory just for the mac. it's got a lot of stuff in it, but once again you can mostly ignore this and copy the ...

MacFAQ - Archive of obsolete content
lineservicemac.cpp", you'll see that it looks for "browser.chromeurl" before defaulting to navigator.xul, and this is called when an xulrunner app is already running, so: create a default preference of "browser.chromeurl" that points to your new "hiddenwindow" as such: "chrome://myxul/content/hiddenwindow.xul" next take the code below and drop it in, to create the hiddenwindow.xul (note: the debug function and nsicommandline try/catch can be removed, all you need is the window.arguments[0]) <?xml version="1.0"?> <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" id="myxul_hidden" windowtype="myxul:hiddenwindow" title="" width="0" height="0" persist="screenx screeny width height sizemode" > <!-- load the mozilla helpers --> <script ty...
...0"?> <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" id="myxul_hidden" windowtype="myxul:hiddenwindow" title="" width="0" height="0" persist="screenx screeny width height sizemode" > <!-- load the mozilla helpers --> <script type="application/javascript" src="chrome://global/content/nsusersettings.js" /> <script><![cdata[ function debug(alogstring) { var mconsoleservice = components.classes["@mozilla.org/consoleservice;1"] .getservice(components.interfaces.nsiconsoleservice) mconsoleservice.logstringmessage("myxul: " + alogstring + "\n"); } function checkotherwindows() { var singletonwindowtype = nspreferences.copyunicharpref("toolkit.singletonwindowtype"); var wind...
...; var win = windowmediator.getmostrecentwindow(singletonwindowtype); if (win) { window.close(); win.focus(); } } if (window.arguments && window.arguments[0]){ try { var cmdline = window.arguments[0] .queryinterface(components.interfaces.nsicommandline); for (var i = 0; i < cmdline.length; ++i) { debug(cmdline.getargument(i)) } } catch(ex) { debug(window.arguments[0]) // do something with window.arguments[0] //nspreferences.setunicharpref("myxul.cmdlinevalue", window.arguments[0]) } window.addeventlistener("load", checkotherwindows , false); } ]]></script> </window> ...

Archived Mozilla and build documentation - Archive of obsolete content
this section contains old spidermonkey documentation. autodial for windows nt this document is intended to explain how the autodial helper feature implemented for bug 93002 works and why it works that way. automated testing tips and tricks automatic mozilla configurator ankh8 automatically handle failed asserts in debug builds as of 2004-12-8, it is now possible to automatically handle failed asserts in debug builds of mozilla for windows. blackconnect blackwood bonsai it is a tool that lets you perform queries on the contents of a cvs archive; you can: get a list of checkins, see what checkins have been made by a given person, or on a given cvs...
...diff, and just editing the output to remove other patches before submitting. however, this approach quickly becomes unscalable, especially when you have different fixes in the same tree. using a distributed versioning system like svk takes out much of the hassle of managing your patches. venkman venkman is the code name for mozilla's javascript debugger. it aims to provide a powerful javascript debugging environment for mozilla based browsers namely firefox, netscape 7.x/9.x and seamonkey. note that it is not included in the gecko-based browsers such as k-meleon, galeon and netscape 8.x. venkman has been provided as part of the mozilla install distribution since october 2001, as well as an extension package in xpi format. ...
...xulrunner application that provides an easy way to experiment with xul. it’s a simple editor that can preview xul inline or in a separate popup window. it has a list of code snippets (small fragments of xul or javascript) that can be quickly inserted into the editor. the xul can be loaded from and saved to files. a xul validator and the error console are both available to help debug problems. the help menu provides access to xul information on mdc. there is even simple “keyword” help lookup for xul elements. xulrunner xulrunner is a mozilla runtime package that can be used to bootstrap xul+xpcom applications that are as rich as firefox and thunderbird. it provides mechanisms for installing, upgrading, and uninstalling these app...

NSPR Release Engineering Guide - Archive of obsolete content
this paper is for engineers performing formal release for the netscape portable runtime (nspr) across all platforms. nspr generally follows the iplanet product lifecycle. ...
...feature complete update ...pr/include/prinit.h with release numbers build all targets, debug and optimized on all platforms using local directories run the test suite on all targets verify release numbers show up in binaries resolve testing anomalies tag the tree with nsprpub_release_x_y_z_beta beta release checkout a whole new tree using the tag from above build all targets, debug and optimized on all platforms using the command: gmake release mdist=<dir>/mdist build_number=vx.y.z [build_opt=1 | use_debug_rtl=1] copy the bits from mdist to /share/builds/components/nspr20/.vx.y.z 1 run explode.pl run the test suite on all targets, using binaries & headers from shipped bits resolve testing anomalies tag the tree with nsprpub_release_x_y[_z] release candidate...
...e_debug_rtl=1] copy the bits from mdist to /share/builds/components/nspr20/.vx.y.z 1 run explode.pl run the test suite on all targets, using binaries & headers from shipped bits resolve testing anomalies tag the tree with nsprpub_release_x_y[_z] release candidate checkout a whole new tree using tag (including fixes) tag the treey with nsprpub_release_x_y_z build all targets, debug and optimized on all platforms using the command: gmake release mdist=<dir>/mdist build_number=vx.y.z [build_opt=1 | use_debug_rtl=1] copy the bits from mdist to /share/builds/components/nspr20/.vx.y.z in /share/builds/components/nspr20/ run the following scripts: explode.pl rename.sh symlink.sh rtm bits rename the .vx.y.z directory to vx.y.z (remove the hidden directory 'dot...

Tamarin Tracing Build Documentation - Archive of obsolete content
ne http://hg.mozilla.org/tamarin-tracing tamarin-tracing building tamarin building tamarin will create all the libraries for the avmplus and garbage collector (mmgc), and create a standalone executable, avmshell, for executing files in the abc file format. running avmshell without any arguments will list the available options. note that additional command-line arguments are only available in the debug configuration. the tamarin codebase contains a cross-platform build system for mozilla developers. the cross-platform build system is used for daily automated build testing so it is the most reliable system. the tamarin codebase has the ability to build additional code which supports debugging hooks. in the xcode project, this is the debug_debugger and release_debugger configurations. the flash p...
...debase contains a cross-platform build system for mozilla developers. the cross-platform build system is used for daily automated build testing so it is the most reliable system. the tamarin codebase has the ability to build additional code which supports debugging hooks. in the xcode project, this is the debug_debugger and release_debugger configurations. the flash player builds tamarin with the debugging hooks off for codesize reasons, but the mozilla client will build tamarin with the debugging hooks on. cross-platform build first, you must have the mozilla build prerequisites for your platform. additionally, you need python 2.4 or later and gnu make 3.81 or later. (gnu make 3.80 does not work. nor does any other brand of make.) with the right prerequisites, use these commands to build tamar...
...oks on. cross-platform build first, you must have the mozilla build prerequisites for your platform. additionally, you need python 2.4 or later and gnu make 3.81 or later. (gnu make 3.80 does not work. nor does any other brand of make.) with the right prerequisites, use these commands to build tamarin tracing: $ hg clone http://hg.mozilla.org/tamarin-tracing $ cd tamarin-tracing $ mkdir objdir-debug $ cd objdir-debug $ python ../configure.py --enable-shell $ make ... $ shell/avmshell avmshell 1.0 build cyclone ... that's all. the avmplus executable is avmshell. for verbose build of tamarin, you can pass cppflags to make. $ make cppflags=-davmplus_verbose windows mobile to build for arm: $ python ../configure.py --target=arm-windows --enable-shell; make to build for thumb: $ pyth...

Settings - Archive of obsolete content
pause on exceptions when this option is enabled, execution of the script will automatically pause whenever a javascript exception is thrown. ignore caught exceptions if this option is set (it is set by default) and "pause on exceptions" is set, then execution will pause on an exception only if that exception is not caught. this is usually the behavior you want. ...
...default) and "pause on exceptions" is set, then execution will pause on an exception only if that exception is not caught. this is usually the behavior you want. you don't generally want to pause execution when an exception that is thrown is caught, since that generally indicates that your program is handling it properly. show panes on startup when this option is enabled, the debugger's variables pane is visible when you first start the debugger. show only enumerable properties do not display non-enumerable javascript properties. show variables filter box enabling this option adds a "filter variables" search box to the variables pane, so that you can filter the displayed list of variables. show original sources enabling this option will m...
...defaults to true. automatically black box minified sources new in firefox 33. ...

Building Mozilla XForms - Archive of obsolete content
psrcdir/browser/config/mozconfig mk_add_options moz_co_project=browser mk_add_options moz_objdir=@topsrcdir@/obj-@config_guess@ #mk_add_options autoconf=autoconf2.13 # possibly needed #mk_add_options moz_make_flags=-jn # (optional) replace n with the number of parallel build processes (e.g. ...
...dd_options moz_objdir=@topsrcdir@/obj-@config_guess@ #mk_add_options autoconf=autoconf2.13 # possibly needed #mk_add_options moz_make_flags=-jn # (optional) replace n with the number of parallel build processes (e.g. 2 on a dual core processor) ac_add_options --enable-extensions="default,xforms" ac_add_options --disable-debug ac_add_options --enable-optimize ac_add_options --disable-tests for a debug build, you could use this configuration: . ...
...s --enable-extensions="default,xforms" ac_add_options --disable-debug ac_add_options --enable-optimize ac_add_options --disable-tests for a debug build, you could use this configuration: . $topsrcdir/browser/config/mozconfig mk_add_options moz_co_project=browser mk_add_options moz_objdir=@topsrcdir@/obj-@config_guess@ ac_add_options --enable-extensions="default,xforms" ac_add_options --enable-debug ac_add_options --disable-optimize ac_add_options --disable-tests building now that you have everything ready, you can rebuild mozilla with the same command you used before to build firefox without xforms. switch to the root of your source directory and start the build with make -f client.mk build after the build finishes, you'll have a xforms.xpi in obj-*/dist/xpi-stage/xforms.xpi. congratulatio...

Solve common problems in your JavaScript code - Learn web development
also, see other common errors for a description of common errors. making ...
...also, see other common errors for a description of common errors. ...
...also, see other common errors for a description of common errors. ...

Benchmarking
any performance metrics gathered by such builds are largely unrelated to what would be found in a release browser. rust optimization level local optimized builds are compiled with rust optimization level 1 by default, unlike nightly builds, which use rust optimization level 2. this setting reduces build times significantly but comes with a serious hit to runtime performance for any rust code (for example stylo and webrender). ...
...erformance for any rust code (for example stylo and webrender). add the following to your mozconfig in order to build with level 2: ac_add_options rustc_opt_level=2 gc poisoning many firefox builds have a diagnostic tool that causes crashes to happen sooner and produce much more actionable information, but also slow down regular usage substantially. in particular, "gc poisoning" is used in all debug builds, and in optimized nightly builds (but not opt developer edition or beta builds). the poisoning can be disabled by setting the environment variable jsgc_disable_poisoning=1 before starting the browser. async stacks async stacks no longer impact performance since firefox 78, as bug 1601179 limits async stack capturing to when devtools is opened. another option that is on by defaul...
...isoning can be disabled by setting the environment variable jsgc_disable_poisoning=1 before starting the browser. async stacks async stacks no longer impact performance since firefox 78, as bug 1601179 limits async stack capturing to when devtools is opened. another option that is on by default in non-release builds is the preference javascript.options.asyncstack, which provides better debugging information to developers. set it to false to match a release build. (this may be disabled for many situations in the future. see bug 1280819. accelerated graphics especially on linux, accelerated graphics can sometimes lead to severe performance problems even if things look ok visually. normally you would want to leave acceleration enabled while profiling, but on linux you may wish to disa...

Creating a Login Manager storage module
uilt-in login manager storage consists of two tasks: implement the nsiloginmanagerstorage interface. register that interface in a specific category. some work has already been done to integrate the login manager with the mac os x keychain (bug 106400) and gnome keyring manager (bug 309807). you should start with the existing code if you want to implement that in your extension. to see some debugging output in the console set signon.debug to true using about:config. sample javascript implementation the following code snippet is a javascript component that implements a dummy nsiloginmanagerstorage interface. see how_to_build_an_xpcom_component_in_javascript for more details about javascript components. const cc = components.classes; const ci = components.interfaces; components.utils.im...
... __logservice : null, get _logservice() { if (!this.__logservice) this.__logservice = cc["@mozilla.org/consoleservice;1"]. getservice(ci.nsiconsoleservice); return this.__logservice; }, log: function (message) { dump("sampleloginmanager: " + message + "\n"); this._logservice.logstringmessage("sampleloginmanager: " + message); }, //...
...gservice() { if (!this.__logservice) this.__logservice = cc["@mozilla.org/consoleservice;1"]. ...

Obsolete Build Caveats and Tips
visual c++ 9 is available from microsoft as part of the free visual c++ 2008 express edition with sp1 (make sure you get this and not the one without sp1!). you do not need to install the silverlight runtime or the sql server 2008 express edition when offered. alternatively you can install the command-line compiler as part of the windows 7 sdk, but you are then expected to use the included windbg debugger. the visual c++ 8 command-line compiler is included with the vista sdk, but you are then expected to use the included windbg debugger. from configuring build options [en-us] note: starting with gecko 5.0, building firefox has become extremely simple. the default application is now firefox, so you can build firefox by simply doing configure && make (for standalone source tarballs) or mak...
...e default application is now firefox, so you can build firefox by simply doing configure && make (for standalone source tarballs) or make -f client.mk (for code from the mercurial repository); this will build something roughly the same as the shipped version of firefox corresponding to the code you have. you only need to follow the steps below if you want to customize the build (e.g., to create a debug build or a release build with debug symbols), you want to build something other than firefox, or you want to build pre-gecko 5.0 source. if you are building mozilla source code from before firefox 5, then you must first select the mozilla application that you want to build (see below), and you will probably also need to set at least some of the other basic configuration options (such as whether...
... if you are building from an older project branch that still uses cvs, you will need to set moz_co_project to the appropriate value or values, using a comma-separated list, such as "mk_add_options moz_co_project=browser,mail,calendar,suite,xulrunner". ...

Firefox and the "about" protocol
nfig provides a way to inspect and change firefox preferences and settings about:compat lists overriding site compatability fixes, linked to specific bug issues. ...
...firefox preferences and settings about:compat lists overriding site compatability fixes, linked to specific bug issues. ...
... about:compat lists overriding site compatability fixes, linked to specific bug issues. ...

How to Report a Hung Firefox
, please note the approximate amount of time you waited before forcing a crash (below) in the bug report. if you suspect a hang (as opposed to slow performance), wait one minute on an idle system before getting the stack trace. the crash report link for a hang, obtained by following the steps below. submit a crash report for a hung firefox the easiest way to help the firefox stability team to debug these kinds of hangs is to make the hung firefox crash and submit a crash report. then file a bug report with the crash report id. the steps to induce a crash are slightly different on each platform: windows on windows, the stability team has written a utility which will inject a crash into firefox which will trigger the crash reporter: download crashfirefox.exe here (source code). running this...
... ...
...s.int32_t));var crash = badptr.contents;}', true); } other techniques on os x if you use a nightly build (>= firefox 16), you can use activity monitor's "sample process" feature to generate a sample. this won't produce useful results on a regular release/beta build. instead of crashing firefox, more advanced developers who know how to use a debugger can try attaching to the firefox process and debugging in place. this is only useful if you have firefox debug symbols, which are available on windows from the mozilla symbol server. ...

Implementing QueryInterface
ce(). a reference implementation of queryinterface ns_imethodimp nsmyimplementation::queryinterface( refnsiid aiid, void** ainstanceptr ) { ns_assertion(ainstanceptr, "queryinterface requires a non-null destination!"); // it's a logic error, not a runtime error, to call me without any place to put my answer! // ...but that won't matter when someone calls me wrongly in a non-debug build. if ( !ainstanceptr ) return ns_error_null_pointer; nsisupports* foundinterface; if ( aiid.equals(nscomtypeinfo<nsix>::getiid()) ) foundinterface = ns_static_cast(nsix*, this); else if ( aiid.equals(nscomtypeinfo<nsiy>::getiid()) ) foundinterface = ns_static_cast(nsiy*, this); // ...as many cases as needed... else if ( aiid.equals(nscomtypeinfo<...
...st, which detects errors when you can't really get to the desired interface. it avoids repeated uses of and assignments to *ainstanceptr, which compilers have trouble optimizing. it clears the result, *ainstanceptr, when returning an error. it generates less code than the typical implementation of queryinterface. it tests for bad input with an ns_assertion, to find logic errors immediately in debug builds. some alternatives the ns_impl_query_interface[012] macros the sample above implements two xpcom interfaces in addition to nsisupports. the ns_impl_query_interface2 macro can write this function for you (though it pains me to recommend macros), e.g., ns_impl_query_interface2(nsmyimplementation, nsix, nsiy) // implements |nsmyimplementation::...
...ated objects, which may then return wrong interfaces. one more reason to avoid aggregation specifically, and complicated hierarchies in general. the ns_get_iid macro you can use the ns_get_iid macro instead of typing out the full getiid expression. in general, i disapprove of macros except in cases where the macro must expand to different text in different situations, e.g., different platforms, debugging vs. non-debugging, et al. in such cases macros are indispensible. in other cases macros may help some people but often cloud the issues for others. they always make the program source more fragile. in this case the macro is for convenience only, so i don't recommend it, but i do offer it up as an alternative. // ... if ( aiid.equals(ns_get_iid(nsix)) ) foundinterface = ns_sta...

AsyncShutdown.jsm
is saved to the profile, this must be completed during phase profilebeforechange. asyncshutdown.profilebeforechange.addblocker( "add-on manager: shutting down", function condition() { let promise = ... // do whatever must be done before the end of phase profilebeforechange return promise; }, function info() { let status = ... // collect any information that may be useful for debugging shutdown issues with this blocker return status; } }); in this example, at some point during phase profilebeforechange, function condition will be called. phase profilebeforechange is guaranteed to not terminate until promise is either resolved or rejected. if, for some reason, promise is never resolved/rejected, firefox will crash during shutdown to avoid blocking system shutdown,...
...ot terminate until promise is either resolved or rejected. if, for some reason, promise is never resolved/rejected, firefox will crash during shutdown to avoid blocking system shutdown, preventing the user from restarting firefox or burning through a battery. in this case, a crash report is produced, with information on all the shutdown blockers that have not been resolved, and all the additional debug information returned by calls to info(). instances of phase note that you cannot create an instance of phase yourself. see attributes for the instances of phase. if you need a new phase added to asyncshutdown, please file a bug. methods overview void addblocker(string name, function|promise condition, optional function info) boolean removeblocker(function|promise conditio...
... void addblocker(string name, function|promise condition, optional function info) boolean removeblocker(function|promise condition) methods addblocker () register a blocker for the completion of a phase. void addblocker( in string name, in function|promise|* condition, optional in function info ) arguments name the human-readable name of the blocker. used for debugging/error reporting. please make sure that the name respects the following model: "some service: some action in progress" - for instance "os.file: flushing all pending i/o". condition a condition blocking the completion of the phase. generally, this is a function returning a promise. this function is evaluated during the phase and the phase is guaranteed to not terminate until the resulting pro...

Investigating leaks using DMD heap scan mode
ll the way through shutdown. you could modify these steps for leaks that go away in shutdown by collecting a cc and dmd log prior to shutdown. however, in that case it may be easier to use refcount logging, or rr with a conditional breakpoint set on calls to release() for the leaking object, to see what object actually does the release that causes the leaked object to go away. prerequisites a debug dmd build of firefox. this page describes how to do that. this should probably be an optimized build. non-optimized dmd builds will generate better stack traces, but they can be so slow as to be useless. the build is going to be very slow, so you may need to disable some shutdown checks. first, in toolkit/components/terminator/nsterminator.cpp, delete everything in runwatchdog but the call to ns...
...y::growby[...] nsattrandchildarray::insertchildat[...] [...] 0x7f089306b000 is the address of the block that contains $leakaddr. 144 bytes is the size of that block. that can be useful for confirming your guess about what class the block actually is. the byte offset tells you were in the block the pointer is. this is mostly useful for larger objects, and you can potentially combine this with debugging information to figure out exactly what field this is. the rest of the entry is the stack trace for the allocation of the block, which is the most useful piece of information. what you need to do now is to go through every one of these entries and place it into three categories: strong reference known to the cycle collector, weak reference, or something else! the goal is to eventually shrink ...
... references in the cc log is from a head element to its child via mattrsandchildren, and that sounds a lot like this, so we can mark it as being a strong known reference. this is an iterative process, where you first go through and mark off the things that are easily categorizable, and repeat until you have a small list of things to analyze. example analysis of block_analyzer.py results in one debugging session where i was investigating the leak from bug 1451985, i eventually reduced the list of entries until this was the most suspicious looking entry: 0x7f0892f29630 size = 392 bytes at byte offset 56 mozilla::dom::scriptloader::processexternalscript[...] [...] i went to that line of scriptloader::processexternalscript(), and it contained a call to scriptloader::createloadrequest(). fo...

NSPR build instructions
la, nspr is independent of the mozilla client source tree. building nspr consists of three steps: run the configure script. you may override the compilers (the cc environment variable) or specify options. build the libraries build the test programs for example, # check out the source tree from mercurial hg clone https://hg.mozilla.org/projects/nspr # create a build directory mkdir target.debug cd target.debug # run the configure script ../nspr/configure [optional configure options] # build the libraries gmake # build the test programs cd pr/tests gmake on mac os x, use make, which is gnu make. configure options although nspr uses autoconf, its configure script has two default values that are different from most open source projects. if the os vendor provides a compiler (for exam...
...build the libraries gmake # build the test programs cd pr/tests gmake on mac os x, use make, which is gnu make. configure options although nspr uses autoconf, its configure script has two default values that are different from most open source projects. if the os vendor provides a compiler (for example, sun and hp), nspr uses that compiler instead of gcc by default. nspr build generates a debug build by default. --disable-debug --enable-optimize specify these two options to generate an optimized (release) build. these two options can actually be used independently, but it's not recommended. --enable-64bit on a dual 32-bit/64-bit platform, nspr build generates a 32-bit build by default. to generate a 64-bit build, specify the --enable-64bit configure option. --target=x86_64-pc-min...
...d on windows. nspr build generates a "winnt" configuration by default on windows for historical reasons. we recommend most applications use the "win95" configuration. the "win95" configuration supports all versions of windows. the "win95" name is historical; it should have been named "win32". to generate a "win95" configuration, specify the --enable-win32-target=win95 configure option. --enable-debug-rtl this option is only used on windows. nspr debug build uses the release c run-time library by default. to generate a debug build that uses the debug c run-time library, specify the --enable-debug-rtl configure option. makefile targets all (default) clean realclean distclean install release running the test programs the tests were built above, in the pr/tests directory. on mac os ...

Build instructions
ke" binary file, unless maybe it is a bsd make. make variables may be set on the gmake command line, e.g., gmake variable=value variable=value target1 target2 or defined in the environment, e.g. (for posix shells), variable=value; export variable gmake target1 target2 here are some (not all) of the make variables that affect nss builds: build_opt: if set to 1, means do optimized non-debug build. default is debug, non-optimized build. use_debug_rtl: if set to 1, on windows, causes build with debug version of the c run-time library. ns_use_gcc: on platforms where gcc is not the native compiler, tells nss to build with gcc instead of the native compiler. default is to build with the native compiler. use_64: on platforms that support both 32-bit and 64-bit abis, tells nss to build ...
...ith debug version of the c run-time library. ns_use_gcc: on platforms where gcc is not the native compiler, tells nss to build with gcc instead of the native compiler. default is to build with the native compiler. use_64: on platforms that support both 32-bit and 64-bit abis, tells nss to build for the 64-bit abi. default is 32-bit abi, except on platforms that do not support a 32-bit abi. moz_debug_symbols: tells nss to build with debug symbols, even in an optimized build. on windows, in both debug and optimized builds, when using msvc, tells nss to put symbols in a .pdb file. required to build with msvc 8 (2005 express). default is not to put debug symbols into optimized builds, and for msvc, is to put symbols into the .exe or .dll file. nsdistmode: if set to 'copy', mozilla/dist/<obj_stu...
...nt versions (mercurial) clone the nspr and nss repositories. hg clone https://hg.mozilla.org/projects/nspr hg clone https://hg.mozilla.org/projects/nss if you want to build a releases other than the tips of these repositories, then switch to the release tags: cd nspr hg update nspr_4_9_5_rtm cd ../nss hg update nss_3_14_2_rtm cd .. set environment variables: if you want a non-debug optimized build, set build_opt=1 in your environment. otherwise, you get a debug build. on windows, if you want a debug build with the system's debug rtl libraries, set use_debug_rtl=1 in your environment. on unix platforms, except alpha/osf1, if you want a build for the system's 64-bit abi, set use_64=1 in your environment. by default, nss builds for the 32-bit environment on all platforms ex...

NSS tools : ssltab
it watches tcp connections and displays the data going by. if a connection is ssl, the data display includes interpreted ssl records and handshaking options -v print a version string for the tool. -h turn on hex/ascii printing. instead of outputting raw data, the command interprets each record as a numbered line of hex values, followed by the same data as ascii characters. the two parts are separated by a vertical bar. ...
...on. -l prefix turn on looping; that is, continue to accept connections rather than stopping after the first connection is complete. -p port change the default rendezvous port (1924) to another port. ...
...tp 119 * nntps 563 (nntp over ssl) usage and examples you can use the ssl debugging tool to intercept any connection information. although you can run the tool at its most basic by issuing the ssltap command with no options other than hostname:port, the information you get in this way is not very useful. for example, assume your development machine is called intercept. the simplest way to use the debugging tool is to execute the following command from a command shell: $ ssltap www.netscape.com the program waits for an incoming connection on the default port 1924. in your browser window, enter the url http://intercept:1924. the browser retrieves the requested page from the server at www.netscape.com, but the page is intercepted and passed on to the browser by the debugging tool on intercept. on ...

NSS tools : ssltap
it watches tcp connections and displays the data going by. if a connection is ssl, the data display includes interpreted ssl records and handshaking options -v print a version string for the tool. -h turn on hex/ascii printing. instead of outputting raw data, the command interprets each record as a numbered line of hex values, followed by the same data as ascii characters. the two parts are separated by a vertical bar. ...
...on. -l prefix turn on looping; that is, continue to accept connections rather than stopping after the first connection is complete. -p port change the default rendezvous port (1924) to another port. ...
...tp 119 * nntps 563 (nntp over ssl) usage and examples you can use the ssl debugging tool to intercept any connection information. although you can run the tool at its most basic by issuing the ssltap command with no options other than hostname:port, the information you get in this way is not very useful. for example, assume your development machine is called intercept. the simplest way to use the debugging tool is to execute the following command from a command shell: $ ssltap www.netscape.com the program waits for an incoming connection on the default port 1924. in your browser window, enter the url http://intercept:1924. the browser retrieves the requested page from the server at www.netscape.com, but the page is intercepted and passed on to the browser by the debugging tool on intercept. on ...

Small Footprint
with various changes js.jar size can be reduced to 204,689 bytes corresponding to 424,774 bytes of uncompressed classes. tools most embeddings won't need any of the classes in org.mozilla.javascript.tools or any of its sub-packages. ...
... do you use policysecuritycontroller then you do not need rhino library for class file generation and you can remove all the classes from in org.mozilla.classfile package. regular expressions the package org.mozilla.javascript.regexp can be removed. rhino will continue to run, although it will not be able to execute any regular expression matches. this change saves 47,984 bytes of class files. debug information debug information in rhino classes consumes about 25% of code size and if you can live without that, you can recompile rhino to remove it. smalljs.jar ant build script in rhino supports smalljar target that will generate smalljs.jar that does not include tools, optimizer, javaadapter and class generation library, regular expressions, e4x implementataion and deprecated files. to bui...
... in rhino classes consumes about 25% of code size and if you can live without that, you can recompile rhino to remove it. smalljs.jar ant build script in rhino supports smalljar target that will generate smalljs.jar that does not include tools, optimizer, javaadapter and class generation library, regular expressions, e4x implementataion and deprecated files. to build such minimalist jar without debug information, run the following command from the top directory of rhino distribution: ant clean ant -ddebug=off -dno-regexp=true -dno-e4x=true smalljar if you omit -dno-regexp=true, then the resulting smalljs.jar will include regular expression support. similarly omitting -dno-e4x=true results in smalljs.jar that includes runtime support for e4x. ...

Introduction to the JavaScript shell
ral/source/js/src/builtin/testingfunctions.cpp#464. if value is not specified, gcparam() returns the current value associated with gc parameter named name. if value is specified, it must be convertable to a positive uint32; gcparam() sets gc parameter name to value. for more information, see the c/c++ functions js_getgcparameter and js_setgcparameter. gczeal(level) added in spidermonkey 1.8 debug only. set the level of gc zeal, a debugging feature. this can be 0 for normal periodic garbage collection, 1 for very frequent gc, or 2 for extremely frequent gc. anything other than 0 will make javascript run extremely slow but may help reveal or reproduce gc-related bugs. for more information, see the c/c++ version of this function, js_setgczeal. getpda(object) returns the property descriptor...
...k quota. throwerror() throws an error from the js_reporterror() function. note: this function is intended only for use when testing the javascript engine. trap([function, [pc,]] expression) sets a trap at the specific point in the javascript code. when the bytecode at the offset specified by pc in the function function is about to be executed, the expression is evaluated. this is a powerful debugging mechanism when used in concert with line2pc(). for example, if you want to display a message when line 6 of a function, dosomething() is executed, you can enter the following: trap(dosomething, line2pc(dosomething, 6), "print('line 6!\n')"); note: when a trap is set, the corresponding bytecode in the program is replaced with a trap bytecode until you use untrap() to remove the trap. untra...
...the offset pc. if pc isn't specified, the trap is removed from the function's entry point. this function has no effect if there is no trap at the specified location. version([number]) the version() function lets you get or set the javascript version number. this may be useful for gaining access to syntax only available in certain versions of javascript (for example, see using javascript 1.7). debug functions these built-in functions are only available in debug builds. dis([function]) disassembles the javascript bytecode for the entire program, or for the specified function. for example, if you enter the javascript function below: function test() { var i = 3; print(i+2); } then run the command dis(test);, you get this output: main: 00000: uint16 3 00003: setvar 0 00006: pop 00...

JS_SET_TRACING_DETAILS
this article covers features introduced in spidermonkey 1.8 set debugging information about the next thing to be traced by a jstracer. syntax js_set_tracing_details(trc, printer, arg, index) name type description trc jstracer * the tracer whose debugging hooks are to be set. printer jstracenameprinter a callback function, described below; or null. arg void * see the description. index size_t see the description. callback syntax typedef void (*jstracenameprinter)(jstracer *trc, char *buf, size_t bufsize); name type description trc jstracer * the tracer. buf char * out parameter. the callback stores a string describing the reference traced in buf. ...
...d below; or null. arg void * see the description. index size_t see the description. callback syntax typedef void (*jstracenameprinter)(jstracer *trc, char *buf, size_t bufsize); name type description trc jstracer * the tracer. buf char * out parameter. the callback stores a string describing the reference traced in buf. bufsize size_t the size of buf, in chars. description set debugging information about a reference to a traceable thing to prepare for the following call to js_calltracer. when printer is null, arg must be const char * or char * c string naming the reference and index must be either (size_t)-1 indicating that the name alone describes the reference or it must be an index into some array vector that stores the reference. when printer is not null, the arg and ind...
...thing to prepare for the following call to js_calltracer. when printer is null, arg must be const char * or char * c string naming the reference and index must be either (size_t)-1 indicating that the name alone describes the reference or it must be an index into some array vector that stores the reference. when printer is not null, the arg and index arguments are available to the callback as the debugprinterarg and debugprintindex fields of trc. the storage for name or callback's arguments needs to live only until the following call to js_calltracer returns. mxr id search for js_set_tracing_details ...

Setting up the Gecko SDK
the standard project view. adding the gecko sdk to the project settings in order to build anything that uses gecko, you have to further modify the project so that it knows where to find the gecko sdk on the disk. to edit project settings, select settings from the project menu (or press alt-f7). most of the changes you make in the following steps apply to all configurations of the project (both debug and optimized), so select "all configurations" from the settings for dropdown menu: on the c/c++ tab, select the preprocessor category. this window is where you add the include paths to the gecko sdk as well as two preprocessor defines: xpcom_glue mozilla_strict_api at a minimum, you must include the nspr, the embedstring and string include directories, and the xpcom include subdirectory...
...this finalizes the project settings and gives you a project that will hold and compile xpcom components. building a windows project this section is writting for those of you who do not wish to install visual studio or the express edition, allowing the user to be able to cre...
...this finalizes the project settings and gives you a project that will hold and compile xpcom components. building a windows project this section is writting for those of you who do not wish to install visual studio or the express edition, allowing the user to be able to create commercial extensions w...

jsdIStackFrame
unique tag among all valid jsdicontext objects, useful as a hash key. ...
...ed as errors. makes eval() use the last object on its 'obj' param's scope chain as the ecma 'variables object'. private data for this object is an nsisupports object. attempting to alter this bit will result in an ns_error_illegal_value. opt_* values above, or'd together. last version set on this context. scripts typically select this with the "language" attribute. see the version_* consts on jsdidebuggerservice. unique tag among all valid jsdicontext objects, useful as a hash key. private data for this context, if it is an nsisupports, |null| otherwise. retrieve the underlying context wrapped by this jsdicontext. top of the scope chain for this context. |true| if this context should be allowed to run scripts, |false| otherwise. this attribute is only valid for contexts which implement nsiscrip...
...type description callee jsdivalue function object running in this stack frame. read only. callingframe jsdistackframe link to the caller's stack frame. read only. executioncontext jsdicontext executon context. read only. functionname autf8string function name executing in this stack frame. read only. isconstructing boolean true if stack frame is constructing a new object. read only. isdebugger boolean true if stack frame represents a frame created as a result of a debugger evaluation. read only. isnative boolean true if stack frame represents a native frame. read only. obsolete since gecko 2.0 jsdcontext jsdcontext internal use only. read only. native code only! jsdstackframeinfo jsdstackframeinfo internal use only. read only. native code only! jsdthreadstate jsdthreadstate ...

Frequently Asked Questions
buildtime errors the build just broke. it's not in your code, or it's not on your platform, but there's an nscomptr on the line where the error is and you're suspicious. you're looking in the right place. comparing an nscomptr to a raw xpcom interface pointer declaring an nscomptr to a forward-declared class not linking to xpcom not including nscomptr.h different settings of nscap_feature_debug_ptr_types runtime errors ns_assertion "queryinterface needed" may be caused by a class that derives from a given interface, when you forgetting to also specify the interface name in the ns_impl_isupports / ns_impl_threadsafe_isupports macro. for example, the assertion occurs when you convert the pointer to the object to a raw pointer to that interface, then assign the raw pointer to another n...
...gn the raw pointer to another nscomptr for that interface. ns_precondition "you can't dereference a null nscomptr with operator->()" ns_precondition "you can't dereference a null nscomptr with operator*()" other issues printf("%x\n", mynscomptr); can cause the program to crash on sigill (illegal instruction), and not on the line with the printf, which can make it tricky to figure out. for debugging purposes you can write printf("%x\n", mynscomptr.get()); how do i... initialize an nscomptr? release an nscomptr before it goes out of scope? assign 0 into it. whenever an nscomptr takes on a new value, it always releases its old value, if any. assigning in the value 0 is just like assigning in a raw pointer that happens to be null. the old referent will be released. [see initialization ...
... nscomptr<nsifoo> foo( do_queryinterface(abar, &rv) ); if ( foo ) foo->dosomefoothing(); // |foo| goes out of scope, and so |release|s its referent, here } // ...tons of stuff here, during which i don't need an |nsifoo| return rv; } editors note: move this discussion to the efficiency section, and link to it from here. make an nscomptr leak (for a debug test)? call a getter that uses a raw xpcom interface pointer as an `in/out' parameter? call a getter that fills in an nsifoo*& parameter? call a getter that doesn't addref its result? any xpcom function that returns an interface pointer, i.e., a `getter', must have already addrefed that pointer. if it didn't, you should probably report it as a bug. no matter which code pattern you use to solv...

Index
older pane. see working with the folder pane for examples and code snippets. 28 gloda thunderbird 3, thunderbird thunderbird includes a new message indexing and search system (gloda) that improves search performance, provides sophisticated full-text search capabilities and categorized search results. "gloda" is short for the thunderbird "global database". 29 gloda debugging the gloda code has log4moz logging statements spread throughout. the following preferences are supported to control how this gets logged: 30 gloda examples thunderbird 3, thunderbird this page provides some examples for using gloda. see creating a gloda message query for more examples. 31 gloda indexing this page provides a big-picture su...
...te folders", and "unread folders") were added, accessible via the scroll-arrows at the top of the pane. 112 customdbheaders preference developing a custom column to display a 'superfluous' column within thunderbird's main view. ...
... header labeled x-superfluous 114 using mapi with thunderbird's windows 7 developer builds thunderbird debug, thunderbird mapi (messaging application programming interface) is a windows feature that allows applications to send files via a system's default mail application. the thunderbird installer sets the installed build as the default mapi/mail client. if you want to set a debug build as the default mail client, you need configure it manually: 115 using the multiple accounts api by alec flett alecf@flett.org 118 libmime content type handlers by richard h. pizzarro <rhp@netscape.com> ...

Using the Mozilla source server
using the mozilla source server is now even more feature-packed. ...
... using the mozilla source server is now even more feature-packed. ...
... source server support does not work correctly out of the box in visual studio 2005. if you install windbg, and copy srcsrv.dll from the windbg install dir to the visual studio install dir (replacing the existing copy) it will work. enable source server support under tools -> options. also, disable (uncheck) the box that says "require source files to exactly match the original version". start debugging your program. symbols will load and then, if you're using a cvs build, when you try to step into or step over a confirmation window will appear asking if you trust the cvs command that source server is trying to run. after the command executes, the source file will load in the window. ...

Examine, modify, and watch variables - Firefox Developer Tools
this feature isn't yet supported in the new debugger. if you need to use it, you can, for now, switch back to the old debugger by visiting about:config and setting the "devtools.debugger.new-debugger-frontend" preference to false. to see the docs for the old debugger, please visit debugger (before firefox 52). examine variables when the code has stopped at a breakpoint, you can examine its state in the variables pane of the debugger: variables are grouped by scope: in function scope you'll see the built-in arguments and this variables as well as local variables defined by the function like user and greeting. similarly, in global scope you'll see global variables you've defined, like greetme, as well as built-in globals like localstorage and console. each object can be expanded,...
...ow its properties. pointing your cursor at a variable's name displays a tooltip that provides additional information about the variable. see object.defineproperty() for details on what these property descriptors mean. ...
...just click on the variable's current value and you'll be able to type there: watch an expression watch expressions are expressions that are evaluated each time execution pauses. you can then examine the results of these expressions. these are useful in that they let you inspect invariants in your code that you know are there but aren't necessarily in the code ready for inspection. ...

