Using CSS custom properties (variables) - CSS: Cascading Style Sheets
custom property fallback values using the var() function, you can define multiple fallback values when the given variable is not yet defined; this can be useful when working with custom elements and shadow dom.
... fallback values aren't used to fix the browser compatibility.
... if the browser doesn't support css custom properties, the fallback value won't help.
...And 6 more matches

JIT Optimization Strategies
inline caches start off as a jump to a separate piece of code called a "fallback".
... the fallback calls into the interpreter vm (which is very slow) to perform the operation, and then decides if the operation can be optimized in that particular case.
... inline caches start off as a jump to a separate piece of code called a "fallback".
...And 5 more matches

Backwards Compatibility of Flexbox - CSS: Cascading Style Sheets
in this guide we will look at how well flexbox is supported in browsers, and look at some potential issues, resources and methods for creating workarounds and fallbacks.
... useful fallback techniques given that flexbox usage is initiated with value of the display property, when needing to support very old browsers which do not support flexbox at all, fallbacks can be created by overwriting one layout method with another.
... you can test the fallback behaviour by removing display: flex from the wrapper.
...And 5 more matches

Index - Web APIs
500 cssvariablereferencevalue.fallback api, css typed object model api, cssvariablereferencevalue, houdini, needsexample, property, reference, fallback the fallback read-only property of the cssvariablereferencevalue interface returns a custom name for a built-in css value.
...</canvas> tags can be used as a fallback for browsers which don't support canvas rendering.
...you can specify an exact value which must be matched, an ideal value that should be matched if at all possible, and a fallback value to attempt to match once all more specific constraints have been applied.
...And 4 more matches

Cross-browser audio basics - Developer guides
c guide to creating a cross-browser html5 audio player with all the associated attributes, properties, and events explained a guide to custom controls created using the media api basic audio example the code below is an example of a basic audio implementation using html5: <audio controls> <source src="audiofile.mp3" type="audio/mpeg"> <source src="audiofile.ogg" type="audio/ogg"> <!-- fallback for non supporting browsers goes here --> <p>your browser does not support html5 audio, but you can still <a href="audiofile.mp3">download the music</a>.</p> </audio> note: you can also use an mp4 file instead of mp3.
...so the ideal place to create a fallback or inform of incompatibility is before the closing </audio> tag.
...</audio> fallbacks although the vast majority of browsers now support the <audio> element, you may want to cater for those that don't, such as ie<9.
...And 4 more matches

@counter-style - CSS: Cascading Style Sheets
if a counter style is used to represent a counter value outside of its ranges, the counter style will drop back to its fallback style.
... fallback specifies a system to fall back into if either the specified system is unable to construct the representation of a counter value or if the counter value outside the specified range.
... if the specified fallback also fails to represent the value, then the fallback style's fallback is used, if one is specified.
...And 3 more matches

font-display - CSS: Cascading Style Sheets
syntax /* keyword values */ font-display: auto; font-display: block; font-display: swap; font-display: fallback; font-display: optional; values auto the font display strategy is defined by the user agent.
... fallback gives the font face an extremely small block period and a short swap period.
... font block period if the font face is not loaded, any element attempting to use it must render an invisible fallback font face.
...And 3 more matches

<video>: The Video Embed element - HTML: Hypertext Markup Language
the content inside the opening and closing <video></video> tags is shown as a fallback in browsers that don't support the element.
... in safari, you can use x-webkit-airplay="deny" as a fallback.
... to test the fallback content on browsers that support the element, you can replace <video> with a non-existing element like <notavideo>.
...And 3 more matches

Browser detection using the user agent - HTTP
if it's not, you use a fallback.
... var camelcaseexpression = new regexp("(?<=[a-z])"); var splitupstring = function(str) { return (""+str).split(camelcaseexpression); }; } else { /*this fallback code is much less performant, but works*/ var splitupstring = function(str){ return str.replace(/[a-z]/g,"z$1").split(/z(?=[a-z])/g); }; } console.log(splitupstring("foobare")); // ["foob", "are"] console.log(splitupstring("jqwhy")); // ["jq", "w", "hy"] the above code would have made several incorrect assumptions: it assumed that all user agent strings that include the sub...
...chscreen = navigator.maxtouchpoints > 0; } else if ("msmaxtouchpoints" in navigator) { hastouchscreen = navigator.msmaxtouchpoints > 0; } else { var mq = window.matchmedia && matchmedia("(pointer:coarse)"); if (mq && mq.media === "(pointer:coarse)") { hastouchscreen = !!mq.matches; } else if ('orientation' in window) { hastouchscreen = true; // deprecated, but good fallback } else { // only as a last resort, fall back to user agent sniffing var ua = navigator.useragent; hastouchscreen = ( /\b(blackberry|webos|iphone|iemobile)\b/i.test(ua) || /\b(android|windows phone|ipad|ipod)\b/i.test(ua) ); } } if (hastouchscreen) document.getelementbyid("examplebutton").style.padding="1em"; as for the screen ...
...And 3 more matches

Authoring MathML - MathML
fallback for browsers without mathml support unfortunately, some browsers are not able to render mathml equations or only have a limited support.
... hence you will need to use a mathml polyfill to provide some fallback rendering.
...there is also a similar script to display a warning at the top of the page for browsers without good mathml support and let the users choose between one of the fallback above: <script src="https://fred-wang.github.io/mathml-warning.js/mpadded-min.js"></script> if you don't want to use this link to github but instead to integrate these polyfills or others in your own project, you might need the detection scripts to verify the level of mathml support.
...And 3 more matches

Other form controls - Learn web development
label for="myfruit">what's your favorite fruit?</label> <input type="text" name="myfruit" id="myfruit" list="mysuggestion"> <datalist id="mysuggestion"> <option>apple</option> <option>banana</option> <option>blackberry</option> <option>blueberry</option> <option>lemon</option> <option>lychee</option> <option>peach</option> <option>pear</option> </datalist> datalist support and fallbacks almost all browsers support datalist, but if you are still supporting older browsers such as ie versions below 10, there is a trick to provide a fallback: <label for="myfruit">what is your favorite fruit?
... (with fallback)</label> <input type="text" id="myfruit" name="fruit" list="fruitlist"> <datalist id="fruitlist"> <label for="suggestion">or pick a fruit</label> <select id="suggestion" name="altfruit"> <option>apple</option> <option>banana</option> <option>blackberry</option> <option>blueberry</option> <option>lemon</option> <option>lychee</option> <option>peach</option> <option>pear</option> </select> </datalist> browsers that support the <datalist> element will ignore all the elements that are not <option> elements, with the datalist working as expected.
... the following screenshot shows the datalist fallback as rendered in safari 6: if you use this fallback, ensure the data for both the <input> and the <select> are collected server-side.
...And 2 more matches

Application cache implementation overview
when aentrystatus is a failure code, entry has not been found, but the url is falling under one of the network or fallback namespaces.
... when matching fallback namespace, the associated fallback entry for it is remembered.
...when load of the resource fails fallback steps are performed (see “falling back on a resource load failure” chapter).
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NSS 3.16.2.3 release notes
nss 3.16.2.3 source distributions are available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_16_2_3_rtm/src/ new in nss 3.16.2.3 this patch release fixes a bug and contains a backport of the tls_fallback_scsv feature, which was originally made available in nss 3.17.1.
... new functionality tls_fallback_scsv is a signaling cipher suite value that indicates a handshake is the result of tls version fallback.
... new macros in ssl.h ssl_enable_fallback_scsv - an ssl socket option that enables tls_fallback_scsv.
...And 2 more matches

FontFace.display - Web APIs
(see below.) block period the browser invisibly prepares a fallback font.
... swap period if the font face is still not loaded, the fallback font will be shown.
... when the font face loads, the fallback will be swaped for the downloaded font.
...And 2 more matches

Using the Payment Request API - Web APIs
// if paymentrequest fails, should the page fallback to manual // web form checkout?
...let shouldcallpaymentrequest = true; let fallbacktolegacyonpaymentrequestfailure = false; (new paymentrequest(supportedpaymentmethods, {total: {label: 'stub', amount: {currency: 'usd', value: '0.01'}}}) .canmakepayment() .then(function(result) { shouldcallpaymentrequest = result; }).catch(function(error) { console.log(error); // the user may have turned off query ability in their privacy settings.
... // let's use paymentrequest by default and fallback to legacy // web form based checkout.
...And 2 more matches

Cross-browser Flexbox mixins - CSS: Cascading Style Sheets
this set uses: fallbacks using 2009 'box' syntax (ff and older webkit) and prefixed syntaxes (ie10, webkit browsers without flex wrapping) final standards syntax (ff, safari, chrome, ie11+, edge, opera) this was inspired by: http://dev.opera.com/articles/view/advanced-cross-browser-flexbox/ with help from: http://w3.org/tr/css3-flexbox/ http://the-echoplex.net/flexyboxes/ http://msdn.microsoft.com/en-us/library/ie/hh772069(v=vs.85).aspx http://css-tricks.com/using-flexbox/ a complete guide to flexbox | css-tricks visual guide to css3 flexbox: flexbox playground | note: mixins are not currently supported natively in browsers.
... values: nowrap (default) | wrap | wrap-reverse spec: https://drafts.csswg.org/css-flexbox/#flex-wrap-property @mixin flex-wrap($value: nowrap) { // no webkit/ff box fallback.
... values: row (default) | nowrap spec: https://drafts.csswg.org/css-flexbox/#flex-flow-property @mixin flex-flow($values: (row nowrap)) { // no webkit/ff box fallback.
...And 2 more matches

image() - CSS: Cascading Style Sheets
the image() css function defines an <image> in a similar fashion to the <url> function, but with added functionality including specifying the image's directionality, specifying fallback images for when the preferred image is not supported, displaying just a part of that image defined by a media fragment, and specifying a solid color as a fallback in case none of the specified images are able to be rendered.
... coloroptional a color, specifying a solid background color to use as a fallback if no image-src is found, supported, or declared.
... color fallback if a color is specified in image() along with your image sources, it acts as a fallback if the images are invalid and do not appear.
...And 2 more matches

var() - CSS: Cascading Style Sheets
an optional second argument to the function serves as a fallback value.
...) note: the syntax of the fallback, like that of custom properties, allows commas.
... for example, var(--foo, red, blue) defines a fallback of red, blue; that is, anything between the first comma and the end of the function is considered a fallback value.
...And 2 more matches

<input type="date"> - HTML: Hypertext Markup Language
even though the date picker doesn't use it, the text input fallback will.
... html the html looks like so: <form> <div class="nativedatepicker"> <label for="bday">enter your birthday:</label> <input type="date" id="bday" name="bday"> <span class="validity"></span> </div> <p class="fallbacklabel">enter your birthday:</p> <div class="fallbackdatepicker"> <span> <label for="day">day:</label> <select id="day" name="day"> </select> </span> <span> <label for="month">month:</label> <select id="month" name="month"> <option selected>january</option> <option>february</option> <option>march</option> ...
...if <input type="date"> isn't supported, we hide the native picker and show the fallback (<select>) instead.
...And 2 more matches

<input type="datetime-local"> - HTML: Hypertext Markup Language
even though the datetime-local input doesn't use it, the text input fallback will.
... the html looks like so: <form> <div class="nativedatetimepicker"> <label for="party">choose a date and time for your party:</label> <input type="datetime-local" id="party" name="bday"> <span class="validity"></span> </div> <p class="fallbacklabel">choose a date and time for your party:</p> <div class="fallbackdatetimepicker"> <div> <span> <label for="day">day:</label> <select id="day" name="day"> </select> </span> <span> <label for="month">month:</label> <select id="month" name="month"> <option selected>january</option> <option>february</option> ...
...if <input type="datetime-local"> is not supported, we hide the native picker and show the fallback picker ui (<select>) instead.
...And 2 more matches

<input type="month"> - HTML: Hypertext Markup Language
html the form that requests the month and year looks like this: <form> <div class="nativedatepicker"> <label for="month-visit">what month would you like to visit us?</label> <input type="month" id="month-visit" name="month-visit"> <span class="validity"></span> </div> <p class="fallbacklabel">what month would you like to visit us?</p> <div class="fallbackdatepicker"> <div> <span> <label for="month">month:</label> <select id="month" name="month"> <option selected>january</option> <option>february</option> <option>march</option> <option>april</option> <option>may</option> <option>june</option> ...
...n>october</option> <option>november</option> <option>december</option> </select> </span> <span> <label for="year">year:</label> <select id="year" name="year"> </select> </span> </div> </div> </form> the <div> with the id nativedatepicker uses the month input type to request the month and year, while the <div> with the id fallbackdatepicker instead uses a pair of <select> elements.
...if <input type="month"> is not supported, we hide the native picker and show the fallback picker ui instead.
...And 2 more matches