Set a conditional breakpoint - Firefox Developer Tools
to set a conditional breakpoint, activate the context menu in the source pane, on the line where you want the breakpoint, and select "add conditional breakpoint". ...
... to set a conditional breakpoint, activate the context menu in the source pane, on the line where you want the breakpoint, and select "add conditional breakpoint". ...
... to set a conditional breakpoint, activate the context menu in the source pane, on the line where you want the breakpoint, and select "add conditional breakpoint". ...

Step through code - Firefox Developer Tools
when the debugger is stopped at a breakpoint, you can step through it using four buttons in the toolbar: in order, the buttons are: play: run to the next breakpoint step over: advance to the next line in the same function. ...
...ped at a breakpoint, you can step through it using four buttons in the toolbar: in order, the buttons are: play: run to the next breakpoint step over: advance to the next line in the same function. step in: advance to the next line in the function, unless on a function call, in which case enter the function being called step out: run to the end of the current function, in which case, the debugger will skip the return value from a function, returning execution to the caller split console when paused, you can press the esc key to open and close the split console to gain more insight into errors and variables: pause on breakpoints overlay since firefox 70, when your code is paused on a breakpoint an overlay appears on the viewport of the tab you are debugging. this lets you kn...
...d also provides a step button and a play button. the thinking here is that if you've got your devtools open in a separate window, as many people do, it can be easier to have the buttons available right there to move the code forward while you are looking at the result. if you want to turn this feature off, since firefox 71 you can do so by going to about:config in a new tab, setting the devtools.debugger.features.overlay pref to false, and restarting the browser. inline variable preview new in firefox 71, the source pane now gives you an instant preview of the variables on each line of code you've stepped through. see set a breakpoint > inline variable preview for more information. ...

Use watchpoints - Firefox Developer Tools
when debugging javascript code, it can be useful to know when properties on objects are read or modified. in a large, complex codebase, it's not always easy to know where in the code a given property is accessed. in the firefox debugger, this information can be provided by watchpoints. by setting a watchpoint on the property, rather than a breakpoint at a particular line, you can discover where that access occurs. there are three types of watchpoints: get, set, and get or set. a get watchpoint pauses whenever a property is read; a set watchpoint pauses whenever a property value changes; a get or set watchpoint pauses whenever a property value is accessed in either way. set a watchpoint run and then pause the debugger. ...
...can discover where that access occurs. there are three types of watchpoints: get, set, and get or set. a get watchpoint pauses whenever a property is read; a set watchpoint pauses whenever a property value changes; a get or set watchpoint pauses whenever a property value is accessed in either way. set a watchpoint run and then pause the debugger. in the scopes pane on the right side of the debugger user interface, find an object you want to watch, and right-click it to open its context menu. choose break on, and then one of property set property get property get or set a watchpoint icon appears to the right of the property in the scopes pane. set watchpoint icons are blue, get watchpoint icons are reddish, and get or set watchpoint icons are dark yellow. click pl...
...operty get property get or set a watchpoint icon appears to the right of the property in the scopes pane. set watchpoint icons are blue, get watchpoint icons are reddish, and get or set watchpoint icons are dark yellow. click play or press f8 to resume execution. view a watchpoint when the watched property is accessed in the way specified by the watchpoint type (get or set), the debugger pauses, enabling you to see line of code responsible, and to inspect anything else you wish at that time. in the following screenshot, the debugger pauses at line 7, where obj.a is set. the message panel in the upper right corner indicates that the debugger is "paused on property set". delete a watchpoint locate the watched property in the scopes pane. click the watchpoint icon, or rig...

All keyboard shortcuts - Firefox Developer Tools
unlike the other toolbox-hosted tools, this shortcut does not also close the web console. instead, it focuses on the web console's command line. to close the web console, use the global toolbox shortcut of ctrl + shift + i (cmd + opt + i on a mac). 2. before firefox 55, the keyboard shortcut was ctrl + shift + q (cmd + opt +...
...ly, when a property is selected) enter or space return or space enter or space open mdn reference page about current property (computed view only, when a property is selected) f1 f1 f1 open current css file in style editor (computed view only, when more information is shown for a property and a css file reference is focused). ...
...l feature: for example, to change the screen brightness or the volume. see this guide to using these keys as standard function keys. to use a remapped key as a standard function key, hold the function key down as well (so to open the profiler, use shift + function + f5). note: before firefox 66, the combination ctrl + shift + s on windows and linux or cmd + opt + s on macos would open/close the debugger. from firefox 66 and later, this is no longer the case. web console command windows macos linux open the web console ctrl + shift + k cmd + opt + k ctrl + shift + k search in the message display pane ctrl + f cmd + f ctrl + f open the object inspector pane ctrl + click ctrl + click ctrl + click clear the obje...

Settings - Firefox Developer Tools
rgb(a) color name as authored. enable layout panel enable the experimental layout panel. this setting only exists in firefox nightly. web console enable timestamps controls whether the web console displays timestamps. the web console defaults to hiding timestamps. enable new console frontend switch to the experimental new console. this setting only exists in firefox nightly. debugger enable source maps enable source map support in the debugger. enable new debugger frontend enable the new debugger. this setting only exists in firefox nightly. style editor show original sources when a css preprocessor supporting source maps is used, this enables the style editor to display the original, preprocessor, sources rather than the generated css. learn more about style e...
.... note that this option was called "disable cache" in firefox versions previous to 49, but it was renamed to make it clearer that this affects the http cache, and not service workers/the cache api. disable javascript reload the current tab with javascript disabled. enable service workers over http enable service worker registrations from insecure websites. ...
...s affects the http cache, and not service workers/the cache api. disable javascript reload the current tab with javascript disabled. enable service workers over http enable service worker registrations from insecure websites. enable browser chrome and add-on debugging toolboxes enable you to use developer tools in the context of the browser itself, and not only web content. enable remote debugging enable the developer tools to debug remote firefox instances. enable worker debugging enable a panel within the debugger to debug workers. note: this option got removed from the ui in firefox 56, because this version ships with a new debugger ui, but it can still be enabled for the old ui by setting the preference devtools.debugger.workers to true. ...

Tips - Firefox Developer Tools
t-click any property and select "show mdn docs" to view the mdn docs for this property. click on the filter icon () next to an overridden property to find which other property overrides it. right-click on a name, value, or rule to copy anything from the name, the value, the declaration or the whole rule to your clipboard. web console in all panels: esc opens the split console; useful when debugging, or inspecting nodes in the command line: $0 references the currently selected node. $() is a shortcut to document.queryselector(). $$() returns an array with the results from document.queryselectorall(). copy copies anything as a string. right-click a node in the inspector and click "use in console" to create a tempn variable for it. cd switches the javascript evaluation context to...
...page appended to it as well. see web console helpers for all parameters. in the console output: click on the inspector icon () next to an element in the output to select it within the inspector. check "enable persistent logs" in the settings to keep logged messages from before even after navigation. check "enable timestamps" in the settings to show timestamps besides the logged messages. debugger skip javascript libraries in debugging sessions via the black box icon (). press ctrl+alt+f to search in all scripts. press ctrl+d to search for a function definition. press ctrl+l to go to a specific line. style editor the black box icon () in the style sheet pane toggles the visibility of a style sheet. click an @media rule to apply it in responsive design mode. click the import...
...en a request is selected click "edit and resend" to modify its headers and send it again. check "enable persistent logs" in the settings to keep requests from before even after navigation. hover the "js" icon within the "cause" column to see the javascript stack trace, which caused the request. check "disable http cache (when toolbox is open)" in the settings to disable the network cache while debugging network issues. storage inspector right-click the column headers to open a menu allowing to toggle the display of the columns. right-click an entry and click "delete name" to delete it or "delete all" to delete all entries. select an entry to see the parsed value of it in the sidebar. ...

console - Web APIs
the web console in firefox). the specifics of how it works varies from browser to browser, but there is a de facto set of features that are typically provided. the console object can be accessed from any global object. window on browsing scopes and workerglobalscope as specific variants in workers via the property console. it's exposed as window.console, and can be referenced as simply console. for example: console.log("failed to open the specified link") this page documents the methods available on the console object and gives a few usage examples. note: this feature is available in web workers. ...
...interface is defined as all lower case (i.e. not console), for historical reasons. methods console.assert() log a message and stack trace to console if the first argument is false. console.clear() clear the console. console.count() log the number of times this line has been called with the given label. console.countreset() resets the value of the counter with the given label. console.debug() outputs a message to the console with the log level debug. console.dir() displays an interactive listing of the properties of a specified javascript object. this listing lets you use disclosure triangles to examine the contents of child objects. console.dirxml() displays an xml/html element representation of the specified object if possible or the javascript object view if it is not possib...
...ding. to exit the current group, simply call console.groupend(). for example, given this code: console.log("this is the outer level"); console.group("first group"); console.log("in the first group"); console.group("second group"); console.log("in the second group"); console.warn("still in the second group"); console.groupend(); console.log("back to the first group"); console.groupend(); console.debug("back to the outer level"); the output looks like this: timers you can start a timer to calculate the duration of a specific operation. to start one, call the console.time() method, giving it a name as the only parameter. to stop the timer, and to get the elapsed time in milliseconds, just call the console.timeend() method, again passing the timer's name as the parameter. up to 10,000 timer...

Pinch zoom gestures - Web APIs
ding this application's pointer handling, the touch-action property is applied to the <body> element. <body onload="init();" style="touch-action:none"> <div id="target">touch and hold with 2 pointers, then pinch in or out.<br/> the background color will change to pink if the pinch is opening (zoom in) or changes to lightblue if the pinch is closing (zoom out).</div> <!-- ui for logging/debugging --> <button id="log" onclick="enablelog(event);">start/stop event logging</button> <button id="clearlog" onclick="clearlog(event);">clear the log</button> <p></p> <output></output> </body> miscellaneous functions these functions support the application but aren't directly involved in the event flow. cache management this function helps manage the global event caches evcache. functio...
... cache management this function helps manage the global event caches evcache. ...
...t(ev) { // remove this event from the target's cache for (var i = 0; i < evcache.length; i++) { if (evcache[i].pointerid == ev.pointerid) { evcache.splice(i, 1); break; } } } event logging these functions are used to send event activity to the application's window (to support debugging and learning about the event flow). ...

A re-introduction to JavaScript (JS tutorial) - JavaScript
branches based on a number or string: switch (action) { case 'draw': drawit(); break; case 'eat': eatit(); break; default: donothing(); } if you don't add a break statement, execution will "fall through" to the next level. this is very rarely what you want — in fact it's worth specifically labeling deliberate fallthrough with a comment if you really meant it to aid debugging: switch (a) { case 1: // fallthrough case 2: eatit(); break; default: donothing(); } the default clause is optional. you can have expressions in both the switch part and the cases if you like; comparisons take place between the two using the === operator: switch (1 + 3) { case 2 + 2: yay(); break; default: neverhappens(); } objects javascript objects c...
... return elm.nodevalue.length; } var count = 0; for (var i = 0, child; child = elm.childnodes[i]; i++) { count += counter(child); } return count; })(document.body); the name provided to a function expression as above is only available to the function's own scope. this allows more optimizations to be done by the engine and results in more readable code. the name also shows up in the debugger and some stack traces, which can save you time when debugging. note that javascript functions are themselves objects — like everything else in javascript — and you can add or change properties on them just like we've seen earlier in the objects section. custom objects for a more detailed discussion of object-oriented programming in javascript, see introduction to object-oriented javascr...
... } return r; }; s.reversed(); // nomis our new method even works on string literals! 'this can now be reversed'.reversed(); // desrever eb won nac siht as mentioned before, the prototype forms part of a chain. the root of that chain is object.prototype, whose methods include tostring() — it is this method that is called when you try to represent an object as a string. this is useful for debugging our person objects: var s = new person('simon', 'willison'); s.tostring(); // [object object] person.prototype.tostring = function() { return '<person: ' + this.fullname() + '>'; } s.tostring(); // "<person: simon willison>" remember how avg.apply() had a null first argument? we can revisit that now. the first argument to apply() is the object that should be treated as 'this'. for exam...

Memory Management - JavaScript
ion: releasing memory manually there are times when it would be convenient to manually decide when and what memory is released. in order to release the memory of an object, it needs to be made explicitly unreachable. as of 2019, it is not possible to explicitly or programmatically trigger garbage collection in javascript. ...
...ally trigger garbage collection in javascript. node.js node.js offers additional options and tools for configuring and debugging memory issues that may not be available for javascript executed within a browser environment. ...
....js node.js offers additional options and tools for configuring and debugging memory issues that may not be available for javascript executed within a browser environment. ...

Lexical grammar - JavaScript
re and early mac systems. \r u+2028 line separator <ls> wikipedia u+2029 paragraph separator <ps> wikipedia comments comments are used to add hints, notes, suggestions, or warnings to javascript code. this can make it easier to read and understand. they can also be used to disable code to prevent it from being executed; this can be a valuable debugging tool. javascript has two long-standing ways to add comments to code. the first way is the // comment; this makes all text following it on the same line into a comment. for example: function comment() { // this is a one line javascript comment console.log('hello world!'); } comment(); the second way is the /* */ style, which is much more flexible. for example, you can use it on a sin...
...script with hasbang. bom will not work when you try to run the script in unix/linux. so use utf-8 without bom if you want to run scripts directly from shell. you must only use the #! comment style to specify a javascript interpreter. in all other cases just use a // comment (or mulitiline comment). keywords reserved keywords as of ecmascript 2015 break case catch class const continue debugger default delete do else export extends finally for function if import in instanceof new return super switch this throw try typeof var void while with yield future reserved keywords the following are reserved as future keywords by the ecmascript specification. they have no special functionality at present, but they might at some future time, so they cannot be used as...
... 1. a semicolon is inserted before, when a line terminator or "}" is encountered that is not allowed by the grammar. { 1 2 } 3 // is transformed by asi into { 1 2 ;} 3; 2. a semicolon is inserted at the end, when the end of the input stream of tokens is detected and the parser is una...

JavaScript
tion of a function and the lexical environment within which that function was declared. advanced inheritance and the prototype chain explanation of the widely misunderstood and under-estimated prototype-based inheritance. strict mode strict mode defines that you can not use any variable before initializing it. it is a restricted variant of ecmascript 5, for faster performance and easier debugging. javascript typed arrays javascript typed arrays provide a mechanism for accessing raw binary data. memory management memory life cycle and garbage collection in javascript. concurrency model and event loop javascript has a concurrency model based on an "event loop". reference browse the complete javascript reference documentation. standard objects get to know standard built-in...
...ehavior of javascript's operators instanceof, typeof, new, this, the operator precedence, and more. statements and declarations learn how do-while, for-in, for-of, try-catch, let, var, const, if-else, switch, and more javascript statements and keywords work. functions learn how to work with javascript's functions to develop your applications. tools & resources helpful tools for writing and debugging your javascript code. firefox developer tools web console, javascript profiler, debugger, and more. javascript shells a javascript shell allows you to quickly test snippets of javascript code. learn javascript an excellent resource for aspiring web developers — learn javascript in an interactive environment, with short lessons and interactive tests, guided by automated assessment. t...
...mplementation status. jsfiddle edit javascript, css, html and get live results. use external resources and collaborate with your team online. plunker plunker is an online community for creating, collaborating on and sharing your web development ideas. edit your javascript, css, html files and get live results and file structure. jsbin js bin is an open-source collaborative web development debugging tool. codepen codepen is another collaborative web development tool used as a live result playground. stackblitz stackblitz is another online playground/debugging tool, which can host and deploy full-stack applications using react, angular, etc. ...

Content Scripts - Archive of obsolete content
pagemod({ include: "*.mozilla.org", contentscriptfile: "./content-script.js" }); unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. you can load multiple scripts by passing an array of strings to either contentscript or contentscriptfile: // main.js var tabs = require("sdk/tabs"); tabs.on('ready', function(tab) { tab.attach({ contentscript: ['document.body.style.border = "5px solid red";', 'window.alert("hi");'] }); }); // main.js var data = require("sdk/self").data; var pagemod = require("sdk/pa...
..., contentscript: contentscriptstring, contentscriptfile: data.url("jquery.js") }); unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. controlling when to attach the script the contentscriptwhen option specifies when the content script(s) should be loaded. it takes one of: "start": load the scripts immediately after the document element for the page is inserted into the dom. at this point the dom content hasn't been loaded yet, so the script won't be able to interact with it. "ready": load the scripts after th...

page-mod - Archive of obsolete content
gemod.pagemod({ include: "*.mozilla.org", contentscriptfile: "./my-script.js" }); unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. a page-mod only attaches scripts to documents loaded in tabs. it will not attach scripts to add-on panels, page-workers, sidebars, or firefox hidden windows. to stop a page-mod from making any more modifications, call its destroy() method. the pagemod constructor takes a number of other options to control its behavior: contentstyle lists stylesheets to attach, supplie...
...ified by this option are loaded after those specified by the contentscriptfile option. unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. name: contentscriptwhen type: string by default, content scripts are attached after all the content (dom, js, css, images) for the document has been loaded, at the time the window.onload event fires. using this option you can customize this behavior. the option takes a single string that may take any one of the following values: "start": load content scripts immediatel...

simple-storage - Archive of obsolete content
--profile option to jpm with a path to a profile - not just a profile name. you may also need to include the --no-copy option to prevent firefox from copying the profile to a temporarry directory each time it starts. jpm run --no-copy --profile path/to/profile/dir if you specify a non-existent profile, the same will be created, don't worry. ...
... profile, the same will be created, don't worry. important: if you use this method, you must end your debugging session by quitting firefox normally, not by cancelling the shell command. if you don't close firefox normally, then simple storage will not be notified that the session is finished, and will not write your data to the backing store. accessing storage from the console in the add-on debugger, you can access your add-on's simple-storage programmatically from the console using the following: loader.modules['resource://gre/modules/commonjs/sdk/simple-storage.js'].exports.storage clarification from mozilla needed: writing the above line in add-on debugger console results in "referenceerror: loader is not defined". constructing arrays be careful to construct array objects conditi...

Release notes - Archive of obsolete content
e sidebar will be shown or hidden. details github commits made between firefox 32 and firefox 33. this will not include any uplifts made after this release entered aurora. bugs fixed between firefox 32 and firefox 33. this will not include any uplifts made after this release entered aurora. firefox 32 highlights added exclude option to pagemod. added anonymous option to request. ...
... updated the default theme used for panels on mac os x. added contentstyle and contentstylefile options to panel. details github commits made between firefox 30 and firefox 31. ...

Tutorials - Archive of obsolete content
their url: whenever a web page whose url matches the filter is loaded, execute a specified script in it. modify the active web page dynamically load a script into the currently active web page. development techniques logging log messages to the console for diagnostic purposes. creating reusable modules structure your add-on in separate modules to make it easier to develop, debug, and maintain. create reusable packages containing your modules, so other add-on developers can use them too. unit testing writing and running unit tests using the sdk's test framework. chrome authority get access to the components object, enabling your add-on to load and use any xpcom object. creating event targets enable the objects you define to emit their own events. listen for...
...wn events. listen for load and unload get notifications when your add-on is loaded or unloaded by firefox, and pass arguments into your add-on from the command line. using third-party modules (jpm) install and use additional modules which don't ship with the sdk itself. localization writing localizable code. mobile development develop add-ons for firefox mobile on android. add-on debugger debug your add-on's javascript. putting it together annotator add-on a walkthrough of a relatively complex add-on. ...

Code snippets - Archive of obsolete content
ad pages, and listen for page loads interaction between privileged and non-privileged code how to communicate from extensions to websites and vice-versa. ...
...vileged and non-privileged code how to communicate from extensions to websites and vice-versa. ...

Hacking wiki - Archive of obsolete content
...
... ...

Running Tamarin performance tests - Archive of obsolete content
.jar. the latest asc.jar can be downloaded from from ftp://ftp.mozilla.org/pub/js/tamarin...latest/asc.jar. also the source to asc.jar may be downloaded and rebuilt from http://opensource.adobe.com/wiki/dis...exsdk/flex+sdk. - set the asc environment variable, as described above. - set the shellabc environment variable to the path of the /generated/shell_toplevel.abc. adb 'adb' stands for android debug bridge. adb is used to access your android device and can run both direct and shell-type commands. if you've correctly edited and run the android-vars.sh script mentioned on the tamarin build documentation page you should already be pathed to the adb executable in the public sdk/ndk, but if not it exists at /android-public/android-sdk-mac_86/platform-tools. adb supports ssh-like commands to an an...
... but if not it exists at /android-public/android-sdk-mac_86/platform-tools. adb supports ssh-like commands to an android device. adb automatically connects to a phone if connected by usb. adb shell "ls /" is a good test to see if connected. the command: $ adb devices lists the device id of each phone. if this fails, do you have a dev os installed? under settings->applications->development, is usb debugging enabled? testsuite setup example commands: root the phone $ adb root copy avmshell to /data/app. the shell can be named variously in the build but on the phone the executable must be 'avmshell' $ adb push avmshell /data/app/avmshell $ adb shell chmod 777 /data/app/avmshell copy android_runner.sh, if it doesn't already exist on the phone in /data/app $ adb push tamarin-redux/platform/android/...

Tamarin Acceptance Testing - Archive of obsolete content
in order to ensure that changes to the tamarin code base are high quality before submitting, all developers are required to complete the following steps. ...
... in order to ensure that changes to the tamarin code base are high quality before submitting, all developers are required to complete the following steps. ...

Venkman Internals - Archive of obsolete content
ed, the js engine doesn't know anything about the file. you can still set breakpoints, but they will be future breakpoints, which will be "real" breakpoints when/if the file is loaded (note that this may never happen!). note also that this is just my knowledge of venkman, which is quite limited. you would be better off asking silver (james ross). gijskruitbosch 05:41, 7 march 2007 (pst) venkman-debugger.js sets hooks in to the jsdidebuggerservice. initdebugger(). scriptmanager in initdebugger() the previous loaded scripts are passed to an onscriptcreated() method which binds them to a scriptmanager. there is one scriptmanager per url (web page). this method is set into jsdiscripthook.onscriptcreated venkman-views.js views are the panels shown within the venkman window. for example, the...
... for example, the "open windows" view shows the browser's windows. venkman-records.js a "record" seems to be data underlying a view. for example, framerecord represents a javascript stack frame. venkman-msg.js localization code, reads venkman.properties from a subdirectory of "locale" and injects variables. things like msg.alert define variables msg_alert. venkman-utils.js defines the dd debug dump and friends windowrecord representation of the open windows. filecontainerrecord - list of script tags found in the parent record's window.document property. to obtain the antecedent files: doc.getelementsbytagname("script"); then extract the urls from the src attributes. scriptwrapper newsgroup, 2002, rgrinda here is a bit more information about how venkman tracks files and funct...

Deprecated and defunct markup - Archive of obsolete content
internal use only? ...
...use only; part of xbl for <tree>) <treefoot> (old/experimental and unsupported xul tags) <treeindentation> (old/experimental and unsupported xul tags) was a part of the old <tree> that predated <outliner> that was not converted to <listbox>--neil 03 march 2011 <treeicon> (old/experimental and unsupported xul tags) <treerows> (internal use only; part of xbl for <tree>) attributes @debug="true" provided struts and springs around boxes to facilitate identification of flex issues but does not seem to work now you need a special debug_layout build --neil 03 march 2011 references xul element reference by neal deakin rapid application development with mozilla, by nigel mcfarlane ...

Index - Archive of obsolete content
t to "dont-build-content", a tree builder will be created. otherwise, a content builder will be created. both types of builder share much of the same code except for how they generate output to be displayed. ...
... 947 template and tree listeners xul, xul_template_guide there are several listeners (or observers) used during the template build process, each used for different purposes. ...

Introduction to XUL - Archive of obsolete content
broadcasters can broadcast any change of state, which can be tied to the value of any attribute in another xul widget. for more complete documentation, see broadcasters and observers. an example window below is a complete sample xul document that describes a window with a menu bar and an html content area. the menu bar has a menu, file, with a single menu item that dumps "hello world!" to the debug console when selected. the content area will display the contents of the file contentframe.html. this code introduces several concepts useful for creating real world windows not explicitly covered in this document. follow the links for details. <?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin/xul.css" type="text/css"?> <!doctype window> <window id="main-window" xmlns:html="http:...
...s that the window should consume the full width and height available to it in a content area. the next element in the example declares the menubar. the menubar contains a single menu called "file". this menu contains a single menu item that has a simple javascript onclick handler attached to it. this handler fires when the menu is selected by the user, and it dumps the text "hello world!" to the debug console. (see menu bars and menus for details.) finally there is an html iframe. note that the frame is qualified with the prefix html:, since it is an html object being used inside a default xul namespace. the frame also has a special attribute called flex, which indicates how much the frame is allowed to stretch to consume available space inside its window. (see the box system for details). i...

Building XULRunner with Python - Archive of obsolete content
cvsroot=:pserver:anonymous@cvs-mirror.mozilla.org:/cvsroot having created amozilla project directory (e.g.c:\projects\mozilla or/c/projects/mozilla in msys) create the following .mozconfig file. note this is complete and does not require the checkout of any other project specific .mozconfig files as sometimes shown. it effectively specifies a release build that is not particularly suitable for debugging xulrunner itself. it uses the trunk (or latest) code in cvs so may be unstable. mk_add_options moz_objdir=@topsrcdir@/../obj-xulrunner mk_add_options moz_co_project=xulrunner ac_add_options --enable-application=xulrunner ac_add_options --enable-extensions=python,default ac_add_options --disable-javaxpcom ac_add_options --disable-activex ac_add_options --disable-activex-scripting ac_add_optio...
... use make -f client.mk build and see client.mk for other options. the built xulrunner can then be found asc:\projects\obj-xulrunner\dist\bin\xulrunner.exe. using python in xul applications add the following to yourprefs.js during development pref("browser.dom.window.dump.enabled", true); pref("javascript.options.showinconsole", true); pref("javascript.options.strict", true); pref("nglayout.debug.disable_xul_cache", true); pref("nglayout.debug.disable_xul_fastload", true); html <script> tags specify that python is used withtype="application/x-python" attribute. dom scripting is pretty much as with java script. for example def onload(): btntest = document.getelementbyid("btntest") btntest.addeventlistener('command', ontest, false) def ontest(): window.alert('button activate...

Developing Mozilla XForms - Archive of obsolete content
then start firefox out of the build directory: cd obj-*/dist/firefox ./firefox -no-remote -jsconsole -p yourprofilename the xforms extension that was built together with firefox should be already installed. then open your form that causes problems and have a look on the console. often you'll find the first starting points here or in the error console. schema validation problems the schema-validation extension contains a logging facility that can show some internals on the schema processing. ...
...roblems and have a look on the console. often you'll find the first starting points here or in the error console. schema validation problems the schema-validation extension contains a logging facility that can show some internals on the schema processing. to activate this logging output, set the nspr_log_modules environment variable: export nspr_log_modules=schemavalidation:5 this only works on a debug build as described above. ...

Index - MDN Web Docs Glossary: Definitions of Web-related terms
ry, javascript the process whereby a lower-level format (e.g. that has been transferred over a network, or stored in a data store) is translated into a readable object or other data structure. 111 developer tools codingscripting, developer tools, glossary developer tools (or "development tools" or short "devtools") are programs that allow a developer to create, test and debug software. 112 digest cryptography, glossary, privacy, security a digest is a small value generated by a hash function from a whole message. ideally, a digest is quick to calculate, irreversible, and unpredictable, and therefore indicates whether someone has tampered with a given message. 113 digital certificate cryptography, glossary, security a digital c...
...l ip address with other devices on their respective local networks. 214 ide codingscripting, glossary an integrated development environment (ide) or interactive development environment is a software application that provides comprehensive facilities to computer programmers for software development. an ide normally consists of a source code editor, build automation tools and a debugger. 215 idl codingscripting, glossary, idl, interface description language an idl (interface description language) is a generic language used to specified objects' interfaces apart from any specific programming language. 216 ietf glossary, ietf, infrastructure, internet the internet engineering task force (ietf) is a worldwide organization that drafts spe...

Cascade and inheritance - Learn web development
portant declaration on a declaration with the same specificity later in the source order, or one with a higher specificity. it is useful to know that !important exists so that you know what it is when you come across it in other people's code. however, we strongly recommend that you never use it unless you absolutely have to. !important changes the way the cascade normally works, so it can make debugging css problems really hard to work out, especially in a large stylesheet. one situation in which you may have to use it is when you are working on a cms where you can't edit the core css modules, and you really want to override a style that can't be overridden in any other way. but really, don't use it if you can avoid it. the effect of css location finally, it is also useful to note that th...
... overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Styling tables - Learn web development
ake things neater and easier to follow. test your skills! we have covered a lot in this article, but can you remember the most important information? you can find some further tests to verify that you've retained this information before you move on — see test your skills: tables. summary with styling tables now behind us, we need something else to occupy our time. the next article explores debugging css — how to solve problems such as layouts not looking like they should, or properties not applying when you think they should. this includes information on using browser devtools to find solutions to your problems. previous overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-...
...us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

CSS building blocks - Learn web development
this module carries on where css first steps left off — now you've gained familiarity with the language and its syntax, and got some basic experience with using it, its time to dive a bit deeper. this module looks at the cascade and inheritance, all the selector types we have available, units, sizing, styling backgrounds and borders, debugging, and lots more. the aim here is to provide you with a toolkit for writing competent css and help you understand all the essential theory, before moving on to more specific disciplines like text styling and css layout. looking to become a front-end web developer? we have put together a course that includes all the essential information you need to work towards your goal. get started prerequisites before starting this module, you should have: ...
...regular boxes. understanding what is and isn't possible can save some frustration, and this lesson will highlight some of the main things that you need to know. styling tables styling an html table isn't the most glamorous job in the world, but sometimes we all have to do it. this article provides a guide to making html tables look good, with some specific table styling techniques highlighted. debugging css sometimes when writing css you will encounter an issue where your css doesn't seem to be doing what you expect. this article will give you guidance on how to go about debugging a css problem, and show you how the devtools included in all modern browsers can help you find out what is going on. organizing your css as you start to work on larger stylesheets and big projects you will disco...

How CSS works - Learn web development
he following diagram also offers a simple view of the process. about the dom a dom has a tree-like structure. each element, attribute, and piece of text in the markup language becomes a dom node in the tree structure. the nodes are defined by their relationship to other dom nodes. some elements are parents of child nodes, and child nodes have siblings. understanding the dom helps you design, debug and maintain your css because the dom is where your css and the document's content meet up. when you start working with browser devtools you will be navigating the dom as you select items in order to see which rules apply. a real dom representation rather than a long, boring explanation, let's look at an example to see how a real html snippet is converted into a dom. take the following html co...
...x solid black; background-color: lime; } the browser will parse the html and create a dom from it, then parse the css. since the only rule available in the css has a span selector, the browser will be able to sort the css very quickly! it will apply that rule to each one of the three <span>s, then paint the final visual representation to the screen. the updated output is as follows: in our debugging css article in the next module we will be using browser devtools to debug css problems, and will learn more about how the browser interprets css. what happens if a browser encounters css it doesn't understand? in an earlier lesson i mentioned that browsers do not all implement new css at the same time. in addition, many people are not using the latest version of a browser. given that css is...

Common questions - Learn web development
spend nothing or your costs may go through the roof. in this article we discuss how much everything costs and what you get for what you pay (or don't pay). what text editors are available? in this article we highlight some things to think about when choosing and installing a text editor for web development. what are browser developer tools? every browser features a set of devtools for debugging html, css, and other web code. this article explains how to use the basic functions of your browser's devtools. how do you make sure your website works properly? so you've published your website online — very good! but are you sure it works properly? this article provides some basic troubleshooting steps. how do you set up a local testing server? this article explains how to...
...s to get a website online so others can access it from their computers. how do i use github pages? this article provides a basic guide to publishing content using github's gh-pages feature. how do you host your website on google app engine? looking for a place to host your website? here's a step-by-step guide to hosting your website on google app engine. what tools are available to debug and improve website performance? this set of articles shows you how to use the developer tools in firefox to debug and improve performance of your website, using the tools to check memory usage, the javascript call tree, the number of dom nodes being rendered, and more. design and accessibility this section lists questions related to aesthetics, page structure, accessibility techniques, etc...

What went wrong? Troubleshooting JavaScript - Learn web development
s provide similar information). from left to right, we've got: a red "x" to indicate that this is an error. an error message to indicate what's gone wrong: "typeerror: guesssubmit.addeventlistener is not a function" a "learn more" link that links through to an mdn page that explains what this error means in greater detail. the name of the javascript file, which links through to the debugger tab of the developer tools. if you follow this link, you'll see the exact line where the error is highlighted. the line number where the error is, and the character number in that line where the error is first seen. in this case, we've got line 86, character number 3. if we look at line 86 in our code editor, we'll find this line: guesssubmit.addeventlistener('click', checkguess); ...
...e earliest instance you'll find in the javascript is on line 48: const loworhi = document.queryselector('loworhi'); at this point we are trying to make the variable contain a reference to an element in the document's html. let's check whether the value is null after this line has been run. add the following code on line 49: console.log(loworhi); note: console.log() is a really useful debugging function that prints a value to the console. so it will print the value of loworhi to the console as soon as we have tried to set it in line 48. save and refesh, and you should now see the console.log() result in your console. sure enough, loworhi's value is null at this point, so there is definitely a problem with line 48. let's think about what the problem could be. line 48 is using...

Handling common HTML and CSS problems - Learn web development
tions. let's go forth and look at how we can reduce cross browser errors that result from html/css. first things first: fixing general problems we said in the first article of this series that a good strategy to begin with is to test in a couple of modern browsers on desktop/mobile, to make sure your code is working generally, before going on to concentrate on the cross browser issues. in our debugging html and debugging css articles, we provided some really basic guidance on debugging html/css — if you are not familiar with the basics, you should definitely study these articles before carrying on. basically, it is a matter of checking whether your html and css code is well formed and doesn't contain any syntax errors. note: one common problem with css and html arises when different cs...
...ilds slightly on the default browser styling to make things more consistent and fix some layout issues. you are advised to apply normalize.css to all your html pages. note: when trying to track down a tricky layout issue, a good technique is to add a brightly colored outline to the offending element, or all the elements nearby. this makes it a lot easier to see where everything is placed. see debug your css with outline visualizations for more details. support for new layout features much of the layout work on the web today is done using floats — this is because floats are well-supported (way back to ie4, albeit with a number of bugs that would also need to be investigated if you were to try to support ie that far back). however, they are not really meant for layout purposes — using ...

Introduction to cross browser testing - Learn web development
te: we'll cover defensive coding later in the module too. why do cross browser issues occur? there are many different reasons why cross browser issues occur, and note that here we are talking about issues where things behave different across different browsers / devices / browsing preferences. before you even get to cross browser issues, you should have already fixed out bugs in your code (see debugging html, debugging css, and what went wrong? troubleshooting javascript from previous topics to refresh your memory if needed). cross browser issues commonly occur because: sometimes browsers have bugs, or implement features differently. this situation is a lot less bad than it used to be; back when ie4 and netscape 4 were competing to be the dominant browser in the 1990s, browser companies ...
.... it might have already been fixed — for example if a bug is present in firefox release 49, but it is no longer there in firefox nightly (version 52), then they have fixed it. if it is not fixed, then you may want to file a bug (see reporting bugs, below). if it is your fault, you need to fix it! finding out the cause of the bug involves the same strategy as any web development bug (again, see debugging html, debugging css, and what went wrong? troubleshooting javascript). once you've discovered what is causing your bug, you need to decide how to work around it in the particular browser it is causing problems in — you can't just change the problem code outright, as this may break the code in other browsers. the general approach is usually to fork the code in some way, for example use javas...

Simple SeaMonkey build
.mozconfig # specify amount of parallel building. if the below is left out, a best guess will be taken automatically. echo 'mk_add_options moz_make_flags="-j4"' >> .mozconfig # ...quickly. # build! # note: this requires autoconf 2.13 (at least initially). # on windows, be sure to use mozmake instead of make, otherwise parallel building will break. ...
...build! # note: this requires autoconf 2.13 (at least initially). # on windows, be sure to use mozmake instead of make, otherwise parallel building will break. make -f client.mk for a debug build, you need different configuration options in your .mozconfig file. this requires more disk space, about 3 gb, and twice as much available ram. mk_add_options moz_objdir=/path/to/comm-central/obj-sm-debug ac_add_options --enable-application=suite ac_add_options --enable-debug ac_add_options --disable-optimize normally a shared build suffices for debugging purposes but current nightly releases are actually static builds which require even more memory to link. the support for libxul builds is still experimental but it should work if you --disable-mailnews. on windows, the above commands will cr...

Simple Sunbird build
lendar' > .mozconfig # let's build sunbird... echo 'mk_add_options moz_objdir=@topsrcdir@/objdir-sb-release' >> .mozconfig # ...in this directory... # use this only if not on windows! parallel compilation on windows is # unreliable now due to bug 524149. echo 'mk_add_options moz_make_flags="-j4"' >> .mozconfig # ...quickly. ...
...his only if not on windows! parallel compilation on windows is # unreliable now due to bug 524149. echo 'mk_add_options moz_make_flags="-j4"' >> .mozconfig # ...quickly. # build make -f client.mk for a debug build, you need different configuration options in your .mozconfig file. this requires more disk space, about 2.5 gb. mk_add_options moz_objdir=@topsrcdir@/objdir-sb-debug ac_add_options --enable-application=calendar ac_add_options --enable-debug ac_add_options --disable-optimize running sunbird the sunbird executable can be found in objdir-sb-release/mozilla/dist/bin/ (on mac, objdir-sb-release/dist/calendar.app/contents/macos/). building sunbird and lightning if you've set up you build environment as above, then all you need to do is: echo 'ac_add_options --e...

mach
urse, in a random dir you just get a cryptic error message to improve the experience. for full help: $ ./mach help try building the tree: $ ./mach build if you get error messages, make sure that you have all of the build requisites for your system. if it works, you can look at compiler warnings: $ ./mach warnings-list try running the program: $ ./mach run try running your program in a debugger: $ ./mach run --debug try running some tests: $ ./mach xpcshell-test services/common/tests/unit/ or run an individual test: $ ./mach mochitest browser/base/content/test/general/browser_pinnedtabs.js you run mach from the source directory, so you should be able to use your shell's tab completion to tab-complete paths to tests. mach figures out how to execute the tests for you! check out ...
...pecific signatures to detect mach commands. currently, this is implemented through python decorators. here is a minimal mach command module: from __future__ import print_function, unicode_literals from mach.decorators import ( commandargument, commandprovider, command, ) @commandprovider class machcommands(object): @command('doit', description='run it!') @commandargument('--debug', '-d', action='store_true', help='do it in debug mode.') def doit(self, debug=false): print('i did it!') from mach.decorators we import some python decorators which are used to define what python code corresponds to mach commands. the decorators are: @commandprovider this is a class decorator that tells mach that this class contains methods that implement mach commands.

Geckoview-Junit Tests
before the existing @test annotation. for example: import org.junit.ignore ... @runwith(testrunner.class) public class testsomethings { @ignore @test public void testsomething() { ... tests can also be conditionally skipped using junit's assume or assumethat methods. for example: import org.junit.assume.assumethat ... ...
...nore ... @runwith(testrunner.class) public class testsomethings { @ignore @test public void testsomething() { ... tests can also be conditionally skipped using junit's assume or assumethat methods. for example: import org.junit.assume.assumethat ... @test fun contentcrashignored() { // cannot test x86 debug builds due to gecko's "ah_crap_handler" // that waits for debugger to attach during a sigsegv. assumethat(sessionrule.env.isdebugbuild && sessionrule.env.cpuarch == "x86", equalto(false)) running tests on try to run these tests on try, use something like: mach try fuzzy -q geckoview-junit --artifact or mach try -b do -p android-x86_64 -u geckoview-junit --artifact currently, geckoview-junit is only run on android-x86_64. cont...

How to get a stacktrace for a bug report
ting its cause. this article describes how to use the mozilla crash reporter (breakpad) to get a crash id, which our engineers can use to get a stacktrace, and alternative ways to get a stacktrace if you can't get a crash id. requirements you need a binary build of firefox from mozilla.org. seamonkey and thunderbird also support crash reporting. mozilla's crash report server currently only has debug information for mozilla builds and thus the crash reporter cannot work if you use a build from a linux distribution or if you compile from source code. in these cases you will need to use one of the alternative methods listed below. note: when filing a crash report, it is important to know whether the crash occurs with firefox safe mode. this helps engineers determine whether a particular extens...
... 'submitted' directory containing the crash id created by the reporting server. if you want breakpad to leave the .dump and .extra files on your computer so that you can examine them locally, then set the moz_crashreporter_no_delete_dump environment variable to 1. ubuntu: instructions from the ubuntu team opensuse: general instructions from opensuse fedora: capturing stack traces gentoo: debugging using gdb ...

Promise
catch() equivalent to then() with an undefined value for the onfulfill parameter. if you chain then( onfulfill ).catch( onreject ), exceptions thrown in onfulfill will be caught and passed to onreject, which is not the case when just passing onreject to then(). ...
...ulfill will be caught and passed to onreject, which is not the case when just passing onreject to then(). promise catch( function onreject ); the following calls are therefore identical: p.then(undefined, logerror); p.catch(logerror); debugging by design, the instant state and value of a promise cannot be inspected synchronously from code, without calling the then() method. to help with debugging, only when inspecting a promise object manually, you can see more information as special properties that are inaccessible from code (this, at present, is implemented by randomizing the property name, for the lack of more sophisticated language or debugger support). these code-inaccessible, inspectable properties are: {{private:status}}: 0 for pending, 1 for fulfilled, or 2 for rejected. ...

BloatView
how to run with bloatview the are two environment variables that can be used. xpcom_mem_bloat_log if set, this causes a bloat log to be printed on program exit, and each time nstracerefcnt::dumpstatistics is called. this log contains data on leaks and bloat (a.k.a. usage). ...
...necessarily the amount of memory consumed at any given time, it does give an indication of how much memory we're consuming. the more memory in general, the worse the performance and footprint. the percentage 99999.99% will show up indicating an "infinite" amount of leakage. this happens when something that didn't leak before is now leaking. bloatview and continuous integration bloatview runs on debug builds for many of the test suites mozilla has running under continuous integration. if a new leak occurs, it will trigger a test job failure. bloatview's output file can also show you where the leaked objects are allocated. to do so, the xpcom_mem_log_classes environment variable should be set to the name of the class from the bloatview table: xpcom_mem_log_classes=myclass mach mochitest [opt...

DMD
ikely be less detailed, due to being unable to symbolicate. you will be able to get function names, but not line numbers. desktop firefox (linux) build build firefox with these options: ac_add_options --enable-dmd if building via try server, modify browser/config/mozconfigs/linux64/common-opt or a similar file before pushing. launch use mach run --dmd; use --mode to choose the mode. add --debug to run under gdb. trigger there are three ways to trigger a dmd snapshot. visit about:memory and click the dmd button (depending on how old your build is, it might be labelled "save" or "analyze reports" or "dmd"). the button won't be present in non-dmd builds, and will be grayed out in dmd builds if dmd isn't enabled at start-up. if you wish to trigger dmd dumps from within c++ or javascri...
... line, it tells you where the file was saved. it's always in a temp directory, and the filenames are always of the form dmd-<pid>. desktop firefox (mac) build build with these options: ac_add_options --enable-dmd if building via try server, modify browser/config/mozconfigs/macosx64/common-opt or a similar file before pushing. launch use mach run --dmd; use --mode to choose the mode. add --debug to run under lldb. trigger follow the trigger instructions for linux. note that on mac this step can take 30+ seconds. desktop firefox (windows) build build with these options: ac_add_options --enable-dmd if building via try server, modify browser/config/mozconfigs/win32/common-opt. also, add this line to build/mozconfig.common: moz_crashreporter_upload_full_symbols=1 launch on a loca...

GC and CC logs
ollector (gc) and cycle collector (cc) logs give information about why various js and c++ objects are alive in the heap. garbage collector logs and cycle collector logs can be analyzed in various ways. in particular, cc logs can be used to understand why the cycle collector is keeping an object alive. these logs can either be manually or automatically generated, and they can be generated in both debug and non-debug builds. this logs the contents of the javascript heap to a file named gc-edges-nnnn.log. it also creates a file named cc-edges-nnnn.log to which it dumps the parts of the heap visible to the cycle collector, which includes native c++ objects that participate in cycle collection, as well as js objects being held alive by those c++ objects. generating logs from within firefox to m...
...se" will generate a smaller cc log, "save verbose" will provide a more detailed cc log. (the gc log will be the same size in either case.) with multiprocess firefox, you can't record logs from the content process, due to sandboxing. you'll need to disable sandboxing by setting moz_disable_content_sandbox=t when you run firefox. from the commandline tldr: if you just want shutdown gc/cc logs to debug leaks that happen in our automated tests, you probably want something along the lines of: moz_disable_content_sandbox=t moz_cc_log_directory=/full/path/to/log/directory/ moz_cc_log_shutdown=1 moz_cc_all_traces=shutdown ./mach ... as noted in the previous section, with multiprocess firefox, you can't record logs from the content process, due to sandboxing. you'll need to disable sandboxing by ...

Refcount tracing and balancing
bled, which produces one or more log files. refcount tracing logs calls to addref and release, preferably for a particular set of classes, including call-stacks in symbolic form (on platforms that support this). refcount balancing is a follow-up step that analyzes the resulting log to help a developer figure out where refcounting went wrong. how to build for refcount tracing build with --enable-debug or --enable-logrefcnt. how to run with refcount tracing on there are several environment variables that can be used. first, you select one of three environment variables to choose what kind of logging you want. you almost certainly want xpcom_mem_refcnt_log. note: due to an issue with the sandbox on windows (bug 1345568), refcount logging currently requires the moz_disable_content_sandbox env...
... xpcom_mem_comptr_log this environment variable enables logging of additions and releases of objects into nscomptrs. this requires c++ dynamic casts, so it is not supported on all platforms. however, having an nscomptr log and using it in the creation of the balance tree allows addref and release calls that we know are matched to be eliminated from the tree, so it makes it much easier to debug reference count leaks of objects that have a large amount of reference counting traffic. xpcom_mem_alloc_log for platforms that don't have stack-crawl support, xpcom supports logging at the call site to addref/release using the usual cpp __file__ and __line__ number macro expansion hackery. this results in slower code, but at least you get some data about where the leaks might be occurrin...

Running NSPR tests
a/nsprpub) only builds the nspr libraries. to build the test programs, you need to change directory to mozilla/nsprpub/pr/tests and run gmake. refer to nspr build instructions for details. ...
...builds the nspr libraries. to build the test programs, you need to change directory to mozilla/nsprpub/pr/tests and run gmake. refer to nspr build instructions for details. ...

JSS FAQ
.tech.crypto content: what versions of jdk and jce do you suggest? does jss have 64 bit support? is jss fips compliant? is there any sample code and documentation? if i don't call setcipherpolicy, is the domestic policy used by default? my ssl connection is hanging on windows? how can i tell which ssl/tls ciphers jss supports? how can i debug my ssl connection? can you explain jss ssl certificate approval callbacks? can i have multiple jss instances reading separate db's? once jss initialized, i can't get anymore instances with certificatefactory.getinstance(x.509)? is it possible to sign data in java with jss? how do i convert org.mozilla.jss.crypto.x509certificate to org.mozilla.jss.pkix.cert.certi...
...pr/nss/jss components (essentially all non-fiber builds) or set the environment variable nspr_native_threads_only=1. you can find more information in bugzilla bug 102251 ssl session cache locking issue with nt fibers how can i tell which ssl/tls ciphers jss supports? check http://lxr.mozilla.org/mozilla/source/security/jss/org/mozilla/jss/ssl/sslsocket.java#730 how can i debug my ssl connection? by using the nss tool ssltap can you explain jss ssl certificate approval callbacks? nss has three callbacks related to certificates. jss has two. but jss combines two of the nss callbacks into one. nss's three ssl cert callbacks are: ssl_authcertificatehook sets a callback to authenticate the peer's certificate. it is called instead ...

NSS_3.12.1_release_notes.html
quires nspr 4.7.1. see the documentation section for the build instructions. nss 3.12.1 source and binary distributions are also available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_1_rtm/src/. binary distributions: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_1_rtm/. both debug and optimized builds are provided. go to the subdirectory for your platform, dbg (debug) or opt (optimized), to get the tar.gz or zip file. the tar.gz or zip file expands to an nss-3.12.1 directory containing three subdirectories: include - nss header files lib - nss shared libraries bin - nss tools and test programs you also need to download the nspr 4.7.1 binary distributi...
...414003: crash [[@ cert_decodecertpackage] sometimes with this testcase bug 415167: memory leak in certutil bug 417399: arena allocation results are not checked in pkix_pl_infoaccess_parselocation bug 420644: improve ssl tracing of key derivation bug 426886: use const char* in pk11_importcertforkey bug 428103: cert_encodesubjectkeyid is not defined in any public header file bug 429716: debug builds of libpkix unconditionally dump socket traffic to stdout bug 430368: vfychain -t option is undocumented bug 430369: vfychain -o succeeds even if -pp is not specified bug 430399: vfychain -pp crashes bug 430405: error log is not produced by cert_pkixverifycert bug 430743: update ssltap to understand the tls session ticket extension bug 430859: pkix: policy mapping fails verifica...

NSS_3.12.2_release_notes.html
quires nspr 4.7.1. see the documentation section for the build instructions. nss 3.12.2 source and binary distributions are also available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_2_rtm/src/. binary distributions: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_2_rtm/. both debug and optimized builds are provided. go to the subdirectory for your platform, dbg (debug) or opt (optimized), to get the tar.gz or zip file. the tar.gz or zip file expands to an nss-3.12.2 directory containing three subdirectories: include - nss header files lib - nss shared libraries bin< - nss tools and test programs you also need to download the nspr 4.7.1 binary distribut...
... bug 455424: nssilckt.h defines the enumeration constant 'lock' bug 456036: stubs for deprecated functions in lib/certdb/stanpcertdb.c should set the pr_not_implemented_error error. bug 456854: cert_decodecertpackage does not set nspr error code upon error bug 457980: hundreds of kilobytes of useless strings in libpkix bug 457984: enable pkcs11 module logging in optimize...

NSS 3.12.4 release notes
keystuff.c on wince bug 496961: provide truncated hmac support for testing tool fipstest bug 497002: lab required nspr-free freebl changes. bug 497217: the first random value ever generated by the rng should be discarded bug 498163: assert if profile path contains cyrillic chars. ...
...ting tool fipstest bug 497002: lab required nspr-free freebl changes. bug 497217: the first random value ever generated by the rng should be discarded bug 498163: assert if profile path contains cyrillic chars. ...

nss tech note1
sec_quickderdecodeitem allows it at any nested sublevel. sec_asn1_choice: allows decoding of components that are of variable type. this must be the first template in a null-terminated array. the offset parameter specifies where to store the type identifier in the target data . subsequent templates specify a custom identifier for each possible component type in the size parameter . sec_asn1_debug_break: makes the decoder assert when processing the template. this option is only supported with sec_quickderdecodeitem . it is useful to debug your templates or when writing new templates if they don't work. differences between sec_asn1decodeitem and sec_quickderdecodeitem the arena argument is required to be non-null for sec_quickderdecodeitem . with sec_asn1decodeitem, it can be null, a...
...h ber and der data, while sec_quickderdecodeitem can only decode der data. ...

nss tech note2
using the pkcs #11 module logger nss technical note: 2 modes of operation extracting output from log files the logger displays all activity between nss and a specified pkcs #11 module. it works by inserting a special set of entry points between nss and the module. to enable the module logger, you must set the environment variable nss_debug_pkcs11_module to the name of the target module. for example, to log the softoken, use: nss_debug_pkcs11_module="nss internal pkcs #11 module" note: in the command prompt on windows, do not quote the name of the target module, otherwise the quotes are considered part of the name. for example, to log the softoken on windows, use: set nss_debug_pkcs11_module=nss internal pkcs #11 module the logger is available by default in debug builds. for ...
...modes of operation the logger has several modes of operation: 1. only display the sequence of pkcs #11 calls. ...

Python binding for NSS
t to better handle unicode parameters which are optional. add certificate_summary_format_lines() utility to generate concise certificate identification info for output. certificate_new_from_certcertificate now takes add_reference parameter to properly reference count certs, should fix shutdown busy problems. add print_traceback(), print_cert() debugging support. release 0.13.0 release date 2012-10-09 scm tag pynss_release_0_13_0 source download https://ftp.mozilla.org/pub/mozilla.org/security/python-nss/releases/pynss_release_0_13_0/src/ change log fix nss secitem_compareitem bug via workaround. fix incorrect format strings in pyarg_parsetuple* for: ...
...hon-nss/releases/pynss_release_0_12_0/src/ change log major new enhancement is additon of pkcs12 support and algorithmid's. setup.py build enhancements now searches for the nss and nspr header files rather than hardcoding their location. this makes building friendlier on other systems (i.e. debian) now takes optional command line arguments, -d or --debug will turn on debug options during the build. fix reference counting bug in pk11_password_callback() which contributed to nss not being able to shutdown due to resources still in use. add utf-8 support to ssl.config_server_session_id_cache() added unit tests for cipher, digest, client_server. all unittests now run, added test/run_tests to invoke full test suite. ...

NSS Tools
the tools information table below describes both the tools that are currently working and those that are still under development. the links for each tool take you to the source code, documentation, plans, and related links for each tool. the links will become active when information is available. currently, you must download the nss 3.1 source and build it to create binary files for the nss tools. for information about downloading the nss source, see https://developer.mozilla.org/nss/building. ...
... sslstrength ssl strength documentation ssltap 3.2 proxy requests for an ssl server and display the contents of the messages exchanged between the client and server. the ssltap tool does not decrypt data, but it shows things like the type of ssl message (clienthello, serverhello, etc) and connection data (protocol version, cipher suite, etc). this tool is very useful for debugging. source, documentation currently points to the netscape certificate management system administration guide on docs.sun.com. for additional information about this tool, see object signing. currently points to the signver documentation on developer.netscape.com. for additional information about this tool, see form signing ...

NSS_3.12.3_release_notes.html
uires nspr 4.7.4. see the documentation section for the build instructions. nss 3.12.3 source and binary distributions are also available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_3_rtm/src/. binary distributions: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_12_3_rtm/. both debug and optimized builds are provided. go to the subdirectory for your platform, dbg (debug) or opt (optimized), to get the tar.gz or zip file. the tar.gz or zip file expands to an nss-3.12.3 directory containing three subdirectories: include - nss header files lib - nss shared libraries bin - nss tools and test programs you also need to download the nspr 4.7.4 binary ...
...it is an error to try to use a pkcs#11 crypto module in a process before it has been initialized in that process, even if the module was initialized in the parent process. beginning in nss 3.12.3, softoken will detect this error. this environment variable controls softoken's response to that error. if set to to "1" or unset, softoken will trigger an assertion failure in debug builds, and will report an error in non-debug builds. if set to "disabled", softoken will ignore forks, and behave as it did in older versions. if set to any other non-empty value, softoken will report an error in both debug and non-debug builds. nss_use_decoded_cka_ec_point boolean (any non-empt...

Rhino JavaScript compiler
ethod of the generated class, overriding any methods in the base class by the same name. -implements java-intf-name specifies that a java class implementing the java interface java-intf-name should be generated from the incoming javascript source file. each global function in the source file is made a method of the generated class, implementing any methods in the interface by the same name. -debug -g specifies that debug information should be generated. may not be combined with optimization at an optlevel greater than zero. -main-method-class classname specify the class name used for main method implementation. the class must have a method matching public static void main(script sc, string[] args). -nosource does not save the source in the class file. functions and scripts compil...
...ing source or simply to save space in the resulting class file. -o outputfile writes the class file to outputfile, which should end in .class and must be a writable filename. -d outputdirectory writes the class file to outputdirectory. -opt optlevel optimizes at level optlevel, which must be an integer between -1 and 9. see optimization for more details. if optlevel is greater than zero, -debug may not be specified. -package packagename specifies the package to generate the class into. the string packagename must be composed of valid identifier characters optionally separated by periods. -version versionnumber specifies the language version to compile with. the string versionnumber must be one of 100, 110, 120, 130, 140, 150, 160, or 170. see javascript language versions for mor...

Rhino license
all rights reserved. ...
... all rights reserved. ...

JSAPI User Guide
vant for the kind of scripts you want to write. it is up to the application developer to decide what objects and methods are exposed to scripts. hello world using the spidermonkey library to build spidermonkey from source, see spidermonkey build documentation. some systems (such as debian) provide spidermonkey as a prebuilt package. build it from source instead. your program will be easier to debug. c++ code accesses spidermonkey via the jsapi, by including the header "jsapi.h". an overview of jsapi functionality follows. for more details, see the jsapi reference. the spidermonkey universe in order to run any javascript code in spidermonkey, an application must have three key elements: a jsruntime, a jscontext, and a global object. this section describes what these things are. the next s...
...erved slots instead. or store the values in private data and implement jsclass.mark. if a function creates new objects, strings, or numbers, it can use js_enterlocalrootscope and js_leavelocalrootscope to keep those values alive for the duration of the function. to keep a value alive permanently, store it in a gc root. still, gc bugs do occur. these two functions, both available only in debug builds, are especially useful for debugging gc-related crashes: use js_setgczeal to enable extra garbage collection. gc zeal usually causes a gc-related crash to occur much sooner (closer to its cause) and more reliably. it's for development and debugging only, because the extra garbage collection makes js very slow. use js_dumpheap to dump the spidermonkey heap or specific interesting par...

JS::Add*Root
ble, so roots are often necessary to protect data from being prematurely collected. vp/rp is the address of a c/c++ variable (or field, or array element) of type js::value, jsstring *, jsobject *, or jsscript *. this variable must already be initialized. (for example, it must not be an uninitialized local variable. that could cause sporadic crashes during garbage collection, which can be hard to debug.) the variable must remain in memory until the balancing call to js::remove*root. note that this means that if the root is meant to live past the end of a function, the address of a local (stack-based) variable may not be used for vp/rp. if js::add*root succeeds, then as long as this variable points to a javascript value or pointer to gc-thing, that value/gc-thing is protected from garbage collec...
...et for the jsruntime associated with cx (or, in js::addnamedvaluerootrt, the runtime rt). the name parameter, if present and non-null, is stored in the jsruntime's root table entry along with rp. the name string's lifetime must last at least until the balancing call to js::remove*root. typically name is a static string constant, identifying the source location of the call to js::addnamed*root for debugging purposes. needs the example for typical usage of the name parameter. all the js::add*root methods are idempotent: multiple calls for the same address will add only one root. correspondingly, only a single js::remove*root is required to unroot the location. on success, these functions return true. otherwise they report an out of memory error and return false. see also mxr id search for ...

JS_Add*Root
unreachable, so roots are often necessary to protect data from being prematurely collected. vp/spp/opp/rp is the address of a c/c++ variable (or field, or array element) of type jsstring *, jsobject *, or jsval. this variable must already be initialized. (for example, it must not be an uninitialized local variable. that could cause sporadic crashes during garbage collection, which can be hard to debug.) the variable must remain in memory until the balancing call to js_removeroot. note that this means that if the root is meant to live past the end of a function, the address of a local (stack-based) variable may not be used for rp. if js_add*root succeeds, then as long as this variable points to a javascript value or pointer to gc-thing, that value/gc-thing is protected from garbage collection. ...
...r's root set for the jsruntime associated with cx (or, in js_addnamedrootrt, the runtime rt). the name parameter, if present and non-null, is stored in the jsruntime's root table entry along with rp. the name string's lifetime must last at least until the balancing call to js_removeroot. typically name is a static string constant, identifying the source location of the call to js_addnamedroot for debugging purposes. js_dumpnamedroots can be used to access this information from a debugger. all the js_add*root methods are idempotent: multiple calls for the same address will add only one root. correspondingly, only a single js_removeroot is required to unroot the location. on success, these functions return js_true. otherwise they report an out of memory error and return js_false. see also ...

JSAPI reference
jsapi 26 js_call_tracer added in spidermonkey 1.8 obsolete since jsapi 23 js_call_value_tracer added in spidermonkey 1.8 obsolete since jsapi 23 js_call_object_tracer added in spidermonkey 1.8 obsolete since jsapi 23 js_call_string_tracer added in spidermonkey 1.8 obsolete since jsapi 23 js_call_double_tracer added in spidermonkey 1.8 obsolete since javascript 1.8.5 js_printtracethinginfo (debug-only) added in spidermonkey 1.8 obsolete since jsapi 16 miscellaneous gc apis: js_updatemalloccounter added in spidermonkey 17 js::setlargeallocationfailurecallback added in spidermonkey 31 js::setoutofmemorycallback added in spidermonkey 31 js_enumeratediagnosticmemoryregions added in spidermonkey 17 jsval_lock obsolete since jsapi 18 jsval_unlock obsolete since jsapi 18 js_lockgct...
...nce javascript 1.8.5 jsfun_getter obsolete since javascript 1.8.5 jsfun_setter obsolete since javascript 1.8.5 jsfun_global_parent obsolete since javascript 1.8.5 jsfun_heavyweight obsolete since jsapi 19 jsfun_lambda obsolete since jsapi 19 c++ features class jsautorequest class jsautolocalrootscope obsolete since javascript 1.8.5 class js::perfmeasurement (in jsperf.h) tracing and debugging js_setfunctioncallback added in spidermonkey 1.8.5 obsolete since jsapi 37 js_getfunctioncallback added in spidermonkey 1.8.5 obsolete since jsapi 37 ...

JSDBGAPI
typedef jsstackframe js_frameiterator js_getframescript js_getframepc js_getscriptedcaller js_stackframeprincipals js_evalframeprincipals js_getframeannotation js_setframeannotation js_getframeprincipalarray js_isnativeframe js_getframeobject js_getframescopechain js_getframecallobject js_getframethis js_getframefunction js_getframefunctionobject js_isconstructorframe js_isdebuggerframe js_getframereturnvalue js_setframereturnvalue js_getframecalleeobject js_getscriptfilename js_getscriptbaselinenumber js_getscriptlineextent js_getscriptversion js_gettopscriptfilenameflags js_getscriptfilenameflags js_flagscriptfilenameprefix jsfilename_null jsfilename_system jsfilename_protected evaluating debug code js_evaluateinstackframe examining object ...
..._system jsfilename_protected evaluating debug code js_evaluateinstackframe examining object properties typedef jspropertydesc jspd_enumerate jspd_readonly jspd_permanent jspd_alias jspd_argument jspd_variable jspd_exception jspd_error typedef jspropertydescarray js_propertyiterator js_getpropertydesc js_getpropertydescarray js_putpropertydescarray hooks js_setdebuggerhandler js_setsourcehandler js_setexecutehook js_setcallhook js_setobjecthook js_setthrowhook js_setdebugerrorhook js_setnewscripthook js_setdestroyscripthook js_getglobaldebughooks js_setcontextdebughooks memory usage js_getobjecttotalsize js_getfunctiontotalsize js_getscripttotalsize system objects js_issystemobject js_newsystemobject profiling these functions can...

Parser API
-specific. interface forofstatement <: statement { type: "forofstatement"; left: variabledeclaration | expression; right: expression; body: statement; } a for/of statement. interface letstatement <: statement { type: "letstatement"; head: [ variabledeclarator ]; body: statement; } a let statement. note: the let statement form is spidermonkey-specific. interface debuggerstatement <: statement { type: "debuggerstatement"; } a debugger statement. note: the debugger statement is new in ecmascript 5th edition, although spidermonkey has supported it for years. declarations interface declaration <: statement { } any declaration node. note that declarations are considered statements; this is because declarations can appear in any statement context in the l...
...tom return statement node. trystatement(body, handlers, fin[, loc]) body: customstatement handlers: [ customcatchclause ] fin: customstatement | null loc: sourcelocation returns: customstatement callback to produce a custom try statement node. throwstatement(arg[, loc]) arg: customexpression loc: sourcelocation returns: customstatement callback to produce a custom throw statement node. debuggerstatement([loc]) loc: sourcelocation returns: customstatement callback to produce a custom debugger statement node. letstatement(head, body[, loc]) head: [ customdeclarator ] body: customstatement loc: sourcelocation returns: customstatement callback to produce a custom let statement node. declarations functiondeclaration(name, args, body, isgenerator, isexpression[, loc]) name: str...

Setting up CDT to work on SpiderMonkey
tion, and field usage information and general ide goodness for c/c++. there is a guide for setting up cdt to work with the mozilla codebase, but it does not cover setting things up for just spidermonkey instead of the whole mozilla codebase. hence, here is a short-ish guide for doing just that. step 1 - preparing a spidermonkey build for cdt to index all code, spidermonkey has to be built with debug information. the full process of and requisites for doing so are described here. please follow those instructions up until the point of invoking configure. the initial build was in clang, so the modified build commands look like this: mkdir _dbg.obj cd _dbg.obj cc='clang -qunused-arguments -fcolor-diagnostics' cxx='clang++ -qunused-arguments -fcolor-diagnostics' \ ../configure --enable-debu...
... of and requisites for doing so are described here. please follow those instructions up until the point of invoking configure. the initial build was in clang, so the modified build commands look like this: mkdir _dbg.obj cd _dbg.obj cc='clang -qunused-arguments -fcolor-diagnostics' cxx='clang++ -qunused-arguments -fcolor-diagnostics' \ ../configure --enable-debug --disable-optimize --enable-debug-symbols note: if you want to use ccache, you can enable it by adding --with-ccache to the arguments list. due to a bug in cdt, you have to make a small change to cdt's build configuration as explained in step 3 below for that to work, though. step 2 - installing eclipse and setting up the project the following run-down is a condensed and updated version of what is explained in much more detai...

Exploitable crashes
you want to look primarily for three things, in order: look at the top frame of the stack trace. ...
...re attention. explain in a comment why the issue seems exploitable. other tools apple has a tool called "crashwrangler" that are still being maintained as of 2012. there is little public information about it, and it is hard to find even on the apple developer site. to get them go to the mac developer center downloads section -> other downloads -> search for "crashwrangler". microsoft released a debugger extension tool in 2009 called "!exploitable". it hasn't been updated since 2009. ...

Secure Development Guidelines
...
... memory leaks example: void *p; size_t new_size; p = realloc(p, new_size); if (p == null) { /* handle error */ } memor...

Component Internals
ion may also provide its own way of registering xpcom components using the interface that is in fact used by both xpinstall and regxpcom, nsicomponentregistrar. an application, for example, could provide a "registration-less" component directory whose components are automatically registered at startup and unregistered at shutdown. component discovery does not currently happen automatically in non-debug builds of gecko, however. when the registration process begins, xpcom broadcasts to all registered observers a notification that says xpcom has begun the registration of new components. after all components are registered, another notification is fired saying that xpcom is done with the registration step. the nsiobserver interface that handles this notification is discussed in starting weblock. ...
...in general, you should avoid any interfaces, symbols in xpcom, or other part of gecko libraries that aren't frozen. however, there are some unfrozen tools in xpcom that are used so often they are practically required parts of component programming. the smart pointer class, nscomptr, for example, which makes reference counting less tedious and error-prone, is not actually frozen, and neither is nsdebug, a class for aiding in tracking down bugs, nor is nsmemory, a class to ensure that everyone uses the same heap, generic factory, and module. instead of asking every developer to find and copy these various files into their own application, xpcom provides a single library of "not-ready-to-freeze-but-really-helpful" classes that you can link into your application, as the following figure demonstrat...

Mozilla internal string guide
not in the windows-1252 sense). these helpers are very similar to the utf-8 / utf-16 conversion helpers above. utf-16 to latin1 converters these converters are very dangerous because they lose information during the conversion process. you should avoid utf-16 to latin1 conversions unless your strings are guaranteed to be latin1 or ascii. (in the future, these conversions may start asserting in debug builds that their input is in the permissible range.) if the input is actually in the latin1 range, each 16-bit code unit in narrowed to an 8-bit byte by removing the high half. unicode code points above u+00ff result in garbage whose nature must not be relied upon. (in the future the nature of the garbage will be cpu architecture-dependent.) if you want to printf() something and don't care what ...
...to do this usually requires converting it to an 8-bit string, because that's what printf expects. use: printf("%s\n", ns_convertutf16toutf8(yourstring).get()); sequence of appends without reallocating setcapacity() allows you to give the string a hint of the future string length caused by a sequence of appends (excludin...

Components.utils.reportError
tension developers who have exception handler blocks which want to "eat" an exception, but still want to report it to the console. it must be called with one parameter, usually an object which was caught by an exception handler. if it is not a javascript error object, the parameter is converted to a string and reported as a new error. this means you can use components.utils.reporterror to report debugging messages to the error console, just like dump() can be used to print messages to the native console. however you should use nsiconsoleservice for logging, as it logs the messages with normal severity, unlike reporterror. function mydump(amessage) { var consoleservice = components.classes["@mozilla.org/consoleservice;1"] .getservice(components.interfaces.ns...
...the preference 'javascript.options.showinconsole' to true, or use nsconsoleservice instead to show a message. ...

XPCshell Test Manifest Expressions
comments if an expression contains a # (pound/hash) character outside of a string, the character and the rest of the line will be treated as a comment. this is useful as the entire line will generally be reported whenever tests are reporte...
... comments if an expression contains a # (pound/hash) character outside of a string, the character and the rest of the line will be treated as a comment. this is useful as the entire line will generally be reported whenever tests are reported as being skipped, meaning the comment...

XPCOM Interface Reference
this is a reference to the xpcom interfaces provided by the mozilla platform. ...
...obsoletensidomstorageitemnsidomstoragelistnsidomstoragemanagernsidomstoragewindownsidomuserdatahandlernsidomwindownsidomwindow2nsidomwindowinternalnsidomwindowutilsnsidomxpathevaluatornsidomxpathexceptionnsidomxpathexpressionnsidomxpathresultnsidomxulcontrolelementnsidomxulelementnsidomxullabeledcontrolelementnsidomxulselectcontrolelementnsidomxulselectcontrolitemelementnsidatasignatureverifiernsidebugnsidebug2nsidevicemotionnsidevicemotiondatansidevicemotionlistenernsidialogcreatornsidialogparamblocknsidictionarynsidirindexnsidirindexlistenernsidirindexparsernsidirectoryenumeratornsidirectoryiteratornsidirectoryservicensidirectoryserviceprovidernsidirectoryserviceprovider2nsidiskcachestreaminternalnsidispatchsupportnsidocshellnsidocumentloadernsidownloadnsidownloadhistorynsidownloadmanagernsid...

Troubleshooting XPCOM components registration
ritten in javascript to fail is that there are parsing errors. these parsing errors should show up in the error console if chrome errors are enabled. to learn more about enabling chrome errors, see "how can i see errors in my code" in the extension faqs. registration failure if the module is loading correctly but doesn't register its components, try adding calls to components.utils.reporterror("debug me!"); in nsgetmodule() and other functions to try and find any errors. general hints you may need to delete compreg.dat in your profile folder to force re-registration. this should not occur if you uninstalled/installed your extension via the extension manager. when adding a component to a xulrunner application, change the buildid in application.ini. if your component requires any external...
...check if you have missing dependent libraries: from your firefox (/xulrunner) install directory, run "./run-mozilla.sh `which ldd` -r path/to/your/component.so". there should be no "not found" entries and no undefined symbols. (the -r switch from gnu ldd lists function relocations; adjust as suitable for your version) trace shared library loading by setting the environment variable ld_debug=all while launching firefox (see `man ld.so` for details). use strace to see if firefox is trying to load your components. pass the -wl,-z,defs flag to gcc when linking your component. this will ensure that undefined symbols show an error at link time instead of failing at run time. mac-specific hints use ktrace to see if firefox is trying to load your components. use dyld environment var...

MailNews fakeserver
e transaction the transaction is an object with two properties: us, and them; us is an array of responses we sent, them an array of commands received resettest none nothing prepares the server for the next test without closing the connection start port number nothing starts the server listening stop none nothing stops the server and closes the connection using fakeserver in qa testing debug output from fakeservers it is possible to get the fakeservers to dump to the console the commands they have sent and received. to enable/disable debugging, call setdebuglevel on your nsmailserver instance with one of the following options: const fsdebugnone = 0; // dump nothing const fsdebugrecv = 1; // dump just the received commands const fsdebugrecvsend = 2; // dump received + sent co...
... it is possible to get the fakeservers to dump to the console the commands they have sent and received. to enable/disable debugging, call setdebuglevel on your nsmailserver instance with one of the following options: const fsdebugnone = 0; // dump nothing const fsdebugrecv = 1; // dump just the received commands const fsdebugrecvsend = 2; // dump received + sent commands, no data const fsdebugall = 3; // dump everything debugging is set to "none" by default. specific fakeserver guidelines pop imap smtp nntp nntpd.js defines a few different classes of nntp servers: compliance for rfc 977, rfc 2980, and rfc 3977, as well as a giganews and an inn server. (full 2980 and 3977 compliance as well as inn is not yet written). for xpcshell tests in mailnews/news, all files in ...

Application - Firefox Developer Tools
this includes inspection of service workers and web app manifests. accessing the application panel the application panel is available on the standard devtools tab menu under application, in firefox 79+. if you can’t see it there, you can enable it by going to the "three dot" menu and selecting settings (also accessible by pressing f1), then checking the application checkbox under default developer tools. ...
... application checkbox under default developer tools. ...

Browser Console - Firefox Developer Tools
rowser's chrome window. this means you can interact with all the browser's tabs using the gbrowser global, and even with the xul used to specify the browser's user interface. nb: the browser console command line (to execute javascript expressions) is disabled by default. to enable it set the devtools.chrome.enabled preference to true in about:config, or set the "enable browser chrome and add-on debugging toolboxes" (firefox 40 and later) option in the developer tool settings. opening the browser console you can open the browser console in one of two ways: from the menu: select "browser console" from the web developer submenu in the firefox menu (or tools menu if you display the menu bar or are on macos). from the keyboard: press ctrl+shift+j (or cmd+shift+j on a mac). you can also s...
...g it easy to find all messages from this add-on using the "filter output" search box. by default, only error messages are logged to the console, although you can change this in the browser's preferences. browser console command line the browser console command line is disabled by default. to enable it set the devtools.chrome.enabled preference to true in about:config, or set the "enable chrome debugging" option in the developer tool settings. like the web console, the command line interpreter enables you to evaluate javascript expressions in real time:also like the web console's command line interpreter, this command line supports autocomplete, history, and various keyboard shortcuts and helper commands. if the result of a command is an object, you can click on the object to see its detail...

Ignore a source - Firefox Developer Tools
in modern web development, we often rely on libraries like jquery, ember, or angular, and 99% of the time we can safely assume that they “just work”. we don’t care about the internal implementation of these libraries. however, a library’s abstraction leaks during debugging sessions when you are forced to step through its stack frames in order to reach your own code. however, you can tell the debugger to ignore the details of selected sources. you can enable or disable ignoring a source file in a couple of ways: in the source list pane, right-click the filename and choose ignore source (or unignore source). if the source file is displayed in the source pane, click the "eye" icon at the bottom. when a source file is ignored: any breakpoints it may have defined are disabled. ...
.... you can enable or disable ignoring a source file in a couple of ways: in the source list pane, right-click the filename and choose ignore source (or unignore source). if the source file is displayed in the source pane, click the "eye" icon at the bottom. when a source file is ignored: any breakpoints it may have defined are disabled. when “pause on exceptions” is enabled in the debugger settings, the debugger won’t pause when an exception is thrown in the ignored source; instead it waits until (and if) the stack unwinds to a frame in a source that isn’t ignored. the debugger skips through ignored sources when stepping. ...

Set a breakpoint - Firefox Developer Tools
at this point you can do useful things like studying the value of different variables at that point, allowing you to work out why a problem is occurring. the source pane context menu in the source pane, you can handle setting breakpoints by bringing up the context menu over a line number. ...
... there are a few options available here: add breakpoint: add a standard unconditional breakpoint at this line number (see below). add condition: add a condition and create a conditional breakpoint (see below). add log: add a log point, which logs a value to your console rather than pausing execution as a breakpoint does. continue to here: when stepping through code, this option tells the debugging to continue execution through to this point. unconditional breakpoints an unconditional breakpoint is one where the code will always pause execution when it is reached. you can set an unconditional breakpoint using the context menu (see above), or by: clicking on the line number for the line you want to break at in the source pane. highlighting the line you want to break at in the sour...