<input type="time"> - HTML: Hypertext Markup Language
even though the time input doesn't use it, the text input fallback will.
... the html looks like so: <form> <div class="nativetimepicker"> <label for="appt-time">choose an appointment time (opening hours 12:00 to 18:00): </label> <input id="appt-time" type="time" name="appt-time" min="12:00" max="18:00" required> <span class="validity"></span> </div> <p class="fallbacklabel">choose an appointment time (opening hours 12:00 to 18:00):</p> <div class="fallbacktimepicker"> <div> <span> <label for="hour">hour:</label> <select id="hour" name="hour"> </select> </span> <span> <label for="minute">minute:</label> <select id="minute" name="minute"> </select> </span> </div> </div> </form> ...
...if <input type="time"> is not supported, we hide the native picker and show the fallback picker ui (<select>s) instead.
...And 2 more matches

<script>: The Script element - HTML: Hypertext Markup Language
nomodule this boolean attribute is set to indicate that the script should not be executed in browsers that support es2015 modules — in effect, this can be used to serve fallback scripts to older browsers that do not support modular javascript code.
... note: an empty string value ("") is both the default value, and a fallback value if referrerpolicy is not supported.
... <script> alert("hello world!"); </script> module fallback browsers that support the module value for the type attribute ignore any script with a nomodule attribute.
...And 2 more matches

Web video codec guide - Web media technologies
of note, however, is that safari supports neither webm nor vp9, so if you choose to use vp9, be sure to offer a fallback format such as avc or hevc for iphone, ipad, and mac users.
... aside from the lack of safari support, vp9 is a good choice if you are able to use a webm container and are able to provide a fallback video in a format such as avc or hevc for safari users.
...if you can't provide a fallback and aren't willing to sacrifice safari compatibility, vp9 in webm is a good option.
...And 2 more matches

From object to iframe — other embedding technologies - Learn web development
say you wanted to include the mdn glossary on one of your web pages — you could try something like this: <iframe src="https://udn.realityripple.com/docs/glossary" width="100%" height="500" frameborder="0" allowfullscreen sandbox> <p> <a href="https://udn.realityripple.com/docs/glossary"> fallback link for browsers that don't support iframes </a> </p> </iframe> this example includes the basic essentials needed to use an <iframe>: allowfullscreen if set, the <iframe> is able to be placed in fullscreen mode using the full screen api (somewhat beyond scope for this article.) frameborder if set to 1, this tells the browser to draw a border between this frame and other frames, whic...
... fallback content in the same way as other similar elements like <video>, you can include fallback content between the opening and closing <iframe></iframe> tags that will appear if the browser doesn't support the <iframe>.
... data accurate media type of the embedded content type type height and width (in css pixels) of the box controlled by the plugin height width height width names and values, to feed the plugin as parameters ad hoc attributes with those names and values single-tag <param> elements, contained within <object> independent html content as fallback for an unavailable resource not supported (<noembed> is obsolete) contained within <object>, after <param> elements note: <object> requires a data attribute, a type attribute, or both.
...the html generated by the adobe flash tool tended to be even worse, using an <object> element with an <embed> element embedded in it, to cover all bases (check out an example.) flash was even used successfully as fallback content for html5 video, for a time, but this is increasingly being seen as not necessary.

Drawing graphics - Learn web development
inside the canvas tags, you can put some fallback content, which is shown if the user's browser doesn't support canvas.
...in a real example you'd want to relate the fallback content to the canvas content.
... for example, if you were rendering a constantly updating graph of stock prices, the fallback content could be a static image of the latest stock graph, with alt text saying what the prices are in text.
... add the following code into it, just below the opening <body> tag: <canvas class="mycanvas"> <p>add suitable fallback here.</p> </canvas> we have added a class to the <canvas> element so it will be easier to select if we have multiple canvases on the page, but we have removed the width and height attributes for now (you could add them back in if you wanted, but we will set them using javascript in a below section).

NSS 3.17.1 release notes
new functionality tls_fallback_scsv is a signaling cipher suite value that indicates a handshake is the result of tls version fallback.
... new macros in ssl.h ssl_enable_fallback_scsv - an ssl socket option that enables tls_fallback_scsv.
... in sslerr.h ssl_error_inappropriate_fallback_alert - a new ssl error code.
... in sslproto.h tls_fallback_scsv - a a signaling cipher suite value that indicates a handshake is the result of tls version fallback.

HTMLImageElement.src - Web APIs
if you use the srcset content attribute to provide multiple image options for different display pixel densities, the url specified by the src attribute is used in one of two ways: as a fallback for browsers that don't support srcset.
... additionally, if you use src along with both sizes (or the corresponding sizes content attribute) and srcset in order to choose an image based on the viewport size, the src attribute is only used as a fallback for browsers that don't support sizes and srcset; otherwise, it's not used at all.
... examples specifying a single image html <img src="https://udn.realityripple.com/samples/d6/7ab36d79bb.jpg" width="160" alt="slices of grapefruit, looking yummy."> result using src with an image set when using a set of images with the srcset property, the src serves as either a fallback for older browsers, or as the 1x size of the image.
... html result specifying a fallback for viewport-based selection when using viewport-bases selection of an image from a srcset by also specifying the sizes property, the src property serves as the fallback to be used on browsers that don't support viewport-based selection.

Browser compatibility and Scroll Snap - CSS: Cascading Style Sheets
the main things to note are as follows: the scroll-snap-type-x and scroll-snap-type-y properties have been dropped the scroll-snap-type property has become a longhand, so the old shorthand syntax like scroll-snap-type:mandatory will stop working can i use the old implementation as a fallback?
... if you have already used the old implementation as a fallback, or feel you want to support users of old firefox (or -webkit prefixed safari), then you can continue to use the old specification as outlined in the example below.
... scroll snapping is one of those nice parts of css in which the fallback is that you don't get the enhanced functionality, but everything still works.
... i would suggest at this point you should implement the new specification only, unless you have data to show a large number of users who would benefit from a fallback version.

cursor - CSS: Cascading Style Sheets
syntax /* keyword value */ cursor: pointer; cursor: auto; /* url, with a keyword fallback */ cursor: url(hand.cur), pointer; /* url and coordinates, with a keyword fallback */ cursor: url(cursor1.png) 4 12, auto; cursor: url(cursor2.png) 2 2, pointer; /* global values */ cursor: inherit; cursor: initial; cursor: unset; the cursor property is specified as zero or more <url> values, separated by commas, followed by a single mandatory keyword value.
...more than one <url> may be provided as fallbacks, in case some cursor image types are not supported.
... a non-url fallback (one or more of the keyword values) must be at the end of the fallback list.
...sshair | text | vertical-text | alias | copy | move | no-drop | not-allowed | e-resize | n-resize | ne-resize | nw-resize | s-resize | se-resize | sw-resize | w-resize | ew-resize | ns-resize | nesw-resize | nwse-resize | col-resize | row-resize | all-scroll | zoom-in | zoom-out | grab | grabbing ] ] examples setting cursor types .foo { cursor: crosshair; } .bar { cursor: zoom-in; } /* a fallback keyword value is required when using a url */ .baz { cursor: url("hyper.cur"), auto; } specifications specification status comment css basic user interface module level 3the definition of 'cursor' in that specification.

<audio>: The Embed Audio element - HTML: Hypertext Markup Language
the content inside the opening and closing <audio></audio> tags is shown as a fallback in browsers that don't support the element.
... in safari, you can use x-webkit-airplay="deny" as a fallback.
...it will autoplay due to the autoplay attribute—if the page has permission to do so—and also includes fallback content.
... also it's a good practice to provide some content (such as the direct download link) as a fallback for viewers who use a browser in which the <audio> element is not supported: <audio controls> <source src="myaudio.mp3" type="audio/mpeg"> <source src="myaudio.ogg" type="audio/ogg"> <p> your browser doesn't support html5 audio.

<input type="week"> - HTML: Hypertext Markup Language
the html looks like so: <form> <div class="nativeweekpicker"> <label for="week">what week would you like to start?</label> <input id="week" type="week" name="week" min="2017-w01" max="2018-w52" required> <span class="validity"></span> </div> <p class="fallbacklabel">what week would you like to start?</p> <div class="fallbackweekpicker"> <div> <span> <label for="week">week:</label> <select id="fallbackweek" name="week"> </select> </span> <span> <label for="year">year:</label> <select id="year" name="year"> <option value="2017" selected>2017</option> <option value="2018">...
...if <input type="week"> is not supported, we hide the native picker and show the fallback picker ui (<select>s) instead.
... // define variables var nativepicker = document.queryselector('.nativeweekpicker'); var fallbackpicker = document.queryselector('.fallbackweekpicker'); var fallbacklabel = document.queryselector('.fallbacklabel'); var yearselect = document.queryselector('#year'); var weekselect = document.queryselector('#fallbackweek'); // hide fallback initially fallbackpicker.style.display = 'none'; fallbacklabel.style.display = 'none'; // test whether a new date input falls back to a text input or not var test = document.createelement('input'); try { test.type = 'week'; } catch (e) { console.log(e.description); } // if it does, run the code inside the if() {} block if(test.type === 'text') { // hide the native picker and show the fallback nativepicker.style.display = 'none'; fallbackpicker.styl...
...e.display = 'block'; fallbacklabel.style.display = 'block'; // populate the weeks dynamically populateweeks(); } function populateweeks() { // populate the week select with 52 weeks for(var i = 1; i <= 52; i++) { var option = document.createelement('option'); option.textcontent = (i < 10) ?

Media container formats (file types) - Web media technologies
consider using this container format compressed files for general-purpose playback mp3 (mpeg-1 audio layer iii) losslessly compressed files flac with alac fallback uncompressed files wav now that mp3's patents have all expired, the choice of audio file format has become much easier to make.
... consider using this container format general purpose video, preferably in an open format webm (ideally with mp4 fallback) general purpose video mp4 (ideally with webm or ogg fallback) high compression optimized for slow connections 3gp (ideally with mp4 fallback) compatibility with older devices/browsers quicktime (ideally with avi and/or mpeg-2 fallback) these suggestions make a number of assumptions.
...for example, you can offer an ogg or webm video as the first choice, with a fallback in mp4 format.
... you could even choose to offer a retro-like quicktime or avi fallback for good measure.

Appendix F: Monitoring DOM changes - Archive of obsolete content
while they are still viable for add-ons targeting only the latest firefox, those wishing to support older browsers will need to provide fallbacks.
... the code below contains an inefficient fallback implementation for older browsers.
... it is worth noting, however, that while the animation-based implementation will fire any time an element which previously did not match the given selector is changed so that it does (when a class is added, for instance), the fallback will only match nodes when they are inserted into the dom tree.

XInclude - MDN Web Docs Glossary: Definitions of Web-related terms
code sample the following code aims to let <xi:include> and <xi:fallback> tags (the two elements in the language) with all of the attributes of <xi:include> be included in an xml document so as to be resolvable into a single xml document.
...ibute('xpointer'); var encoding = xinclude.getattribute('encoding'); // e.g., utf-8 // "text/xml or application/xml or matches text/*+xml or application/*+xml" before encoding (then utf-8) var accept = xinclude.getattribute('accept'); // header "accept: "+x var acceptlanguage = xinclude.getattribute('accept-language'); // "accept-language: "+x var xifallback = xinclude.getelementsbytagnamens('http://www.w3.org/2001/xinclude', 'fallback')[0]; // only one such child is allowed if (href === '' || href === null) { // points to same document if empty (null is equivalent to empty string) href = null; // set for uniformity in testing below if (parse === 'xml' && xpointer === null) { alert('ther...
...lace xinclude with the response as text var textnode = docu.createtextnode(response); xincludeparent.replacechild(textnode, xinclude); } // replace xinclude in doc with response now (as plain text or xml) } } } catch (e) { // use xi:fallback if xinclude retrieval above failed var xifallbackchildren = xifallback.childnodes; // prepend any node(s) then remove xinclude for (j=0; j < xifallbackchildren.length ; j++) { xincludeparent.insertbefore(xifallbackchildren[j], xinclude); } xincludeparent.removechild(xinclude); } ...