Set a logpoint - Firefox Developer Tools
want to view a value in your code but you don't want to pause execution. rather than sprinkle console.log() statements throughout your code, you can use a special type of breakpoint, the logpoint. logpoints print a message to the console panel instead of pausing code execution. the logpoint is especially useful in cases where breaking the execution breaks testing procedures, such as when you are debugging popup windows, or executing focus-related logic. to create a logpoint: right click on a line number in the debugger panel and pick add log action from the context menu. create an expression inline. the result is logged in the console panel every time the line with the logpoint executes. you can use any variable or function available in the current scope. working with logpoints ...
...ng with logpoints when you set a logpoint, the indicator is purple, rather than the blue of an unconditional breakpoint or the orange of a conditional breakpoint. you can view the list of logpoints in the breakpoints side panel. when execution hits a logpoint, the message you have defined is logged to the console. you can make it easier to see the message by opening a split console under the debugger. (either press esc or select the elipsis menu (...) and then click show split console.) when should you use logpoints? when you want to know that a specific line in your code has executed, but you don’t want to break code execution, set a logpoint. logpoints are useful to log the value of a variable at a specific point in the code. it’s faster than changing the underlying source cod...

Set event listener breakpoints - Firefox Developer Tools
to break when event listeners are hit, check the boxes next the events you are interested in. all of the standard events supported in your version of firefox are listed, arranged by which api or api area they're part of. now when a keydown, keyup, keypress, or input event occurs, execution will pause as soon as it enters the listener code. ...
...ox overlaid on the viewport saying "paused on event breakpoint", with buttons to step over that line of code or resume execution. you could add regular breakpoints at the entry point of the listener to achieve the same effect. if however you have multiple elements, all of which have event listeners attached that you want to break on, this becomes an enormous time saver. this is also useful when debugging code that you're unfamiliar with, to save time over hunting down your event handler within your code, or when trying to understand why a web site isn't working as expected in your browser. use event breakpoints to stop execution at the triggering event for the action that fails, then step through the code or watch the console to see what happens. logging on events in firefox 71 onwards, the...

Dominators view - Firefox Developer Tools
the box labeled "record call stacks" before you run the code that allocates the objects. then take a snapshot, then select "call stack" in the "label by" drop-down. now the node's name will contain the name of the function that allocated it, and the file, line number and character position of the exact spot where the function allocated it. clicking the file name will take you to that spot in the debugger. sometimes you'll see "(no stack available)" here. in particular, allocation stacks are currently only recorded for objects, not for arrays, strings, or internal structures. retaining paths panel the retaining paths panel is new in firefox 47. the retaining paths panel shows you, for a given node, the 5 shortest paths back from this node to a gc root. this enables you to see all the no...
...eferencing the array, it would still not be eligible for garbage collection. this means that the object does not dominate the array, and is therefore not shown in the dominators tree view. see the relevant section of the dominators concepts article. using the call stack view finally, you can switch to the call stack view, see where the objects are being allocated, and jump to that point in the debugger: ...

Toolbox - Firefox Developer Tools
the developer tools that are built into firefox. there are a few different ways to open the toolbox: select "toggle tools" from the web developer menu (under "tools" on os x and linux, or "firefox" on windows) click the wrench icon (), which is in the main toolbar or under the hamburger menu (), then select "toggle tools" activate any tool hosted in the toolbox (for example, the javascript debugger or the page inspector) press ctrl + shift + i on windows and linux, or cmd + opt + i on os x. see also keyboard shortcuts. by default, the window appears docked to the bottom side of the firefox window, but you can detach it if you like. this is what it looks like when it's docked: the window itself is split into two parts: a toolbar along the top, and a main pane underneath: note: sin...
...dow, and to close the window. node picker on the far left there's a button to activate the node picker. this lets you select a page element for inspection. see "selecting elements". toolbox-hosted tools then there is an array of labeled buttons which enables you to switch between the different tools hosted by the toolbox. the array may include the following tools: web console javascript debugger page inspector style editor profiler network monitor note that not all the hosted tools are always listed here: only the tools actually available in this context are shown (for example, not all tools support remote debugging yet, so if the debugging target is not the firefox instance that launched the window, not all the hosted tools will be shown). extra tools next there's an array of...

Console messages - Firefox Developer Tools
css errors or warnings. by default, they are disabled. you can enable them by clicking the "css" button in the toolbar and selecting "reflows". each message is labeled "reflow" and shows the time taken to execute the reflow. if the reflow is a synchronous reflow triggered from javascript, it also shows a link to the line of code that triggered the reflow. click the link to open the file in the debugger. synchronous and asynchronous reflows if a change is made that invalidates the current layout — for example, the browser window is resized or some javascript modifies an element's css — the layout is not recalculated immediately. instead, the reflow happens asynchronously, the next time the browser decides it needs to be done (generally, the next time the browser repaints). in this way t...
...le.error("it explodes"); } function bar() { foo(); } function dostuff() { bar(); } dostuff(); server server-side log messages was introduced in firefox 43, but removed in firefox 56. you can install the chrome logger extension to (re)-enable the feature. with the chrome logger extension, web console can display messages sent from the server. this enables you to use the web console to debug server-side code. it uses the chrome logger protocol. briefly, the way it works is: your server-side code — python, php, node.js, etc. — includes a library that provides a console api. your server-side code uses this api to log messages. the server-side library creates json objects from the messages and encodes them for transmission. the messages are transmitted to the client as a resp...

Rich output - Firefox Developer Tools
tool. export output to the clipboard once you have output in the console window, you can save it to the clipboard by right-clicking on the output and selecting export visible messages to clipboard: this will copy all of the output to the clipboard. then you can paste it into a document. the output will look something like this: console.log(todolist) array(4) [ {…}, {…}, {…}, {…} ] debugger eval code:1:9 undefined if you expand objects, such as arrays, you get slightly different content. for example, by expanding the array in the above list, i get the following: console.log(todolist) (4) […] ​ 0: object { status: "done", description: "morning pages", datecreated: 1552404478137 } ​ 1: object { status: "in progress", description: "refactor styles", datecreated: 155240449316...
... ...

Console API - Web APIs
concepts and usage the console api started as a largely proprietary api, with different browsers implementing it, albeit it in inconsistent ways. the console api spec was created to define consistent behavior, and all modern browsers eventually settled on implementing this behavior — although some implementations still have their own additional proprietary functions. ...
...lthough some implementations still have their own additional proprietary functions. find out about these at: google chrome devtools implementation safari devtools implementation usage is very simple — the console object — available via window.console, or workerglobalscope.console in workers; accessible using just console — contains many methods that you can call to perform rudimentary debugging tasks, generally focused around logging various values to the browser's web console. by far the most commonly-used method is console.log, which is used to log the current value contained inside a specific variable. interfaces console provides rudimentary debugging functionality, including logging, stack traces, timers, and counters. examples let mystring = 'hello world'; // output "...

Multi-touch interaction - Web APIs
clear the log. to prevent the browser's default touch behavior from overriding this application's pointer handling, the touch-action property is applied to the <body> element. <body onload="init();" style="touch-action:none"> <div id="target1"> tap, hold or swipe me 1</div> <div id="target2"> tap, hold or swipe me 2</div> <div id="target3"> tap, hold or swipe me 3</div> <!-- ui for logging/debugging --> <button id="log" onclick="enablelog(event);">start/stop event logging</button> <button id="clearlog" onclick="clearlog(event);">clear the log</button> <p></p> <output></output> </body> miscellaneous functions these functions support the application but aren't directly involved with the event flow. cache management these functions manage the global event caches evcache1, evcache2 ...
... // log events flag var logevents = false; function enablelog(ev) { logevents = logevents ? false : true; } function log(name, ev) { var o = document.getelementsbytagname('output')[0]; var s = name + ": pointerid = " + ev.pointerid + " ; pointertype = " + ev.pointertype + " ; isprimary = " + ev.isprimary; o.innerhtm...

PromiseRejectionEvent - Web APIs
for details on promise rejection events, see promise rejection events in using promises. ...
...its methods from its parent event. events rejectionhandled fired when a javascript promise is rejected, and after the rejection is handled by the promise's rejection handling code. unhandledrejection fired when a javascript promise is rejected but there is no rejection handler to deal with the rejection. examples this simple example catches unhandled promise rejections and logs them for debugging purposes. window.onunhandledrejection = function(e) { console.log(e.reason); } specifications specification status comment html living standardthe definition of 'promiserejectionevent' in that specification. living standard initial definition. ...

RTCIceCandidate.relatedPort - Web APIs
d port provide the mapped address selected by the turn server. for host candidates, relatedport is null, meaning the field is not included in the candidate's a-line. usage notes the related address and port are not used by ice itself, and are only present for diagnostic and quality-of-service purposes. they may in fact be omitted for security reasons, but if present can be a useful tool during debugging. see the example, which shows a bit of this. here's an sdp attribute line (a-line) describing an ice candidate discovered by the stun server: a=candidate:4234997325 1 udp 2043278322 192.168.0.56 6502 typ srflx raddr 192.168.2.77 rport 32768 generation 0 the remote port, relatedport, is the number immediately following the "rport" label on the a-line, or 32768. example in this example, th...
... of this. here's an sdp attribute line (a-line) describing an ice candidate discovered by the stun server: a=candidate:4234997325 1 udp 2043278322 192.168.0.56 6502 typ srflx raddr 192.168.2.77 rport 32768 generation 0 the remote port, relatedport, is the number immediately following the "rport" label on the a-line, or 32768. example in this example, the candidate's type is checked, and then debugging output is presented, based on the candidate type, including the candidate's type, address (ip and port), and related address (relatedaddress and relatedport). var ip = candidate.ip; var port = candidate.port; var relip = candidate.relatedaddress; var relport = candidate.relatedport; if (relip && relport) { console.log("candidate type '" + type + "' -- contact address: " + ip + " " + port ...

Using Service Workers - Web APIs
when testing you can get around the https restriction by checking...
... when testing you can get around the https restriction by checking the "enable service workers over http (when toolbox is open)" option in the firefox developer tools settings. ...

SharedWorker() - Web APIs
browsers. syntax var myworker = new sharedworker(aurl, name); var myworker = new sharedworker(aurl, options); parameters aurl a domstring representing the url of the script the worker will execute. it must obey the same-origin policy. name optional a domstring specifying an identifying name for the sharedworkerglobalscope representing the scope of the worker, which is mainly useful for debugging purposes. options optional an object containing option properties that can set when creating the object instance. available properties are as follows: type: a domstring specifying the type of worker to create. the value can be classic or module. if not specified, the default used is classic. credentials: a domstring specifying the type of credentials to use for the worker. the value c...
... default used is classic. credentials: a domstring specifying the type of credentials to use for the worker. the value can be omit, same-origin, or include. if not specified, or if type is classic, the default used is omit (no credentials required). name: a domstring specifying an identifying name for the sharedworkerglobalscope representing the scope of the worker, which is mainly useful for debugging purposes. return value the created worker. exceptions a securityerror is raised if the document is not allowed to start workers, for example if the url has an invalid syntax or if the same-origin policy is violated. a networkerror is raised if the mime type of the worker script is incorrect. it should always be text/javascript. a syntaxerror is raised if aurl cannot be parsed. ...

WebGLRenderingContext.getExtension() - Web APIs
recommendation initial definition. ...
... recommendation initial definition. ...

WebGLRenderingContext.getSupportedExtensions() - Web APIs
recommendation initial definition. ...
... recommendation initial definition. ...

WebGL constants - Web APIs
functions. all constants are of type glenum. standard webgl constants are installed on the webglrenderingcontext and webgl2renderingcontext objects, so that you use them as gl.constant_name: var canvas = document.getelementbyid('mycanvas'); var gl = canvas.getcontext('webgl'); gl.getparameter(gl.line_width); some constants are also provided by webgl extensions. a list is provided below. var debuginfo = gl.getextension('webgl_debug_renderer_info'); var vendor = gl.getparameter(debuginfo.unmasked_vendor_webgl); the webgl tutorial has more information, examples, and resources on how to get started with webgl. table of contents standard webgl 1 constants standard webgl 2 constants webgl extension constants standard webgl 1 constants these constants are defined on the webglrenderingc...
... 0x8cad invalid_index 0xffffffff timeout_ignored -1 max_client_wait_timeout_webgl 0x9247 constants defined in webgl extensions angle_instanced_arrays constant name value description vertex_attrib_array_divisor_angle 0x88fe describes the frequency divisor used for instanced rendering. webgl_debug_renderer_info constant name value description unmasked_vendor_webgl 0x9245 passed to getparameter to get the vendor string of the graphics driver. unmasked_renderer_webgl 0x9246 passed to getparameter to get the renderer string of the graphics driver. ext_texture_filter_anisotropic constant name value description ...

Using WebGL extensions - Web APIs
for example: var float_texture_ext = gl.getextension('oes_texture_float'); the return value is null if the extension is not supported, or an extension object otherwise. extensio...
...for example: var float_texture_ext = gl.getextension('oes_texture_float'); the return value is null if the extension is not supported, or an extension object otherwise. extension objects if an extension ...

WebGL best practices - Web APIs
o matter what browser or hardware your users run. general topics address and eliminate webgl errors your application should run without generating any webgl errors (as returned by geterror). every webgl error is reported in the web console as a javascript warning with a descriptive message. after too many errors (32 in firefox), webgl stops generating descriptive messages, which really hinders debugging. the only errors a well-formed page generates are out_of_memory and context_lost. know your limits (and extensions) the availability of most webgl extensions depends on the client system. when using webgl extensions, if possible, try to make them optional by gracefully adapting to the case there they are not supported. likewise the limits of your system will be different than your clients...
...in practice, effectively all systems support at least the following: max_cube_...

WebGL: 2D and 3D graphics for the web - Web APIs
it is based on opengl es 3.0 and new features include: 3d...
...it is based on opengl es 3.0 and new features include: 3d textures, sampler objects...

window.dump() - Web APIs
the message passed to dump() is sent to the system console (native console) if the firefox process was started with the -console option. if the -console option was not specified then the output goes to stderr. output from dump() is not sent to the browser console. output can be sent to the browser console using console.log(). ...
...o the error console/browser console. dump() is also available to xpcom components implemented in javascript, even though window is not the global object in components. it is also explicitly made available in sandboxes. however, this use of dump is not affected by the preference mentioned below -- it will always be shown. it is therefore advisable to either check this preference yourself or use a debugging preference of your own to make sure you don't send lots of debugging content to a user's console when they might not be interested in it at all. note that dump output from xpcom components goes to stderr, while dump called elsewhere will output to stdout. in gecko dump() is disabled by default – it doesn't do anything but doesn't raise an error either. to see the dump output you have to en...

CSS: Cascading Style Sheets
tart using it to add styling to html. css building blocks this module carries on where css first steps left off — now you've gained familiarity with the language and its syntax, and got some basic experience with using it, its time to dive a bit deeper. this module looks at the cascade and inheritance, all the selector types we have available, units, sizing, styling backgrounds and borders, debugging, and lots more. the aim here is to provide you with a toolkit for writing competent css and help you understand all the essential theory, before moving on to more specific disciplines like text styling and css layout. styling text with the basics of the css language covered, the next css topic for you to concentrate on is styling text — one of the most common things you'll do with css...
...mon layout patterns, things you might need to implement in your sites. in addition to providing code you can use as a starting point in your projects, these recipes highlight the different ways layout specifications can be used, and the choices you can make as a developer. tools for css development you can use the w3c css validation service to check if your css is valid. this is an invaluable debugging tool. firefox developer tools lets you view and edit a page's live css via the inspector and style editor tools. the web developer extension for firefox lets you track and edit live css on watched sites. the web community has created various other miscellaneous css tools for you to use. meta bugs firefox: bug 1323667 ...

HTTP Index - HTTP
se header used to send cookies from the server to the user agent, but has been deprecated by the specification. use set-cookie instead. 183 sourcemap http, http header, reference, response header, header the sourcemap http response header links generated code to a source map, enabling the browser to reconstruct the original source and present the reconstructed original in the debugger. 184 strict-transport-security hsts, http, https, security, header the http strict-transport-security response header (often abbreviated as hsts) lets a web site tell browsers that it should only be accessed using https, instead of using http. 185 te http, reference, header the te request header specifies the transfer encodings the user agent is willin...
... content-type header. 214 put http, http method, reference, request method the http put request method creates a new resource or replaces a representation of the target resource with the request payload. 215 trace http, reference, trace method the http trace method performs a message loop-back test along the path to the target resource, providing a useful debugging mechanism. 216 http resources and specifications guide, http http was first specified in the early 1990s. designed with extensibility in mind, it has seen numerous additions over the years; this lead to its specification being scattered through numerous specification documents (in the midst of experimental abandoned extensions). this page lists relevant resources about ht...

An overview of HTTP - HTTP
and transport layers. http is on top, at the application layer. although important to diagnose network problems, the underlying layers are mostly irrelevant to the description of http. client: the user-agent the user-agent is any tool that acts on the behalf of the user. this role is primarily performed by the web browser; other possibilities are programs used by engineers and web developers to debug their applications. the browser is always the entity initiating the request. it is never the server (though some mechanisms have been added over the years to simulate server-initiated messages). to present a web page, the browser sends an original request to fetch the html document that represents the page. it then parses this file, making additional requests corresponding to execution scripts,...
...at is easy to use. the client-server structure, combined with the ability to simply add headers, allows http to advance along with the extended capabilities of the web. though http/2 adds some complexity, by embedding http messages in frames to improve performance, the basic structure of messages has stayed the same since http/1.0. session flow remains simple, allowing it to be investigated, and debugged with a simple http message monitor. ...

Error.prototype.stack - JavaScript
specifications not part of any standard. ...
... specifications not part of any standard. ...

Object.create() - JavaScript
exceptions the proto parameter has to be either null or an object excluding primitive wrapper objects. if proto is neither of these a typeerror is thrown. custom and null objects a new object created from a completely custom object (especially one created from the null object, which is basically a custom object with no members) can behave in unexpected ways. this is especially true when debugging, since common object-property converting/detecting utility functions may generate errors, or simply lose information (especially if using silent error-traps that ignore errors). for example, here are two objects: oco = object.create( {} ); // create a normal object ocn = object.create( null ); // create a "null" object > console.log(oco) // {} -- seems normal > console.log(ocn) // {} -- s...
...() // throws error: ocn.tostring is not a function > oco.valueof() // shows {} > ocn.valueof() // throws error: ocn.valueof is not a function > oco.hasownproperty("p") // shows "true" > ocn.hasownproperty("p") // throws error: ocn.hasownproperty is not a function > oco.constructor // shows "object() { [native code] }" > ocn.constructor // shows "undefined" as said, these differences can make debugging even simple-seeming problems quickly go astray. for example: a simple common debugging function: // display top-level property name:value pairs of given object function showproperties(obj){ for(var prop in obj){ console.log(prop + ": " + obj[prop] + "\n" ); } } not such simple results: (especially if silent error-trapping had hidden the error messages) ob={}; ob.po=oco; ob.pn=ocn;...

Using the WebAssembly JavaScript API - WebAssembly
tep to turn the response into an arraybuffer before compiling/instantiating the wasm module. the equivalent code would look like this: fetch('simple.wasm').then(response => response.arraybuffer() ).then(bytes => webassembly.instantiate(bytes, importobject) ).then(results => { results.instance.exports.exported_func(); }); viewing wasm in developer tools in firefox 54+, the developer tool debugger panel has functionality to expose the text representation of any wasm code included in a web page. to view it, you can go to the debugger panel and click on the “wasm://” entry. starting soon in firefox, in addition to viewing webassembly as text, developers will be able to debug (place breakpoints, inspect the callstack, single-step, etc.) webassembly using the text format. see webasse...
... memory in the low-level memory model of webassembly, memory is represented as a contiguous range of untyped bytes called linear memory that are read and written by load and store instructions inside the module. ...

Loading Content Scripts - Archive of obsolete content
t library like jquery by url, then pass in a simple script inline that can use jquery. unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. the contentscriptwhen option specifies when the content script(s) should be loaded. it takes one of three possible values: "start" loads the scripts immediately after the document element for the page is inserted into the dom. at this point the dom content hasn't been loaded yet, so the script won't be able to interact with it. "ready" loads the scripts after the dom for...

Content Processes - Archive of obsolete content
...

context-menu - Archive of obsolete content
ntscriptfile property. see working with content scripts for more information. warning: unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. show an "edit page source" item when the user right-clicks a non-interactive part of the page: require("sdk/context-menu").item({ label: "edit page source", contentscript: 'self.on("click", function (node, data) {' + ' self.postmessage(document.url);' + '});', onmessage: function (pageurl) { editsource(pageurl); } }); show an "edit im...

page-worker - Archive of obsolete content
nt scripts in separate files and pass their urls using the contentscriptfile property. unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. to learn much more about content scripts, see the working with content scripts guide. scripting trusted page content we've already seen that you can package html files in your add-on's data directory and load them using page-worker. we can call this "trusted" content, because unlike content loaded from a source outside the add-on, the add-on author knows exactly what it's doing. t...

panel - Archive of obsolete content
is a url pointing to a script file saved under your add-on's data directory. warning: unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. getting user input note: this example uses the action button api, which is only available from firefox 29 onwards. the following add-on adds a button which displays a panel when clicked. the panel just contains a <textarea> element: when the user presses the return key, the contents of the <textarea> is sent to the main add-on code. the add-on consists of six files: main.j...

widget - Archive of obsolete content
he script using either the postmessage() api or (preferably, usually) the port api. unless your content script is extremely simple and consists only of a static string, don't use contentscript: if you do, you may have problems getting your add-on approved on amo. instead, keep the script in a separate file and load it using contentscriptfile. this makes your code easier to maintain, secure, debug and review. for example, suppose we want to implement a media player as an add-on. we could implement the main user interface as a widget hosting an array of buttons to control play/pause/stop functions. we can then use a content script to listen for clicks on those buttons. but because content scripts can't use the sdk's apis, we'll want the content script to send messages to the main add-on ...

/loader - Archive of obsolete content
requirements[id]; else throw error('module "' + requirer + '" has no authority to require ' + 'module "' + id + "') } }); thrown exceptions will propagate to the caller of require(). if the function assigned to resolve does not return a string value, an exception will still be thrown as the loader will be unable to resolve the required module's location. id add-on debugging requires knowing which objects belong to which add-on. when created with this option, loader will transparently mark all new global objects with the provided value. all together all of these options can be combined to configure the loader for a specific use case. don't get too excited about configuration options, keep in mind that modules are more useful if they can be used across loader in...

Implementing the widget - Archive of obsolete content
tor is inactive by default. it creates the widget and responds to messages from the widget's content script by toggling its activation state. since we don't have any code to display annotations yet, we just log the right-click events to the console. now from the annotator directory type cfx run. you should see the widget in the add-on bar: left- and right-clicks should produce the appropriate debug output, and a left-click should also change the widget icon to signal that it is active. next we'll add the code to create annotations. ...

Logging - Archive of obsolete content
because dom objects aren't available to the main add-on code, the sdk provides its own global console object with most of the same methods as the dom console, including methods to log error, warning, or informational messages. you don't have to require() anything to get access to the console. it is automatically made available to you. ...

Modifying Web Pages Based on URL - Archive of obsolete content
elow is what you should see. specifying the match pattern match pattern uses match-pattern syntax. you can pass a single match-pattern string, or an array. keeping the content script in a separate file in the example above, we've supplied content script as a string. unless the script is extremely simple, maintain the script as a separate file though. this makes the code easier to maintain, debug, and review. to do this, you need to: save the script in add-on's data directory. use contentscriptfile option instead of contentscript and pass it script url which can be obtained using self.data.url("my-script.js"). from firefox 34 onwards, you can just use "./my-script.js" instead. for example, if we save the script above under the add-on's data directory in a file called my-script.js: ...

Modifying the Page Hosted by a Tab - Archive of obsolete content
the page. then open any web page in the browser window, and click the button . you should see a red border appear around the page, like this: keeping content scripts in a separate file in the example above, we've passed in content script as a string. unless script is extremely simple, maintain the script as a separate file in add-on's data directory. this makes the code easier to maintain, debug, and review. to do this, provide option contentscriptfile not contentscript, whose value is a url pointing to one or more content script files. for example, if we save the script above under the add-on's data directory in a file called my-script.js: var self = require("sdk/self"); var button = require("sdk/ui/button/action").actionbutton({ id: "style-tab", label: "style tab", icon: "./ic...

Bootstrapped extensions - Archive of obsolete content
alled, if the reason is addon_upgrade or addon_downgrade, and the method is shutdown or uninstall. note: an add-on may be upgraded/downgraded at application startup, in this case the startup method reason is app_startup, and the oldversion property is not set. also be aware that in some circumstances an add-on upgrade/downgrade may occur without the uninstall method being called. add-on debugger from firefox 31 onwards, you can use the add-on debugger to debug bootstrapped add-ons. localization (l10n) localizing bootstrapped add-ons is very much the same since firefox 7, as that is when chrome.manifest compatibility landed. js and jsm files - using property files to localize your .js and .jsm files you have to use property files. the absolute minimum needed here is: file: ins...

Enhanced Extension Installation - Archive of obsolete content
ity when saving data. it also makes it more difficult to support multiple instances of a single extension at different install locations due to the singleton nature of rdf resources. extension metadata is structured and not relational in the sense encouraged by rdf, and so a simple text storage format is probably desirable. making the database file format human readable would also help developers debug their installation problems. footnotes the term "extension" is used in this document to imply any item managed by the extension manager, including themes. the term "firefox" is used in this document to imply any application built on xulrunner that uses the extension system. original document information author(s): ben goodger last updated date: april 18, 2005 copyright information: c...

Extension Versioning, Update and Compatibility - Archive of obsolete content
signature in update.rdf when the author creates the update rdf file a tool is used to sign it using the private part of the key. roughly speaking the update information is converted to a string, then hashed using a sha512 hashing algorithm and this hash is signed using the private key. the resultant data is der encoded then base 64 encoded for inclusion in the update.rdf as an signature entry. debugging and solving problems the update mechanism logs information to the console, and display various information which can help you to find problem. to enable the log: set the value of extensions.logging.enabled to true (using url about:config) run firefox from command with option -console if you encounter problems, search the output in console for your extension id, and see if failures were...

Jetpack Processes - Archive of obsolete content
non-standard javascript objects for that matter, though new globals can be endowed by simply attaching them to the global scope as properties. evalinsandbox(asandbox, ascript) evaluates the given script contents in the given sandbox's global scope. at minimum, javascript 1.8.1 is used. individual lines of the form //@line 1 "foo.js" can be used to specify filename and line number information for debugging purposes. gc() synchronously performs garbage collection. handles messages that communicate between the browser and jetpack process may contain only serializable (json) data and handles. a handle can be used to provide context for messages. either the browser or the jetpack implementation may create one. a handle keeps any arbitrary properties attached to it alive, but those properties are n...

Migrating from Internal Linkage to Frozen Linkage - Archive of obsolete content
rk with frozen linkage. strings the most obvious change required by frozen linkage is using the frozen string api. - #include "nsastring.h"- #include "nsstring.h"- #include "nsreadableutils.h"- #include "nsescape.h" + #include "nsstringapi.h" on windows, if you see the following error, you are including a header you shouldn't be: nsstringfwd.h(60) : fatal error c1001: internal compiler error to debug this error, make in the failing directory, adding the /showincludes directive to figure out what is being included incorrectly: make -c directory/that/failed os_cppflags=-showincludes the frozen string api is similar but not identical to the nonfrozen string api. the frozen string api does not have (or need) nsxpidlstring: - nsxpidlstring value; + nsstring value; ptr->gettermethod(getter_copie...

Adding windows and dialogs - Archive of obsolete content
ow object, but those are meant for unprivileged html javascript code. alert the alert is the simplest form of dialog. all it does is display a text message that the user can read and then click the ok button to dismiss it. we have been using the window.alert function to open alert messages in our examples so far, but that's not the right way to do it. it's ok to use this function if you're just debugging some problem and want to see if the program reaches a specific line of code, or to inspect the value of a variable, but your final extension should not have alert calls anywhere. if you use window.alert, the alert window will have the title [javascript application], indicating that the source of the message is not well defined. the prompt service allows better alerts to be displayed. here's ...

Connecting to Remote Content - Archive of obsolete content
uld use this to generate a script to run on your local database. you would of course need to be very careful about escaping characters and protecting yourself against sql injection attacks. convert xml into rdf. this was more useful when rdf was the default storage format. you can still use rdf as an intermediate format, though, and then use templates to generate xul and display the data. http debugging when you start debugging http requests, you may find it hard to know exactly what data was sent, especially with post data. we recommend you to use extensions like tamper data. they help you to track http/https requests and responses occurring in firefox. after installation, you can find a tamper data menu item in the menu bar: tools > tamper data or view > sidebar > tamper data once ...

List of Mozilla-Based Applications - Archive of obsolete content
ylizer css editor css editor css editor with built-in firebug-like diagnostics and gecko 1.8 preview sun java enterprise system server products uses nss sundial browser with advanced domain name technology based on firefox surfeasy private and secure web browsing sweet16 apple ii computer emulator uses spidermonkey as a scriptable debugger for software running in the emulator mozilla sunbird/mozilla lightning calendar tabpress authoring tool talend open studo data integration software seems to use xulrunner talking clipboard text to speech software read epub books, web pages, chm, pdf, ms word, rtf, rss feeds taskpool productivity telasocial ...

Source code directories overview - Archive of obsolete content
ry). the [#seamonkey-webshell webshell] code wraps these interfaces according to the particular platform and way (e.g. activex) that is being supported. extensions contains c interfaces, c code, xul and javascript code for various add-ins that are related to browsing. these include: cookies, irc, wallet, dom inspector, p3p, schema validation, spellchecker, transformiix, typeaheadfind, javascript debugger, xforms, etc. gfx contains c interfaces and code for platform independent drawing and imaging. it can be used to draw rectangles, lines, images, etc. essentially, it is a a set of interfaces for a platform-independent device (drawing) context. it does not handle widgets or specific drawing routines; it just provides the primitive operations for drawing. intl contains c interfaces and code fo...

ActiveX Control for Hosting Netscape Plug-ins in IE - Archive of obsolete content
ging in to anonymous@cvs-mirror.mozilla.org) cvs password: anonymous c:\> cvs -z3 co mozilla/embedding/browser/activex/src/pluginhostctrl this fetches the source for the control into mozilla\embedding\browser\activex\src\pluginhostctrl. you can also see the code online. build it it is quite simple to build the control locate the pluginhostctrl directory: open pluginhostctrl.dsp build "win32 debug" or another target open some of the test files under pluginhostctrl\tests in internet explorer to verify the control has built and registered correctly. the control currently reads plug-ins from your most current netscape 4.x and ie installations. there is no support for mozilla or ns 6.x yet. a note to developers if you intend to modify this control in any way then you must also change the cl...

Dehydra Function Reference - Archive of obsolete content
a javascript object where each parameter is a property. if a property is not specified then it will not be passed to the runtime. version integer: this sets js version similar to version() in js 1.7. strict boolean: controls js strict mode werror boolean: turns js warnings into errors gczeal int: this is a write-only parameter to set turn on frequent garbage collection. it is a mainly useful for debugging dehydra for rooting bugs. gczeal is only enabled when spidermonkey and dehydra are compiled with debug macro defined. require() example require({strict:true, gczeal:2}) if (require().werror) print("werror is set") warning([code,] msg [, loc]) print a warning message using the gcc warning mechanism. if -werror is specified this will cause compilation to fail. optional: code is an integer pa...

Installing Dehydra - Archive of obsolete content
ibution. dehydra is not supported on mac os x. building spidermonkey it is recommended that you use spidermonkey revision aurora_base_20110705 when building dehydra. cd $home hg clone http://hg.mozilla.org/mozilla-central/ cd mozilla-central hg update aurora_base_20110705 cd js/src autoconf-2.13 mkdir $home/obj-js cd $home/obj-js $home/mozilla-central/js/src/configure --enable-optimize --disable-debug make it has to be checked whether later/newer branches (like aurora_base_20120131) are working, too. please also note that autoconf v2.13 is really needed: it does not work with e.g. v2.68. there is no need for some installation after make. you can skip the next section "building gcc 4.5" if you are using gcc 4.6 or above. building gcc 4.5 for treehydra's process_tree_decl to work, when compilin...

Extension Frequently Asked Questions - Archive of obsolete content
ful. if you're looking for a place to get started, try our tutorial, building an extension or mozillazine's getting started tutorial. use the extension wizard to generate a template to start with. be sure to set the development preferences. todo: add content. where can i get more help? please see extensions:other resources and extensions:community. before asking for help, be sure to set the debugging prefs and check the error console for related messages. also, don't forget to do at least a simple web search before asking. and read this faq! ...

JavaScript Client API - Archive of obsolete content
o, for me, doing weave.engines.register(fooengine) worked better then doing weave.fooengine = fooengine. reason for this is, weave will iterate through the registerengines preference and try to instantiate each engine it has there before you the line mentioned above ever has a chance to execute.this means the constructor to your engine is not ready when weave tries to instantiate it. testing and debugging your engine set observers in the tracker to tell when your datatype changes, after which the score needs to be set. you can also add api's to the engine, get a handle of the engine by going weave.engines.get("foo") and call it directly. ...

Jetpack Snippets - Archive of obsolete content
no longer under active development. read the experiment report for what we learned from it and the blog post announcing the first sdk release for what we're up to next! bits of code that may come in handy. ...

Modularization techniques - Archive of obsolete content
release() decrements it. if a call to release() causes the reference count to hit zero, the object will generally free itself. a successful queryinterface() will call addref() on the requested interface before returning. both addref() and release() return the resulting reference count. the convenience macros ns_addref() and ns_release() are preferred over calling addref and release directly. in debug builds, these macros provide useful reference counting logs. use them wherever possible. /* * the nsisupports interface */ class nsisupports { public: ns_imethod queryinterface(const nsiid &aiid, void **aresult) = 0; ns_imethod_(nsrefcnt) addref(void) = 0; ns_imethod_(nsrefcnt) release(void) = 0; }; the ns_imethod and ns_imethod_(type) macros are ba...

Mozilla Application Framework - Archive of obsolete content
k and connect it with other components. web services built-in support for xmlhttprequest, xml-rpc, soap, and wsdl to enable mozilla-based application authors to take advantage of the exploding world of web services. xpinstall our cross-platform installer for trivial packaging and installation of your mozilla framework applications. and much much more... tools venkman a javascript debugger with support for breakpoints, conditional breakpoints, local variable inspection, watch variables, single step, stop on error, profile data collection, report generation, code reformatting (pretty printing), and more. dom inspector a tool for inspecting and editing the structure and widgets of your user interface while your application is running. xulmaker a gui builder currently und...

LIR - Archive of obsolete content
r allocate stack space (result is an address) 6 reti void return an int 7 retq void 64 bit return a quad 8 retd void return a double 9 livei void extend live range of an int 10 liveq void 64 bit extend live range of a quad 11 lived void extend live range of a double 12 file void source filename for debug symbols 13 line void source line number for debug symbols 14 comment void a comment shown, on its own line, in lir dumps 15 not in use load 16 not in use 17 ldc2i integer load char and sign-extend to an int 18 lds2i integer load short and sign-extend to an int 19 lduc2ui integer load unsign...

Plug-n-Hack - Archive of obsolete content
without integration between security tools and browsers, a user must often switch between the tool and their browser several times to perform a simple task, such as intercepting an http(s) request. pnh allows security tools to declare the functionality that they support which is suitable for invoking directly from the browser. a browser tha...

Build - Archive of obsolete content
heckout the latest prism code : cd mozilla/ svn co http://svn.mozilla.org/projects/webrunner/trunk prism create a file called .mozconfig make sure it is in the mozilla/ directory. the contents of the file should look something like this : mk_add_options moz_co_project=xulrunner mk_add_options moz_objdir=@topsrcdir@/mozilla-obj ac_add_options --enable-application=xulrunner ac_add_options --disable-debug ac_add_options --enable-optimize ac_add_options --disable-tests ac_add_options --disable-javaxpcom build xulrunner : make -f client.mk build once the build is done, there will be a directory called mozilla-obj. go into the prism/ directory and create a .mozconfig file mk_add_options moz_objdir=@topsrcdir@/mozilla-obj/prism ac_add_options --with-libxul-sdk=../dist ac_add_options --enable-applic...

Priority Content - Archive of obsolete content
wiki location: soap in gecko-based browsers migrators: doron rosenberg in progress: css support charts original: css support charts and archive.org mirror wiki location: css support charts migrators: serge k. keller licensing: these css charts appear to be under a cc:by-nc-sa license, please make note of that on the page when you do the migration. started: using mozilla in testing and debugging web sites original: using mozilla in testing and debugging web sites wiki location: using mozilla in testing and debugging web sites migrators: serge k. keller note: henrik contacted me on apr 27 and gave us permission to use any of his materials in devedge in the devmo wiki under the cc:by-sa license (yay!) started: browser feature detection original: browser feature detection wiki ...

Frequently Asked Questions - Archive of obsolete content
tell the browser that too. mozilla is strict about this, and no, it's not a bug. failing to respect the mime types servers send is incorrect and has been a source of security holes in other browsers. mozilla will not be changing this behaviour. for more information on server configuration for svg see this link. why does mozilla show an "xml parsing error" message instead of svg? this is an xml debugging message to help xml authors correct errors in their xml documents. mozilla will show this message when there's an xml well formedness error in the file it tried to load. (it doesn't mean there's an error in mozilla.) there are many different xml errors, but the most common one in svg files is "xml parsing error: prefix not bound to a namespace". this is (almost certainly) because the 'xmlns:x...

Static Analysis for Windows Code under Linux - Archive of obsolete content
pile cross_compile=1 ac_add_options --enable-application=browser ac_add_options --host=i686-linux ac_add_options --target=i686-mingw32 ac_add_options --enable-default-toolkit=cairo-windows mk_add_options moz_objdir=@topsrcdir@/../mozilla-mingw # mozilla trunk uses many vista only features on windows, so we should disable some components to make it buildable with mingw32. ac_add_options --enable-debug ac_add_options --disable-optimize ac_add_options --disable-tests ac_add_options --disable-embedding-tests ac_add_options --disable-installer ac_add_options --disable-accessibility ac_add_options --disable-vista-sdk-requirements ac_add_options --disable-updater #change this to where your libidl-config file locate. host_libidl_config=/usr/bin/libidl-config #config your moztools position glib...