Adding vector graphics to the Web - Learn web development
in the below code, older browsers will stick with the png that they understand, while newer browsers will load the svg: background: url("fallback.png") no-repeat center; background-image: url("image.svg"); background-size: contain; like the <img> method described above, inserting svgs using css background images means that the svg can't be manipulated with javascript, and is also subject to the same css limitations.
... you may include fallback in a <foreignobject> element, but browsers that support svg still download any fallback images.
... here's a quick review: <iframe src="triangle.svg" width="500" height="500" sandbox> <img src="triangle.png" alt="triangle with three unequal sides" /> </iframe> this is definitely not the best method to choose: cons iframes do have a fallback mechanism, as you can see, but browsers only display the fallback if they lack support for iframes altogether.

nsIApplicationCacheNamespace
method overview void init(in unsigned long itemtype, in acstring namespacespec, in acstring data); attributes attribute type description data acstring data associated with the namespace, such as a fallback.
... namespace_fallback 2 items matching this namespace can be fetched from the network when loading from this cache; however, if the load fails, the cache entry specified by the data attribute should be loaded intstead.
...this can be combined with namespace_fallback to provide a fallback entry in the data attribute.

nsIHttpChannelInternal
m: nsisupports last changed in gecko 6.0 (firefox 6.0 / thunderbird 6.0 / seamonkey 2.3) method overview void getrequestversion(out unsigned long major, out unsigned long minor); void getresponseversion(out unsigned long major, out unsigned long minor); void httpupgrade(in acstring aprotocolname, in nsihttpupgradelistener alistener); void setcookie(in string acookieheader); void setupfallbackchannel(in string afallbackkey); attributes attribute type description canceled boolean returns true if and only if the channel has been canceled.
... setupfallbackchannel() sets up this channel as an application cache fallback channel.
... void setupfallbackchannel( in string afallbackkey ); parameters afallbackkey the fallback key.

CSSVariableReferenceValue() - Web APIs
syntax new cssvariablereferencevalue(variable[, fallback]]) parameters variable a custom property name.
... fallback optional.
... a custom property fallback value.

HTMLImageElement.srcset - Web APIs
if the condition descriptor is not provided (in other words, the image candidate provides only a url), the candidate is used as the fallback if none of the other candidates match.
...an additional, fallback image candidate is provided without any condition at all, to be used for any other width.
...a fallback image is provided as an svg file that should be used in all other cases.

HTMLMediaElement.srcObject - Web APIs
const mediasource = new mediasource(); const video = document.createelement('video'); video.srcobject = mediasource; supporting fallback to the src property the examples below support older browser versions that require you to create an object url and assign it to src if srcobject isn't supported.
... first, a mediastream from a camera is assigned to a newly-created <video> element, with fallback for older browsers.
... video.src = url.createobjecturl(mediastream); } second, a new mediasource is assigned to a newly-created <video> element, with fallback for older browsers and browsers that don't yet support assignment of mediasource directly.

Recommended Drag Types - Web APIs
it is recommended to always add data of the text/plain type as a fallback for applications or drop targets that do not support other types, unless there is no logical text alternative.
...for example: var dt = event.datatransfer; dt.setdata("text/uri-list", "https://www.mozilla.org"); dt.setdata("text/plain", "https://www.mozilla.org"); as usual, set the text/plain type last, as a fallback for the text/uri-list type.
... the text/plain fallback for multiple links should include all urls, but no comments.

Using Service Workers - Web APIs
: { 'content-type': 'text/html' } }); if a match wasn’t found in the cache, you could tell the browser to simply fetch the default network request for that resource, to get the new resource from the network if it is available: fetch(event.request); if a match wasn’t found in the cache, and the network isn’t available, you could just match the request with some kind of default fallback page as a response using match(), like this: caches.match('./fallback.html'); you can retrieve a lot of information about each request by calling parameters of the request object returned by the fetchevent: event.request.url event.request.method event.request.headers event.request.body recovering failed requests so caches.match(event.request) is great when there is a match in the...
...let’s provide a default fallback so that whatever happens, the user will at least get something: self.addeventlistener('fetch', (event) => { event.respondwith( caches.match(event.request).then((resp) => { return resp || fetch(event.request).then((response) => { let responseclone = response.clone(); caches.open('v1').then((cache) => { cache.put(event.request, responseclone); }); ...
... return response; }); }).catch(() => { return caches.match('./sw-test/gallery/mylittlevader.jpg'); }) ); }); we have opted for this fallback image because the only updates that are likely to fail are new images, as everything else is depended on for installation in the install event listener we saw earlier.

CSS Box Alignment - CSS: Cascading Style Sheets
fallback alignment if you set an alignment that cannot be fulfilled, then the fallback alignment will come into play and deal with the available space.
... this fallback alignment is specified individually for each layout method and detailed on the page for that method.
...ment in css grid layout box alignment in multiple-column layout box alignment for block, absolutely positioned and table layout reference css properties justify-content align-content place-content justify-items align-items place-items justify-self align-self place-self row-gap column-gap gap glossary entries cross axis main axis alignment container alignment subject fallback alignment guides css flexbox guide: basic concepts of flexbox css flexbox guide: aligning items in a flex container css grid guide: box alignment in css grid layouts external resources box alignment cheatsheet css grid, flexbox and box alignment thoughts on partial implementations of box alignment ...

Using feature queries - CSS: Cascading Style Sheets
we can't create a fallback by checking for browsers which do not have support, as ie11 doesn't support feature queries either!
... this may mean you have a little more code but comes with the benefit of being able to test the fallback by misspelling the property or value name.
...as you can wrap up the css for supporting browsers, you do not run the risk of styles used for the fallback display leaking through, as shown in our grid example above.

attr() - CSS: Cascading Style Sheets
/* simple usage */ attr(data-count); attr(title); /* with type */ attr(src url); attr(data-count number); attr(data-width px); /* with fallback */ attr(data-count number, 0); attr(src url, ""); attr(data-width px, inherit); attr(data-something, "default"); syntax values attribute-name is the name of an attribute on the html element referenced in the css.
... <fallback> the value to be used if the associated attribute is missing or contains an invalid value.
...[, <attr-fallback> ]?

env() - CSS: Cascading Style Sheets
syntax /* using the four safe area inset values with no fallback values */ env(safe-area-inset-top); env(safe-area-inset-right); env(safe-area-inset-bottom); env(safe-area-inset-left); /* using them with fallback values */ env(safe-area-inset-top, 20px); env(safe-area-inset-right, 1em); env(safe-area-inset-bottom, 0.5vh); env(safe-area-inset-left, 1.4rem); values safe-area-inset-top, safe-area-inset-right, safe-area-inset-bottom, safe-area-inset-left th...
...) examples the below example makes use of the optional second parameter of env(), which allows you to provide a fallback value in case the environment variable is not available.
...r all rectangular user agents */ padding: env(safe-area-inset-bottom, 50px); /* 50px because ua properties are case sensitive */ padding: env(x, 50px 20px); /* as if padding: '50px 20px' were set because x is not a valid environment variable */ padding: env(x, 50px, 20px); /* ignored because '50px, 20px' is not a valid padding value and x is not a valid environment variable */ the syntax of the fallback, like that of custom properties, allows commas.

Live streaming web audio and video - Developer guides
for example: <video src="rtsp://myhost.com/mymedia.format"> <!-- fallback here --> </video> media source extensions (mse) media source extensions is a w3c working draft that plans to extend htmlmediaelement to allow javascript to generate media streams for playback.
... internet explorer 10+ ✓ 11 ✓ [2] firefox mobile ✓ ✓ ✓ safari ios6+ ✓ chrome mobile ✓ ✓ [2] opera mobile ✓ [1] ✓ internet explorer mobile ✓ 11 ✓ [2] android ✓ [1] via javascript and mse [2] via javascript and a cors proxy video fallbacks between dash and hls we can cover a significant portion of modern browsers but we still need a fallback if we want to support the rest.
... one popular approach is to use a flash fallback that supports rtmp.

Creating a cross-browser video player - Developer guides
<figure id="videocontainer"> <video id="video" controls preload="metadata" poster="img/poster.jpg"> <source src="video/tears-of-steel-battle-clip-medium.mp4" type="video/mp4"> <source src="video/tears-of-steel-battle-clip-medium.webm" type="video/webm"> <source src="video/tears-of-steel-battle-clip-medium.ogg" type="video/ogg"> <!-- flash fallback --> <object type="application/x-shockwave-flash" data="flash-player.swf?videourl=video/tears-of-steel-battle-clip-medium.mp4" width="1024" height="576"> <param name="movie" value="flash-player.swf?videourl=video/tears-of-steel-battle-clip-medium.mp4" /> <param name="allowfullscreen" value="true" /> <param name="wmode" value="transparent" /> <param name="f...
...in addition a download link is displayed to allow users to download the mp4 video file, should they wish to (providing those without flash installed with a method of viewing the video, a fallback for a fallback if you like).
...for the progress bar, the progress element is taken advantage of, with a fallback provided for browsers that don't support it (e.g.

HTML elements reference - HTML: Hypertext Markup Language
<rp> the html ruby fallback parenthesis (<rp>) element is used to provide fall-back parentheses for browsers that do not support display of ruby annotations using the <ruby> element.
... <noembed> the <noembed> element is an obsolete, non-standard way to provide alternative, or "fallback", content for browsers that do not support the <embed> element or do not support the type of embedded content an author wishes to use.
... <noframes> the obsolete html no frames or frame fallback element, <noframes>, provides content to be presented in browsers that don't support (or have disabled support for) the <frame> element.

HTML documentation index - HTML: Hypertext Markup Language
165 <noembed>: the embed fallback element (obsolete) element, embedded content, embedding, html, non-standard, obsolete, reference, noembed the <noembed> element is an obsolete, non-standard way to provide alternative, or "fallback", content for browsers that do not support the <embed> element or do not support the type of embedded content an author wishes to use.
... 166 <noframes>: the frame fallback element element, frames, html, html frames, obsolete, reference, web, noframes the obsolete html no frames or frame fallback element, <noframes>, provides content to be presented in browsers that don't support (or have disabled support for) the <frame> element.
... 181 <rp>: the ruby fallback parenthesis element element, html, html text-level semantics, reference, ruby, text, web the html ruby fallback parenthesis (<rp>) element is used to provide fall-back parentheses for browsers that do not support display of ruby annotations using the <ruby> element.

CSP: script-src-attr - HTTP
csp version 3 directive type fetch directive default-src fallback yes.
... if this directive is absent, the user agent will look for the script-src directive, and if both of them are absent, fallback to default-src directive.
... examples fallback to script-src if script-src-attr is absent, user agent falls back to the script-src directive, and if that is absent as well, to default-src.

CSP: script-src-elem - HTTP
csp version 3 directive type fetch directive default-src fallback yes.
... if this directive is absent, the user agent will look for the script-src directive, and if both of them are absent, fallback to default-src directive.
... examples fallback to script-src if script-src-elem is absent, user agent falls back to the script-src directive, and if that is absent as well, to default-src.

Codecs used by WebRTC - Web media technologies
it is generally used as a least common denominator to ensure that browsers can achieve an audio connection regardless of platforms and browsers, or as a fallback option in general.
... if you choose to prefer a codec other than the mandatory ones, you should at least allow for fallback to one of the mandatory codecs if support is unavailable for the codec you prefer.
...for voice-only connections in a constrained environment, using g.711 at an 8 khz sample rate can provide an acceptable experience for conversation, but typically you'll use g.711 as a fallback option, since there are other options which are more efficient and sound better, such as opus in its narrowband mode.

util/array - Archive of obsolete content
if such element is found it's retured back otherwise third optional fallback argument is returned back.
... if fallback is not provided returns undefined.

Index - MDN Web Docs Glossary: Definitions of Web-related terms
140 fallback alignment css, glossary, alignment in css box alignment, a fallback alignment is specified in order to deal with cases where the requested alignment cannot be fullfilled.
...if there is not, the fallback alignment is used.

Creating fancy letterheaded paper - Learn web development
add another background declaration that just adds the top image to the top of the letter, as a fallback for browsers that don't support the previous declaration.
... hints and tips remember that you can create a fallback for older browsers by putting the fallback version of a declaration first, followed by the version that works across newer browsers only.

Client-side form validation - Learn web development
ving the "required" attribute suffices in making a selection a requirement --> <input type="radio" required name="driver" id="r1" value="yes"><label for="r1">yes</label> <input type="radio" required name="driver" id="r2" value="no"><label for="r2">no</label> </fieldset> </p> <p> <label for="n1">how old are you?</label> <!-- the pattern attribute can act as a fallback for browsers which don't implement the number input type but support the pattern attribute.
... its usage here acts only as a fallback --> <input type="number" min="12" max="120" step="1" id="n1" name="age" pattern="\d+"> </p> <p> <label for="t1">what's your favorite fruit?<abbr title="this field is mandatory" aria-label="required">*</abbr></label> <input type="text" id="t1" name="fruit" list="l1" required pattern="[bb]anana|[cc]herry|[aa]pple|[ss]trawberry|[ll]emon|[oo]range"> <datalist id="l1"> <option>banana</option> <option>cherry</option> <option>apple</option> <option>strawberry</option> <option>lemon</option> <option>orange</option> </datalist> </p> <p> ...

Test your skills: Multimedia and embedding - Learn web development
add some appropriate fallback text for browsers that don't support <audio>.
... add some appropriate fallback text for browsers that don't support <video>.

CSS performance optimization - Learn web development
will-change: opacity, transform; the font-display property applied to the @font-face rule, the font-display property defines how font files are loaded and displayed by the browser, allowing text to appear with a fallback font while a font loads, or fails to load.
... @font-face { font-family: somefont; src: url(/path/to/fonts/somefont.woff) format('woff'); font-weight: 400; font-style: normal; font-display: fallback; } the contain property the contain css property allows an author to indicate that an element and its contents are, as much as possible, independent of the rest of the document tree.

Implementing feature detection - Learn web development
note: often such an approach is overkill for a minor feature detection problem — you can often get away with using multiple vendor prefixes and fallback properties, as described in css fallback behavior and handling css prefixes.
...go into modernizr-css.css, and replace the two @supports blocks with the following: /* properties for browsers with modern flexbox */ .flexbox main { display: flex; } .flexbox main div { padding-right: 4%; flex: 1; } .flexbox main div:last-child { padding-right: 0; } /* fallbacks for browsers that don't support modern flexbox */ .no-flexbox main div { width: 22%; float: left; padding-right: 4%; } .no-flexbox main div:last-child { padding-right: 0; } .no-flexbox footer { clear: left; } so how does this work?

Strategies for carrying out testing - Learn web development
by coding defensively, we mean trying to build in intelligent fallbacks so that if a feature or style doesn't work in a browser, the site will be able to downgrade to something less exciting that still provides an acceptable user experience — the core information is still accessible, for example, even if it doesn't look quite as nice.
...serve the full site, which should work, at least with the fallbacks provided by our defensive coding.

Hacking Tips
0ca9c6e in js::calljsnative(jscontext*, bool (*)(jscontext*, unsigned int, js::value*), js::callargs const&) (cx=0x14f2640, native=0xf89960 , args=...) at js/src/jscntxtinlines.h:235 #2 0x0000000000c87625 in js::invoke(jscontext*, js::callargs const&, js::maybeconstruct) (cx=0x14f2640, args=..., construct=js::no_construct) at js/src/vm/interpreter.cpp:476 #3 0x000000000069bdcf in js::jit::docallfallback(jscontext*, js::jit::baselineframe*, js::jit::iccall_fallback*, uint32_t, js::value*, js::mutablehandlevalue) (cx=0x14f2640, frame=0x7fffffff6ad8, stub_=0x1798838, argc=1, vp=0x7fffffff6a88, res=jsval_void) at js/src/jit/baselineic.cpp:6113 #4 0x00007ffff7f41395 in <<jitframe_exit>> () #5 0x00007ffff7f42223 in <<jitframe_baselinestub>> () #6 0x00007ffff7f4423d in <<jitframe_baselinejs>> () #7 ...
... $ ionfilter=pdfjs.js:16934 ionflags=logs,scripts,osi,bailouts ./js --ion-offthread-compile=off ./run.js 2>&1 | less the bailouts channel is likely to be the first thing you should focus on, because this means that something does not stay in ionmonkey and fallback to the interpreter.

Bytecode Descriptions
this is the fallback get instruction that handles all unoptimized cases.
...this is the fallback set instruction that handles all unoptimized cases.

nsIDocShell
override that character set for documents for which the specified fallback or auto-detected character set is incorrect.
... overriding the character set also sets the fallback encoding for the container frame.

nsIHttpServer
if the handler throws an * exception during server operation, fallback is to the genericized error * handler (the x00 version), then to 500, using a user-defined error * handler if one exists or the server default handler otherwise.
... fallback * will never occur from a user-provided handler that throws to the same * handler as provided by the server, e.g.

Flash Activation: Browser Comparison - Plugins
mozilla firefox google chrome microsoft edge setting name ask to activate html5 by default click-to-run 'application/x-shockwave-flash' in navigator.mimetypes by default when flash is inactive yes no no 'application/x-shockwave-flash' in navigator.mimetypes when user enables flash yes yes yes <object> with fallback content triggers ui yes, with exceptions no yes small/hidden flash triggers additional ui yes no no enabling flash automatically reloads the page no yes yes other features related to flash domain blocking plugin power saver peripheral content pause each of the browser vendors has a roadmap about the future of flash and changes ...
...the user can click on the flash object or the location bar icon to activate flash: users have the choice to allow flash just for the current session, or to remember their choice: google chrome in-page ui is displayed when the site attempts to use flash without fallback content: a user can click the plugin element to show a prompt for allowing flash: if the site provides fallback content for an object element, chrome will display that content and will not prompt the user to enable flash.

Hit regions and accessibility - Web APIs
fallback content the content inside the <canvas> ...
... </canvas> tags can be used as a fallback for browsers which don't support canvas rendering.

HTMLImageElement.alt - Web APIs
the htmlimageelement property alt provides fallback (alternate) text to display when the image specified by the <img> element is not loaded.
...if the image doesn't require a fallback (such as for an image which is simply decorative or an advisory icon of minimal importance), you may specify an empty string ("").

HTMLSlotElement - Web APIs
if no assigned nodes are found, it returns the slot's fallback content.
...if no assigned nodes are found, it returns the slot's fallback content.

Starting up and shutting down a WebXR session - Web APIs
either way, you need to be prepared for the lack of an xr property and either gracefully handle the error or provide some form of fallback.
... falling back to the webxr polyfill one fallback option is the webxr polyfill, provided by the immersive web working group that's in charge of the webxr standardization process.

@supports - CSS: Cascading Style Sheets
sion @supports ((perspective: 10px) or (-moz-perspective: 10px) or (-webkit-perspective: 10px) or (-ms-perspective: 10px) or (-o-perspective: 10px)) { … /* css applied when 3d transforms, prefixed or not, are supported */ } testing for the non-support of a specific css property @supports not ((text-align-last: justify) or (-moz-text-align-last: justify)) { … /* css to provide fallback alternative for text-align-last: justify */ } testing for the support of custom properties @supports (--foo: green) { body { color: var(--varname); } } testing for the support of a selector (eg.
... :is()) /* this rule won't be applied in browsers which don't support :is() */ :is(ul, ol) > li { … /* css applied when the :is(…) selector is supported */ } @supports not selector(:is(a, b)) { /* fallback for when :is() is unsupported */ ul > li, ol > li { … /* the above expanded for browsers which don't support :is(…) */ } } @supports selector(:nth-child(1n of a, b)) { /* this rule needs to be inside the @supports block, otherwise it will be partially applied in browsers which don't support the `of` argument of :nth-child(…) is supported */ :is(:nth-child(1n of ul, ol) a, details > summary) { … /* css applied when the :is(…) selector and the `of` argument of :nth-child(…) are both supported */ } } specifications speci...

Detecting CSS animation support - CSS: Cascading Style Sheets
if( animation === false ) { // animate in javascript fallback } else { elem.style[ animationstring ] = 'rotate 1s linear infinite'; var keyframes = '@' + keyframeprefix + 'keyframes rotate { '+ 'from {' + keyframeprefix + 'transform:rotate( 0deg ) }'+ 'to {' + keyframeprefix + 'transform:rotate( 360deg ) }'+ '}'; if( document.stylesheets && document.stylesheets.length ) { document.sty...
...lesheets[0].insertrule( keyframes, 0 ); } else { var s = document.createelement( 'style' ); s.innerhtml = keyframes; document.getelementsbytagname( 'head' )[ 0 ].appendchild( s ); } } this code looks at the value of animation; if it's false, we know we need to use our javascript fallback code to perform our animation.

Box alignment for block, absolutely positioned and table layout - CSS: Cascading Style Sheets
if a content distribution method such as space-between, space-around or space-evenly is requested then the fallback alignment will be used, as the content is treated as a single alignment subject.
... reference css properties justify-content align-content justify-self align-self glossary entries alignment subject alignment container fallback alignment ...

Relationship of flexbox to other layout methods - CSS: Cascading Style Sheets
you might however want to use flexbox as a fallback for grid layout, as there is better support for flexbox in older browsers.
... you can use the box alignment properties across both layout methods, so using flexbox as a fallback for grid layout can work very well.

Cookbook template - CSS: Cascading Style Sheets
if you want to add an additional example here — for example a version with fallbacks, please do.
... useful fallbacks or alternative methods if there are useful alternative methods for building the recipe, or fallback recipes to use if you have to support non-supporting browsers, include them in separate sections down here.

font-family - CSS: Cascading Style Sheets
this lets the browser select an acceptable fallback font when necessary.
... <generic-name> generic font families are a fallback mechanism, a means of preserving some of the style sheet author's intent when none of the specified fonts are available.

font-weight - CSS: Cascading Style Sheets
451) will be translated to one of these values for non-variable fonts using the fallback weights system.
... fallback weights if the exact weight given is unavailable, then the following rule is used to determine the weight actually rendered: if the target weight given is between 400 and 500 inclusive: look for available weights between the target and 500, in ascending order.

image-rendering - CSS: Cascading Style Sheets
formal definition initial valueautoapplies toall elementsinheritedyescomputed valueas specifiedanimation typediscrete formal syntax auto | crisp-edges | pixelated examples setting image scaling algorithms in practical use, the pixelated and crisp-edges rules can be combined to provide some fallback for each other.
... (just prepend the actual rules with the fallback.) the canvas api can provide a fallback solution for pixelated through manual image data manipulation or with imagesmoothingenabled.

Setting up adaptive streaming media sources - Developer guides
<video src="my.mpd" type="application/dash+xml"></video> it might be wise to provide a fallback for browsers that don't yet support mpeg-dash: <video> <source src="my.mpd" type="application/dash+xml"> <!-- fallback --> <source src="my.mp4" type="video/mp4"> <source src="my.webm" type="video/webm"> </video> live profile a useful piece of software when dealing with mpeg-dash is dash encoder.
... once you have generated your mpd file you can reference as expected it from within the <video> element: <video src="my.mpd" type="application/dash+xml"></video> it might be wise to provide a fallback: <video> <source src="my.mpd" type="application/dash+xml"> <!-- fallback --> <source src="my.mp4" type="video/mp4"> <source src="my.webm" type="video/webm"> </video> note: mpeg-dash playback relies on dash.js and browser support for media source extensions, see the latest dash.js reference player.

<canvas>: The Graphics Canvas element - HTML: Hypertext Markup Language
providing a useful fallback text or sub dom helps to make the the canvas more accessible.
...a fallback text is provided if a browser is unable to render the canvas, or if can't read a canvas.

CSP: style-src-attr - HTTP
csp version 3 directive type fetch directive default-src fallback yes.
... if this directive is absent, the user agent will look for the style-src directive, and if both of them are absent, fallback to default-src directive.

CSP: style-src-elem - HTTP
csp version 3 directive type fetch directive default-src fallback yes.
... if this directive is absent, the user agent will look for the style-src directive, and if both of them are absent, fallback to default-src directive.

Index - HTTP
the apis that are restricted are: 33 csp: default-src csp, directive, http, reference, security the http content-security-policy (csp) default-src directive serves as a fallback for the other csp fetch directives.
...less accurate than an etag header, it is a fallback mechanism.

HTTP Index - HTTP
the apis that are restricted are: 81 csp: default-src csp, content-security-policy, directive, http, reference, security, default, default-src, source the http content-security-policy (csp) default-src directive serves as a fallback for the other csp fetch directives.
...less accurate than an etag header, it is a fallback mechanism.

BigInt.prototype.toLocaleString() - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: var bigint = 123456789123456789n; // german uses period for thousands console.log(bigint.tolocalestring('de-de')); // → 123.456.789.123.456.789 // arabic in most arabic speaking countries uses eastern arabic digits console.log(bigint.tolocalestring('ar-eg')); // → ١٢٣٬٤٥٦٬٧٨٩٬١٢٣٬٤٥٦٬٧٨٩ // india uses thousands/lakh/crore separ...
...chinese decimal console.log(bigint.tolocalestring('zh-hans-cn-u-nu-hanidec')); // → 一二三,四五六,七八九,一二三,四五六,七八九 // when requesting a language that may not be supported, such as // balinese, include a fallback language, in this case indonesian console.log(bigint.tolocalestring(['ban', 'id'])); // → 123.456.789.123.456.789 using options the results provided by tolocalestring can be customized using the options argument: var bigint = 123456789123456789n; // request a currency format console.log(bigint.tolocalestring('de-de', { style: 'currency', currency: 'eur' })); // → 123.456.789.123.456.789,00 € // the japane...

Date.prototype.toLocaleDateString() - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: var date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // formats below assume the local time zone of the locale; // america/los_angeles for the us // us english uses month-day-year order console.log(date.tolocaledatestring('en-us')); // → "12/19/2012" // british english uses day-month-year order console.log(date.tolocaledatestring('en-gb')); // → "20...
...ountries uses real arabic digits console.log(date.tolocaledatestring('ar-eg')); // → "٢٠‏/١٢‏/٢٠١٢" // for japanese, applications may want to use the japanese calendar, // where 2012 was the year 24 of the heisei era console.log(date.tolocaledatestring('ja-jp-u-ca-japanese')); // → "24/12/20" // when requesting a language that may not be supported, such as // balinese, include a fallback language, in this case indonesian console.log(date.tolocaledatestring(['ban', 'id'])); // → "20/12/2012" using options the results provided by tolocaledatestring() can be customized using the options argument: var date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // request a weekday along with a long date var options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' }; c...