Table Cellmap - Archive of obsolete content
p the row count begins every time with 0. a typical code segment to come from the table level down to the rowgroup level nscellmap* map = mfirstmap; while (map) { if (map->getrowcount() > rowindex) { // add your action here } rowindex -= map->getrowcount(); map = map->getnextsibling(); } data entry the usual way to populate the cellmap is via nstableframe::insertrows. enabling the debug code at the function entrance and exit gives a quite complete picture of the cellmap structure. below follows the dump for the 2x2 table. insertrowsbefore firstrow=0 ***start table dump*** mcolwidths= row(0)=02763344 cell(0)=02763528 cell(0)=0276381c row(0)=02763940 cell(0)=02763990 cell(0)=02763ab4 ***** start table cell map dump ***** 023566b0 cols array orig/span-> 023566b0 ***** start grou...

Abc Assembler Tests - Archive of obsolete content
compare_numbereq(name:string, expected:*, actual:*, fractiondigits:int=-1):void - compare 2 numbers up to fractiondigits this is to be used for high precision numbers that may vary slightly due to platform differences. sample abcasm test /* ***** begin license block ***** * version: mpl 1.1/gpl 2.0/lgpl 2.1 * * the contents of this file are subject to the mozilla pub...

Actionscript Acceptance Tests - Archive of obsolete content
by time.tzname tuple. # (see http://docs.python.org/library/time.html for details) # e.g.: eastern standard time/eastern daylight time = ('est','edt') # write timezones as tuples, one to each line. ('est', 'edt') ('cst', 'cdt') ('mst', 'mdt') ('pst', 'pdt') testname.err this file is used when the test throws an uncatchable error. the first line must contain the expected error (without the extra debugger information). the exitcode is optional, but must be defined in this file if non-zero. verifyerror: error #1021 exitcode: 1 testname.exitcode file that specifies the expected exitcode. should just be an integer with nothing else. (note that if a .err file is defined, the .exitcode file will be ignored). in this example the .as test runs out of memory and so the expected exitcode is: 128 t...

Tamarin Build System Documentation - Archive of obsolete content
failures, and the newest testcases. the idea is to catch test failures in a few minutes rather than running the complete test run (1h 45m). the smoke test including downloading the shell takes about 3-4 minutes. the test phase runs all functional testcases including acceptance tests, cmdline tests, and selftests. the acceptance tests are the majority and are run on all shells (release, release-debugger, debug, debug-debugger). the test phase takes approximately 1 hour 45 minutes. the performance and deep phases do not run synchronously. the phases run when slaves are available and the other phases do not wait for completion to start the next build. how are builds triggered? checkins (hg push) to http://hg.mozilla.org/tamarin-redux and sandbox requests will trigger a buildbot build when...

Video presentations - Archive of obsolete content
out the mozilla community and how you can get involved smoothly. (as quicktime; 170 mb and 80 mb) mozilla-seneca projects q&a with mike shaver (part 1, part 2) mike shaver answers questions about the mozilla project. (as quicktime; 138 mb and 132 mb) developing mozilla these presentations cover various aspects of the process of working on the mozilla project, including building, testing, and debugging. how the build works (part 1, part 2, part 2; second camera, slides) this presentation covers how the mozilla build system works, how to configure the build system, and how to build mozilla projects. (as quicktime; 127 mb, 50 mb, and 68 mb) the life cycle of a bug (part 1, part 2) mike connor describes how a bug goes from bug report to patch to implemented fix. learn how to properly fil...

Learn XPI Installer Scripting by Example - Archive of obsolete content
ain block if the earlier verification process is not successful. note also the comments that indicate the success of various steps in the process--including the performinstall and cancelinstall steps--are written to the install log using the logcomment, described in the following section. installation logging logging is an important feature of the xpinstall api that can help you streamline and debug your installations. in the example in the executing the installation section and in many places in the installation script, the logcomment api is used to write data to a log file that can then be reviewed when things don't go as planned. the install log is created in the product directory by default (where the browser executable is). if the installation doesn't have proper permission, the instal...

Adding Event Handlers - Archive of obsolete content
ript (except as related to event handling) as this is a fairly large topic and there are plenty of other resources that are available for this. by default the javascript console only shows errors from web content. to show errors in chrome javascript, it is necessary to change the preference javascript.options.showinconsole to true. you can also change the preference javascript.options.strict for debugging. by setting this value to true, non-standard, poorly written, or syntax prone to cause logic errors are logged to the javascript console. responding to events the script will contain code which responds to various events triggered by the user or other situations. there are about thirty or so different events that may be handled in several different ways. a typical event is the user pressing...

Introduction - Archive of obsolete content
c platform making building cross-platform software time-consuming and costly. a number of cross-platform solutions have been developed in the past. java, for example, has portability as a main selling point. xul is one such language designed specifically for building portable user interfaces. it takes a long time to build an application even for only one platform. the time required to compile and debug can be lengthy. with xul, an interface can be implemented and modified quickly and easily. xul has all the advantages of other xml languages. for example xhtml or other xml languages such as mathml or svg can be inserted within it. also, text displayed with xul is easily localizable, which means that it can be translated into other languages with little effort. what kinds of user interfaces can...

Manifest Files - Archive of obsolete content
lled-chrome.txt ends with a slash and the file itself ends with a blank line. on windows, file urls are of the form file:///c:/files/app/, where c is the drive letter. make sure the contents.rdf file is in the right directory and is well-formed. open the contents.rdf file in mozilla to see if it parses as well-formed xml. if not, you will see an error on a yellow background. if you are using a debug build of mozilla, some info will be printed to the terminal when starting up indicating what chrome applications are being checked. check if your application is listed. the error message "xml parsing error: undefined entity" in your xul file can be caused by an error in the manifest or in the jar file referenced by the manifest. for example, in <!doctype window system "chrome://fireclipse/locale...

XUL Structure - Archive of obsolete content
t having to repackage or reinstall the files. by default, mozilla applications parse xul files and scripts, and store a pre-compiled version in memory for the remainder of the application session. this improves performance. however, because of this, the xul will be not be reloaded even when the source files are changed. to disable this mechanism, it is necessary to change the preference nglayout.debug.disable_xul_cache. in firefox, this preference may be added to the user preferences by typing "about:config" in the address field, and setting this value to true. or, just manually edit your user.js preferences file and add the following line: pref("nglayout.debug.disable_xul_cache", true); there are usually three different parts to a chrome package, although they are all optional. each part i...

XUL accessibility tool - Archive of obsolete content
accessibility cause within the mozilla project. add usability, i18n, security and other considerations to xul a11y guidelines -- make them more general sprinkle the a11y techniques throughout the turorial and reference. run checking tool on firefox, thunderbird and other apps looking for bugs and fixing them. improve tool along the way add checking tool to dom inspector or other popular xul debugging tools. merge with other xul checking tools -- this doesn't need to be a11y-specific. one problem is that mark finkle's xul validator tool uses a different engine. add the tool into the addons.mozilla.org review process go through the most useful/popular extensions with tool and fix a11y issues add checker to tinderbox so that bugs are caught at checkin time some or all of this work could ...

xulauncher - Archive of obsolete content
ko] minversion=1.8 maxversion=1.9 ">$xulappini # create chrome.manifest file ############################################################################## echo " content $xulname file:$xulname/ ">$xulmanifest # create prefs.js file ############################################################################## echo " pref(\"toolkit.defaultchromeuri\", \"chrome://$xulname/content/$xulfile\"); /* debugging prefs */ pref(\"browser.dom.window.dump.enabled\", true); pref(\"javascript.options.showinconsole\", true); pref(\"javascript.options.strict\", true); pref(\"nglayout.debug.disable_xul_cache\", true); pref(\"nglayout.debug.disable_xul_fastload\", true); ">$xulprefs # copy xul file to right location and run it ############################################################################## cp $...

XULRunner - Archive of obsolete content
the xul tutorial to expand it into a fantastic xul application. xulrunner tips a collection of tips for working with xulrunner. deploying xulrunner an introduction on how to package your application with xulrunner. xulrunner hall of fame tracks all available applications based on xulrunner. build documentation learn how to get the source and build it. debug documentation steps to configure venkman to debug your app xulrunner guide a fairly complete, but outdated, introduction and tutorial for xulrunner which collates much of the documentation found here. view all... community view mozilla forums... mailing list newsgroup rss feed #xulrunner on irc.mozilla.org other community links..

XUL Explorer - Archive of obsolete content
xul explorer is a xulrunner application that provides an easy way to experiment with xul. it’s a simple editor that can preview xul inline or in a separate popup window. it has a list of code snippets (small fragments of xul or javascript) that can be quickly inserted into the editor. the xul can be loaded from and saved to files. a xul validator and the error console are both available to help debug problems. the help menu provides access to xul information on mdc. there is even simple “keyword” help lookup for xul elements. roadmap features: the preview pane can be toggled with the editor. previewing in a popup window is still available. option to automatically update the preview as the editor changes. indicator in the statusbar shows errors. double-click to display error console...

Mozilla release FAQ - Archive of obsolete content
few representative systems (please send your specs in to me) removed because the tree has changed enough that we'll probably need new times for all the builds. please send stats to me in the following format: cpu/mhz, architecture, ram, disk type, os version, compiler version, build type, tree date -- build time example: 21164/533, alpha, 512m edo, ultra2 scsi, linux kernel 2.2.11, gcc 2.95, non-debug, 19 august 1999 cvs -- 25 minutes how do i run the binary on unix? i get library errors in dist/bin there's a script called mozilla. use that to launch mozilla for you -- it sets ld_library_path automatically. to launch other binaries from dist/bin with the correct environment, use run-mozilla.sh ./your_binary features, patches what platforms is mozilla available for? mozilla is currently targete...

2006-10-26 - Archive of obsolete content
magic of search engine cloaking mark describes the magic of search engine cloaker. (what it is, how to use it) cross-post-and followup fx2 announcment to support-firefox request for when the announcement about firefox 2's release to be posted on the mozilla.dev.apps.firefox newsgroup. firefox killer features suggestion john describes his suggestions for "killer features" for firefox. debug minefield on intel mac an inqury about how to debug minefield on an intel mac. rebuild firefox after modifying source code an inqury about how to rebuild the code after making a minor change - the user is unfamiliar with how to use the command prompt. bug in firefox when import passwords from seamonkey a possible bug find - perhaps a version error instead? there should be a 'changes' ...

2006-10-27 - Archive of obsolete content
magic of search engine cloaking mark describes the magic of search engine cloaker. (what it is, how to use it) cross-post-and followup fx2 announcment to support-firefox request for when the announcement about firefox 2's release to be posted on the mozilla.dev.apps.firefox newsgroup. firefox killer features suggestion john describes his suggestions for "killer features" for firefox. debug minefield on intel mac an inqury about how to debug minefield on an intel mac. rebuild firefox after modifying source code an inqury about how to rebuild the code after making a minor change - the user is unfamiliar with how to use the command prompt. bug in firefox when import passwords from seamonkey a possible bug find - perhaps a version error instead? there should be a 'changes' ...

2006-11-17 - Archive of obsolete content
meetings none this week. authors sara minchella (sara) dave manley (senemanley) back to summary list ...

2006-10-27 - Archive of obsolete content
10 x86 october 26: alex was trying to build firefox 2 source on a solaris 10 x86 machine but was not successful with the build. he has already built firefox 1.5.0.7 on the same machine with no problems. the following is his configuration script that he used to build firefox 2 on solaris. ./configure --prefix=/export/home/alex/thunderbird --enable-application=browser --disable-tests --disable-debug -disable-auto-deps --disable-freetype2 -enable-official-branding --enable-default-toolkit=gtk2 --enable-optimize=-xo5 --enable-static --disable-shared --enable-xft --enable-svg the build tools that he used to build firefox 2 are listed in his posting along with the error that he receives when he tries to build it. alex is not sure if he is missing a library or if he needs to pass extra options ...

Extentsions FAQ - Archive of obsolete content
ird!) is there any way to write a regular extension that returns a "dummy" object when an instance of "@mozilla.org/helperapplauncherdialog;1" is created? you can write a dummy xpcom component implementing the necessary interfaces and register it with the sane contract id. http://developer.mozilla.org/en/docs...pcom_component would anyone be able to suggest the best way to do source level debugging in a firefox extension? in the debug menu, uncheck exclude browser files. use the debugger by typing in a command like this: /break chrome://myextension/content/myfile.js 123 then i suggest using flat chrome. if you turn off the xul cache you don't even need to restart to see changes, simply open a new window. how can i backup some of the files before upgrade an extension and put them b...

2006-11-17 - Archive of obsolete content
summary: mozilla.dev.tech.layout - november 11 - november 17, 2006 announcements none this week. discussions testing accesskey conflicts discussion about the complexity of access keys and how to detect conflicts there in the l10n community. bug #360589 describes this ongoing issue. site not loading with seamonkey a user built seamonkey in debug mode and is currently receiving a "bad request" error on some websites. reflow branch testing wanted l. david baron would like users to test the reflow branch as it is coming close to being merged with the trunk. nightly builds, instructions and the current list of known regressions on the branch can be found at: http://wiki.mozilla.org/gecko:reflow...ng#quick_links. users are asked to file bugs on encountered problems that are not prese...

2006-12-01 - Archive of obsolete content
summary: mozilla.dev.tech.xpcom - nov 25- dec 01, 2006 announcements none during this week. discussions nsicontentpolicy and user interaction the proper way to get user confirmation before trying to load certain file types. debugging firefox extesnion? a tip on how to debug firefox extensions using a debugger. segmentation fault while running the browser browser crashes after installation of subjects extension. meetings none during this week. ...

2006-11-17 - Archive of obsolete content
ndar - november 10 - november 17, 2006 announcements no meeting for this week. discussions itip and imip new designs for sending invitations available for comment discussion about the new interface designs for itip. view performance discussion about tests on view performance. webdav server a discussion related to remote calendar modifications. calendar xpcom component discussion about a debug error of additem function from calicalendar. meetings no meetings were scheduled this week. authors mark paruzel yi (eric) shen [back to weekly summaries ] ...

Plugins - Archive of obsolete content
supporting private browsing in plugins firefox 3.5 introduced support for private browsing; learn how to make your plugin respect the user's privacy wishes. multi-process plugin architecture how firefox loads plugins into a separate process. firefox 3.6.4 introduced out-of-process plugins which execute in a separate process so that a crashing plugin does not crash the browser. logging and debugging for multi-process plugins how to create a plugin log to aid in debugging problems with multi-process plugins. writing a plugin for mac os x learn how to write a plugin for mac os x; a template xcode project is provided. monitoring plugins use an observer service notification to monitor the amount of time spent executing calls in plugins. this can be useful when trying to determin...

Table Reflow Internals - Archive of obsolete content
le height, it allocates extra height to its row groups, rows and cells. in each pass, row groups reflow rows which reflow cells which reflow cell blocks. ...

Common Firefox theme issues and solutions - Archive of obsolete content
2 13 2 13 stretch; /* for ff13- */ -moz-border-image: url("chrome://browser/skin/devtools/breadcrumbs/ltr-middle.png") 2 13 2 13 fill stretch; /* for ff14+ */ } responsive design view responsive design view is missing background for unused area the responsive design view tool (tools > web developer > responsive design view) needs background styling for the unused area of the content window. debugger debugger toolbar buttons are missing icons on the debugger (tools > web developer > debugger) the toolbar buttons are missing their icons. miscellaneous issues html 5 media controls html 5 media controls are not styled the html5 video control bar is not styled. please go to mozilla's mission page using both your theme and the default theme and try the video on that page. this issue needs...

Scratchpad - Archive of obsolete content
reloads the page, then executes the code when the page's "load" event fires. this is useful for running the code in a pristine environment. running scratchpad in the browser context you can run scratchpad in the context of the browser as a whole rather than a specific web page. this is useful if you are working on firefox itself or developing add-ons. to do this check "enable chrome and add-on debugging" in the developer tool settings. once you've done this, the environment menu has a browser option; once that's selected, your scope is the entire browser rather than just the page content, as you will see from examining some globals: window /* [object chromewindow] */ gbrowser /* [object xulelement] */ the scratchpad execution context is set to browser when a snippet file has // -sp-conte...

References - Archive of obsolete content
part 1 from makiko itoh preparing for standard-compliant browsers, part 2 from makiko itoh javascript best practices lists 15 of the most frequent coding practices which create problems for javascript and dhtml-driven webpages. the webpage explains and proposes with small examples the best coding practices and most recommendable ways of developing problem-free javascript code. from matt kruse debugging html and css is a well designed website explaining well the how, why and where of html validation, css validation and debugging tools. we highly recommend this site. it is also available in french. from dan. <- previous section: summary of changes ...

Microsoft JavaScript extensions - Archive of obsolete content
warning: these apis will only work in microsoft applications, and are not on a standards track. microsoft browsers (internet explorer, and in a few cases, microsoft edge) support a number of special microsoft extensions to the otherwise standard javascript apis. ...

Object.prototype.unwatch() - Archive of obsolete content
rious negative impact on performance, which is especially true when used on global objects, such as window. you can usually use setters and getters or proxies instead. the unwatch() method removes a watchpoint set with the watch() method. syntax obj.unwatch(prop) parameters prop the name of a property of the object to stop watching. return value undefined. description the javascript debugger has functionality similar to that provided by this method, as well as other debugging options. for information on the debugger, see venkman. by default, this method is inherited by every object descended from object. note: the reason for unwatch() to take the property name prop as its only parameter is due to the "single handler allowing" behavior of the watch() method. examples see watc...

Object.prototype.watch() - Archive of obsolete content
y) the value assignment, by returning a modified newval (or by returning oldval). if you delete a property for which a watchpoint has been set, that watchpoint does not disappear. if you later recreate the property, the watchpoint is still in effect. to remove a watchpoint, use the unwatch() method. by default, the watch method is inherited by every object descended from object. the javascript debugger has functionality similar to that provided by this method, as well as other debugging options. for information on the debugger, see venkman. in firefox, handler is only called from assignments in script, not from native code. for example, window.watch('location', myhandler) will not call myhandler if the user clicks a link to an anchor within the current document. however, window.location += ...

Back to the Server: Server-Side JavaScript On The Rise - Archive of obsolete content
led into a string and appended to the dump file. database access for more robust data management, jaxer comes with the ability to manage data in either a sqlite database which is included in jaxer, or a mysql database, and is extensible to others. much like the file i/o namespace, database access in jaxer can be as simple or complicated as you want or need it to be. for debugging, jaxer will also send database errors to the client if you want. upgrading the example application to include database access requires just a few lines of code added to the formprocessor method. listing 9 demonstrates these changes. listing 9 - jaxer database access <script runat="server"> function formprocessor( name, email, message ) { /...

Standards-Compliant Authoring Tools - Archive of obsolete content
, xhtml and xml authors to edit, format, lookup help, validate, preview and publish web pages. validation is done with html tidy, so you can verify standards compliance. macromedia™ dreamweaver™ cs6 style master and layout master by western civilisation some caveats: it appears that tools currently available from namo generate ie-specific or netscape 4-specific code that may require extra debugging for compatibility with standards-based browsers. newer versions of microsoft frontpage™ have improved, however be sure not to rely on frontpage-specific extensions for critical website content or functionality. some versions of microsoft word create invalid html code that only works with internet explorer. always be sure to validate your web pages. original document information last up...

Choosing Standards Compliance Over Proprietary Practices - Archive of obsolete content
loped the star office system. it was an elegant workstation with an iconic desktop developed by the engineers at parc (palo alto research center). the star office system offered functionality that neither microsoft nor apple has been able to match with their current offerings. the engineers developed star on a proprietary development operating system known as pilot. pilot had a highly-integrated debugging tool called co-pilot that allowed the xerox development organization to quickly and easily debug issues. however, what xerox neglected to understand was that regardless of how powerful pilot and co-pilot was, the star workstation could not evolve with the times because it was proprietary. xerox was bound to a unique hardware platform and to a closed development operating system. and xerox cho...

RDF in Mozilla FAQ - Archive of obsolete content
being properly parsed by mozilla. rdfpoll url [interval ] takes as a parameter a url from which to read an rdf/xml file. it also accepts an optional poll interval, where it will re-load the url. it outputs the assertions that are generated from each load. note that a polling reload generates a set of differences between the current and previous contents of the rdf/xml file. this is useful for debugging generated rdf/xml that may change over time. both these programs are slow to load and run (but they will run, eventually). they initialize xpcom and bring up necko to be able to load and process urls just like mozilla does. nothing happens after i call adddatasource. note that the template builder will not rebuild the contents of a template automatically after adddatasource or removedatas...

Anatomy of a video game - Game development
game will update and draw. you might even want update and draw to occur at different rates. you will also need to consider how gracefully your game will fail if the user's system cannot keep up with the workload. let us start by assuming that you will handle user input and update the game state every time you draw. we will branch out later. note: changing how your main loop deals with time is a debugging nightmare, everywhere. think about your needs carefully before working on your main loop. what most browser games should look like if your game can hit the maximum refresh rate of any hardware you support then your job is fairly easy. you can simply update, render, and then do nothing until vsync. /* * starting with the semicolon is in case whatever line of code above this example * relie...

Index - Game development
deo communications; however, it also offers peer-to-peer data channels. this article explains more about this, and shows you how to use libraries to implement data channels in your game. 39 tools for game development games, gecko, guide, javascript on this page you can find links to our game development tools articles, which eventually aims to cover frameworks, compilers, and debugging tools. 40 asm.js deprecated, javascript, asm.js asm.js is a specification defining a subset of javascript that is highly optimizable. this article looks at exactly what is permitted in the asm.js subset, what improvements it confers, where and how you can make use of it, and further resources and examples. 41 tutorials canvas, games, javascript, web, workfl...

Game distribution - Game development
n quite easily with the availability of wrappers that can help you prepare native builds of your game see packaging games. it's also nice to provide desktop controls for your games even if you're mostly targeting mobile. players are enjoying your games on any platform available, and desktop is one of them. plus, it is usually easier to build and test the game first on desktop, and then move on to debugging mobile. publishing the game there are three main options when it comes to publishing a game: self-hosting publishers stores remember that the name of your game should be unique enough to be quickly promoted later on, but also catchy enough, so people don't forget it. self-hosting if you are a front-end developer, you may already know what to do. an html5 game is just another websit...

Bounding volume collision detection with THREE.js - Game development
iss sphere tests, but the tradeoffs are well worth it. the advantages of using this helper are: it has an update() method that will resize its bounding box mesh if the linked mesh rotates or changes its dimensions, and update its position. it takes into account the child meshes when computing the size of the bounding box, so the original mesh and all its children are wrapped. we can easily debug collisions by rendering the meshes that boxhelper creates. by default they are created with a linebasicmaterial material (a three.js material for drawing wireframe-style geometries). the main disadvantage is that it only creates box bounding volumes, so if you need spheres vs aabb tests you need to create your own sphere objects. to use it, we need to create a new boxhelper instance and supply...

Desktop gamepad controls - Game development
ttons.status = pressed; return pressed; }, the function above clears the buttons cache, and copies their status from the previous frame to the cache. next, the button status is cleared and the new information is added. the same goes for the axes information — looping through axes adds the values to the array. received values are assigned to the proper objects and returns the pressed info for debugging purposes. the button.pressed() function detects the actual button presses: pressed: function(button, hold) { var newpress = false; for(var i=0,s=gamepadapi.buttons.status.length; i<s; i++) { if(gamepadapi.buttons.status[i] == button) { newpress = true; if(!hold) { for(var j=0,p=gamepadapi.buttons.cache.length; j<p; j++) { if(gamepadapi.buttons.cache[j] ...

Mobile touch controls - Game development
gstop.add(ondragstop, this); function ondragstart(sprite, pointer) { // do something when dragging } we can pull the ship around and do something in the meantime, and react when the drag is stopped. hauling in phaser, if enabled, will work out of the box — you don't have to set the position of the sprite yourself manually, so you could leave the ondragstart() function empty, or place some debug output to see if it's working correctly. the pointer element contains the x and y variables storing the current position of the dragged element. dedicated plugins you could go even further and use dedicated plugins like virtual joystick — this is a paid, official phaser plugin, but you can find free and open source alternatives. the initialization of virtual joystick looks like this: this.pa...

Implementing controls using the Gamepad API - Game development
then it loops through buttons and axes to get their actual states and values. detecting button presses the buttonpressed() method is also placed in the main game loop to listen for button presses. it tak...

2D breakout game using pure JavaScript - Game development
work you like and use it for your projects. frameworks are just tools built with the javascript language; so even if you plan on working with them, it's good to learn about the language itself first to know what exactly is going on under the hood. frameworks speed up development time and help take care of boring parts of the game, but if something is not working as expected, you can always try to debug that or just write your own solutions in pure javascript. note: if you are interested in learning about 2d web game development using a game library, consult this series' counterpart, 2d breakout game using phaser. note: this series of articles can be used as material for hands-on game development workshops. you can also make use of the gamedev canvas content kit based on this tutorial if yo...

Visual typescript game engine - Game development
physics engine based on matter.js. multiplatform video chat (for all browsers) implemented. socketio used for session staff. multirtc2 used for data transfer also for video chat. multirtc3 alias 'broadcaster' used for video chat. ...

Plug-in Development Overview - Gecko Plugin API Reference
his chapter, as well as separate chapters for all of the major functional areas of the plug-in api. also see making plug-ins scriptable for more information about making plug-ins accessible from the browser. build the plug-in for your operating system. see "building plug-ins". install the plug-in in the plug-in directory for your operating system. see installing plug-ins. test your plug-in and debug as necessary. create an html page and embed the plug-in object. for information about the html elements to use, see using html to display plug-ins. to see your plug-in in action, simply display the html page that calls it in the browser. registering plug-ins gecko identifies a plug-in by the mime type it supports. when it needs to display data of a particular mime type, the browser finds and ...

Developer Tools - MDN Web Docs Glossary: Definitions of Web-related terms
developer tools (or "development tools" or short "devtools") are programs that allow a developer to create, test and debug software. current browsers provide integrated developer tools, which allow to inspect a website. they let users inspect and debug the page's html, css, and javascript, allow to inspect the network traffic it causes, make it possible to measure it's performance, and much more. learn more general knowledge web development tools on wikipedia technical reference firefox developer tools on mdn firebug (former developer tool for firefox) chrome devtools on chrome.com safari web inspector on apple.com edge dev tools on microsoft.com ...

First-class Function - MDN Web Docs Glossary: Definitions of Web-related terms
le. example | assign a function to a variable javascript const foo = function() { console.log("foobar"); } // invoke it using the variable foo(); we assigned an anonymous function in a variable, then we used that variable to invoke the function by adding parentheses () at the end. even if your function was named, you can use the variable name to invoke it. naming it will be helpful when debugging your code. but it won't affect the way we invoke it. example | pass a function as an argument javascript function sayhello() { return "hello, "; } function greeting(hellomessage, name) { console.log(hellomessage() + name); } // pass `sayhello` as an argument to `greeting` function greeting(sayhello, "javascript!"); we are passing our sayhello() function as an argument to the greeti...

IDE - MDN Web Docs Glossary: Definitions of Web-related terms
learn more general knowledge ide on wikipedia ...

Symbol - MDN Web Docs Glossary: Definitions of Web-related terms
in javascript, symbol is a primitive value. a value having the data type symbol can be referred to as a "symbol value". in a javascript runtime environment, a symbol value is created by invoking the function symbol, which dynamically produces an anonymous, unique value. a symbol may be used as an object property. symbol can have an optional description, but for debugging purposes only. a symbol value represents a unique identifier. for example: // here are two symbols with the same description: let sym1 = symbol("sym") let sym2 = symbol("sym") console.log(sym1 === sym2) // returns "false" // symbols are guaranteed to be unique. // even if we create many symbols with the same description, // they are different values. note: if you are familiar with ruby's (or another language) t...

MDN Web Docs Glossary: Definitions of Web-related terms
world wide web wrapper x xforms xhr (xmlhttprequest) xhtml xinclude xlink xml xpath xquery xslt other 404 502 alpn at-rule attack byte-order mark character set client cryptosystem debug digital signature execution flex-direction glsl interface library memory management routers self-executing anonymous function stylesheet vector image ...

Backgrounds and borders - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Handling different text directions - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Images, media, and form elements - Learn web development
previous overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Organizing your CSS - Learn web development
previous overview: building blocks in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Overflowing content - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Attribute selectors - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Combinators - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Pseudo-classes and pseudo-elements - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Type, class, and ID selectors - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

CSS selectors - Learn web development
or h1 ~ p general sibling in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Sizing items in CSS - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

The box model - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

CSS values and units - Learn web development
us overview: building blocks next in this module cascade and inheritance css selectors type, class, and id selectors attribute selectors pseudo-classes and pseudo-elements combinators the box model backgrounds and borders handling different text directions overflowing content values and units sizing items in css images, media, and form elements styling tables debugging css organizing your css ...

Introduction to CSS layout - Learn web development
e for displaying tabular data, but many years ago — before even basic css was supported reliably across browsers — web developers used to also use tables for entire web page layouts — putting their headers, footers, different columns, etc. in various table rows and columns. this worked at the time, but it has many problems — table layouts are inflexible, very heavy on markup, difficult to debug, and semantically wrong (e.g., screen reader users have problems navigating table layouts). the way that a table looks on a webpage when you use table markup is due to a set of css properties that define table layout. these properties can be used to lay out elements that are not tables, a use which is sometimes described as "using css tables". the example below shows one such use; using css tab...

CSS FAQ - Learn web development
.. </div> if the same property is declared in both rules, the conflict is resolved first through specificity, then according to the order of the css declarations. the order of classes in the class attribute is not relevant. why don't my style rules work properly? style rules that are syntactically correct may not apply in certain situations. you can use dom inspector's css style rules view to debug problems of this kind, but the most frequent instances of ignored style rules are listed below. html elements hierarchy the way css styles are applied to html elements depends also on the elements hierarchy. it is important to remember that a rule applied to a descendent overrides the style of the parent, in spite of any specificity or priority of css rules. .news { color: black; } .corpname {...

Use CSS to solve common problems - Learn web development
face when working with css. ...

Learn to style HTML using CSS - Learn web development
tart using it to add styling to html. css building blocks this module carries on where css first steps left off — now you've gained familiarity with the language and its syntax, and got some basic experience with using it, its time to dive a bit deeper. this module looks at the cascade and inheritance, all the selector types we have available, units, sizing, styling backgrounds and borders, debugging, and lots more. the aim here is to provide you with a toolkit for writing competent css and help you understand all the essential theory, before moving on to more specific disciplines like text styling and css layout. styling text with the basics of the css language covered, the next css topic for you to concentrate on is styling text — one of the most common things you'll do with css...

Publishing your website - Learn web development
a web-based ide such as codepen there are a number of web apps that emulate a website development environment, allowing you to enter html, css and javascript, and then display the result of that code as a website — all in one browser tab. generally speaking, these tools are relatively easy, great for learning, good for sharing code (for example, if you want to share a technique with or ask for debugging help from colleagues in a different office), and free (for basic features). they host your rendered page at a unique web address. however, the features are limited, and these apps usually don't provide hosting space for assets (like images). try playing with some of these examples to find out which one works best for you: jsfiddle glitch js bin codepen publishing via github now le...

The web and web standards - Learn web development
crowave, or hairdryer — the things that give your house useful functionality tooling once you've learned the "raw" technologies that can be used to build web pages (such as html, css, and javascript), you'll soon start to come across various tools that can be used to make your work easier or more efficient. examples include: the developer tools inside modern browsers that can be used to debug your code. testing tools that can be used to run tests to show whether your code is behaving as you intended it to. libraries and frameworks built on top of javascript that allow you to build certain types of web site much more quickly and effectively. so-called "linters", which take a set of rules, look at your code, and highlight places where you haven't followed the rules properly. minifie...

Advanced text formatting - Learn web development
tion would be a great place to start.) in the next article we will look at the html elements you'd use to structure the different parts of an html document. previous overview: introduction to html next in this module getting started with html what’s in the head? metadata in html html text fundamentals creating hyperlinks advanced text formatting document and website structure debugging html marking up a letter structuring a page of content ...

Creating hyperlinks - Learn web development
html, we'll return to text semantics and look at some more advanced/unusual features that you'll find useful — advanced text formatting is your next stop. previous overview: introduction to html next in this module getting started with html what’s in the head? metadata in html html text fundamentals creating hyperlinks advanced text formatting document and website structure debugging html marking up a letter structuring a page of content ...

Document and website structure - Learn web development
...

HTML text fundamentals - Learn web development
rticle, later on in the course. ...

Marking up a letter - Learn web development
ding problem without seeing their code. ...

Structuring a page of content - Learn web development
p someone with a coding problem if you can't see their code. ...

What’s in the head? Metadata in HTML - Learn web development
d we just wanted to give you an idea of the most common things you'll find in there for now! in the next article we'll be looking at html text fundamentals. previous overview: introduction to html next in this module getting started with html what’s in the head? metadata in html html text fundamentals creating hyperlinks advanced text formatting document and website structure debugging html marking up a letter structuring a page of content ...

Introduction to HTML - Learn web development
, contact information, and more. document and website structure as well as defining individual parts of your page (such as "a paragraph" or "an image"), html is also used to define areas of your website (such as "the header," "the navigation menu," or "the main content column.") this article looks into how to plan a basic website structure and how to write the html to represent this structure. debugging html writing html is fine, but what if something goes wrong, and you can't work out where the error in the code is? this article will introduce you to some tools that can help. assessments the following assessments will test your understanding of the html basics covered in the guides above. marking up a letter we all learn to write a letter sooner or later; it is also a useful example...

Responsive images - Learn web development
et to the narrowest width, have a look at what the viewport is (you can approximate it by going into the browser's javascript console and typing in document.queryselector('html').clientwidth). different browsers have minimum sizes that they'll let you reduce the window width to, and they might be wider than you'd think. when testing it with a mobile browser, you can use tools like firefox's about:debugging page to inspect the page loaded on the mobile using the desktop developer tools. to see which images were loaded, you can use firefox devtools's network monitor tab. older browsers that don't support these features will just ignore them. instead, those browsers will go ahead and load the image referenced in the src attribute as normal. note: in the <head> of the example linked above, y...

HTML table basics - Learn web development
ontents to the user. because tables are not the right tool for layout, and the markup is more complex than with css layout techniques, the screenreaders' output will be confusing to their users. tables produce tag soup: as mentioned above, table layouts generally involve more complex markup structures than proper layout techniques. this can result in the code being harder to write, maintain, and debug. tables are not automatically responsive: when you use proper layout containers (such as <header>, <section>, <article>, or <div>), their width defaults to 100% of their parent element. tables on the other hand are sized according to their content by default, so extra measures are needed to get table layout styling to effectively work across a variety of devices. active learning: creating your...

Storing the information you need — Variables - Learn web development
as at that point the mynumber variable contains a string, '500'. have a look and see what it returns the second time you call it. constants in javascript many programming languages have the concept of a constant — a value that once declared can't be changed. there are many reasons why you'd want to do this, from security (if a third party script changed such values it could cause problems) to debugging and code comprehension (it is harder to accidentally change values that shouldn't be changed and mess things up). in the early days of javascript, constants didn't exist. in modern javascript, we have the keyword const, which lets us store values that can never be changed: const daysinweek = 7; const hoursinday = 24; const works in exactly the same way as let, except that you can't give a ...

Inheritance in JavaScript - Learn web development
itance, you are advised to not have too many levels of inheritance, and to keep careful track of where you define your methods and properties. it is possible to start writing code that temporarily modifies the prototypes of built-in browser objects, but you should not do this unless you have a really good reason. too much inheritance can lead to endless confusion, and endless pain when you try to debug such code. ultimately, objects are just another form of code reuse, like functions or loops, with their own specific roles and advantages. if you find yourself creating a bunch of related variables and functions and want to track them all together and package them neatly, an object is a good idea. objects are also very useful when you want to pass a collection of data from one place to another. ...

Server-side web frameworks - Learn web development
ode is easy to read and to maintain. popular sites using django (from django home page) include: disqus, instagram, knight foundation, macarthur foundation, mozilla, national geographic, open knowledge foundation, pinterest, open stack. flask (python) flask is a microframework for python. while minimalist, flask can create serious websites out of the box. it contains a development server and debugger, and includes support for jinja2 templating, secure cookies, unit testing, and restful request dispatching. it has good documentation and an active community. flask has become extremely popular, particularly for developers who need to provide web services on small, resource-constrained systems (e.g. running a web server on a raspberry pi, drone controllers, etc.) express (node.js/javascript...

Dynamic behavior in Svelte: working with variables and props - Learn web development
tus, show how many of them are completed and apply filters. to recap, we covered the following topics: creating and using components. turning static markup into a live template. embedding javascript expressions in our markup. iterating over lists using the {#each} directive. passing information between components with props. listening to dom events. declaring reactive statements. basic debugging with console.log() and reactive statements. binding html properties with the bind:property directive. triggering reactivity with assignments. using reactive expressions to filter data explicitly defining our reactive dependencies in the next article we will add further functionality, which will allow users to edit todos. previous overview: client-side javascript frameworks next ...

Creating our first Vue component - Learn web development
done. to achieve this, we want to bind the component's done prop to the checked attribute on the <input> element, so that it can serve as a record of whether the checkbox is checked or not. however, it's important that props serve as one-way data binding — a component should never alter the value of its own props. there are a lot of reasons for this. in part, components editing props can make debugging a challenge. if a value is passed to multiple children, it could be hard to track where the changes to that value were coming from. in addition, changing props can cause components to re-render. so mutating props in a component would trigger the component to rerender, which may in-turn trigger the mutation again. to work around this, we can manage the done state using vue’s data property. ...

Introduction to automated testing - Learn web development
capture a bug (looks like a camera) — takes a screenshot, then allows you to annotate and save it. issue tracker (looks like a deck of cards) — view previously captured bugs/screenshots. settings (cog icon) — allows you to alter general settings for the session. help (question mark) — accesses help/support functions. devtools — allows you to use your browser's devtools to directly debug or manipulate the page being shown in the test browser. this currently only works when testing the safari browser on ios devices. device info — displays information about the testing device. features — shows you what features the current configuration supports, e.g. copy to clipboard, gesture support, etc. stop — ends the session. note: this is already very useful, and way more conven...

Setting up your own test automation environment - Learn web development
usingserver('http://hub-cloud.browserstack.com/wd/hub'). withcapabilities(capabilities). build(); driver.get('http://www.google.com'); driver.findelement(by.name('q')).sendkeys('webdriver'); driver.sleep(1000).then(function() { driver.findelement(by.name('q')).sendkeys(webdriver.key.tab); }); driver.findele...

Tools and testing - Learn web development
e a front-end web developer? we have put together a course that includes all the essential information you need to work towards your goal. get started prerequisites you should really learn the basics of the core html, css, and javascript languages first before attempting to use many the tools detailed here. for example, you'll need to know the fundamentals of these languages before you start debugging problems in complex web code, making effective use of javascript frameworks, or writing tests and running them against your code using test runners. in addition, you should start with the first module in this topic, which gives a useful overview of the general area. modules understanding client-side web development tools client-side tooling can be intimidating, but this series of articl...