Date.prototype.toLocaleString() - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: let date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // formats below assume the local time zone of the locale; // america/los_angeles for the us // us english uses month-day-year order and 12-hour time with am/pm console.log(date.tolocalestring('en-us')); // → "12/19/2012, 7:00:00 pm" // british english uses day-month-year order and 24-hour time with...
...l arabic digits console.log(date.tolocalestring('ar-eg')); // → "٢٠‏/١٢‏/٢٠١٢ ٥:٠٠:٠٠ ص" // for japanese, applications may want to use the japanese calendar, // where 2012 was the year 24 of the heisei era console.log(date.tolocalestring('ja-jp-u-ca-japanese')); // → "24/12/20 12:00:00" // when requesting a language that may not be supported, such as // balinese, include a fallback language (in this case, indonesian) console.log(date.tolocalestring(['ban', 'id'])); // → "20/12/2012 11.00.00" using options the results provided by tolocalestring() can be customized using the options argument: let date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // request a weekday along with a long date let options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' }...

Date.prototype.toLocaleTimeString() - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: var date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // formats below assume the local time zone of the locale; // america/los_angeles for the us // us english uses 12-hour time with am/pm console.log(date.tolocaletimestring('en-us')); // → "7:00:00 pm" // british english uses 24-hour time without am/pm console.log(date.tolocaletimestring('en-gb')); /...
.../ → "03:00:00" // korean uses 12-hour time with am/pm console.log(date.tolocaletimestring('ko-kr')); // → "오후 12:00:00" // arabic in most arabic speaking countries uses real arabic digits console.log(date.tolocaletimestring('ar-eg')); // → "٧:٠٠:٠٠ م" // when requesting a language that may not be supported, such as // balinese, include a fallback language, in this case indonesian console.log(date.tolocaletimestring(['ban', 'id'])); // → "11.00.00" using options the results provided by tolocaletimestring() can be customized using the options argument: var date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // an application may want to use utc and make that visible var options = { timezone: 'utc', timezonename: 'short' }; console.log(date.tolocaletimestring('en-us', options)...

Intl.DateTimeFormat - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: var date = new date(date.utc(2012, 11, 20, 3, 0, 0)); // results below use the time zone of america/los_angeles (utc-0800, pacific standard time) // us english uses month-day-year order console.log(new intl.datetimeformat('en-us').format(date)); // → "12/19/2012" // british english uses day-month-year order console.log(new intl.datetimeformat('en-gb').
...digits console.log(new intl.datetimeformat('ar-eg').format(date)); // → "١٩‏/١٢‏/٢٠١٢" // for japanese, applications may want to use the japanese calendar, // where 2012 was the year 24 of the heisei era console.log(new intl.datetimeformat('ja-jp-u-ca-japanese').format(date)); // → "24/12/19" // when requesting a language that may not be supported, such as // balinese, include a fallback language, in this case indonesian console.log(new intl.datetimeformat(['ban', 'id']).format(date)); // → "19/12/2012" using options the date and time formats can be customized using the options argument: var date = new date(date.utc(2012, 11, 20, 3, 0, 0, 200)); // request a weekday along with a long date var options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' }; co...

Intl.DisplayNames.prototype.resolvedOptions() - JavaScript
fallback the value provided for this property in the options argument of the constructor or the default value ("code").
... examples using resolvedoptions const displaynames = new intl.displaynames(['de-de'], {type: 'region'}); const usedoptions = displaynames.resolvedoptions(); console.log(usedoptions.locale); // "de-de" console.log(usedoptions.style); // "long" console.log(usedoptions.type); // "region" console.log(usedoptions.fallback); // "code" specifications specification intl.displaynamesthe definition of 'resolvedoptions()' in that specification.

Intl.NumberFormat - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: var number = 123456.789; // german uses comma as decimal separator and period for thousands console.log(new intl.numberformat('de-de').format(number)); // → 123.456,789 // arabic in most arabic speaking countries uses real arabic digits console.log(new intl.numberformat('ar-eg').format(number)); // → ١٢٣٤٥٦٫٧٨٩ // india uses thousands/lakh/...
...chinese decimal console.log(new intl.numberformat('zh-hans-cn-u-nu-hanidec').format(number)); // → 一二三,四五六.七八九 // when requesting a language that may not be supported, such as // balinese, include a fallback language, in this case indonesian console.log(new intl.numberformat(['ban', 'id']).format(number)); // → 123.456,789 using options the results can be customized using the options argument: var number = 123456.789; // request a currency format console.log(new intl.numberformat('de-de', { style: 'currency', currency: 'eur' }).format(number)); // → 123.456,79 € // the japanese yen doesn't use a minor unit conso...

Number.prototype.toLocaleString() - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: var number = 123456.789; // german uses comma as decimal separator and period for thousands console.log(number.tolocalestring('de-de')); // → 123.456,789 // arabic in most arabic speaking countries uses eastern arabic digits console.log(number.tolocalestring('ar-eg')); // → ١٢٣٤٥٦٫٧٨٩ // india uses thousands/lakh/crore separators console.lo...
...chinese decimal console.log(number.tolocalestring('zh-hans-cn-u-nu-hanidec')); // → 一二三,四五六.七八九 // when requesting a language that may not be supported, such as // balinese, include a fallback language, in this case indonesian console.log(number.tolocalestring(['ban', 'id'])); // → 123.456,789 using options the results provided by tolocalestring can be customized using the options argument: var number = 123456.789; // request a currency format console.log(number.tolocalestring('de-de', { style: 'currency', currency: 'eur' })); // → 123.456,79 € // the japanese yen doesn't use a minor unit console.log(number.tolocalestring('ja-jp', { style: 'currency', c...

async function - JavaScript
consider the following code: function getprocesseddata(url) { return downloaddata(url) // returns a promise .catch(e => { return downloadfallbackdata(url) // returns a promise }) .then(v => { return processdatainworker(v) // returns a promise }) } it can be rewritten with a single async function as follows: async function getprocesseddata(url) { let v try { v = await downloaddata(url) } catch(e) { v = await downloadfallbackdata(url) } return processdatainworker(v) } in the above example, notice th...
...it returns null if processdatainworker rejects with an error: async function getprocesseddata(url) { let v try { v = await downloaddata(url) } catch(e) { v = await downloadfallbackdata(url) } try { return await processdatainworker(v) // note the `return await` vs.

stroke-linejoin - SVG: Scalable Vector Graphics
h: effect of the "round" value --> <path d="m7,5 a2,2 0,0,0 2,-3 a3,3 0 0 1 2,3.5" stroke="black" fill="none" stroke-linejoin="round" /> <!-- upper right path: effect of the "bevel" value --> <path d="m13,5 a2,2 0,0,0 2,-3 a3,3 0 0 1 2,3.5" stroke="black" fill="none" stroke-linejoin="bevel" /> <!-- bottom left path: effect of the "miter-clip" value with fallback to "miter" if not supported.
... --> <path d="m3,11 a2,2 0,0,0 2,-3 a3,3 0 0 1 2,3.5" stroke="black" fill="none" stroke-linejoin="miter-clip" /> <!-- bottom right path: effect of the "arcs" value with fallback to "miter" if not supported.

XSLT elements reference - XSLT: Extensible Stylesheet Language Transformations
use the {{listsubpages}} macro once the bcd for <xsl:fallback>, <xsl:import>, <xsl:namespace-alias>, <xsl:number>, <xsl:output>, <xsl:stylesheet>, <xsl:text> and <xsl:value-of> is fully migrated.
... <xsl:apply-imports><xsl:apply-templates><xsl:attribute-set><xsl:attribute><xsl:call-template><xsl:choose><xsl:comment><xsl:copy-of><xsl:copy><xsl:decimal-format><xsl:element><xsl:fallback><xsl:for-each><xsl:if><xsl:import><xsl:include><xsl:key><xsl:message><xsl:namespace-alias><xsl:number><xsl:otherwise><xsl:output><xsl:param><xsl:preserve-space><xsl:processing-instruction><xsl:sort><xsl:strip-space><xsl:stylesheet><xsl:template><xsl:text><xsl:transform><xsl:value-of><xsl:variable><xsl:when><xsl:with-param> <xsl:apply-imports> <xsl:apply-templates> <xsl:attribute> <xsl:attribute-set> <xsl:call-template> <xsl:choose> <xsl:comment> <xsl:copy> <xsl:copy-of> <xsl:decimal-format> <xsl:element> <xsl:fallback> (not supported) <xsl:for-each> <xsl:if> <xsl:import> (mostly supported) <xsl...

CSS3 - Archive of obsolete content
the control of the aspect ratio to use when fallback fonts are selected via the css font-size-adjust property.

GRE Registration - Archive of obsolete content
the <tt>-register-global</tt> flag has special fallback semantics so that multiple xulrunners of the same version can be installed without overwriting registration files.

Creating a Help Content Pack - Archive of obsolete content
this attribute is optional, with fallback to the value welcome.

Reading textual data - Archive of obsolete content
you can fallback to the default character encoding stored in preferences (intl.charset.default, a localized pref value) when reading from a file, the question is harder to answer.

confirm - Archive of obsolete content
see the notes at the end of this document for a safe way to implement a fallback.

XUL accessibility guidelines - Archive of obsolete content
(firefox's "print preview" window uses this fallback technique.) this should only be used as a last resort, and it should be consistent throughout a window (that is either all toolbar buttons are tabbable or none of them are).

How to enable locale switching in a XULRunner application - Archive of obsolete content
defaults/preferences/prefs.js /* don't inherit os locale */pref("intl.locale.matchos", "false");/* choose own fallback locale; later it can be overridden by the user */pref("general.useragent.locale", "en-gb"); note that some distributions of xulrunner or firefox don't honour the "intl.locale.matchos" setting, so in those cases you won't be able to override the os locale [debian iceweasel bug #417961].

XEmbed Extension for Mozilla Plugins - Archive of obsolete content
if you've built your plugin so that it will support either xt or xembed you can include a fallback for older style hosting.

Developing cross-browser and cross-platform pages - Archive of obsolete content
it requires from the web author to make assumptions about what will happen with future browsers or to decide to provide future browsers a safe fallback service.

Building up a basic demo with Three.js - Game development
thanks to this approach, a fallback can be used, if a desired technology is not supported by the browser.

Selector (CSS) - MDN Web Docs Glossary: Definitions of Web-related terms
#customized { font: 16px lucida grande, arial, helvetica, sans-serif; } the selectors here are "p" (which applies the color green to the text inside any <p> element), "div.warning" (which makes any <div> element with the class "warning" look like a warning box), and "#customized", which sets the base font of the element with the id "customized" to 16-pixel tall lucida grande or one of a few fallback fonts.

Graceful degradation - MDN Web Docs Glossary: Definitions of Web-related terms
polyfills can be used to build in missing features with javascript, but acceptable alternatives to features like styling and layout should be provided where possible, for example by using the css cascade, or html fallback behaviour.

Brotli - MDN Web Docs Glossary: Definitions of Web-related terms
brotli is compatible with most modern browsers, but you may want to consider a fallback.

MDN Web Docs Glossary: Definitions of Web-related terms
ncy signaling) dynamic programming language dynamic typing e ecma ecmascript effective connection type element empty element encapsulation encryption endianness engine entity entity header event exception expando f fallback alignment falsy favicon fetch directive fetch metadata request header firefox os firewall first contentful paint first cpu idle first input delay first interactive first meaningful paint first paint first-class function flex flex container flex item ...

Accessible multimedia - Learn web development
for more information on how to add more complex features to video/audio players, including flash fallbacks for older browsers, see: audio and video delivery video player styling basics creating a cross-browser video player we've also created an advanced example to show how you could create an object-oriented system that finds every video and audio player on the page (no matter how many there are) and adds our custom controls to it.

Organizing your CSS - Learn web development
you may have used a css property in a specific way to get around older browser incompatibilities, for example: .box { background-color: red; /* fallback for older browsers that don't support gradients */ background-image: linear-gradient(to right, #ff0000, #aa0000); } perhaps you followed a tutorial to achieve something, and the css is a little non-obvious.

Legacy layout methods - Learn web development
this knowledge will be helpful to you if you need to create fallback code for browsers that do not support newer methods, in addition to allowing you to work on existing projects which use these types of systems.

How CSS works - Learn web development
i might give a fallback width for a box in pixels, then go on to give a width with a calc() value of 100% - 50px.

Styling lists - Learn web development
if both a type and an image are specified, the type is used as a fallback if the image can't be loaded for some reason.

Advanced form styling - Learn web development
so if you choose to use one of those libraries, you should always have robust fallback html in case the script fails.

Basic native form controls - Learn web development
the value text for this attribute is also the fallback value if the value you specify for the type attribute is unknown by the browser (for example if you specify type="color" and the browser doesn't support native color pickers).

The HTML5 input types - Learn web development
the reference pages linked to above provide suggestions on how to program fallbacks for non-supporting browsers; another option is to consider using a javascript library to provide a date picker.

How to build custom form controls - Learn web development
as seen previously, we already use a native select control as a fallback for accessibility reasons; we can simply synchronize its value with that of our custom control: // this function updates the displayed value and synchronizes it with the native control.

Responsive images - Learn web development
this provides a default case that will apply when none of the media conditions return true (you could actually remove the second <source> element in this example), and a fallback for browsers that don't support the <picture> element.

Video and audio content - Learn web development
the paragraph inside the <video> tags this is called fallback content — this will be displayed if the browser accessing the page doesn't support the <video> element, allowing us to provide a fallback for older browsers.

Multimedia and Embedding - Learn web development
video and audio content next, we'll look at how to use the html5 <video> and <audio> elements to embed video and audio on our pages, including basics, providing access to different file formats to different browsers, adding captions and subtitles, and how to add fallbacks for older browsers.

Index - Learn web development
152 supporting older browsers beginner, css, guide, layout, learn, feature queries, flexbox, float, grid, legacy you now have the knowledge to confidently use techniques such as grid and flexbox, create fallbacks for older browsers, and make use of any new techniques that might come along in the future.

Making asynchronous programming easier with async and await - Learn web development
on encountering a browser that does not support async/await, babel's polyfill can automatically provide fallbacks that work in older browsers.

Video and Audio APIs - Learn web development
you'll see a number of features; the html is dominated by the video player and its controls: <div class="player"> <video controls> <source src="video/sintel-short.mp4" type="video/mp4"> <source src="video/sintel-short.webm" type="video/webm"> <!-- fallback content here --> </video> <div class="controls"> <button class="play" data-icon="p" aria-label="play pause toggle"></button> <button class="stop" data-icon="s" aria-label="stop"></button> <div class="timer"> <div></div> <span aria-label="timer">00:00</span> </div> <button class="rwd" data-icon="b" aria-label="rewind"></button> <button class="fwd" data-icon=...

Multimedia: Images - Learn web development
should such an image only exist as a bitmap, then png would be the fallback format to chose.

Perceived performance - Learn web development
make fallback fonts the same size and weight so that when fonts load the page change is less noticeable.

Web performance resources - Learn web development
the following snippet includes an onload attribute, requiring javascript, so it is important to include a noscript tag with a traditional fallback.

Chrome registration
n.b.: because older versions of firefox do not understand the contentaccessible flag, any extension designed to work with both firefox 3 and older versions of firefox will need to provide a fallback.

Localizing extension descriptions
the current app locale will be searched for and then there will be a fallback search for en-us.

Localizing extension metadata on addons.mozilla.org
the values you provide here are used as fallback values if someone requests a language that doesn't exist.

MathML Demo: <mtable> - tables and matrices
anyway, this is buggy in mozilla because what you see above is a fallback to the rendering code used for the baseline case (see below).

TimerFirings logging
indicates that the function timer lacks an explicit name, and the comment within the square brackets explains why the fallback mechanism wasn't used.

L20n HTML Bindings
there is no language negotiation nor locale fallback possible in the monolingual mode.

NSS 3.17.3 release notes
nss 3.17.3 source distributions are available on ftp.mozilla.org for secure https download: source tarballs: https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/nss_3_17_3_rtm/src/ new in nss 3.17.3 new functionality support for tls_fallback_scsv has been added to the ssltap and tstclnt utilities.

NSS 3.43 release notes
sha-256 fingerprint: 5a2fc03f0c83b090bbfa40604b0988446c7636183df9846e17101a447fb8efd6 the following ca certificates were removed: none bugs fixed in nss 3.43 bug 1528669 and bug 1529308 - improve gyp build system handling bug 1529950 and bug 1521174 - improve nss s/mime tests for thunderbird bug 1530134 - if docker isn't installed, try running a local clang-format as a fallback bug 1531267 - enable fips mode automatically if the system fips mode flag is set bug 1528262 - add a -j option to the strsclnt command to specify sigschemes bug 1513909 - add manual for nss-policy-check bug 1531074 - fix a deref after a null check in seckey_setpublicvalue bug 1517714 - properly handle esni with hrr bug 1529813 - expose hkdf-expand-label with mechanism bug 1535122 - align t...

NSS 3.48 release notes
rng known-answer-test scripts bug 1586176 - encryptupdate should use maxout not block size (cve-2019-11745) bug 1593141 - add `notbefore` or similar "beginning-of-validity-period" parameter to mozilla::pkix::trustdomain::checkrevocation bug 1591363 - fix a pbkdf2 memory leak in nsc_generatekey if key length > max_key_len (256) bug 1592869 - use arm neon for ctr_xor bug 1566131 - ensure sha-1 fallback disabled in tls 1.2 bug 1577803 - mark pkcs#11 token as friendly if it implements ckp_public_certificates_token bug 1566126 - power ghash vector acceleration bug 1589073 - use of new pr_assert_arg in certdb.c bug 1590495 - fix a crash in pk11_makecertfromhandle bug 1591742 - ensure des iv length is valid before usage from pkcs#11 bug 1588567 - enable mozilla::pkix gtests in nss ci bug 1591...

Python binding for NSS
a ssl.tls_dh_anon_with_rc4_128_md5 ssl.tls_ecdhe_ecdsa_with_aes_128_cbc_sha256 ssl.tls_ecdhe_ecdsa_with_aes_128_gcm_sha256 ssl.tls_ecdhe_rsa_with_aes_128_cbc_sha256 ssl.tls_ecdhe_rsa_with_aes_128_gcm_sha256 ssl.tls_ecdh_ecdsa_with_aes_128_gcm_sha256 ssl.tls_ecdh_rsa_with_aes_128_gcm_sha256 ssl.tls_empty_renegotiation_info_scsv ssl.tls_fallback_scsv ssl.tls_null_with_null_null ssl.tls_rsa_export_with_des40_cbc_sha ssl.tls_rsa_export_with_rc2_cbc_40_md5 ssl.tls_rsa_export_with_rc4_40_md5 ssl.tls_rsa_with_3des_ede_cbc_sha ssl.tls_rsa_with_aes_128_cbc_sha256 ssl.tls_rsa_with_aes_128_gcm_sha256 ssl.tls_rsa_with_aes_256_cbc_sha256 ssl.tls_rsa_with_camellia_128_cbc_sha ssl.

JS::OrdinaryToPrimitive
it implements the default conversion behavior shared by most objects in js, so it's useful as a fallback.

JS_SetCheckObjectAccessCallback
description js_setcheckobjectaccesscallback sets the runtime-wide check-object-access callback, which is used as the fallback jsclass.checkaccess method for all classes that leave the checkaccess field null.

nsIApplicationCache
item_fallback 32 this item was listed as a fallback entry.

nsIApplicationCacheChannel
this value may be false even if the resource is assigned to an application cache if, for example, it was loaded as a fallback.

nsIDOMFontFace
fromsystemfallback boolean indicates whether or not the font is the system fallback font.

nsIMsgCompFields
nfo nsisupports subject astring templatename astring temporaryfiles char * obsolete temporaryfiles obsolete, do not use anymore to astring usemultipartalternative prbool uuencodeattachments prbool methods utility methods prbool checkcharsetconversion ( out char * fallbackcharset ); nsimsgrecipientarray splitrecipients ( in prunichar * recipients, in prbool emailaddressonly ); void convertbodytoplaintext ( ); attachment handling methods void addattachment ( in nsimsgattachment attachment ); void removeattachment ( in nsimsgattachment attachment ); void removeattachments ( ); header methods void...

nsIMsgIncomingServer
loginatstartup boolean logonfallback boolean maxmessagesize long offlinesupportlevel long password acstring passwordpromptrequired boolean if the password for the server is available either via authentication in the current session or from password manager stored entries, return false.

nsIPrintingPrompt
defaults for platform service: showprintdialog - displays a native dialog showpagesetup() - displays a xul dialog showprogress() - displays a xul dialog summary for windows embedders: stated once again: there is no "fallback" native platform support in gfx for the displaying of the native print dialog.

nsIXPConnect
void setreportalljsexceptions( in boolean reportalljsexceptions ); parameters reportalljsexceptions missing description exceptions thrown missing exception missing description setsafejscontextforcurrentthread() set fallback jscontext to use when xpconnect can't find an appropriate context to use to execute javascript.

Blocking By Domain - Plugins
any attempt to use a plugin (via the <object> or <embed> element) will behave as if the plugin was not installed, and use fallback content as specified by the html standard.

Edit fonts - Firefox Developer Tools
they are system fallback fonts used when nothing from the font-family css declaration has been applied.

AudioNode.channelInterpretation - Web APIs
this fallback is therefore not future proof as the behavior of the browsers for a specific number of channels may change in the future.

Background Tasks API - Web APIs
you can do so with a simple shim that uses settimeout() as a fallback option.

CSSCounterStyleRule - Web APIs
csscounterstylerule.fallback is a domstring object that contains the serialization of the fallback descriptor defined for the associated rule.

CSSVariableReferenceValue - Web APIs
cssvariablereferencevalue.fallback read only returns the built-in css value for the custom name.

Cache.put() - Web APIs
if this fails (e.g., because the network is down), return a fallback response.

CacheStorage.match() - Web APIs
if this fails (e.g., because the network is down), return a fallback response.

CacheStorage - Web APIs
because the network is down), return a fallback response.

CanvasRenderingContext2D.addHitRegion() - Web APIs
parentid the id of the parent region for cursor fallback and navigation by accessibility tools.

CanvasRenderingContext2D - Web APIs
canvasrenderingcontext2d.demote() this causes a context that is currently using a hardware-accelerated backend to fallback to a software one.

ConstrainBoolean - Web APIs
you can specify an exact value which must be matched, an ideal value that should be matched if at all possible, and a fallback value to attempt to match once all more specific constraints have been applied.

DOMTokenList.supports() - Web APIs
example let iframe = document.getelementbyid('display'); if (iframe.sandbox.supports('an-upcoming-feature')) { // support code for mystery future feature } else { // fallback code } if (iframe.sandbox.supports('allow-scripts')) { // instruct frame to run javascript // // (note: this feature is well-supported; this is just an example!) // } specifications specification status comment credential management level 1 working draft initial definition.

Element.classList - Web APIs
erty(window.element.prototype, "classlist", { enumerable: 1, get: function(val){ if (!hasownprop.call(this, "classlist")) polyfillclasslist(this); return this.classlist; }, configurable: 0, set: function(val){this.classname = val} }); } catch(e) { // less performant fallback for older browsers (ie 6-8): window[" ucl"] = polyfillclasslist; // the below code ensures polyfillclasslist is applied to all current and future elements in the doc.

Element.getBoundingClientRect() - Web APIs
cross-browser fallback scripts requiring high cross-browser compatibility can use window.pagexoffset and window.pageyoffset instead of window.scrollx and window.scrolly.

HTMLCollection - Web APIs
htmlcollection.nameditem() returns the specific node whose id or, as a fallback, name matches the string specified by name.

HTMLImageElement.sizes - Web APIs
syntax let sizes = htmlimageelement.sizes; htmlimageelement.sizes = sizes; value a usvstring containing a comma-separated list of source size descriptors followed by an optional fallback size.

HTMLImageElement - Web APIs
htmlimageelement.alt a domstring that reflects the alt html attribute, thus indicating the alternate fallback content to be displayed if the image has not been loaded.

HTMLOrForeignElement.nonce - Web APIs
examples retrieving a nonce value in the past, not all browsers supported the nonce idl attribute, so a workaround is to try to use getattribute as a fallback: let nonce = script['nonce'] || script.getattribute('nonce'); however, recent browsers version hide nonce values that are accessed this way (an empty string will be returned).

HTMLScriptElement.referrerPolicy - Web APIs
note: an empty string value ("") is both the default value, and a fallback value if referrerpolicy is not supported.

HTMLScriptElement - Web APIs
htmlscriptelement.nomodule is a boolean that if true, stops the script's execution in browsers that support es2015 modules — used to run fallback scripts in older browsers that do not support javascript modules.

HTMLSlotElement.assignedElements() - Web APIs
if no assigned nodes are found, it returns the slot's fallback content.

HTMLSlotElement.assignedNodes() - Web APIs
if no assigned nodes are found, it returns the slot's fallback content.

Drag Operations - Web APIs
this allows data to be provided in more specific types, often custom types, yet still provide fallback data for drop targets that do not support more specific types.

HashChangeEvent - Web APIs
change event using any of the following options: window.onhashchange = funcref; or <body onhashchange="funcref();"> or window.addeventlistener("hashchange", funcref, false); basic example function locationhashchanged() { if (location.hash === '#somecoolfeature') { somecoolfeature(); } } window.addeventlistener('hashchange', locationhashchanged); polyfill there are several fallback scripts listed on the modernizr github page.