Embedding API for Accessibility
esents 100%, or normal zoom. for double-sized text, use nsidomwindow::settextzoom(2.0); using accessibility preferences there are a number of prefs related to accessibility. for the most part, an automatic reframe is performed when one of these prefs is changed. a reframe fixes the appearance of the page to match the new prefs, without reloading the document over the network. ...

Browser chrome tests
directory within the mozilla source tree. if the path points to a directory, then the tests in that directory and all of its subdirectories will be run. for example, to run the tests in browser/base/content/test the command would be: ./mach mochitest -f browser browser/base/content/test/ or without mach test_path=<path_to_the_tests> make -c <objdir> mochitest-browser-chrome to run tests in debugger the following should work ./mach mochitest -f browser --debugger gdb browser/base/content/test/ run ./mach help mochitest-browser for more options. writing browser chrome tests browser chrome tests are snippets of javascript code that run in the browser window's global scope. a simple test would look like this: function test() { ok(gbrowser, "gbrowser exists"); is(gbrowser.tabs.len...

Building SpiderMonkey with UBSan
use the script to compile spidermonkey. this enables all the cheap undefined behavior checks other than: alignment, which hits known bugs in spidermonkey, and is more implementation-defined (slow on x86 / crash on arm) than undefined behavior float-cast-overflow, which hits known bugs in spidermonkey, and isn't exploited by today's compilers float-div...

Chrome registration
this is very helpful when trying to write a chrome.manifest file as you can inspect where the files are being mapped from (jar files, local directory, etc.) old-style contents.rdf manifests before the plaintext manifests were introduced (which happened in firefox 1.5, toolkit 1.8), rdf manifests named "contents.r...

Creating reftest-based unit tests
.html you are now ready to run the test (but first you must go back to the root of firefox's source code tree): $ ./mach reftest path/to/reftest.list 2>&1 | grep reftest reftest pass: file:///users/ray/mozilla-central/path/to/foo.html $ congratulations! you have just created your first reftest! the re-direct and the grep reduce the amount of excess output from the browser. if you built a debug version of the browser, there can be a lot of extra console output. the reftest.list file can be named whatever you want, not necessarily reftest.list (but it has to end with .list). more to do create more reftests. new tests can be added to the reftest.list file, which can contain any number of tests. the file can include other things, but it does not get very complicated. keep in mind new tes...

Makefile - variables
tool_dirs a list of directories to process makefile 'tool' targets in. moz_ variable description moz_auto_deps moz_build_app moz_build_projects build multiple projects in the same sandbox. ...

Old Thunderbird build
--enable-application=mail you can create a file with this line by doing this: cd comm-central echo 'ac_add_options --enable-application=mail' > mozconfig if you omit this line, the build system will build firefox instead. other build configuration options can be added to this file, although it's strongly recommended that you only use options that you fully understand. for example, to create a debug build instead of a release build, that file would contain: ac_add_options --enable-debug for more on configuration options, see the page configuring build options. note that if you use an moz_objdir it cannot be a sibling folder to your source directory. use an absolute path to be sure! building thunderbird before you start, make sure that the version you checked out is not busted. for hg ti...

Simple Instantbird build
icial instantbird release builds. if that's not exactly what you want, there are many build configuration options to choose from, although it's strongly recommended that you only use options that you fully understand. the normal way to specify build options is to place them in a file called '.mozconfig' at the root of your mozilla source tree, i.e. your comm-central repo. for example, to create a debug build instead of a release build, that file would contain: ac_add_options --enable-debug for more on configuration options, see the page configuring build options. note that if you use an moz_objdir it cannot be a sibling folder to your source directory. use an absolute path to be sure! building instantbird what you need to do to build instantbird rather than firefox is: echo 'ac_add_option...

Simple Thunderbird build
n=comm/mail you can create a file with this line by doing this in the source/ directory: echo 'ac_add_options --enable-application=comm/mail' > mozconfig if you omit this line, the build system will build firefox instead. other build configuration options can be added to this file, although it's strongly recommended that you only use options that you fully understand. for example, to create a debug build instead of a release build, that file would also contain the line: ac_add_options --enable-debug each of these ac_add_options entries needs to be on its own line. for more on configuration options, see the page configuring build options. note that if you use an moz_objdir it cannot be a sibling folder to your source directory. use an absolute path to be sure! to also build lightning whe...

The Firefox codebase: CSS Guidelines
he value and it is usually good practice to do so. in general, it's good to first think of how some css could be written cleanly without the css variable(s) and then think of how the css variable could improve that css. using variables use the variable according to its naming do this: xul|tab:hover { background-color: var(--in-content-box-background-hover); } not this: #certificateerrordebuginformation { background-color: var(--in-content-box-background-hover); } localization text direction for margins, padding and borders, use inline-start/inline-end rather than left/right. example: use margin-inline-start: 3px; instead of margin-left: 3px. for rtl-aware positioning (left/right), use inset-inline-start/inset-inline-end. for rtl-aware float layouts, float: inline-start|in...

Reviewer Checklist
custom view does animations, it's better to clean up runnables in ondetachfromwindow().] ensure all file handles and other closeable resources are closed appropriately. [fennec: when writing tests that use paintedsurface, ensure the paintedsurface is closed when you're done with it.] performance impact check for main-thread io [fennec: android may warn about this with strictmode]. remove debug logging that is not needed in production. threading issues enormous: correct use of locking and volatility; livelock and deadlock; ownership. [fennec: all view methods should be touched only on ui thread.] [fennec: activity lifecycle awareness (works with "never keep activities"). also test with oom-fennec (https://hg.mozilla.org/users/blassey_mozilla.com/oom-fennec/)]. compatibility ...

Developer guide
as you develop. mozilla modules and module ownership this article provides information about mozilla's modules, what the role of a module owner is, and how module owners are selected. code snippets useful code samples for a wide variety of things you might need to figure out how to do. mozilla development strategies tips for how to make the most of your time working on the mozilla project. debugging find helpful tips and guides for debugging mozilla code. performance performance guides and utilities to help you make your code perform well (and to play nicely with others). the mozilla platform information about the workings of the mozilla platform. mozilla much more additional information about mozilla coding practices. adding apis to the navigator object how to augment the wind...

Performance best practices for Firefox front-end engineers
feature to help you detect when and where paints are occurring. this feature is called “paint flashing,” and it can be activated for both web content and the browser chrome. paint flashing tints each region being painted with a randomly selected color so that it’s more easy to see what on the screen is being painted. you can activate paint flashing for browser chrome by setting nglayout.debug.paint_flashing_chrome to true. you can activate paint flashing for web content by setting nglayout.debug.paint_flashing to true. after enabling these, exercise your function and see what’s painting. see a lot of flashing / colors? that means a lot of painting is going on. the worst case is called over-painting. this is when you draw multiple times over the same space. unless transparency is ...

Storage access policy: Block cookies from trackers
ccess api is made, the pre-existing storage access expiration will be extended by 30 days, counting from the time the previous access was granted. please note that in the future we expect to make changes to how long storage access will remain valid for. as mentioned before, the way to know that you will be able to use storage as a third-party going forward will be using the storage access api. debugging we encourage site owners to test their sites, particularly those that rely on third-party content integrations. we’ve added several new features to firefox to make testing easier. developer tools notifications the network monitor in firefox developer tools now includes an indicator for all resource requests that have been classified as tracking resources. this indicator is shown as a shi...

Tracking Protection
se loads. sometimes users won’t notice at all, if the page grid works such that other page elements slide in to fill holes left by blocked elements. when firefox blocks content, it logs a message to the web console like this: the resource at "http://some/url" was blocked because tracking protection is enabled. note that with firefox for android, you can access console output using the remote debugger. click the ⓘ symbol in the address bar to view information about the currently loaded page. the popup that appears will notify you when content has been blocked. you will also be able to disable tracking protection entirely if you choose by accessing the tracking settings. if tracking cookies were present, you would be able to view the list by clicking on "blocking tracking cookies" in ...

Http.jsm
get, post or put (this is automatically set if postdata exists). onload a function handle to call when the load is complete, it takes two parameters: the responsetext and the xhr object. onerror a function handle to call when an error occurs, it takes three parameters: the error, the responsetext and the xhr object. logger an object that implements the debug and log methods (e.g. log.jsm). headers or post data are given as an array of arrays, for each inner array the first value is the key and the second is the value. for example: [["key1", "value1"], ["key2", "value2"]]. submitting post data httprequest allows attaching data to the post requests. the data can be specified via postdata option. postdata can be of 2 different types: a string o...

JavaScript OS.Constants
components.classes["@mozilla.org/net/osfileconstantsservice;1"]. getservice(components.interfaces.nsiosfileconstantsservice). init(); from a chrome worker no initialization is required. module os.constants is always available for chrome workers. os.constants.sys constants related to system configuration. name the name of the operating system (e.g. "darwin"). debug set to true on debug build configurations, non-existent otherwise. os.constants.path paths of well-known files and directories. libxul the path to the file containing libxul. useful, for instance, to access the platform code from javascript in conjunction with js-ctypes. profiledir the path to the current profile. homedir the path to the user's home...

Examples
sful and reason was = "' + asuccessreason + '"'); }, function(arejectreason) { alert('mypromise failed for reason = "' + uneval(arejectreason) + '"'); } ); function myuserdefinedpromise() { return 'i didnt do a promise.resolve so this will not understand that mypromise is a promise'; } // creates this error: /* exception: mypromise.then is not a function @scratchpad/5:8:1 wca_evalwithdebugger@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/actors/webconsole.js:1069:7 wca_onevaluatejs@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/actors/webconsole.js:734:9 dsc_onpacket@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/devtools/server/main.js:1098:9 ldt_send/<@resource:...

source-editor.jsm
a line annotation. sourceeditor.events.selection "selection" fired when the current selection in the editor changes. sourceeditor.events.text_changed "textchanged" fired when the editor's content changes. methods addbreakpoint adds a breakpoint to be triggered at a certain line in the code, under an optional condition. note: implementing actual support for debugger features such as breakpoints is up to you. the editor simply tracks their existence and marks them with annotations in the editor. void addbreakpoint( number alineindex, [optional] string acondition ); parameters alineindex the 0-based line number at which to place the breakpoint. acondition optional a string describing the condition under which the breakpoint should be triggere...

Release phase
onfig has the correct user set under the hg.mozilla.org host. this should be your mozilla ldap account name. next, try issuing the following command: $ ssh hg.mozilla.org if ssh is working fine, you should see the following message: no interactive shells allowed here! connection to hg.mozilla.org closed. if you don't see this message, try running the same command in a more verbose mode (with the debugging information): $ ssh -vvv hg.mozilla.org this should tell you why your connection is not succeeding. if you can't figure it out on your own, copy the output of the above command, paste it on http://pastebin.mozilla.org and ask in #l10n on the irc.mozilla.org server. technical and sign-off reviews you've done some localization work and your ready for it to be released. the merge date for migrat...

Mozilla Framework Based on Templates (MFBT)
and enforce various c++-related restrictions on inheritance and use. the class macros permit controlling the inheritability of a class. likely.h provides moz_likely and moz_unlikely macros to annotate conditions with their expected truthiness. util.h implements various other bits of useful functionality. (this header will likely be further split up so that its functionality is less grab-bag.) debugging assertions.h provides assertion macros in implementing runtime assertions and compile-time assertions. guardobjects.h provides macros which can be used to annotate an raii-style guard class, so that any attempt to create an unnamed temporary for it will assert. (an unnamed temporary lives for a shorter period of time than the scope where it's found, so it usually isn't what was desired.) d...

Mozilla DOM Hacking Guide
o its helper class and to the interfaces that are exposed to javascript. it is an array of type nsdomclassinfodata, which is a structure defined in nsidomclassinfo.h. the array uses two macros to define its items: ns_define_classinfo_data and ns_define_classinfo_data_with_name. the first one calls the second one. the first argument passed to ns_define_classinfo_data_with_name, _class, is used for debug purposes. the second argument, _name, is the name that should appear in javascript. the third argument, _helper, is the name of the helper class for this dom class. helper classes are detailed in section 1.3. the fourth and last argument, _flags, is a bitvector of nsixpcscriptable flags. the macros for those flags are defined nsdomclassinfo.cpp. the flags give special behavior through xpconnect. ...

Mozilla projects on GitHub
ich helps you figure out how you can contribute to mozilla. bugsahoy a web page to help new mozilla contributors identify bugs to fix. bugzilla-dashboard a convenient dashboard to help you get an overview of your bugs. codefirefox the codefirefox site, with videos and tutorials about how to contribute to the firefox project and mozilla code in general. debugger.html the debugger.html, a modern universal js debugger for firefox devtools, node, and every other js environment. dxr an intelligent tool for browsing source code. emscripten the emscripten llvm-to-javascript compiler. fxdt-adapters the firefox developer tools adapter that lets you debug various remote targets from the firefox developer tools. f...

GPU performance
nvidia perfhud - last i checked required a special build to be used. nvidia parallel nsight - haven't tried. amd gpu shaderanalyzer - will compile a shader and show the machine code and give static pipeline estimations. not that useful for firefox because all of our shaders are pretty simple. ...

Gecko Profiler FAQ
the said leaks have happened capture the profiles and study what went wrong. [ehsan] i have been profiling my real browser usage for months now, and so can you. :-) however, if it’s really just “leaks” that are the problem, it’s possible that those profiles only show you that we spend a lot of time in gc / cc. in that case, the gecko profiler is the wrong tool to debug this. even about:memory would be more useful. overview of the changes in the last (year?) to cleopatra/etc faster, hopefully more reliable has a timeline tab lets you hide threads with a context menu supports symbolication for local builds on windows if you run “mach buildsymbols” first profiling non-nsthreads? ...

Profiling with Xperf
for more information microsoft's documentation for xperf is pretty good; there is a lot of depth to this tool, and you should look there for more details. ...

Profiling with the Gecko Profiler and Local Symbols on Windows
ou want proper c++ callstacks in your profiles, add ac_add_options --enable-profiling to your firefox .mozconfig file. you don't need to do this if you're building nightly, because --enable-profiling is the default on nightly. build firefox as usual, e.g. using ./mach build. generate the breakpad symbol files by running ./mach buildsymbols: https://developer.mozilla.org/en/building_firefox_with_debug_symbols#breakpad_symbol_files this will have created symbols under $objdir/dist/ , named after the binary name, architecture and version, so something like "firefox-40.0a1.en-us-win32.crashreporter-symbols.zip" point talos to this zipfile by passing its path to the --symbolspath flag. ...

javascript.options.showInConsole
the preference javascript.options.showinconsole controls whether errors or warnings in chrome code are shown in the error console. type:boolean default value: false (true in debug builds) exists by default: yes application support:firefox 1.0 status: active introduction:2002-02-26 bugs: bug 125181 bug 337875 values false only errors and warnings from content code are shown. true (default) errors and warnings from both chrome and content are shown in the error console. note: since the web console was introduced in firefox 4 specifically for debugging content, the default value for this preference has changed to true as of gecko 2.0. ...

Preference reference
ipt.options.showinconsolethe preference javascript.options.showinconsole controls whether errors or warnings in chrome code are shown in the error console.javascript.options.stricttechnical review completed.mail.tabs.drawintitlebarstarting in thunderbird 17.0, the tabs are drawn in the title bar. the old behavior can be restored by setting the preference mail.tabs.drawintitlebar to false.nglayout.debug.disable xul fastloadthe preference nglayout.debug.disable_xul_fastload controls whether or not xul fastload is used.nglayout.debug.disable_xul_cacheto improve performance, mozilla caches chrome xul documents the first time they load for faster loading later. the effect is that the source xml file is not read and re-parsed each time the chrome in question is displayed. the xul cache is serialized ...

Crash reporting
set of mozilla employees have access to directly query the underlying data in either sql summary or using mapreduce on the storage cluster. ...

Emscripten techniques
this page contains specific emscripten-related techniques. debugging out-of-memory problems a common bug to diagnose with emscripten is where a big game fails due to an out of memory error (oom) somewhere during load time. by the time about:memory is loaded in a new tab and you have clicked the "measure" button to diagnose what's happened, the memory usage causing the spike has gone away, making temporary memory spikes difficult to diagnose. this article explains how to debug such problems. ...

Firefox Sync
nd) and has a blog where he talks about the various challenges syncing this kind of data. servers documentation for the various servers, including information on how to host your own. android searchfox has links to the main sync code and the storage layer. there are also some notes in a google document (that we really must move to its own wiki page) there's also information available to help debug and diagnose android sync issues. ios there is some in-tree documentation and there are some extensive comments here and here. desktop notes on how to file a good bug for desktop sync. there are some notes on how to run our tps testing infrastructure. we have a google document on how bookmark repair works. ...

Leak And Bloat Tests
rlk reference count leaks mail lk total bytes malloc'ed and not free'd mail mh maximum heap size mail a allocations - number of calls to malloc and friends. there are currently no graphs for these results. manually running tests setting up build set up build thunderbird or seamonkey with your standard mozconfig file, but with the following options set: ac_add_options --enable-debug ac_add_options --enable-trace-malloc running the tests in your <objdir> run the following command: make mailbloat this will run the tests and produce some result files. see debugging memory leaks for more information on what to do with this data. todo: add more information on processing output. code locations the files specific to leak and bloat testing are be stored in: http://mxr.mozilla.org/...

Nonblocking IO In NSPR
viously used in a <tt>pr_transmitfile()</tt> call. since <tt>pr_transmitfile()</tt> only operates in blocking mode, this recycled socket can only be reused in blocking mode, hence the above constraint. because these constraints only apply to nt, it is advised that you test your cross-platform code that uses nonblocking io on nt early in the development cycle. these constraints are enforced in the debug nspr library by assertions. differences from blocking io in nonblocking mode, the timeout argument for the io functions is ignored. <tt>pr_acceptread()</tt> and <tt>pr_transmitfile()</tt> only work on blocking sockets. they do not make sense in nonblocking mode. <tt>pr_write()</tt>, <tt>pr_send()</tt>, <tt>pr_writev()</tt> in blocking mode block until the entire buffer is sent. in nonblocki...

NSPR LOG FILE
pecify a log file other than the default. if nspr_log_file is not in the environment, then log output is written to stdout or stderr, depending on the platform. set nspr_log_file to the name of the log file you want to use. nspr logging, when enabled, writes to the file named in this environment variable. for ms windows systems, you can set nspr_log_file to the special (case-sensitive) value windebug. this value causes logging output to be written using the windows function outputdebugstring(), which writes to the debugger window. ...

NSPR LOG MODULES
me:level[, modulename:level]* modulename is the name specified in a pr_newlogmodule call or one of the handy magic names listed below. level is a numeric value between 0 and 5, with the values having the following meanings: 0 = pr_log_none: nothing should be logged 1 = pr_log_always: important; intended to always be logged 2 = pr_log_error: errors 3 = pr_log_warning: warnings 4 = pr_log_debug: debug messages, notices 5: everything! description specify a modulename that is associated with the name argument in a call to pr_newlogmodule and a non-zero level value to enable logging for the named modulename. special log module names are provided for controlling nspr's log service at execution time. these controls should be set in the nspr_log_modules environment variable at execution...

PR_Abort
aborts the process in a nongraceful manner. syntax #include <prinit.h> void pr_abort(void); description pr_abort results in a core file and a call to the debugger or equivalent, in addition to causing the entire process to stop. ...

PR_LOG
yntax #include <prlog.h> void pr_log ( prlogmoduleinfo *_module, prlogmodulelevel _level ... _args); parameters the macro has these parameters: _module a pointer to a log module structure. _level a level value. possible values are: pr_log_none = 0 pr_log_always = 1 pr_log_error = 2 pr_log_warning = 3 pr_log_debug = 4 pr_log_notice = pr_log_debug pr_log_warn = pr_log_warning pr_log_min = pr_log_debug pr_log_max = pr_log_debug _args a variable length argument list, as if to printf. returns nothing description this macro formats the specified arguments and writes the output to the log file, if logging is enabled for the specified module and level.

PR_LOG_TEST
syntax #include <prlog.h> prbool pr_log_test ( prlogmoduleinfo *_module, prlogmodulelevel _level); parameters the macro has these parameters: _module a pointer to a log module structure. _level a level value. possible values are: pr_log_none = 0 pr_log_always = 1 pr_log_error = 2 pr_log_warning = 3 pr_log_debug = 4 pr_log_notice = pr_log_debug pr_log_warn = pr_log_warning pr_log_min = pr_log_debug pr_log_max = pr_log_debug returns pr_true when logging is enabled for the given module and level, otherwise pr_false. description this macro tests whether logging is enabled for the specified module and level. use it as an expression in a conditional execution stat...

NSPR
t-get. debian: install the libnspr4-dev package via apt-get. opensuse linux: install one or more of the following via yast or zypper : mozilla-nspr : binary libraries for your platform mozilla-nspr-32bit : binary libraries needed to run 32-bit programs on a 64-bit os mozilla-nspr-devel : files needed (in addition to the above libraries) to compile programs using nspr mozilla-nspr-debuginfo : debug information (including build symbols) for package mozilla-nspr mozilla-nspr-debuginfo-32bit : debug information (including build symbols) for package mozilla-nspr-32bit mozilla-nspr-debugsource : debug sources for all of the above community view mozilla forums... mailing list newsgroup rss feed related topics necko, nss ...

Building NSS
ke alternatively, there is a make target called "nss_build_all", which produces a similar result. this supports some alternative options, but can be a lot slower. make -c nss nss_build_all use_64=1 the make-based build system for nss uses a variety of variables to control the build. below are some of the variables, along with possible values they may be set to. build_opt 0 build a debug (non-optimized) version of nss. this is the default. 1 build an optimized (non-debug) version of nss. use_64 0 build for a 32-bit environment/abi. this is the default. 1 build for a 64-bit environment/abi. this is recommended. use_asan 0 do not create an addresssanitizer build. this is the default. 1 create an addresssanitizer build. unit testing nss c...

NSS_3.11.10_release_notes.html
res nspr 4.7.1. see the documentation section for the build instructions. nss 3.11.10 source and binary distributions are also available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_11_10_rtm/src/. binary distributions: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_11_10_rtm/. both debug and optimized builds are provided. go to the subdirectory for your platform, dbg (debug) or opt (optimized), to get the tar.gz or zip file. the tar.gz or zip file expands to an nss-3.11.10 directory containing three subdirectories: include - nss header files lib - nss shared libraries bin - nss tools and test programs you also need to download the nspr 4.7.1 binary distribut...

NSS 3.35 release notes
on this fedora linux project page: https://fedoraproject.org/wiki/changes/nssdefaultfileformatsql added formally verified implementations of non-vectorized chacha20 and non-vectorized poly1305 64-bit. for stronger security, when creating encrypted pkcs#7 or pkcs#12 data, the iteration count for the password based encryption algorithm has been increased to one million iterations. note that debug builds will use a lower count, for better performance in test environments. as a reminder, debug builds should not be used for production purposes. nss 3.30 had introduced a regression, preventing nss from reading some aes encrypted data, produced by older versions of nss. nss 3.35 fixes this regression and restores the ability to read affected data. the following ca certificates were removed: ...

NSS 3.46 release notes
hangs on windows x64 when building nss since changeset 9162c654d06915f0f15948fbf67d4103a229226f bug 1564875 - improve rebuilding with build.sh bug 1565243 - support tc_owner without email address in nss taskgraph bug 1563778 - increase maxruntime on mac taskcluster tools, ssl tests bug 1561591 - remove -wmaybe-uninitialized warni...

NSS 3.47 release notes
267894 - allow per-socket run-time ordering of the cipher suites presented in clienthello bug 1570501 - add cmac to freebl and pkcs #11 libraries bugs fixed in nss 3.47 bug 1459141 - make softoken cbc padding removal constant time bug 1589120 - more cbc padding tests bug 1465613 - add ability to distrust certificates issued after a certain date for a specified root cert bug 1588557 - bad debug statement in tls13con.c bug 1579060 - mozilla::pkix tag definitions for issueruniqueid and subjectuniqueid shouldn't have the constructed bit set bug 1583068 - nss 3.47 should pick up fix from bug 1575821 (nspr 4.23) bug 1152625 - support aes hw acceleration on armv8 bug 1549225 - disable dsa signature schemes for tls 1.3 bug 1586947 - pk11_importandreturnprivatekey does not store nickname f...

NSS 3.52 release notes
ore information. bug 1623374 - support new pkcs #11 v3.0 message interface for aes-gcm and chachapoly. bug 1612493 - integrate avx2 chacha20, poly1305, and chacha20poly1305 from hacl*. bugs fixed in nss 3.52 bug 1633498 - fix unused variable 'getauxval' error on ios compilation. bug 1630721 - add softoken functions for fips. bug 1630458 - fix problem of gyp msvc builds not producing debug symbol files. bug 1629663 - add ikev1 quick mode kdf. bug 1629661 - mpconfig calls in ssl initialize policy before nss is initialized. bug 1629655 - support temporary session objects in ckfw. bug 1629105 - add pkcs11 v3.0 functions to module debug logger. bug 1626751 - fix error in generation of fuzz32 docker image after updates. bug 1625133 - fix implicit declaration of function 'getopt' e...

NSS Tools sslstrength
the letter in the first column of the output is used to identify the cipher preferences in the ciphers= command. the second form attempts to connect to the named ssl host. the hostname argument must be present. ...

Overview of NSS
nss software crypto module has been validated three times for conformance to fips 140 at security levels 1 and 2. for more information, see the nss fips page (or this one). the nss libraries passed the niscc tls/ssl and s/mime test suites (1.6 million test cases of invalid input data). complete software development kit in addition to libraries and apis, nss provides security tools required for debugging, diagnostics, certificate and key management, cryptography module management, and other development tasks. nss comes with an extensive and growing set of documentation, including introductory material, api references, man pages for command-line tools, and sample code. nss is available as source and shared (dynamic) libraries. every nss release is backward compatible with previous releases, ...

Sample manual installation
with "gmake nss_build_all", the resulting build can be found in the nss source tree as follows: nss header files: mozilla/dist/public/nss nspr header files: mozilla/dist/<obj-dir>/include nspr/nss shared libs: mozilla/dist/<obj-dir>/lib nss binary executables: mozilla/dist/<obj-dir>/bin. where <obj-dir> would vary according to the type of build and the platform. for example, <obj-dir> for a debug build of nss on the x86 platform with a linux kernel version 2.6 with glibc would be: linux2.6_x86_glibc_pth_dbg.obj from these directories, you can copy the files to any system (or other) directory. if the destination directories are not what's standard for the system (e.g. /usr/include, /usr/lib and /usr/bin for a linux system), you need to edit the corresponding environment variables or compil...

NSS tools : pk12util
icate and key databases. this option is provided as a special case. changing the names of the certificate and key databases is not recommended. -r dumps all of the data in raw (binary) form. this must be saved as a der file. the default is to return information in a pretty-print ascii format, which displays the information about the certificates and public keys in the p12 file. -v enable debug logging when importing. -w p12filepasswordfile specify the text file containing the pkcs #12 file password. -w p12filepassword specify the pkcs #12 file password. return codes o 0 - no error o 1 - user cancelled o 2 - usage error o 6 - nls init error o 8 - certificate db open error o 9 - key db open error o 10 - file initialization error o 11 - unicode conversion error o 12 - tempor...

NSS troubleshooting
on this page, let's collect information on how to troubleshoot nss at runtime. debugging tips, how to enable tracing of the various modules, etc. list of environment variables ...

NSS Tools pk12util
onment), or to ./.netscape (when $home does not exist in the environment). -p prefix specify the prefix used on the cert8.db and key3.db files (for example, my_cert8.db and my_key3.db). this option is provided as a special case. changing the names of the certificate and key databases is not recommended. ...

NSS Tools sslstrength
the letter in the first column of the output is used to identify the cipher preferences in the ciphers= command. the second form attempts to connect to the named ssl host. the hostname argument must be present. ...

NSS tools : pk12util
the given databases are in the old format. -p prefix specify the prefix used on the certificate and key databases. this option is provided as a special case. changing the names of the certificate and key databases is not recommended. -h tokenname specify the name of the token to import into or export from. -v enable debug logging when importing. -k slotpasswordfile specify the text file containing the slot's password. -k slotpassword specify the slot's password. -w p12filepasswordfile specify the text file containing the pkcs #12 file password. -w p12filepassword specify the pkcs #12 file password. -c keycipher specify the key encrypti...

NSS tools : signtool
n your database. an asterisk appears to the left of the nickname for any certificate that can be used to sign objects with signtool. --leavearc retains the temporary .arc (archive) directories that the -j option creates. these directories are automatically erased by default. retaining the temporary directories can be an aid to debugging. -m metafile specifies the name of a metadata control file. metadata is signed information attached either to the jar archive itself or to files within the archive. this metadata can be any ascii string, but is used mainly for specifying an installer script. the metadata file contains one entry per line, each with three fields: field...

Network Security Services
tures and supplementary documentation for advanced topics in programming with nss. tools, testing, and other technical details build instructions for nss describe how to check out and build nss releases. nss developer tutorial how to make changes in nss. coding style, maintaining abi compatibility. nss tools tools for developing, debugging, and managing applications that use nss. sample code demonstrates how nss can be used for cryptographic operations, certificate handling, ssl, etc. third-party code a list of third-party code included in the nss library. nss 3.2 test suite archived version. describes how to run the standard nss tests. nss performance reports archived version. links to p...

Installing Pork
see the mcpp manual. in particular, -k tells mcpp to add the macro annotations we use to get exact source positions. c++ files from other projects can be preproce...

Renaming With Pork
r and merges their output. one can also run the ./renamer command directly on the .ii files. 5. apply the patch in the test sources. ...

Rhino documentation
ino releases optimization details on the various optimization levels. faq answers to frequently asked questions about rhino. rhino history history of the beast. writing scripts scripting java how to use rhino to script java classes. performance hints some tips on writing faster javascript code. javascript tools rhino shell interactive or batch execution of scripts. javascript debugger debugging scripts running in rhino. javascript compiler compiling scripts into java class files. running the rhino tests running the javascript test suite with rhino. embedding rhino embedding tutorial a short tutorial on how to embed rhino into your application. api javadoc reference (link broken? try this at jarvana.) an annotated outline of the programming interface to rhino (...

Rhino overview
ipts to their html web pages. however, rhino is an implementation of the core language only and doesn't contain objects or methods for manipulating html documents. rhino contains all the features of javascript 1.7 allows direct scripting of java a javascript shell for executing javascript scripts a javascript compiler to transform javascript source files into java class files a javascript debugger for scripts executed with rhino language the javascript language itself is standardized by standard ecma-262 ecmascript: a general purpose, cross-platform programming language. rhino 1.3 and greater conform to edition 3 of the standard. rhino 1.6 and greater implement ecma-357 ecmascript for xml (e4x). see the specification for more information on the standard, and rhino version 1.6r1 rele...

Rhino scopes and contexts
may not be suitable with shared scopes since if a script by mistake adds a property to a library object from the shared scope, that object would not be garbage collected until there are no active references to the shared scope potentially leading to memory leaks. in addition if a script alters some of the standard objects, the library may not work properly for other scripts. such bugs are hard to debug and to remove a possibility for them to occur one can seal the shared scope and all its objects. a notion of a sealed object is a javascript extension supported by rhino and it means that properties can not be added/deleted to the object and the existing object properties can not be changed. any attempt to modify sealed object throws an exception. to seal all objects in the standard library pass...

How to embed the JavaScript engine
return 1; } jsstring *str = rval.tostring(); printf("%s\n", js_encodestring(cx, str)); } js_destroycontext(cx); js_shutdown(); return 0; } build and run the hello world example build command line depends on the os and the tools. here are sample mac and linux command lines (where <objdir> is the directory where spidermonkey was built): # if you're using debug build of spidermonkey, you need -ddebug in addition to the command below. # if you're using version other than spidermonkey 31, please change -lmozjs-xx to your version. [mac] clang++ -std=c++11 -i<objdir>/dist/include -l<objdir>/dist/lib helloworld.cpp -o helloworld -lmozjs-31 -lz [linux] g++ -std=c++11 -i<objdir>/dist/include -l<objdir>/dist/lib helloworld.cpp -o helloworld -lmozjs-31 -lz -l...

Self-hosted builtins in SpiderMonkey
ctionspec array using the js_self_hosted_fn macro. example: js_self_hosted_fn("foreach", "arrayforeach", 1,0) this causes the self-hosted function arrayforeach to be installed as the host object's method foreach. making jsnatives available to self-hosted code for a jsnative to be available to self-hosted code, add it to the intrinsic_functions jsfunctionspec array in selfhosting.cpp. debugging self-hosted code self-hosted code by default is hidden from client javascript code; in particular, self-hosted frames will be filtered out of the stack traces of exceptions. to include self-hosted frames in stack traces (in debug builds only), set the environment variable moz_show_all_js_frames. ...

JIT Optimization Outcomes
level of recursion is inlinable. cantinlineheavyweight unable to inline function call. the interpreted callee function contains variables bindings that are closed over. for example, function f() { var x; return function () { x++; } } closes over x in f. cantinlineneedsargsobj unable to inline function call. the interpreted callee function requires an arguments object to be created. cantinlinedebuggee unable to inline function call. the interpreted callee function is being debugged by the debugger api. cantinlineunknownprops unable to inline function call. the engine knows nothing definite about the type of the callee function object. cantinlineunreachable unable to inline function call. the call site has not been observed to have ever been executed. it lacks observed type information ...

JS::CallArgs
s an object, otherwise calls js_computethis and returns it. bool isconstructing() const returns true if the function is called via new. mutablehandlevalue rval() const returns the currently-set return value. the initial contents of this value are unspecified. once this method has been called, callee() and calleev() can no longer be used. (if you're compiling against a debug build of spidermonkey, these methods will assert to aid debugging.) if the method you're implementing succeeds by returning true, you *must* set this. (spidermonkey doesn't currently assert this, but it will do so eventually.) you don't need to use or change this if your method fails. description js::callargs is helper class encapsulating access to the callee, this value, argumen...

JS::CompileOptions
assed to setinterval as a string. the following are used in js shell: "js shell file" "js shell interactive" "js shell load" "js shell evaluate" "js shell run" "js shell disfile" "js shell compfile" "js shell parse" "js shell syntaxparse" "js shell offthreadcompilescript" and the following are used in self-hosted code and debugger: "self-hosted" "debugger eval" introductionlineno unsigned line number in the source code which introduces this source code. introductionoffset uint32_t bytecode offset in the code which introduces this source code. hasintroductioninfo bool true if setintroductioninfo is called. description in the most common use cas...

JS::Value
t() when val.isnull(). the now-deprecated jsval methods allowed jsval_to_object(val) when jsval_is_null(val), but this was a source of constant bugs. val.toobject() is only permitted when val.isobject(). an assertion is thrown in the case that the type is not correct (val.isx() is called for each val.tox(), where x is the type). it is highly recommended that you develop and test with an --enable-debug build to detect most js::value misuse. debug builds will assert correct jsapi use in many other instances as well. js::value is subject to garbage collection a js::value can refer to a string or object located in spidermonkey's garbage-collected heap. the garbage collector is designed to automatically free unreachable memory. it is rather eager about its job. it's like a robot that goes around...

JSFastNative
d to the caller. on success, the callback must call js_set_rval (at least once) and return js_true. on error or exception, it must return js_false. to create a jsfunctionspec that points to a jsfastnative, use js_fn. when a jsfastnative is called, no jsstackframe is generated. this is what makes a fast native fast. however, it causes the function not to appear on the stack in javascript debuggers. it also means that applications that use spidermonkey's security features, particularly those that implement jscheckaccessop or jscheckaccessidop in terms of apis such as js_frameiterator and js_stackframeprincipals, must take extra care, as the native function's principals will be missing from the stack. see also jsnative ...

JSNative
js_setpendingexception), and the callback must return false. (returning false without reporting an error or raising an exception terminates the script with an uncatchable error. this has limited use cases; it's used to implement firefox's "slow script" dialog, for example.) when a jsnative is called, no jsstackframe is generated. this causes the function not to appear on the stack in javascript debuggers. it also means that applications that implement jscheckaccessop or jscheckaccessidop in terms of apis such as js_frameiterator and js_stackframeprincipals, must take extra care, as the native function's principals will be missing from the stack. see also mxr id search for jsnative js::callargs js_reporterror js_reportoutofmemory js_setpendingexception ...

JSObjectOps.defaultValue
callback to implement customized [[defaultvalue]] behavior. the jsclass.convert callback should convert obj to the given type, returning js_true with the resulting value in *vp on success, and returning js_false on error or exception. on success, *vp must be a primitive value: per es5 §8.12.8, every object "must ensure that its [[defaultvalue]] internal method can return only primitive values." debug builds of spidermonkey will assert if a convert callback is successful but leaves *vp holding a primitive value. js_convertstub implements the default behavior for the jsclass.convert hook, which is to call obj.valueof() and obj.tostring() in accordance with the algorithm in es5 §8.12.8. ...

JSObjectPrincipalsFinder
callback, passing the watchpoint handler, to ensure that watchpoint handlers are invoked only when the watcher is permitted to watch the currently executing script. another example: when the function constructor is called, the javascript engine calls the object principals finder callback to obtain principals for the local scope object, to check that the caller has access to that object. the two debugger functions js_stackframeprincipals and js_evalframeprincipals also use this callback. since it is very common for jsobjectops.checkaccess or jsclass.checkaccess hooks to call these functions, the object principals finder callback is a key security feature. the callback returns a pointer to the principals associated with obj, possibly via the immutable parent chain leading from obj to a top-lev...

JS_BeginRequest
s_threadsafe build, many jsapi functions must only be called from within a request. in this reference, the cx parameter of such functions is documented with the phrase “requires request”, like this: name type description cx jscontext * the context to use. requires request. in a js_threadsafe build, the caller must be in a request on this jscontext. in a debug build, this is enforced with assertions. requests constrain garbage collection. if any thread is in a requests, garbage collection can happen only when that thread calls into the jsapi. if one thread needs garbage collection, it blocks until each other thread makes a jsapi call. it is therefore imperative that native code executing within an active request on cx not block, or simply take too lon...

JS_DumpHeap
dump the object graph of heap-allocated things. ...

JS_FlattenString
str jsstring * the string to flatten. description js_flattenstring flattens a string str and returns a pointer to jsflatstring. to catch errors, an opaque jsflatstring type is returned. note: the input and output of js_flattenstring() are the same actual gc-thing so only one needs to be rooted. if a jsstring is known to be flat, you can use js_assert_string_is_flat to make a debug-checked cast. example: // in a fallible situation jsflatstring *fstr = js_flattenstring(cx, str); if (!fstr) return false; js_assert(fstr == js_assert_string_is_flat(str)); // in an infallible situation, for the same 'str' const jschar *chars = js_getflatstringchars(fstr) js_assert(chars); see also mxr id search for js_flattenstring js_assert_string_is_flat js_forget_string_flatness bu...

JS_NewContext
it returns a pointer to the new context. otherwise it returns null. for more details about contexts, see jscontext. for sample code that creates and initializes a jscontext, see jsapi user guide. the stackchunksize parameter does not control the javascript stack size. (the jsapi does not provide a way to adjust the stack depth limit.) passing a large number for stackchunksize is a mistake. in a debug build, large chunk sizes can degrade performance dramatically. the usual value of 8192 is recommended. the application must call js_destroycontext when it is done using the context. before a jsruntime may be destroyed, all the jscontexts associated with it must be destroyed. the new jscontext initially has no global object. the new jscontext is associated with the calling thread. no other thr...

JS_NewObjectForConstructor
gs js::callargs &amp; call argument to get a constructor as callee. added in spidermonkey 38 description js_newobjectforconstructor creates a new object exactly as the given constructor would if invoked with new. this function does not run the code of the constructor function--it just creates the object. if the constructor argument is not an object jsval, this function will assert (in debug builds). if the constructor does not have a prototype property, this function will return null and set an exception on cx. the standard object creation api, js_newobject, takes explicit arguments for the class, prototype, and parent of the new object. with js_newobjectforconstructor, the prototype and parent are determined by the constructor, and class is still determined by the caller. the proto...

JS_SetContextCallback
stance. the callback can initialize the instance as required. if the callback returns js_false, the instance will be destroyed and js_newcontext returns null. in this case the callback is not called again. jscontext_destroy one of js_destroycontext, js_destroycontextnogc, or js_destroycontextmaybegc was called. the callback may perform its own cleanup and must always return true. in a debug build, if the callback returns false, the js engine will halt with an assertion. description js_setcontextcallback specifies a callback function that is automatically called when jscontexts are created or destroyed. only one callback function may be specified per js runtime. this function returns the previous context callback, if any, else null. see also mxr id search for js_setcontextcal...

JS_SetFunctionCallback
he callback must not modify the current state of execution. the call stack cannot be relied upon, because this callback may be invoked from the jit code when the stack frame and context are in an indeterminate state. description js_setfunctioncallback sets a c function to be called each time a javascript function is invoked or exits. fcb is a pointer to the c function to call. ...

JS_THREADSAFE
k, sent to another process or even another machine, or just passed to another thread. then use js_readstructuredclone on the other side to turn the serialized data back into javascript objects, strings, and so on. sharing native functions and private data among threads in a js_threadsafe build, spidermonkey's internal data structures that represent javascript values are single-thread-only. in a debug build, this is enforced with assertions. however, spidermonkey does not protect the application's data structures. jsnatives and other callback functions can be called concurrently by multiple threads. multiple threads can end up accessing private data or c/c++ global variables at the same time. it is up to the application to practice safe threading. sharing contexts among threads ordinarily, ...

JS_TracerInit
name type description trc jstracer * the tracer visiting obj. thing void * a gc thing. kind uint32 one of the constants jstrace_object, jstrace_double, jstrace_string; or a tag denoting an internal implementation-specific traversal kind. in the latter case, the only operations the callback may perform on thing are to call js_tracechildren or the debug-only js_printtracethinginfo function. description js_tracechildren and other tracing apis call the tracer callback for each traceable thing directly referenced by a particular object or runtime structure. it is the callback's responsibility to ensure the traversal of the full object graph, if desired, by eventually calling js_tracechildren on the passed thing. in this case the callback must...

Profiling SpiderMonkey
instructions 1.) get yourself an optimized libxul build of firefox, with debugger info. for the mac, you'll want to read up on profiling javascript with shark. here's a sample mozconfig: mk_add_options moz_objdir=@topsrcdir@/ff-opt-libxul mk_add_options moz_make_flags=-j3 ac_add_options --enable-optimize ac_add_options --enable-libxul ac_add_options --enable-shark ac_add_options --enable-debugger-info-modules ac_add_options --enable-application=browser 2.) you'll want to run shark on both the browser and [xpcshell], since the host environments differ. here are some instrumented tests to work from: media:profiling-ammo.zip 3.) once you have some changes you'd like to try, you can just rebuild the js/src directory, since it produces its own shared library, even in libxul and static build...

SpiderMonkey 1.8.5
ball should be copied to wes@page.ca. spidermonkey embedders should also be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. the team is considering the removal of tinyids js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! jsxdrapi changes were missed jsstrictpropertyop for setters (affects jsclass) - maybe general notes about es5 strict mode changes in jsapi tricks like argv[-2] not guaranteed to work any more; is js_cal...

SpiderMonkey 1.8.7
ball should be copied to wes@page.ca. spidermonkey embedders should also be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. the team is considering the removal of tinyids js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! jsxdrapi changes were missed jsstrictpropertyop for setters (affects jsclass) - maybe general notes about es5 strict mode changes in jsapi tricks like argv[-2] not guaranteed to work any more; is js_cal...

SpiderMonkey 1.8.8
imental-library-versioning-scheme-here spidermonkey embedders should also be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. the team is considering the removal of tinyids js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! don't add anything here -- this is for after the release notes are completed. :-) ...

SpiderMonkey 1.8
egardless of whether they use threads. there are two new jsextendedclass hooks, jsextendedclass.iteratorobject and jsextendedclass.wrappedobject. both are documented but obscure. many new memory management features have been added as well. the new function js_setscriptstackquota limits the size of the javascript stack. two new functions, js_setgczeal and js_dumpheap, aim to help developers debug gc-related problems. these functions are only present in debug builds. js_setgczeal is especially helpful. when gc zeal is enabled, gc happens extremely frequently. this makes gc-related problems easier to reproduce, reveals gc problems that you may not have noticed before, and causes gc-safety bugs to surface much closer to their cause. js_dumpheap dumps parts of the gc heap and can help detect ...

SpiderMonkey 17
imental-library-versioning-scheme-here spidermonkey embedders should also be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. the team is considering the removal of tinyids js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. in the future every api is going to take handles instead of raw pointers. exact stack rooting is requirement for a (moving) generational garbage collector. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! don't add anything here -- this is for after th...

SpiderMonkey 24
ion ...insert details on future plans... spidermonkey embedders should be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. the team is considering the removal of tinyids js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! don't add anything here -- this is for after the release notes are completed. :-) ...

SpiderMonkey 31
detail any known issues here... future direction ...insert details on future plans... spidermonkey embedders should be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! don't add anything here -- this is for after the release notes are completed. :-) ...

SpiderMonkey 38
detail any known issues here... future direction ...insert details on future plans... spidermonkey embedders should be aware that mozilla has no plans to keep the jsapi, nor the jsdbgapi, stable for embedders. we have chosen to concentrate on performance and correctness as primary concerns instead. js_threadsafe is going away, with future versions supporting only thread-safe builds a new debugging api is on the way to replace jsd. release notes errata this is a list of changes which need to be made to the release notes asap. feel free to fix any problems you spot -- this is a wiki! don't add anything here -- this is for after the release notes are completed. :-) ...

Running Automated JavaScript Tests
run with the -h option to see all the options. the jstests test suite also includes some tests from web-platform-tests. by default, these are only run when no tests paths are specified; this can be overridden by the --wpt=enabled flag. running jstest in a browser jstests also runs on browser, with the following command: ./mach jstestbrowser to run specific test...

SavedFrame
savedframe a savedframe instance is a singly linked list of stack frames. it represents a javascript call stack at a past moment of execution. younger frames hold a reference to the frames that invoked them. the older tails are shared across many younger frames. savedframe stacks should generally be captured, allocated, and live within the compartment that is being observed or debugged. usually this is a content compartment. capturing savedframe stacks from c++ use js::capturecurrentstack declared in jsapi.h. from js use savestack, accessible via components.utils.getjstestingfunction(). including and excluding chrome frames consider the following savedframe stack. arrows represent links from child to parent frame, content.js is from a compartment with content principals, and chrome.js i...

SpiderMonkey: The Mozilla JavaScript runtime
ng on spidermonkey new to spidermonkey a guide to hacking on spidermonkey. setting up cdt to work on spidermonkey how to configure eclipse to work on the spidermonkey code. running automated javascript tests how to run the javascript test suites. creating javascript tests how to add tests to the javascript test suites. reference jsapi reference spidermonkey api reference. js debugger api reference api reference for the debugger object introduced in spidermonkey 1.8.6, which corresponds to gecko 8.0 (firefox 8.0 / thunderbird 8.0 / seamonkey 2.5). bytecode descriptions listing of spidermonkey's bytecodes. parser api reflection of the spidermonkey parser, made available as a javascript api. tips, tricks and philosophy future directions future directions for functi...

Mozilla Projects
d most other behaviors that occurred while recording. webreplayroadmap this document describes existing, planned, and potential features for the firefox developer tools that are based on web replay, along with their ui. the low level, yet flexible architecture (described here) provides an extremely powerful platform for implementing debugging and analysis features. we would like to use web replay to radically improve not just the debugging experience but the entire web development experience. to that end, this document will be revised over time as we find new and better ways of helping developers. zest zest is an experimental specialized scripting language (also known as a doma...

Using RAII classes in Mozilla
ect_notifier_init is added as a statement in the constructor. moz_decl_use_guard_object_notifier is added where private members should be declared. however, there are some variations for special cases: first, if the constructor (otherwise) takes no arguments, then you have to use the moz_guard_object_notifier_only_param macro instead. ...

Signing Mozilla apps for Mac OS X
on and would like to be signed for secure launching on os 10.8 mountain lion and later, this guide should provide some insight into how to make sure applications are signed correctly using apple's codesign tool. apple's code signing guide is also a good resource on the subject. getting a signing certificate in order to code-sign an application, you need a signing certificate. while testing and debugging for test and debug purposes, the easiest way to get a signing certificate is to use apple's keychain feature to create one. there are good instructions available under "to use the certificate assistant to create a self-signed signing identity". for release creating a developer id requires a paid apple developer account. once you have that you can do the following to create your id: open...

XPCOM glue
zilla 1.7 or earlier, you must define mozilla_strict_api when using any form of the glue. linux and mac: make sure the gecko libraries are listed after your object (.o) files on the link line. linux and mac: write the linker options exactly as stated (just replacing the /path/to/sdk/), otherwise you get an undefined symbol: ...ns_tabledrivenqi...qitableentry... at runtime (not compile time) (in debug builds) or your module just won't load (in optimized builds). in principle, #include "mozilla-config.h" should also work, if it's the first #include in .cpp, but preprocessor option is how it's usually included. for xulrunner 2.0, you also need to link against mozalloc. this is not a backwards-compatible change with 1.9.x and earlier. on linux and mac, add "-lmozalloc" exactly after "-lnspr4...

Avoiding leaks in JavaScript XPCOM components
...

Using XPCOM Utilities to Make Things Easier
macros the general case is to use ns_impl_nsgetmodule, which doesn't take any callbacks, but all the macros follow the same general pattern. all of these macros work on an array of structures represented by the components parameter. each structure describes a cid that is to be registered with xpcom. the first parameter for each of these macros is an arbitrary string that names the module. in a debugging environment, this string will be printed to the screen when the component library is loaded or unloaded. you should pick a name that makes sense and helps you keep track of things. the four required parts[other-parts] of the structure contain the following information: a human readable class name the class id (cid) the contract id (an optional but recommended argument) a constructor for...

How To Pass an XPCOM Object to a New Window
t to be able to call functions within an xpcom object from a xul window's code, you can do so if you pass the xpcom object as one of the arguments to the window creation method. for example: var ww = components.classes["@mozilla.org/embedcomp/window-watcher;1"]. getservice(components.interfaces.nsiwindowwatcher); var win = ww.openwindow(null, "chrome://myextension/content/debug.xul", "debug history", "chrome,centerscreen,resizable", myobject); note in this example that myobject is passed to the openwindow() method; you can pass any xpcom object (or any other value, for that matter) in this way. to access the xpcom object from the window's code, you can access the window.arguments[] array, as shown in the example below: components.utils.reporterror(string(window...

Components.utils.Sandbox
transparent wrapper rather than an xray wrapper. however, sandboxes are often used when chrome wants to run script as another origin, possibly to interact with the page. in this case, same-origin xrays are desirable, and wantxrays should be set to true. see safely accessing content dom from chrome for more details. methods available on the sandbox object dump() - similar to window.dump(). debug() for more information on the built-in sandbox functions, please consult the source code. importing functions or objects into the sandbox you can import functions or objects into the sandbox simply by assigning them to the sandbox object. for example: mysandbox.dosomething = function() { ... }; complex objects can be cloned into the sandbox using components.utils.cloneinto: mysandbox.someob...

Components.utils.setGCZeal
this method lets scripts set the zeal level for garbage collection. you can get details on what this method does in js_setgczeal. this method calls through to that thusly: js_setgczeal(<current context>, zeal, js_default_zeal_freq, false); syntax components.utils.setgczeal(zeal); where zeal is the zeal value you wish to use. this method has no effect unless running in a debug build. ...

XPCShell Reference
ful to print something to the screen. it dumps whatever is passed to the screen, putting spaces between arguments and appending a newline at the end. an example print(1, 2, 3) will print 1 2 3<newline>. dump(object) dump() is almost like print. it only handles one parameter and it doesn't append a newline. dumpxpc(depth) this function dumps the xpconnect object. see the documentation on debugdump() for the nsixpconnect interface for more information. version(newversion) version() returns the javascript engine version number. if you pass a number to it, it will set the version number (and return the old version number). see the above documentation on the -v command-line argument for more information. quit(exitcode) quit() exits the shell. you can specify arguments that will g...

xpcshell
xpcshell is almost always in the same directory as run-mozilla.sh. $ locate run-mozilla.sh /usr/lib/firefox-0.10.1/run-mozilla.sh /usr/lib/thunderbird-0.9/run-mozilla.sh /usr/local/mozilla/run-mozilla.sh /opt/mozilla/run-mozilla.sh /root/.trash/mozilla/run-mozilla.sh just pick one, cd over there, and run-mozilla.sh xpcshell, if it's present. (however, it might not be there if you have a non-debug version of firefox, mozilla, thunderbird, etc.) $ cd /opt/mozilla $ ./run-mozilla.sh ./xpcshell js> execute xpcshell from window the built xpcshell.exe can't be executed under the mozilla build shell(bash). it should be executed under the window command prompt source_directory/obj-xxxxx/dist/bin> xpcshell.exe using the latest version of javascript at present, xpcshell doesn't use the lates...

nsICommandLineHandler
command line handler is registered in the category "command-line-handler". the entries in this category are read in alphabetical order, and each category value is treated as a service contract id implementing this interface. by convention, handlers with ordinary priority should begin with "m". ...

nsIContentSecurityPolicy
when queried, so this value should not be cached. read only. isinitialized boolean set to true when the content security policy has been read in and parsed and is ready to enforce. this is a barrier for the nsdocument so it doesn't load any sub-content until either it knows that a content security policy is ready or will not be used. policy astring a read-only string version of the policy for debugging. read only. reportonlymode boolean when set to true, content load-blocking and fail-closed are disabled: content security policy will only send reports, and not modify behavior. methods permitsancestry() verifies ancestry as permitted by the policy. calls to this may trigger violation reports when queried, so this value should not be cached. boolean permitsancestry( in nsidocshell docs...

nsIDOMWindowUtils
e accessed from unprivileged context (not content-accessible) will throw a dom security error if called without universalxpconnect privileges. void forceupdatenativemenuat( in astring indexstring ); parameters indexstring garbagecollect() force a garbage collection followed by a cycle collection. will throw a dom security error if called without universalxpconnect privileges in non-debug builds. available to all callers in debug builds. void garbagecollect( in nsicyclecollectorlistener alistener optional ); parameters alistener optional listener that receives information about the cc graph (see @mozilla.org/cycle-collector-logger;1 for a logger component) getcursortype() get current cursor type from this window. short getcursortype(); parameters none. return val...

nsIEditor
void removeeditorobserver(in nsieditorobserver observer obsolete since gecko 18); void addeditactionlistener(in nsieditactionlistener listener); void removeeditactionlistener(in nsieditactionlistener listener); void adddocumentstatelistener(in nsidocumentstatelistener listener); void removedocumentstatelistener(in nsidocumentstatelistener listener); debug methods void dumpcontenttree(); void debugdumpcontent() ; void debugunittests(out long outnumtests, out long outnumtestsfailed); [notxpcom] boolean ismodifiablenode(in nsidomnode anode); constants load flags constant value description enone 0 enext 1 eprevious 2 enextword ...

nsIEventListenerService
1.0 66 introduced gecko 1.9.2 inherits from: nsisupports last changed in gecko 7.0 (firefox 7.0 / thunderbird 7.0 / seamonkey 2.4) implemented by: @mozilla.org/eventlistenerservice;1. ...

nsIHttpActivityDistributor
netwerk/protocol/http/nsihttpactivityobserver.idlscriptable this interface is used to register and unregister clients that wish to observe http transport activity. this is primarily useful for debuggers and other traffic monitoring tasks. 1.0 66 introduced gecko 1.9.2 inherits from: nsihttpactivityobserver last changed in gecko 1.9.2 (firefox 3.6 / thunderbird 3.1 / fennec 1.0) implemented by: mozilla.org/network/http-activity-distributor;1 as a service: var httpactivitydistributor = components.classes["@mozilla.org/network/http-activity-distributor;1"] .getservice(components.interfaces.nsihttpactivitydistributor); method overview void addobserver(in nsihttpactivityobserver aobserver); void removeobserver(in nsihttpactivityob...

nsIJetpack
ssagename the name of the message to unregister all callbacks from. evalscript() this asynchronously sends code to the jetpack process for evaluation. the code will be evaluated using at least javascript 1.8.1. when evaluated, the script's global scope will include all privileged apis. individual lines of the form //@line 1 "foo.js" can be used to specify filename and line number information for debugging purposes. void evalscript( in astring ascript ); parameters ascript the full contents of the script to evaluate in the jetpack process. createhandle() this creates an opaque handle that can transparently be exchanged between processes. nsivariant createhandle(); parameters none. return value the new handle. destroy() this terminates the jetpack process. void destroy(); parameters none.

nsIMsgIdentity
getintattribute() getter for int attributes. long getintattribute(in string name); parameters name name of the attribute to get. setintattribute() getter for int attributes. void setintattribute(in string name, in long value); parameters name name of the attribute to set. value value to set the attribute to. tostring() converts the nsimsgidentity to a string. useful for debugging. astring tostring(); ...

nsITransferable
adatalen ); parameters aflavor the flavor of data to retrieve. adata on return, this is the data itself, which is an instance of a class based upon nsisupportsprimitives. adatalen on return, this value contains the size of the returned data. init() initializes a transferable object. this should be called on all transferable objects. failure to do so will result in fatal assertions in debug builds. void init( in nsiloadcontext acontext ); parameters acontext the load context associated with the transferable object. this can be set to null if a load context is not available. remarks the load context is used to track whether the transferable is storing privacy-sensitive information. for example, we try to delete data that you copy to the clipboard when you close a private b...

NS_ASSERTION
an assertion failure should be thrown on critical program errors only. a triggered assertion failure is equivalent to crashing in tinderbox tests. note on terminology: "assertion" is the condition to test. there is always an assertion in ns_assertion; it is the first argument. only if the assertion evaluates to false is there an "assertion failure", which is thrown. ...

NS_ENSURE_ARG_POINTER
syntax ns_ensure_arg_pointer(apointer); ...

NS_ERROR
this macro is meant for critical errors; like assertions, ns_errors should not be reachable. syntax ns_error("error text"); ...

NS_WARNING
summary macro shows a warning on the console (stderr) and in debug logs (nspr logging). contrary to ns_error this is meant for noncritical errors. syntax ns_warning("warning text"); ...

XPCOM Interface Reference by grouping
nsiobserverservice nsiproperties nsiproperty nsipropertybag nsipropertybag2 nsipropertyelement nsiserversocket nsiserversocketlistener nsiservicemanager nsisocketprovider nsisocketproviderservice nsisockettransport nsisockettransportservice nsisupports nsiuuidgenerator debug nsistackframe device display nsiscreen nsiscreenmanager geolocation nsigeolocationprovider nsigeolocationupdate orientation nsiacceleration nsiaccelerationlistener nsiaccelerometer ...

XPCOM reference
ll inherit from nsmsgdbfolder, which implements a lot of the core functionality. rss feeds are implemented by nslocalmailfolder.ns ensure successmacrons ensure truemacrons_abort_if_falsethis was removed in bug 1127201ns_addrefmacrons_assertionmacrons_ensure_arg_pointermacrons_errorthrows a assertion (ns_assertion) with the text "error: (error text)", so writes this text to console (stderr) and to debug logs (nspr logging). this macro is meant for critical errors; like assertions, ns_errors should not be reachable.ns_if_addrefmacrons_if_releasemacrons_releasemacrons_warningmacronsgetmoduleprocthis function prototype provides the xpcom entry-point into a module.nsiabcard/thunderbird3the nsiabcard interface is used to represent and manipulate cards in the address book. in a big change from the ori...

nsCOMPtr versus RefPtr
on how to choose between them. general rule of thumb for nscomptr versus refptr the general rule of thumb is to use nscomptr<t> when t is an interface type, and refptr<t> when t is a concrete type. this basic rule derives from the fact that some of the nscomptr<t> code is factored into the nscomptr_base base class, which stores the underlying mrawptr as an nsisupports*. (although, confusingly, debug builds don't work this way). this design saves some space in the binary (or at least it used to). since nscomptr stores the pointer as an nsisupports*, it must be possible to unambiguously cast from t* to nsisupports*. many concrete classes inherit from nsisupports in more than one way, so they cannot be unambiguously cast to nsisupports*. thus, these concrete classes cannot be used with nscomptr...

Testing Mozilla code
ightly projectthe asan nightly project involves building a firefox nightly browser with the popular addresssanitizer tool and enhancing it with remote crash reporting capabilities for any errors detected.clang static analysisthis document is split in two parts. the first part will focus on the modern and robust way of static-analysis and the second part will present the build-time static-analysis.debugging mozilla with valgrindthis page describes how to use valgrind (specifically, its memcheck tool) to find memory errors.firefox and address sanitizeraddress sanitizer (asan) is a fast memory error detector that detects use-after-free and out-of-bound bugs in c/c++ programs. it uses a compile-time instrumentation to check all reads and writes during the execution. in addition, the runtime part re...

Account Provisioner
the account provisioner is the dialog that first comes up when starting thunderbird. the account provisioner gives the user the chance to search for and order a vanity email account from a list of partner providers. if the user already has an email account, the user can switch to the original account setup wizard. debugging the account provisioner dialog logs most if not all of its activities, which is useful for debugging. logs can either be dumped to the terminal via dump, or to the error console. to have logs dumped to the terminal, create a string preference called mail.provider.logging.dump and set its value to all. to have logs dumped to the error console, create a string preference called mail.provider.logging.console and set its value to all. a mozillazine article on how ...

Building a Thunderbird extension 1: introduction
ost developers use an editing program optimized for writing code (also known as an integrated development environment). these provide features like syntax highlighting and code coloration, indentation, auto-complete, etc. file archive utility: any utility that is capable of creating archive files can be used. there are also a number of extension and applications that are useful for testing and debugging thunderbird extensions, such as javascript consoles and xpcom inspectors. these are described on the page "setting up an extension development environment". documentation thunderbird extensions (documentation overview) firefox addons developer guide (many topics are applicable to thunderbird) mozilla cross-reference source code browser ("comm-central" contains the thunderbird code repos...

Finding the code for a feature
lid tags, so it is not the correct way to tag messages. tags are applied using the message database property "keyword". i know the underlying code, but i don't remember the user interface level function to do it. but here is how i find out. there are two key tools that you need. the first is the dom inspector extension which i have routinely installed in all of my thunderbird installations. (for debug builds, you can make it appear by default using "ac_add_options --enable-extensions=default,venkman,inspector" which is part of my standard configuration). the second is mozilla's source code search tool mxr. i keep two prominent links to this on my firefox toolbar, one to comm-central string search, and one to comm-central file search. so, how did i use those to figure out how to do this? i kno...

Thunderbird extensions
rm], find all messages from [person], find all messages in the same thread as [a given message], find all messages involving [person], etc. etc. gloda is extremely powerful and is used heavily by add-ons such as thunderbird conversations. learn more about gloda: an overview of gloda how to create your first message query and read the gloda examples gloda internals: gloda debugging, gloda indexing more thunderbird-specific links some links may be out of date, but they still provide valuable information on the codebase. an overview of thunderbird components developer reference docs: folder classes db views (message list) message summary database mailnews protocols mailnews filters error...

Using MAPI with Thunderbird's Windows 7 developer builds
mapi (messaging application programming interface) is a windows feature that allows applications to send files via a system's default mail application. the thunderbird installer sets the installed build as the default mapi/mail client. if you want to set a debug build as the default mail client, you need configure it manually: in the objdir/mozilla/dist/bin directory, copy mozmapi32.dll to mozmapi32_inuse.dll and mapiproxy to mapiproxy_inuse.dll. (be sure to copy - not move - these files.) in the uninstall sub-directory of the bin directory, run these two commands: helper.exe /setasdefaultappglobal helper.exe /setasdefaultappuser create an elevated shell and register the mapi proxy.dll as a com server. (one way to create an elevated shell is to invoke the command prompt from the...

Thunderbird
liar high-productivity environment. (from early 2007 to early 2011 thunderbird was developed by mozilla messaging, a subsidiary owned by mozilla.) documentation building thunderbird information about building thunderbird with the comm-central repository. there's also information about how the review process works and how to use the mozilla symbol server to help with debugging. mailnews protocols rough documentation about mail protocols.. database views backend information about nsimsgdbview and related interfaces. thunderbird api documentation thunderbird api documentation extension documentation tutorials and tips for building thunderbird extensions view all... community thunderbird product ...

CData
tchpad mdnfirefox" at js array position 36 (so 37 if count from 1), we see 183, and at 77 we see char code of 0 if casted to unsigned_char, if casted to char we see -73 at pos 36 but pos 77 still 0, if casted to jschar we see chineese characters in all spots expect spaces even null terminator is a chineese character console.info('ptrasarr.length:', ptrasarr.length); //console.log('debug-msg :: datacasted:', datacasted, uneval(datacasted), datacasted.tostring()); var charcode = []; var fromcharcode = [] for (var i=0; i<ptrasarr.length; i++) { //if known_len is correct, then will not hit null terminator so like in example of "_scratchpad/entehandle.js at master · noitidart/_scratchpad mdnfirefox" if you pass length of 77, then null term will not get hit by...

Int64
high the high-order 32 bits of the value to create. low the low-order 32 bits of the value to create. return value a new 64-bit integer object comprised of the two values merged together. the returned value is (high << 32) + low. exceptions thrown typeerror one or both of the specified numbers is not a javascript number with an integral value. tosource() this method is for internal debugging use only. warning: do not rely on the value returned by this method, as it's subject to change at any time, depending on the debugging needs of the developers. tostring() returns a string representation of the object's numeric value. string tostring( [radix] ); parameters radix optional the radix (base) to use when constructing the string. if you don't specify a radix, base 10 is ...

UInt64
igh the high-order 32 bits of the value to create. low the low-order 32 bits of the value to create. return value a new 64-bit integer object comprised of the two values merged together. the returned value is (high << 32) + low. exceptions thrown typeerror one or both of the specified numbers is not a javascript number with an integral value. tosource() this method is for internal debugging use only. warning: do not rely on the value returned by this method, as it's subject to change at any time, depending on the debugging needs of the developers. tostring() returns a string representation of the object's numeric value. string tostring( [radix] ); parameters radix optional the radix (base) to use when constructing the string. if you don't specify a radix, base 10 i...

Plug-in Development Overview - Plugins
his chapter, as well as separate chapters for all of the major functional areas of the plug-in api. also see making plug-ins scriptable for more information about making plug-ins accessible from the browser. build the plug-in for your operating system. see "building plug-ins". install the plug-in in the plug-in directory for your operating system. see installing plug-ins. test your plug-in and debug as necessary. create an html page and embed the plug-in object. for information about the html elements to use, see using html to display plug-ins. to see your plug-in in action, simply display the html page that calls it in the browser. registering plug-ins gecko identifies a plug-in by the mime type it supports. when it needs to display data of a particular mime type, the browser finds and ...

Accessibility Inspector - Firefox Developer Tools
ee. this is a bit like the dom tree, except that it contains a more limited set of elements and slightly different information about them. assistive technologies like screenreaders use this information to find out what's on a web page, tell their users what's there, and enable them to interact with the page. the accessibility inspector also uses this information to provide valuable accessibility debugging capabilities in the devtools. accessing the accessibility inspector when you first open any of the other developer tools, the accessibility features are turned off (unless you've already got them turned on in another browser tab, or got the firefox accessibility engine started already, e.g., you might be a screenreader user or tester). this is because the accessibility engine runs in the ba...

Introduction to DOM Inspector - Firefox Developer Tools
nterfaces were exactly the aspects of your own application development that were missing. the dom inspector not only presents all this information about pages in a clear and structured way, it gives you way to find and update those structures, and it's simple to access via shortcuts and menus already available in the mozilla browser. used in concert with mozilla tools like venkman, the javascript debugger, the dom inspector can give you a complete view of any web page or dom-based application interface. ...

Break on DOM mutation - Firefox Developer Tools
ples for when this breakpoint is triggered are calling element.setattribute(), element.removeattribute(), and element.classlist.add(), or setting element.id. node removal execution pauses if the element the option is set on is removed. examples for when this breakpoint is triggered are calling element.remove() or node.removechild() on its parent node. once you set the breakpoint, go to the debugger. you can see the breakpoint listed in the right-most panel under dom mutation breakpoints. click on the icon following the node name to go back to the page inspector with the node selected. when you execute the code, the debugger will pause execution when the dom mutation occurs. in the following example, the selected node (the unordered list) is modified by adding a new child node. the...

Breaking on exceptions - Firefox Developer Tools
a tooltip describes the exception. starting in firefox 80, a disclosure triangle within the tooltip reveals a stack trace. ...

Highlight and inspect DOM nodes - Firefox Developer Tools
a dom object in the watch expressions area, for example, includes a target. hover over the target to highlight the item on the page, click on the target to switch to the page inspector with the item highlighted. ...

Pretty-print a minified file - Firefox Developer Tools
after you click the icon, the source code looks like this: the pretty print source icon is available only if the source file is minified (i.e., not an original file), and is not already "prettified". ...

Search - Firefox Developer Tools
h term. the source pane will display a list of all matching files as you type. you can use the up and down arrows to move through the list, and return to open the file you want: searching within a file to search for a particular substring in the file currently loaded into the source pane, press control + f (or command + f on a mac) while the source pane is focused. press return to search. the debugger will display the number of matches in the code and highlight each result: using the outline tab if you are searching for a specific function within the current javascript file, you can use the outline tab in the debugger to find it quickly. the outline tab lists the functions in the current file. the default sort order is by the order in the file but you can simplify the search by click on...

Set an XHR breakpoint - Firefox Developer Tools
an xhr (xmlhttprequest) breakpoint breaks code execution when an xhr request is dispatched so that you can examine the current state of the program. you can break on all requests or on those that include a specific url. to turn on the feature: open the debugger click on "pause on any url" which acts as a wild card, causing the code to pause on any call, or, click the plus sign next to the xhr breakpoints header, enter the url in which you are interested, and press enter. note: if you enter a key word instead of a url, code execution will pause on any call to a url that contains that keyword. when your code breaks on an xhr request, the righthand pane will have two additional sections: call stack the list of functions that were executed in order ot get to the currently executing...

Source map errors - Firefox Developer Tools
map data can be invalid — either simply not a json file at all, or with an incorrect structure. typical error messages here are: syntaxerror: json.parse: unexpected character at line 1 column 1 of the json data error: "version" is a required argument original source missing an original source may be missing. you may encounter this when trying to open one of the original sources in the debugger. the message looks a little different in this case: in this case, the error will also be displayed in the source tab in the debugger: networkerror when attempting to fetch resource a bug in firefox prevents it from loading source maps for web extensions. see bug 1437937: webextensions doesn't find source maps for details. source-map-fehler: typeerror: networkerror when attempting to f...

Aggregate view - Firefox Developer Tools
seful: they show allocation size and number of allocations at that exact point. so in the example above, we can see that we made 4002 allocations, accounting for 89% of the total heap, in createtoolbarbutton(), at alloc.js line 9, position 23: that is, the exact point where we create the <span> elements. the file name and line number is a link: if we click it, we go directly to that line in the debugger: inverted call stack the call stack view is top-down: it shows allocations that happen at that point or points deeper in the call tree. so it's good for getting an overview of where your program is memory-hungry. however, this view means you have to drill a long way down to find the exact place where the allocations are happening. the "inverted call stack" view helps with that. it gives y...

Network monitor recording - Firefox Developer Tools
you can pause and resume the monitoring of network traffic using the pause button. pausing and resume network traffic recording the network monitor has a button that pauses and resumes recording of the current page's network traffic. this is useful in situations where, for example, you are trying to get a stable view of a page for debugging purposes, but under normal circumstances the view keeps evolving due to persistent network requests. the pause button allows you to look at a certain snapshot. the button can be found at the far left of the main network monitor toolbar, and looks like a typical pause button — . you can see it here in context: once pressed, the button changes to a play icon, and you can toggle network traffic recording back on by pressing it again. network monitor ...

Network request list - Firefox Developer Tools
the request as it was originally sent with no changes made. edit and resend opens an editor enabling you to edit the request's method, url, parameters, and headers, and resend the request. block url blocks the selected url for future requests. see blocking a specific url from the request list. open in new tab resends the request in a new tab — very useful for debugging asynchronous requests. open in style editor for a css resource, opens it in the style editor. start performance analysis use as fetch in console submits the request as a call to the fetch() method in the console. copy as curl the command may include the following options: -x [method] if the method is not get or post --data ...

Network Monitor - Firefox Developer Tools
rmation. the just opened tool looks like this: either action causes the network monitor to begin monitoring network activity. once the tool is monitoring network requests, the display looks like this: when it is actively monitoring activity, the network monitor records network requests any time the toolbox is open, even if the network monitor itself is not selected. this means you can start debugging a page in, for example, the web console, then switch to the network monitor to see network activity without having to reload the page. ui overview the ui is divided into four main pieces: the main screen contains the toolbar, the network request list, and the network request details pane: the performance analysis view is a separate screen: working with the network monitor the ...

CSS Flexbox Inspector: Examine Flexbox layouts - Firefox Developer Tools
discovering flex containers when an html element on your page has display: flex applied to it, a number of features are made available in the devtools to provide easy access to flexbox layout features. ...

Examine Event Listeners - Firefox Developer Tools
firefox can display: standard dom events jquery events react events ...

CSS Grid Inspector: Examine grid layouts - Firefox Developer Tools
note: the examples shown in the screenshots appearing in this article are jen simmons' futurismo and variations on a grid experiments, and a live named grid area example from rachel andrew. discovering css grids when an html element on your page has display: grid applied to it, a number of features are made available in the devtools to provide easy access to grid features. ...

Page Inspector - Firefox Developer Tools
user interface tour to find your way around the inspector, here's a quick tour of the ui. you can split the rules view out into its own pane, separate from the other tabs on the css pane — this is called 3-pane mode. ...

Extension Storage - Firefox Developer Tools
when selecting an extension id in the storage tree of the storage inspector, a table lists the details of all the extension storage present for the extension. this table contains the following columns: key — the name of the stored item. value — the value of the stored item. ...

Style Editor - Firefox Developer Tools
the right-hand side whenever the current sheet contains any @media rules. the sidebar lists the rules and provides a link to the line of the sheet where the rule is defined. click an item to jump to that rule in the sheet. the condition text of the rule is greyed-out if the media query doesn’t currently apply. the media sidebar works especially well with responsive design view for creating and debugging responsive layouts: from firefox 46 onwards, if an @media rule contains a screen size in a condition, then it is made clickable: clicking it then resizes the screen to that size using the responsive design view: creating and importing style sheets you can create a new style sheet by clicking the new button in the toolbar. then you can just start entering css into the new editor and wat...

Split console - Firefox Developer Tools
elect the "show split console" command in the toolbar menu. the toolbox will now appear split, with the original tool above and the web console underneath. you can close the split console by pressing esc again, or by selecting the "hide split console" menu command. as usual, $0 works as a shorthand for the element currently selected in the inspector: when you use the split console with the debugger, the console's scope is the currently executing stack frame. so if you hit a breakpoint in a function, the scope will be the function's scope. you'll get autocomplete for objects defined in the function, and can easily modify them on the fly: ...

Working with iframes - Firefox Developer Tools
you can point the developer tools at a specific iframe within a document. you'll see a button in the toolbar: click it, and you'll see a popup listing all the iframes in the document, as well as the main document itself. if you select an entry in the list, all the tools in the toolbox - the inspector, the console, the debugger and so on - will now target only that iframe, and will essentially behave as if the rest of the page does not exist. ...

DedicatedWorkerGlobalScope - Web APIs
ilable to workers. properties this interface inherits properties from the workerglobalscope interface, and its parent eventtarget, and therefore implements properties from windowtimers, windowbase64, and windoweventhandlers. dedicatedworkerglobalscope.name read only the name that the worker was (optionally) given when it was created using the worker() constructor. this is mainly useful for debugging purposes. properties inherited from workerglobalscope workerglobalscope.self returns an object reference to the dedicatedworkerglobalscope object itself. workerglobalscope.console read only returns the console associated with the worker. workerglobalscope.location read only returns the workerlocation associated with the worker. workerlocation is a specific location object, mostly ...

Document.requestStorageAccess() - Web APIs
s decremented by one. note: if the requesting origin is not classified as a tracking origin, the access request is automatically given an ephemeral storage access grant, which will go away when the page is reloaded. the user is never shown a prompt in this case, and calling requeststorageaccess() won’t have any side effects besides changing the value returned by document.hasstorageaccess(). debugging the storage access grant threshold may make it more difficult to test your website under the condition where firefox prompts the user for access. to make testing easier, we have added two preferences in about:config that control prompting upon requeststorageaccess() calls: dom.storage_access.auto_grants can be set to false to disable the automatic granting of ephemeral storage access gran...