MediaTrackConstraints.cursor - Web APIs
let displaymediaoptions = { cursor: "always" }; example: cursor visible during motion with fallback in this example, the cursor property is configured to request that the cursor be visible when in motion, falling back to always being visible if the user agent doesn't support in-motion only cursor rendering.

Capabilities, constraints, and settings - Web APIs
diadevices.getusermedia({ video: { width: { min: 640, ideal: 1920 }, height: { min: 400, ideal: 1080 }, aspectratio: { ideal: 1.7777777778 } }, audio: { samplesize: 16, channelcount: 2 } }).then(stream => { videoelement.srcobject = stream; }).catch(handleerror); in this example, constraints are applied at getusermedia() time, asking for an ideal set of options with fallbacks for the video.

Navigator.msLaunchUri() - Web APIs
this enables developers to provide a custom fallback experience for the user.

Using the Notifications API - Web APIs
" + i, {tag: 'somanynotification'}); if (i++ == 9) { window.clearinterval(interval); } }, 200); } // otherwise, we can fallback to a regular modal alert else { alert("hi!"); } }); } // if the user refuses to get notified else { // we can fallback to a regular modal alert alert("hi!"); } }); }); see the live result below: specifications specification status comment notifications api living standard living standard ...

PaintWorklet - Web APIs
<script> if ('paintworklet' in css) { css.paintworklet.addmodule('checkerboard.js'); } </script> use a paintworklet this example shows how to use a paintworklet in a stylesheet, including the simplest way to provide a fallback if paintworklet isn't supported.

PublicKeyCredentialCreationOptions.pubKeyCredParams - Web APIs
examples var publickey = { pubkeycredparams: [ // we would like an elliptic curve to be used if possible { type: "public-key", alg: -7 }, // if not, then we will fallback on an rsa algorithm { type: "public-key", alg: -37 } ], challenge: new uint8array(26) /* this actually is given from the server */, rp: { name: "example corp", id : "login.example.com" }, user: { id: new uint8array(26), /* to be changed for each user */ name: "jdoe@example.com", displayname: "john doe", } }; navigator.credentials.create({ publ...

RTCConfiguration.iceServers - Web APIs
while it can be useful to provide a second server as a fallback in case the first is offline, listing too many servers can delay the user's connection being established, depending on the network's performance and how many servers get used for negotiation before a connection is established.

RTCIceServers.urls - Web APIs
this is useful if the server is, for example, available both on "turn" and "turns" schemes, or if there's a fallback address available for the server.

Reporting API - Web APIs
the endpoints are arranged into groups; an endpoint group can work together to provide load balancing (each endpoint will receive a specified proportion of report traffic) and safeguarding against failure (fallback endpoints can be specified to use if the primary ones fail).

TextEncoder - Web APIs
er.prototype.tostring = function(){return "[object textencoder]"}; try { // object.defineproperty only works on dom prototypes in ie8 object.defineproperty(textencoder.prototype,"encoding",{ get:function(){if(textencoder.prototype.isprototypeof(this)) return"utf-8"; else throw typeerror("illegal invocation");} }); } catch(e) { /*ie6-8 fallback*/ textencoder.prototype.encoding = "utf-8"; } if(typeof symbol!=="undefined")textencoder.prototype[symbol.tostringtag]="textencoder"; } source: https://github.com/anonyco/fastestsmallesttextencoderdecoder specifications specification status comment encodingthe definition of 'textencoder' in that specification.

WebGL best practices - Web APIs
use this if you are finished with any contexts, such as probe contexts, or if you hit a fallback case.

Using DTMF with WebRTC - Web APIs
although this method is obsolete, this example supports it as a fallback to let older browsers (and those not yet updated to support the current webrtc dtmf api) run the example.

The WebSocket API (WebSockets) - Web APIs
signalr: signalr will use websockets under the covers when it's available, and gracefully fallback to other techniques and technologies when it isn't, while your application code stays the same.

Geometry and reference spaces in WebXR - Web APIs
to support progressive enhancement—and thus broaden the availability of your app or site—you should choose a reference space that offers the lowest amount of functionality needed, or provide a fallback mechanism that detects failed attempts to obtain reference spaces and tries again with a less powerful alternative.

Inputs and input sources - Web APIs
{ "profileid": "generic-trigger-squeeze-touchpad", "fallbackprofileids": [], "layouts" : { "left-right-none" : { "selectcomponentid": "xr-standard-trigger", "components": { "xr-standard-trigger": { "type": "trigger" }, "xr-standard-squeeze": { "type": "squeeze" }, "xr-standard-touchpad": { "type": "touchpad" } }, "gamepad": { "mapping...

Basic concepts behind Web Audio API - Web APIs
this fallback is therefore not future proof as the behavior of the browsers for a specific number of channels may change in the future.

Window.open() - Web APIs
99% of all those scripts disable window resizability and disable scrollbars when in fact they should enable both of these features to allow a cautious and sane fallback mechanism if their calculations are wrong.

Window.setImmediate() - Web APIs
do note that internet explorer 8 includes a synchronous version of postmessage, which means it cannot be used as a fallback.

Window: unhandledrejection event - Web APIs
this is useful for debugging and for providing fallback error handling for unexpected situations.

-moz-context-properties - CSS: Cascading Style Sheets
' stroke-width='30px' fill='context-fill red' stroke='context-stroke' fill-opacity='0.5'/></svg>"> here we've set the image src to a data uri containing a simple svg image; the <rect> inside has been made to take its fill and stroke values from the fill and stroke set on the <img> element by giving them the context-fill/context-stroke keywords in their values, along with a fallback color for the fill (red) which will be used in the case that the svg is loaded standalone in a top-level window (where it will have no context element to provide context values).

:focus-visible - CSS: Cascading Style Sheets
<custom-button tabindex="0" role="button">click me</custom-button> custom-button { display: inline-block; margin: 10px; } custom-button:focus { /* provide a fallback style for browsers that don't support :focus-visible */ outline: none; background: lightgrey; } custom-button:focus:not(:focus-visible) { /* remove the focus indicator on mouse-focus for browsers that do support :focus-visible */ background: transparent; } custom-button:focus-visible { /* draw a very noticeable focus style for keyboard-focus on browsers that do support ...

range - CSS: Cascading Style Sheets
if a counter value is outside the specified range, then the fallback style will be used to construct the representation of that marker.

speak-as - CSS: Cascading Style Sheets
if included, the counter will be spoken out in the form specified in that counter style, kind of like specifying the fallback descriptor.

system - CSS: Cascading Style Sheets
if the algorithm specified in the system descriptor is unable to construct the representation for a particular counter value, then that value's representation will be constructed using the fallback system provided.

-moz-device-pixel-ratio - CSS: Cascading Style Sheets
example: @media (-webkit-min-device-pixel-ratio: 2), /* webkit-based browsers */ (min--moz-device-pixel-ratio: 2), /* older firefox browsers (prior to firefox 16) */ (min-resolution: 2dppx), /* the standard way */ (min-resolution: 192dpi) /* dppx fallback */ note: see this csswg article for compatibility good practices regarding resolution and dppx.

display-mode - CSS: Cascading Style Sheets
display mode description fallback display mode fullscreen all of the available display area is used and no user agent chrome is shown.

prefers-reduced-data - CSS: Cascading Style Sheets
in this example the montserrat-regular.woff2 font file will neither be preloaded nor downloaded if the user prefers reduced data, in this case the "system font stack" will serve as the fallback font: html <head> <link rel="preload" href="fonts/montserrat-regular.woff2" as="font" media="(prefers-reduced-data: no-preference)" crossorigin> <link rel="stylesheet" href="style.css"> </head> css @media (prefers-reduced-data: no-preference) { @font-face { font-family: montserrat; font-style: normal; font-weight: 400; font-display: swap; /* la...

Box alignment in Multi-column Layout - CSS: Cascading Style Sheets
reference css properties justify-content align-content column-gap glossary entries alignment subject alignment container fallback alignment ...

Handling content breaks in multicol - CSS: Cascading Style Sheets
in most cases, the fallback to breaks not being controlled is something you can live with, with suboptimal breaking being untidy rather than a disaster to your layout.

CSS Counter Styles - CSS: Cascading Style Sheets
reference properties counter-increment counter-reset at-rules @counter-style system additive-symbols negative prefix suffix range pad speak-as fallback guides using css counters describes how to use counters to number any html element or to perform complex counting.

Typical use cases of Flexbox - CSS: Cascading Style Sheets
in reality we also often use flexbox for jobs that might be better done by grid layout, as a fallback for grid, and also in order to get alignment capabilities.

OpenType font features guide - CSS: Cascading Style Sheets
re-settings codes 'the complete css demo for opentype features' (can't vouch for the truth of the name, but it's pretty big) a list of opentype features on wikipedia using css feature detection for implementation since not all properties are evenly implemented, it's good practice to set up your css using feature detection to utilize the correct properties, with font-feature-settings as the fallback.

Overview of CSS Shapes - CSS: Cascading Style Sheets
as in this level of the specification an element has to be floated in order to apply <basic-shape> to it; this has the side-effect of creating a simple fallback for many cases.

CSS data types - CSS: Cascading Style Sheets
index the data types defined by the set of css specifications include the following: <angle> <angle-percentage> <angular-color-hint> <angular-color-stop> <attr-fallback> <attr-name> <basic-shape> <blend-mode> <calc-product> <calc-sum> <calc-value> <color> <color-stop> <color-stop-angle> <counter-style> <custom-ident> <dimension> <filter-function> <flex> <frequency> <frequency-percentage> <gradient> <ident> <image> <integer> <length> <length-percentage> <number> <number-percentage> <percentage> <position> <quote> <ratio> <resolution> ...

Card - CSS: Cascading Style Sheets
useful fallbacks or alternative methods flexbox could be used to lay out the card, in which case you should make the content area grow, and other items not grow.

Grid wrapper - CSS: Cascading Style Sheets
useful fallbacks or alternative methods when using this recipe at page level it can be useful to set a max-width along with left and right auto margins to center the content horizontally: .grid { max-width: 1200px; margin: 0 auto; // horizontally centers the container } /* remove the max-width and margins if the browser supports grid */ @supports (display: grid) { .grid { display: grid; /* other...

Recipe: Media objects - CSS: Cascading Style Sheets
fallbacks there are a number of possible fallbacks for this pattern, depending on the browsers you wish to support.

CSS Layout cookbook - CSS: Cascading Style Sheets
css grid, float fallback, fit-content() sizing columns when to choose multi-column layout, flexbox or grid for your columns.

CSS reference - CSS: Cascading Style Sheets
-gradient()containcontentcontrast()<counter>counter-incrementcounter-resetcounter-set@counter-stylecounters()cross-fade()cubic-bezier()::cue::cue-regioncursor<custom-ident>d:defaultdeg<dimension>:dirdirection:disableddisplay<display-box><display-inside><display-internal><display-legacy><display-listitem><display-outside>dpcmdpidppxdrop-shadow()eelement()ellipse()em:emptyempty-cells:enabledenv()exffallback (@counter-style)filter<filter-function>:first:first-child::first-letter (:first-letter)::first-line (:first-line):first-of-typefit-content()<flex>flexflex-basisflex-directionflex-flowflex-growflex-shrinkflex-wrapfloat:focusfont@font-facefont-familyfont-family (@font-face)font-feature-settingsfont-feature-settings (@font-face)@font-feature-valuesfont-kerningfont-language-overridefont-optical-sizin...

align-content - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

align-self - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

background-image - CSS: Cascading Style Sheets
if the images cannot be loaded—for instance, when the network is down—the background color will be used as a fallback.

font-variant-position - CSS: Cascading Style Sheets
font-variant-position: normal; font-variant-position: sub; font-variant-position: super; /* global values */ font-variant-position: inherit; font-variant-position: initial; font-variant-position: unset; when the usage of these alternate glyphs is activated, if one character in the run doesn't have such a typographically-enhanced glyph, the whole set of characters of the run is rendered using a fallback method, synthesizing these glyphs.

justify-content - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

justify-items - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

justify-self - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

list-style - CSS: Cascading Style Sheets
if list-style-type and list-style-image are both set, then list-style-type is used as a fallback if the image is unavailable.

place-content - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

place-items - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

place-self - CSS: Cascading Style Sheets
the fallback alignment for first baseline is start, the one for last baseline is end.

shape-outside - CSS: Cascading Style Sheets
if this results in network errors such that there is no valid fallback image, the effect is as if the value none had been specified.

url() - CSS: Cascading Style Sheets
yfont.woff); url(#idofsvgpath); /* associated properties */ background-image: url("https://mdn.mozillademos.org/files/16761/star.gif"); list-style-image: url('../images/bullet.jpg'); content: url("pdficon.jpg"); cursor: url(mycursor.cur); border-image-source: url(/media/diamonds.png); src: url('fantasticfont.woff'); offset-path: url(#path); mask-image: url("masks.svg#mask1"); /* properties with fallbacks */ cursor: url(pointer.cur), pointer; /* associated short-hand properties */ background: url('https://mdn.mozillademos.org/files/16761/star.gif') bottom right repeat-x blue; border-image: url("/media/diamonds.png") 30 fill / 30px / 30px space; /* as a parameter in another css function */ background-image: cross-fade(20% url(first.png), url(second.png)); mask-image: image(url(mask.png), skyblue...