Event.currentTarget - Web APIs
// click around and make paragraphs disappear note: the value of event.currenttarget is only available while the event is being handled. if you console.log() the event object, storing it in a variable, and then look for the currenttarget key in the console, its value will be null. instead, you can either directly console.log(event.currenttarget) to be able to view it in the console or use the debugger statement, which will pause the execution of your code thus showing you the value of event.currenttarget. specifications specification status comment domthe definition of 'event.currenttarget' in that specification. living standard dom4the definition of 'event.currenttarget' in that specification. obsolete document object model (dom) l...

FileException - Web APIs
a fileexception object represents error conditions that you might encounter while accessing the file system using the synchronous api. it extends the fileexception interface described in file writer and adds several new error codes. basic concepts synchronous apis do not have error callbacks, which makes it difficult to catch errors. the added complexity of using webworkers with this api makes debugging even more challenging. to simplify things a bit, wrap your worker code in a try/catch. when errors occur, forward them to the main app using postmessage() as in the following: function onerror(e) { postmessage('error:' + e.tostring()); } try { //error is thrown if "log.txt" already exists. var fileentry = fs.root.getfile('log.txt', {create: true, exclusive:true}0; } catch (e) { onerrr...

GeolocationPositionError - Web APIs
returned an internal error. 3 timeout the time allowed to acquire the geolocation, defined by positionoptions.timeout information was reached before the information was obtained. geolocationpositionerror.message read only secure context returns a human-readable domstring describing the details of the error. specifications note that this is primarily intended for debugging use and not to be shown directly in a user interface. methods the geolocationpositionerror interface neither implements nor inherits any method. specifications specification status comment geolocation apithe definition of 'geolocationpositionerror' in that specification. recommendation initial specification. ...

In depth: Microtasks and the JavaScript runtime environment - Web APIs
that's what this section covers introduction javascript is an inherently single-threaded language. it was designed in an era in which this was a positive choice; there were few multi-processor computers available to the general public, and the expected amount of code that would be handled by javascript was relatively low at that time. as time passed, of course, we know that computers have evolved into powerful multi-core systems, and javascript has become one of the most prolifically-used languages in the computing world. ...

IntersectionObserver.thresholds - Web APIs
e the observer, the value of thresholds is simply [0]. be careful! although the options object you can specify when creating an intersectionobserver has a field named threshold, this property is called thresholds. confusing? yes. if you accidentally use thresholds as the name of the field in your options, the thresholds array will wind up being simply [0.0], which is likely not what you expect. debugging chaos may ensue. examples <<<...>>> specifications specification status comment intersection observerthe definition of 'intersectionobserver.thresholds' in that specification. working draft initial definition ...

LayoutShiftAttribution - Web APIs
properties layoutshiftattribution.node returns the element that has shifted (null if it has been removed). layoutshiftattribution.previousrect returns a domrect representing the position of the element before the shift. layoutshiftattribution.currentrect returns a domrect representing the position of the element after the shift. ...

MediaRecorderErrorEvent() - Web APIs
minimum. error a domexception that describes the error that occurred. this object's name property should indicate the name of the error that occurred. the other fields may or may not be present. some user agents add to the error object other properties that provide information such as stack dumps, the name of the javascript file and the line number where the error occurred, and other debugging aids, but you should not rely on this information in a production environment. specifications specification status comment mediastream recordingthe definition of 'mediarecordererrorevent()' in that specification. working draft initial definition. ...

MediaTrackSupportedConstraints - Web APIs
ack object. an object conforming to mediatracksupportedconstraints is returned by mediadevices.getsupportedconstraints(). because of the way interface definitions in webidl work, if a constraint is requested but not supported, no error will occur. instead, the specified constraints will be applied, with any unrecognized constraints stripped from the request.that can lead to confusing and hard to debug errors, so be sure to use getsupportedconstraints() to retrieve this information before attempting to establish constraints if you need to know the difference between silently ignoring a constraint and a constraint being accepted. an actual constraint set is described using an object based on the mediatrackconstraints dictionary. to learn more about how constraints work, see capabilities, const...

PerformanceObserver.observe() - Web APIs
not be used together with the entrytypes option. buffered: a boolean flag to indicate whether buffered entries should be queued into the observer's buffer. must be used only with the "type" option. see performanceentry.entrytype for a list of valid performance entry type names. unrecognized types are ignored, though the browser may output a warning message to the console to help developers debug their code. if no valid types are found, observe() has no effect. examples this example creates and configures two performanceobservers; one watches for "mark" and "frame" events, and the other watches for "measure" events. var observer = new performanceobserver(function(list, obj) { var entries = list.getentries(); for (var i=0; i < entries.length; i++) { // process "mark" and "fra...

PushManager.getSubscription() - Web APIs
working draft initial definition. ...

PushManager.register() - Web APIs
eturn a domrequest object to handle the success or failure of the method call. if the method call is successful, the request's result will be a string, which is the endpoint url. note: if you do not need the url any more, please use pushmanager.unregister() to clean up after yourself. example var req = navigator.push.register(); req.onsuccess = function(e) { var endpoint = req.result; debug("new endpoint: " + endpoint ); } req.onerror = function(e) { debug("error getting a new endpoint: " + json.stringify(e)); } specification specification status comment push api working draft defines the pushmanager interface. ...

PushManager.unregister() - Web APIs
ing the endpoint that has been unregistered. pushregistration those objects are anonymous javascript objects with the following properties: pushendpoint a string representing the url of the unregistered endpoint. version undefined when unregister.onsuccess is called. example var req = navigator.push.unregister(pushendpoint); req.onsuccess = function(e) { var endpoint = req.result; debug("unregistered endpoint: " + endpoint ); } req.onerror = function(e) { debug("error unregistering the endpoint: " + json.stringify(e)); } specification specification status comment push api working draft defines the pushmanager interface. ...

RTCDataChannel.id - Web APIs
een 0 and 65,535) which uniquely identifies the data channel. while the label property doesn't have to be unique, this id number is guaranteed to be unique among all data channels. additionally, known implementations of webrtc use the same id on both peers. a unique id makes it easier for your code to do its own out-of-band data channel-related signaling. this can be also useful for logging and debugging purposes. example var pc = new rtcpeerconnection(); var dc = pc.createdatachannel("my channel"); console.log("channel id: " + dc.id); specifications specification status comment webrtc 1.0: real-time communication between browsersthe definition of 'rtcdatachannel.id' in that specification. candidate recommendation initial specification. ...

RTCIceCandidate.relatedAddress - Web APIs
ice candidate discovered by the stun server: a=candidate:4234997325 1 udp 2043278322 192.168.0.56 6502 typ srflx raddr 192.168.2.77 rport 32768 generation 0 the remote address, relatedaddress, is the dotted quad (for ipv4) or colon-delineated 64-bit address (for ipv6) immediately following the text "raddr", or "192.168.2.77". example in this example, the candidate's type is checked, and then debugging output is presented, based on the candidate type, including the candidate's ip and relatedaddress. switch(candidate.type) { case "host": console.log("host candidate's ip address is " + candidate.ip); break; case "srflx": console.log("server reflexive candidate's base address is " + candidate.relatedaddress + "; reachable at " + candidate.ip); break; case "prflx"...

RTCPeerConnection.signalingState - Web APIs
ive an answer while the signalingstate isn't "have-local-offer", you know that something is wrong, since you should only receive answers after creating an offer but before an answer has been received and passed into rtcpeerconnection.setlocaldescription(). your code will be more reliable if you watch for mismatched states like this and handle them gracefully. this value may also be useful during debugging, for example. in addition, when the value of this property changes, a signalingstatechange event is sent to the rtcpeerconnection instance. syntax var state = rtcpeerconnection.signalingstate; value the allowed values are those included in the enum rtcsignalingstate. rtcsignalingstate enum the rtcsignalingstate enum specifies the possible values of rtcpeerconnection.signalingstate, wh...

Request - Web APIs
t object. you could then fetch this api request by passing the request object in as a parameter to a windoworworkerglobalscope.fetch() call, for example and get the response: fetch(request) .then(response => { if (response.status === 200) { return response.json(); } else { throw new error('something went wrong on api server!'); } }) .then(response => { console.debug(response); // ... }).catch(error => { console.error(error); }); specifications specification status comment fetchthe definition of 'request' in that specification. living standard initial definition ...

SharedWorkerGlobalScope - Web APIs
workers. properties this interface inherits properties from the workerglobalscope interface, and its parent eventtarget, and therefore implements properties from windowtimers, windowbase64, and windoweventhandlers. sharedworkerglobalscope.name read only the name that the sharedworker was (optionally) given when it was created using the sharedworker() constructor. this is mainly useful for debugging purposes. sharedworkerglobalscope.applicationcache read only this property returns the applicationcache object for the worker (see using the application cache). properties inherited from workerglobalscope workerglobalscope.self returns an object reference to the dedicatedworkerglobalscope object itself. workerglobalscope.console read only returns the console associated with the ...

Multi-touch interaction - Web APIs
function enablelog(ev) { logevents = logevents ? false : true; } function log(name, ev, printtargetids) { var o = document.getelementsbytagname('output')[0]; var s = name + ": touches = " + ev.touches.length + " ; targettouches = " + ev.targettouches.length + " ; changedtouches = " + ev.changedtouches.length; o.inner...

WebGLRenderingContext.getActiveAttrib() - Web APIs
syntax webglactiveinfo gl.getactiveattrib(program,index); parameters program a webglprogram containing the vertex attribute. index a gluint specifying the index of the vertex attribute to get. this value is an index 0 to n - 1 as returned by gl.getprogramparameter(program, gl.active_attributes). ...

WebGLRenderingContext.getActiveUniform() - Web APIs
syntax webglactiveinfo webglrenderingcontext.getactiveuniform(program, index); parameters program a webglprogram specifying the webgl shader program from which to obtain the uniform variable's information. index a gluint specifying the index of the uniform attribute to get. ...

WebGLRenderingContext.getShaderInfoLog() - Web APIs
syntax gl.getshaderinfolog(shader); parameters shader a webglshader to query. return value a domstring that contains diagnostic messages, warning messages, and other information about the last compile operation. when a webglshader object is initially created, its information log will be a string of length 0. examples checking compilation messages /* load shader source code. */ gl.shadersource(shader, shadercode); /* compile shader source code. ...

WebGLRenderingContext.vertexAttribPointer() - Web APIs
a constant color. querying current settings you can call gl.getvertexattrib() and gl.getvertexattriboffset() to get the current parameters for an attribute, e.g. the data type or whether the attribute should be normalized. keep in mind that these webgl functions have a slow performance and it is better to store the state inside your javascript application. however, these functions are great for debugging a webgl context without touching the application code. examples this example shows how to send your vertex attributes to the shader program. we use an imaginary data structure where the attributes of each vertex are stored interleaved with a length of 20 bytes per vertex: position: we need to store the x, y and z coordinates. for highest precision, we use 32-bit floats; in total this use...

Signaling and video calling - Web APIs
; } }; note: the closed signaling state has been deprecated in favor of the closed iceconnectionstate. we are watching for it here to add a bit of backward compatibility. ice gathering state icegatheringstatechange events are used to let you know when the ice candidate gathering process state changes. our example doesn't use this for anything, but it can be useful to watch these events for debugging purposes, as well as to detect when candidate collection has finished. function handleicegatheringstatechangeevent(event) { // our sample just logs information to console here, // but you can do whatever you need. } next steps you can now try out this example on glitch to see it in action. open the web console on both devices and look at the logged output—although you don't see it i...

WebSocket.onmessage - Web APIs
the websocket.onmessage property is an eventhandler that is called when a message is received from the server. it is called with a messageevent. syntax awebsocket.onmessage = function(event) { console.debug("websocket message received:", event); }; value an eventlistener. specifications specification status comment html living standardthe definition of 'websocket: onmessage' in that specification. living standard initial definition ...

Tools for analyzing Web Audio usage - Web APIs
this article discusses tools available to help you do that. chrome a handy web audio inspector can be found in the chrome web store. ...

Web Audio API - Web APIs
ornode, periodicwave, and gainnode.migrating from webkitaudiocontextin this article, we cover the differences in web audio api since it was first implemented in webkit and how to update your code to use the modern web audio api. tools for analyzing web audio usagewhile working on your web audio api code, you may find that you need tools to analyze the graph of nodes you create or to otherwise debug your work. this article discusses tools available to help you do that.using iir filtersthat's it for our iirfilter demo. this should have shown you how to use the basics, and helped you to understand what it's useful for and how it works.using the web audio apigreat! we have a boombox that plays our 'tape', and we can adjust the volume and stereo panning, giving us a fairly basic working audio gr...

Web Locks API - Web APIs
n, allowing a lock request to be aborted. this can be used to implement a timeout on requests. ifavailable: if specified, the lock request will fail if the lock cannot be granted immediately without waiting. the callback is invoked with null. monitoring the navigator.locks.query() method can be used by scripts to introspect the state of the lock manager for the origin. this can be useful when debugging, for example, identifying why a lock could not be acquired. the results are a snapshot of the lock manager state, which identifies held and requested locks and some additional data (e.g. mode) about each, at the time the snapshot was taken. advanced use for more complicated cases, such as holding the lock for an arbitrary amount of time, the callback can return a promise explicitly resolved...

Functions and classes available to Web Workers - Web APIs
es) no support 43 ? channel messaging api allows two separate scripts running in different browsing contexts attached to the same document (e.g., two iframes, or the main document and an iframe, two documents via a sharedworker, or two workers) to communicate directly via two ports. 41 (41) (yes) (yes) (yes) console api provides access to the browser's debugging console (e.g., the web console in firefox). the specifics of how it works vary from browser to browser, but there is a de facto set of features that are typically provided. 38 (38) (yes) (yes) (yes) crypto the crypto interface represents basic cryptography features available in the current context. it allows access to a cryptographically strong random number generator ...

Window.console - Web APIs
examples logging to console the first example logs text to the console. console.log("an error occurred while loading the content"); the next example logs an object to the console, with the object's fields expandable using disclosure widgets: console.dir(someobject); see usage in console for more thorough examples. ...

Window: rejectionhandled event - Web APIs
the rejectionhandled event is sent to the script's global scope (usually window but also worker) whenever a javascript promise is rejected but after the promise rejection has been handled. this can be used in debugging and for general application resiliency, in tandem with the unhandledrejection event, which is sent when a promise is rejected but there is no hander for the rejection. bubbles no cancelable no interface promiserejectionevent event handler property onrejectionhandled example you can use the rejectionhandled event to log promises that get rejected to the console, along with the reasons why they were rejected: window.addeventlistener("rejectionhandled", event => { console.log("promise rejected; reason: " + event.reason); }...

Window: unhandledrejection event - Web APIs
bubbles no cancelable yes interface promiserejectionevent event handler property onunhandledrejection usage notes allowing the unhandledrejection event to bubble will eventually result in an error message being output to the console. ...

Window - Web APIs
oworworkerglobalscope and windoweventhandlers mixins. note that properties which are objects (e.g.,. for overriding the prototype of built-in elements) are listed in a separate section below. window.closed read only this property indicates whether the current window is closed or not. window.console read only returns a reference to the console object which provides access to the browser's debugging console. window.controllers read only returns the xul controller objects for the current chrome window. window.customelements read only returns a reference to the customelementregistry object, which can be used to register new custom elements and get information about previously registered custom elements. window.crypto read only returns the browser crypto object. window.devicepix...

Worker() - Web APIs
fault used is classic. credentials: a domstring specifying the type of credentials to use for the worker. the value can be omit, same-origin, or include. if not specified, or if type is classic, the default used is omit (no credentials required). name: a domstring specifying an identifying name for the dedicatedworkerglobalscope representing the scope of the worker, which is mainly useful for debugging purposes. exceptions a securityerror is raised if the document is not allowed to start workers, e.g. if the url has an invalid syntax or if the same-origin policy is violated. a networkerror is raised if the mime type of the worker script is incorrect. it should always be text/javascript. a syntaxerror is raised if aurl cannot be parsed. examples the following code snippet shows...

WorkerGlobalScope.console - Web APIs
the console read-only property of the workerglobalscope interface returns a console object providing access to the browser console for the worker. syntax var consoleobj = self.console; value a console object. example this property allows you to have access to a browser console for debugging purposes, inside a worker. so for example you could call console.log('test'); inside a worker (which would basically be the equivalent of self.console.log('test');, as these are being called on the worker scope, which can be referenced with workerglobalscope.self), to return a test message out to the browser console. if you are calling console.log() from a dedicatedworkerglobalscope or other worker scope that acts on a single loaded window, that tab's web console will receive the logs. however, i...

msWriteProfilerMark - Web APIs
esult. if this method succeeds, it returns s_ok. otherwise, it returns an hresult error code. notes mswriteprofilermark enables you to inject dom based performance markers in addition to existing javascript api to learn exactly when parts of the page are being rendered, building a waterfall view for every one of our impressions showing latency per object, which can be useful for more accurately debugging real users perf issues. internet explorer 10. this method is also available in the web worker global scope. for windows xp, this method sends an event to an event tracing session with traceevent; for systems after windows xp, this method writes an event with eventwrite. the event includes a pointer to a window object, current markup, and the event name passed as bstrprofilermarkname. the ...

Web APIs
handler userproximityevent v vttcue vttregion validitystate videoconfiguration videoplaybackquality videotrack videotracklist visualviewport w webgl_color_buffer_float webgl_compressed_texture_astc webgl_compressed_texture_atc webgl_compressed_texture_etc webgl_compressed_texture_etc1 webgl_compressed_texture_pvrtc webgl_compressed_texture_s3tc webgl_compressed_texture_s3tc_srgb webgl_debug_renderer_info webgl_debug_shaders webgl_depth_texture webgl_draw_buffers webgl_lose_context wakelock wakelocksentinel waveshapernode webgl2renderingcontext webglactiveinfo webglbuffer webglcontextevent webglframebuffer webglprogram webglquery webglrenderbuffer webglrenderingcontext webglsampler webglshader webglshaderprecisionformat webglsync webgltexture webgltransformfeedback webglunifo...

ARIA Test Cases - Accessibility
table legend - no info/test yet n/a not applicable (not supported technically) pass expected behaviour met fail expected behaviour notmet 1. 2. reference to link example note regarding dojo/dijit test files the main purpose of dojo's dijit test files are for dojo developers to exercise and debug the code. as such, they are used to test a variety of features, such as styling, behavior, mouse, and keyboard interactions, to name few. these test files are not specifically for testing aria. still, dojo's widgets implement aria, and the noted test files could be used as an "aria test file". new tests for internet explorer 8 rc1 on this msdn page the aria state/role mapping in ie8 to msaa rol...

Web applications and ARIA FAQ - Accessibility
the dom and the desktop. browsers expose aria-enabled elements to the assistive technology api as if they were native widgets. as a result, the user potentially gets a more consistent user experience, where dynamic javascript-driven widgets on the web are comparable to their equivalents on the desktop. how do i test my use of aria? are there any tools available for free? several inspecting and debugging tools exist to help you test aria in action: object inspector on windows accessibility inspector on os x accprobe on linux firebug's dom inspector the accessibility inspector for firebug the audits tab in chrome devtools there are several free or open source screen readers that can be used to do hands-on testing with aria. they include: orca for linux nvda for windows voiceover...

Implementing a Microsoft Active Accessibility (MSAA) Server - Accessibility
&ptr); not all msaa objects implemented by 3rd party vendors problem: as described above, screen readers tend to look first for window classes they know, such as button, listbox, combobox, msctls_statusbar32, msctls_trackbar32, #32770 (dialog class), systreeview32, static, edit and richedit. at vendors have typically spent the most time making windows with these classes work, so they are fully debugged. in addition, the user comes to expect appropriate behavior for status bars, dialog boxes and tree views based on the fact that most apps use the standard control. unfortunately, the msaa implementation often lags. for example, tree views will probably not be accessible with most assistive technologies even if you have a perfect msaa implementation. automatic screen reading of dialog boxes and...

Robust - Accessibility
ith future ones too. success criteria how to conform to the criteria practical resource 4.1.1 parsing (a) content should be well-formed so it can be parsed successfully by browsers and other user agents such as screenreaders. to pass this criterion, make sure that your html is as valid as possible. use the w3c validator to validate your markup. see debugging html for a practical guide. 4.1.2 name, role, value (a) the name and role of user interface components (e.g. form inputs, buttons, links, etc.) should be programmatically determinable. when using semantic elements correctly for their intended purpose, this criterion should be passed automatically. when scripting custom components, you will need to use wai-aria roles and ...

Using CSS transitions - CSS: Cascading Style Sheets
re less strict. using animations with auto may lead to unpredictable results, depending on the browser and its version, and should be avoided. defining transitions css transitions are controlled using the shorthand transition property. this is the best way to configure transitions, as it makes it easier to avoid out of sync parameters, which can be very frustrating to have to spend lots of time debugging in css. you can control the individual components of the transition with the following sub-properties: (note that these transitions loop infinitely only for the purpose of our examples; css transitions only visualize a property change from start to finish. if you need visualizations that loop, look into the css animation property.) transition-property specifies the name or names of the ...

Specificity - CSS: Cascading Style Sheets
n external stylesheets, and thus can be thought of as having the highest specificity. the !important exception when an important rule is used on a style declaration, this declaration overrides any other declarations. although technically !important has nothing to do with specificity, it interacts directly with it. using !important, however, is bad practice and should be avoided because it makes debugging more difficult by breaking the natural cascading in your stylesheets. when two conflicting declarations with the !important rule are applied to the same element, the declaration with a greater specificity will be applied. some rules of thumb: always look for a way to use specificity before even considering !important only use !important on page-specific css that overrides foreign css (fr...

Guide to scroll anchoring - CSS: Cascading Style Sheets
ent the user is looking at remains in the viewport, which may mean their scroll position actually changes in terms of how far they have moved through the document. how do i turn on scroll anchoring? you don't! the feature is enabled by default in supporting browsers. in most cases anchored scrolling is exactly what you want — content jumping is a poor experience for anyone. what if i need to debug it? if your page is not behaving well with scroll anchoring enabled, it is probably because some scroll event listener is not handling well the extra scrolling to compensate for the anchor node movement. you can check whether disabling scroll anchoring fixes the issue in firefox by changing layout.css.scroll-anchoring.enabled to false in about:config. if it does, you can check what node is fir...

Getting Started - Developer guides
turn xml, rather than a static html file, you must set response headers to work in internet explorer. if you do not set header content-type: application/xml, ie will throw a javascript "object expected" error after the line where you tried to access an xml element. note 2: if you do not set header cache-control: no-cache the browser will cache the response and never re-submit the request, making debugging challenging. you can also add an always-different get parameter, like a timestamp or random number (see bypassing the cache) note 3: if the httprequest variable is used globally, competing functions calling makerequest() can overwrite each other, causing a race condition. declaring the httprequest variable local to a closure containing the ajax functions avoids this. in the event of a commu...

<button>: The Button element - HTML: Hypertext Markup Language
ormenctype html5 if the button is a submit button (it's inside/associated with a <form> and doesn't have type="button"), specifies how to encode the form data that is submitted. possible values: application/x-www-form-urlencoded: the default if the attribute is not used. multipart/form-data: use to submit <input> elements with their type attributes set to file. text/plain: specified as a debugging aid; shouldn’t be used for real form submission. if this attribute is specified, it overrides the enctype attribute of the button's form owner. formmethod html5 if the button is a submit button (it's inside/associated with a <form> and doesn't have type="button"), this attribute specifies the http method used to submit the form. possible values: post: the data from the form are ...

<figure>: The Figure with Optional Caption element - HTML: Hypertext Markup Language
"; "; txt+= "browser version: " + navigator.appversion + "; "; txt+= "cookies enabled: " + navigator.cookieenabled + "; "; txt+= "platform: " + navigator.platform + "; "; txt+= "user-agent header: " + navigator.useragent + "; "; console.log("navigatorexample", txt); } </pre> </figure> quotations <figure> <figcaption><cite>edsger dijkstra:</cite></figcaption> <blockquote>if debugging is the process of removing software bugs, then programming must be the process of putting them in.</blockquote> </figure> poems <figure> <p style="white-space:pre"> bid me discourse, i will enchant thine ear, or like a fairy trip upon the green, or, like a nymph, with long dishevell'd hair, dance on the sands, and yet no footing seen: love is a spirit all compact of fire, not g...

<form> - HTML: Hypertext Markup Language
y a formaction attribute on a <button>, <input type="submit">, or <input type="image"> element. enctype if the value of the method attribute is post, enctype is the mime type of the form submission. possible values: application/x-www-form-urlencoded: the default value. multipart/form-data: use this if the form contains <input> elements with type=file. text/plain: introduced by html5 for debugging purposes. this value can be overridden by formenctype attributes on <button>, <input type="submit">, or <input type="image"> elements. method the http method to submit the form with. possible (case insensitive) values: post: the post method; form data sent as the request body. get: the get method; form data appended to the action url with a ? separator. use this method when the ...

<input type="image"> - HTML: Hypertext Markup Language
this, the default value, sends the form data as a string after url encoding the text using an algorithm such as encodeuri(). multipart/form-data uses the formdata api to manage the data, allowing for files to be submitted to the server. you must use this encoding type if your form includes any <input> elements of type file (<input type="file">). text/plain plain text; mostly useful only for debugging, so you can easily see the data that's to be submitted. if specified, the value of the formenctype attribute overrides the owning form's action attribute. this attribute is also available on <input type="submit"> and <button> elements. formmethod a string indicating the http method to use when submitting the form's data; this value overrides any method attribute given on the owning form.

<input type="submit"> - HTML: Hypertext Markup Language
this, the default value, sends the form data as a string after url encoding the text using an algorithm such as encodeuri(). multipart/form-data uses the formdata api to manage the data, allowing for files to be submitted to the server. you must use this encoding type if your form includes any <input> elements of type file (<input type="file">). text/plain plain text; mostly useful only for debugging, so you can easily see the data that's to be submitted. if specified, the value of the formenctype attribute overrides the owning form's action attribute. this attribute is also available on <input type="image"> and <button> elements. formmethod a string indicating the http method to use when submitting the form's data; this value overrides any method attribute given on the owning form. ...

CORS errors - HTTP
he same origin policy disallows reading the remote resource at $somesite" indicating that the request was blocked due to violating the cors security rules. this might not necessarily be a set-up mistake, though. it's possible that the request is in fact intentionally being disallowed by the user's web application and remote external service. however, if the endpoint is meant to be available, some debugging is needed to succeed. identifying the issue to understand the underlying issue with the cors configuration, you need to find out which request is at fault and why. these steps may help you do so: navigate to the web site or web app in question and open the developer tools. now try to reproduce the failing transaction and check the console if you are seeing a cors violation error message...

HTTP conditional requests - HTTP
on who wins, is not communicated to the other party. which client's changes are to be kept, will vary with the speed they commit; this depends on the performance of the clients, of the server, and even of the human editing the document at the client. the winner will change from one time to the next. this is a race condition and leads to problematic behaviors, which are difficult to detect and to debug: there is no way to deal with this problem without annoying one of the two clients. however, lost updates and race conditions are to be avoided. we want predictable results, and expect that the clients are notified when their changes are rejected. conditional requests allow implementing the optimistic locking algorithm (used by most wikis or source control systems). the concept is to allow al...

Forwarded - HTTP
the forwarded header contains information from the reverse proxy servers that is altered or lost when a proxy is involved in the path of the request. the alternative and de-facto standard versions of this header are the x-forwarded-for, x-forwarded-host and x-forwarded-proto headers. this header is used for debugging, statistics, and generating location-dependent content and by design it exposes privacy sensitive information, such as the ip address of the client. therefore the user's privacy must be kept in mind when deploying this header. header type request header forbidden header name no syntax forwarded: by=<identifier>;for=<identifier>;host=<host>;proto=<http|https> directives <identifier> an identifier disclosing the information that is altered or...

Index - HTTP
se header used to send cookies from the server to the user agent, but has been deprecated by the specification. use set-cookie instead. 102 sourcemap http, http header, reference, response header, header the sourcemap http response header links generated code to a source map, enabling the browser to reconstruct the original source and present the reconstructed original in the debugger. 103 strict-transport-security hsts, http, https, security, header the http strict-transport-security response header (often abbreviated as hsts) lets a web site tell browsers that it should only be accessed using https, instead of using http. 104 te http, reference, header the te request header specifies the transfer encodings the user agent is willin...

SourceMap - HTTP
the sourcemap http response header links generated code to a source map, enabling the browser to reconstruct the original source and present the reconstructed original in the debugger. header type response header forbidden header name no syntax sourcemap: <url> x-sourcemap: <url> (deprecated) directives <url> a relative (to the request url) or absolute url pointing to a source map file. examples sourcemap: /path/to/file.js.map specifications specification title draft document source map revision 3 proposal ...

X-Forwarded-For - HTTP
de-facto standard header for identifying the originating ip address of a client connecting to a web server through an http proxy or a load balancer. when traffic is intercepted between clients and servers, server access logs contain the ip address of the proxy or load balancer only. to see the original ip address of the client, the x-forwarded-for request header is used. this header is used for debugging, statistics, and generating location-dependent content and by design it exposes privacy sensitive information, such as the ip address of the client. therefore the user's privacy must be kept in mind when deploying this header. a standardized version of this header is the http forwarded header. x-forwarded-for is also an email-header indicating that an email-message was forwarded from anothe...

X-Forwarded-Host - HTTP
the x-forwarded-host (xfh) header is a de-facto standard header for identifying the original host requested by the client in the host http request header. host names and ports of reverse proxies (load balancers, cdns) may differ from the origin server handling the request, in that case the x-forwarded-host header is useful to determine which host was originally used. this header is used for debugging, statistics, and generating location-dependent content and by design it exposes privacy sensitive information, such as the ip address of the client. therefore the user's privacy must be kept in mind when deploying this header. a standardized version of this header is the http forwarded header. header type request header forbidden header name no syntax x-forwarde...

TRACE - HTTP
the final recipient of the request should reflect the message received, excluding some fields described below, back to the client as the message body of a 200 (ok) response with a content-type of message/http. the final recipient is either the origin server or the first server to receive a max-forwards value of 0 in the request. ...

Proxy servers and tunneling - HTTP
pictures, compression: compress and optimize content to speed up load time. forwarding client information through proxies proxies can make requests appear as if they originated from the proxy's ip address. this can be useful if a proxy is used to provide client anonymity, but in other cases information from the original request is lost. the ip address of the original client is often used for debugging, statistics, or generating location-dependent content. a common way to disclose this information is by using the following http headers: the standardized header: forwarded contains information from the client-facing side of proxy servers that is altered or lost when a proxy is involved in the path of the request. or the de-facto standard versions: x-forwarded-for identifies the o...

HTTP
esponses, redirections, client errors, and servers errors. csp directives the content-security-policy response header fields allows web site administrators to control resources the user agent is allowed to load for a given page. with a few exceptions, policies mostly involve specifying server origins and script endpoints. tools & resources helpful tools and resources for understanding and debugging http. firefox developer tools network monitor mozilla observatory a project designed to help developers, system administrators, and security professionals configure their sites safely and securely. redbot tools to check your cache-related headers how browsers work a very comprehensive article on browser internals and request flow through http protocol. a must-read for any web de...

JavaScript data types and data structures - JavaScript
a substring of the original by picking individual letters or using string.substr(). a concatenation of two strings using the concatenation operator (+) or string.concat(). beware of "stringly-typing" your code! it can be tempting to use strings to represent complex data. doing this comes with short-term benefits: it is easy to build complex strings with concatenation. strings are easy to debug (what you see printed is always what is in the string). strings are the common denominator of a lot of apis (input fields, local storage values, xmlhttprequest responses when using responsetext, etc.) and it can be tempting to only work with strings. with conventions, it is possible to represent any data structure in a string. this does not make it a good idea. for instance, with a separator, ...

Control flow and error handling - JavaScript
ws an exception. when the exception occurs, control transfers to the catch block. try { throw 'myexception'; // generates an exception } catch (err) { // statements to handle any exceptions logmyerrors(err); // pass exception object to error handler } best practice: when logging errors to the console inside a catch block, using console.error() rather than console.log() is advised for debugging. it formats the message as an error, and adds it to the list of error messages generated by the page. the finally block the finally block contains statements to be executed after the try and catch blocks execute. additionally, the finally block executes before the code that follows the try…catch…finally statement. it is also important to note that the finally block will execute wheth...

Functions - JavaScript
ch a function can be anonymous; it does not have to have a name. for example, the function square could have been defined as: const square = function(number) { return number * number } var x = square(4) // x gets the value 16 however, a name can be provided with a function expression. providing a name allows the function to refer to itself, and also makes it easier to identify the function in a debugger's stack traces: const factorial = function fac(n) { return n < 2 ? 1 : n * fac(n - 1) } console.log(factorial(3)) function expressions are convenient when passing a function as an argument to another function. the following example shows a map function that should receive a function as first argument and an array as second argument. function map(f, a) { let result = []; // create a new...

JavaScript modules - JavaScript
this clear — module features are imported into the scope of a single script — they aren't available in the global scope. therefore, you will only be able to access imported features in the script they are imported into, and you won't be able to access them from the javascript console, for example. you'll still get syntax errors shown in the devtools, but you'll not be able to use some of the debugging techniques you might have expected to use. default exports versus named exports the functionality we've exported so far has been comprised of named exports — each item (be it a function, const, etc.) has been referred to by its name upon export, and that name has been used to refer to it on import as well. there is also a type of export called the default export — this is designed to ...

Regular expressions - JavaScript
specifications specification ecmascript (ecma-262)the definition of 'regexp' in that specification. ...

Using Promises - JavaScript
edrejection sent when a promise is rejected but there is no rejection handler available. in both cases, the event (of type promiserejectionevent) has as members a promise property indicating the promise that was rejected, and a reason property that provides the reason given for the promise to be rejected. these make it possible to offer fallback error handling for promises, as well as to help debug issues with your promise management. these handlers are global per context, so all errors will go to the same event handlers, regardless of source. one case of special usefulness: when writing code for node.js, it's common that modules you include in your project may have unhandled rejected promises. these get logged to the console by the node runtime. you can capture these for analysis and hand...

Warning: -file- is being assigned a //# sourceMappingURL, but already has one - JavaScript
en javascript source. message warning: -file- is being assigned a //# sourcemappingurl, but already has one. error type a warning. javascript execution won't be halted. what went wrong? a source map has been specified more than once for a given javascript source. javascript sources are often combined and minified to make delivering them from the server more efficient. with source maps, the debugger can map the code being executed to the original source files. there are two ways to assign a source map, either by using a comment or by setting a header to the javascript file. examples setting source maps setting a source map by using a comment in the file: //# sourcemappingurl=http://example.com/path/to/your/sourcemap.map or, alternatively, you can set a header to your javascript file:...

SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead - JavaScript
ing: syntaxerror: using //@ to indicate sourcemappingurl pragmas is deprecated. use //# instead error type a warning that a syntaxerror occurred. javascript execution won't be halted. what went wrong? there is a deprecated source map syntax in a javascript source. javascript sources are often combined and minified to make delivering them from the server more efficient. with source maps, the debugger can map the code being executed to the original source files. the source map specification changed the syntax due to a conflict with ie whenever it was found in the page after //@cc_on was interpreted to turn on conditional compilation in the ie jscript engine. the conditional compilation comment in ie is a little known feature, but it broke source maps with jquery and other libraries. examp...

SyntaxError: test for equality (==) mistyped as assignment (=)? - JavaScript
s an assignment (=) when you would normally expect a test for equality (==). message warning: syntaxerror: test for equality (==) mistyped as assignment (=)? error type (firefox only) syntaxerror warning which is reported only if javascript.options.strict preference is set to true. what went wrong? there was an assignment (=) when you would normally expect a test for equality (==). to help debugging, javascript (with strict warnings enabled) warns about this pattern. examples assignment within conditional expressions it is advisable to not use simple assignments in a conditional expression (such as if...else), because the assignment can be confused with equality when glancing over the code. for example, do not use the following code: if (x = y) { // do the right thing } if you ne...

SyntaxError: missing variable name - JavaScript
is so hard. check to ensure the previous lines / declaration does not end with a comma instead of a semi-colon. examples missing a variable name var = "foo"; it's tough coming up with good variable names. we all have been there. var ohgodwhy = "foo"; reserved keywords can't be variable names there are a few variable names that are reserved keywords. you can't use these. sorry :( var debugger = "whoop"; // syntaxerror: missing variable name declaring multiple variables pay special attention to commas when declaring multiple variables. is there an excess comma? did you accidentally add commas instead of semicolons? var x, y = "foo", var x, = "foo" var first = document.getelementbyid('one'), var second = document.getelementbyid('two'), // syntaxerror: missing variable name th...

JavaScript error reference - JavaScript
the pages below will provide additional details about these errors. each error is an object based upon the error object, and has a name and a message. errors displayed in the web console may include a link to the corresponding page below to help you quickly comprehend the problem in your code. for a beginner's introductory tutorial on fixing javascript errors, see what went wrong? troubleshooting javascript. ...

Array.prototype.toSource() - JavaScript
e method returns the following values: for the built-in array object, tosource returns the following string indicating that the source code is not available: function array() { [native code] } for instances of array, tosource returns a string representing the source code. this method is usually called internally by javascript and not explicitly in code. you can call tosource while debugging to examine the contents of an array. examples examining the source code of an array to examine the source code of an array: var alpha = new array('a', 'b', 'c'); alpha.tosource(); //returns ['a', 'b', 'c'] specifications not part of any standard. implemented in javascript 1.3. ...

Error.prototype.fileName - JavaScript
the filename property contains the path to the file that raised this error. description this non-standard property contains the path to the file that raised this error. if called from a debugger context, the firefox developer tools for example, "debugger eval code" is returned. examples using filename var e = new error('could not parse input'); throw e; // e.filename could look like "file:///c:/example.html" specifications not part of any standard. ...

Error - JavaScript
stomerror extends error { constructor(foo = 'bar', ...params) { // pass remaining arguments (including vendor specific ones) to parent constructor super(...params) // maintains proper stack trace for where our error was thrown (only available on v8) if (error.capturestacktrace) { error.capturestacktrace(this, customerror) } this.name = 'customerror' // custom debugging information this.foo = foo this.date = new date() } } try { throw new customerror('baz', 'bazmessage') } catch(e) { console.error(e.name) //customerror console.error(e.foo) //baz console.error(e.message) //bazmessage console.error(e.stack) //stacktrace } es5 custom error object all browsers include the customerror constructor in the stack trace when using a pr...

Function.prototype.toSource() - JavaScript
syntax function.tosource(); return value a string representing the source code of the object. ...