Video player styling basics - Developer guides
as mentioned in the previous article, there is a fallback provided for browsers that do not support the <progress> element; this also needs to be styled appropriately: .controls progress[data-state="fake"] { background:#e6e6e6; height:65%; } .controls progress span { width:0%; height:100%; display:inline-block; background-color:#2a84cd; } a .data-state class is also used here when a <progress> element is being "faked"; when it's in ...

Using HTML sections and outlines - Developer guides
p>javascript is an object-oriented computer programming language commonly used to create interactive effects within web browsers.</p> <p><a href="https://goo.gl/koeeaj">how to enable javascript?</a></p> </noscript> this leads to the following code to allow the support of the html5 sections and headings elements in non-html5 browsers, even for internet explorer (8 and older), with a proper fallback for the case where this latter browser is configured not to use scripting: <!--[if lt ie 9]> <script> document.createelement("article"); document.createelement("aside"); document.createelement("footer"); document.createelement("header"); document.createelement("nav"); document.createelement("section"); document.createelement("time"); </script> <![endif]--> <noscri...

Mobile Web Development - Developer guides
for browsers that don't support these features, provide an acceptable fallback.

Writing forward-compatible websites - Developer guides
when using cutting-edge features (even standard ones) that are not universally implemented, make sure to test fallback paths make sure to test what happens in a browser that doesn't implement the feature you're using, especially if you don't use such a browser day-to-day while working on the site.

<img>: The Image Embed element - HTML: Hypertext Markup Language
this gives users without pointing devices a fallback destination.

<input type="button"> - HTML: Hypertext Markup Language
<div class="toolbar"> <input type="color" aria-label="select pen color"> <input type="range" min="2" max="50" value="30" aria-label="select pen size"><span class="output">30</span> <input type="button" value="clear canvas"> </div> <canvas class="mycanvas"> <p>add suitable fallback here.</p> </canvas> body { background: #ccc; margin: 0; overflow: hidden; } .toolbar { background: #ccc; width: 150px; height: 75px; padding: 5px; } input[type="color"], input[type="button"] { width: 90%; margin: 0 auto; display: block; } input[type="range"] { width: 70%; } span { position: relative; bottom: 5px; } var canvas = document.queryselector('.mycanvas')...

<link>: The External Resource Link element - HTML: Hypertext Markup Language
browsers not supporting css3 media queries won't necessarily recognize the adequate link; do not forget to set fallback links, the restricted set of media queries defined in html 4.

<picture>: The Picture element - HTML: Hypertext Markup Language
it provides a fallback in case none of the offered <source> elements are able to provide a usable image.

<source>: The Media or Image Source element - HTML: Hypertext Markup Language
<picture> <source srcset="mdn-logo-wide.png" media="(min-width: 800px)"> <source srcset="mdn-logo-medium.png" media="(min-width: 600px)"> <img src="mdn-logo-narrow.png" alt="mdn web docs"> </picture> with the <picture> element, you must always include an <img> with a fallback image, with an alt attribute to ensure accessibility (unless the image is an irrelevant background decorative image).

<track>: The Embed Text Track element - HTML: Hypertext Markup Language
<track kind="subtitles" src="samplesubtitles_ja.vtt" srclang="ja"> <track kind="subtitles" src="samplesubtitles_oz.vtt" srclang="oz"> <track kind="metadata" src="keystage1.vtt" srclang="en" label="key stage 1"> <track kind="metadata" src="keystage2.vtt" srclang="en" label="key stage 2"> <track kind="metadata" src="keystage3.vtt" srclang="en" label="key stage 3"> <!-- fallback --> ...

title - HTML: Hypertext Markup Language
some typical uses: labeling <iframe> elements for assistive technology providing a programmatically associated label for an <input> element as a fallback for a real <label> labeling controls in data tables additional semantics are attached to the title attributes of the <link>, <abbr>, <input>, and <menuitem> elements.

Content Security Policy (CSP) - HTTP
your policy should include a default-src policy directive, which is a fallback for other resource types when they don't have policies of their own (for a complete list, see the description of the default-src directive).

Connection management in HTTP/1.x - HTTP
in http/1.1, persistence is the default, and the header is no longer needed (but it is often added as a defensive measure against cases requiring a fallback to http/1.0).

Content negotiation - HTTP
the 300 (multiple choices) or 406 (not acceptable) http response codes by the server (agent-driven negotiation or reactive negotiation), that are used as fallback mechanisms.

CSP: base-uri - HTTP
csp version 2 directive type document directive default-src fallback no.

CSP: child-src - HTTP
csp version 2 directive type fetch directive default-src fallback yes.

CSP: connect-src - HTTP
note: connect-src 'self' does not resolve to websocket schemas in all browsers, more info: https://github.com/w3c/webappsec-csp/issues/7 csp version 1 directive type fetch directive default-src fallback yes.

CSP: default-src - HTTP
the http content-security-policy (csp) default-src directive serves as a fallback for the other csp fetch directives.

CSP: font-src - HTTP
csp version 1 directive type fetch directive default-src fallback yes.

CSP: form-action - HTTP
csp version 2 directive type navigation directive default-src fallback no.

CSP: frame-ancestors - HTTP
csp version 2 directive type navigation directive default-src fallback no.

CSP: frame-src - HTTP
csp version 1 directive type fetch directive fallback if this directive is absent, the user agent will look for the child-src directive (which falls back to the default-src directive).

CSP: img-src - HTTP
csp version 1 directive type fetch directive default-src fallback yes.

CSP: manifest-src - HTTP
csp version 3 directive type fetch directive default-src fallback yes.

CSP: media-src - HTTP
csp version 1 directive type fetch directive default-src fallback yes.

CSP: navigate-to - HTTP
csp version 3 directive type navigation directive default-src fallback no.

CSP: object-src - HTTP
csp version 1 directive type fetch directive default-src fallback yes.

CSP: plugin-types - HTTP
csp version 2 directive type document directive default-src fallback no.

CSP: prefetch-src - HTTP
csp version 3 directive type fetch directive default-src fallback yes.

CSP: script-src - HTTP
csp version 1 directive type fetch directive default-src fallback yes.

CSP: style-src - HTTP
csp version 1 directive type fetch directive default-src fallback yes.

CSP: upgrade-insecure-requests - HTTP
note that, if the requested resource is not actually available via https, the request will fail without any fallback to http.

CSP: worker-src - HTTP
csp version 3 directive type fetch directive fallback if this directive is absent, the user agent will first look for the child-src directive, then the script-src directive, then finally for the default-src directive, when governing worker execution.

Content-Security-Policy - HTTP
connect-src restricts the urls which can be loaded using script interfaces default-src serves as a fallback for the other fetch directives.

Last-Modified - HTTP
less accurate than an etag header, it is a fallback mechanism.

Referrer-Policy - HTTP
example.com/page anywhere http://example.com/ strict-origin-when-cross-origin https://example.com/page https://example.com/otherpage https://example.com/page https://mozilla.org https://example.com/ http://example.org (no referrer) unsafe-url https://example.com/page?q=123 anywhere https://example.com/page?q=123 specifying a fallback policy if you want to specify a fallback policy in any case the desired policy hasn't got wide enough browser support, use a comma-separated list with the desired policy specified last: referrer-policy: no-referrer, strict-origin-when-cross-origin in the above scenario, no-referrer will only be used if strict-origin-when-cross-origin is not supported by the browser.

Using Promises - JavaScript
these make it possible to offer fallback error handling for promises, as well as to help debug issues with your promise management.

Intl.Collator - JavaScript
in order to get the sort order of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: // in german, ä sorts with a console.log(new intl.collator('de').compare('ä', 'z')); // → a negative value // in swedish, ä sorts after z console.log(new intl.collator('sv').compare('ä', 'z')); // → a positive value using options the results provided by collator.prototype.compare() can be customized using the options argument: // in german, ä ...

Intl.DisplayNames() constructor - JavaScript
"language" "region" "script" "currency" fallback the fallback to use, the default is "code".

Intl.PluralRules - JavaScript
in order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: // arabic has different plural rules new intl.pluralrules('ar-eg').select(0); // → 'zero' new intl.pluralrules('ar-eg').select(1); // → 'one' new intl.pluralrules('ar-eg').select(2); // → 'two' new intl.pluralrules('ar-eg').select(6); // → 'few' new intl.pluralrules('ar-eg').select(18); // → 'many' specifications specification ...

String.prototype.localeCompare() - JavaScript
in order to get the sort order of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument: console.log('ä'.localecompare('z', 'de')); // a negative value: in german, ä sorts before z console.log('ä'.localecompare('z', 'sv')); // a positive value: in swedish, ä sorts after z using options the results provided by localecompare() can be customized using the options argument: // in german, ä has a as the base letter console.log('ä'.localeco...

export - JavaScript
using the default export if we want to export a single value or to have a fallback value for your module, you could use a default export: // module "my-module.js" export default function cube(x) { return x * x * x; } then, in another script, it is straightforward to import the default export: import cube from './my-module.js'; console.log(cube(3)); // 27 using export from let's take an example where we have the following hierarchy: childmodule1.js: exporting myfunc...

display - Web app manifests
values the possible values are: display mode description fallback display mode fullscreen all of the available display area is used and no user agent chrome is shown.

Web audio codec guide - Web media technologies
typically, most modern applications will use g.711 only as a fallback option, unless the limitations have specific value to their use cases.

Handling media support issues in web content - Web media technologies
topics we will examine fallbacks, baseline media formats, and error handling practices that will let your content work in as many situations as possible.

Media type and format guide: image, audio, and video content - Web media technologies
handling media support issues in web content in this guide, we look at how to build web content that maximizes quality or performance while providing the broadest possible compatibility, by choosing media formats wisely, and offering fallbacks and alternate formats where it would be helpful.

Web media technologies
this includes recommendations for what formats to use for what kinds of content, best practices including how to provide fallbacks and how to prioritize media types, and also includes general browser support information for each media container and codec.

Lazy loading - Web Performance
event handlers when browser compatibility is crucial, there are a few options: polyfill intersection observer fallback to scroll, resize or orientation change event handlers to determine if a specific element is in viewport specifications specification status comment html living standard living standard ...

Graphic design for responsive sites - Progressive web apps (PWAs)
the downsides here are that css3 properties and svg don't work on old browsers such as ie6-8 (although polyfills are available, and you could build in fallbacks), and svg isn't suitable for high detail images, such as photographs.

Mobile first - Progressive web apps (PWAs)
when they are not supported, the <html> tag looks like this: <html class=" js no-rgba no-multiplebgs"> when these are present, we can serve alternative styling rules to provide sensible fallbacks using descendant selectors — see the following in my code.

<switch> - SVG: Scalable Vector Graphics
the switch element will display the first of its child elements whose systemlanguage attribute matches the user's language, or the fallback element with no systemlanguage attribute if none of them match.

SVG fonts - SVG: Scalable Vector Graphics
this defines what should be displayed if a certain glyph is not found in the font and if there are no fallback mechanisms.

Using templates and slots - Web Components
so, if we want to add a slot into our trivial example, we could update our template's paragraph element like this: <p><slot name="my-text">my default text</slot></p> if the slot's content isn't defined when the element is included in the markup, or if the browser doesn't support slots, <my-paragraph> just contains the fallback content "my default text".

Index - XSLT: Extensible Stylesheet Language Transformations
31 <xsl:fallback> element, reference, xslt, fallback the <xsl:fallback> element specifies what template to use if a given extension (or, eventually, newer version) element is not supported.

The Netscape XSLT/XPath Reference - XSLT: Extensible Stylesheet Language Transformations
elements xsl:apply-imports (supported) xsl:apply-templates (supported) xsl:attribute (supported) xsl:attribute-set (supported) xsl:call-template (supported) xsl:choose (supported) xsl:comment (supported) xsl:copy (supported) xsl:copy-of (supported) xsl:decimal-format (supported) xsl:element (supported) xsl:fallback (not supported) xsl:for-each (supported) xsl:if (supported) xsl:import (mostly supported) xsl:include (supported) xsl:key (supported) xsl:message (supported) xsl:namespace-alias (not supported) xsl:number (partially supported) xsl:otherwise (supported) xsl:output (partially supported) xsl:param (supported) xsl:preserve-space (supported) xsl:processing-instruction xsl:so...

Transforming XML with XSLT - XSLT: Extensible Stylesheet Language Transformations
xslt/xpath reference elements xsl:apply-imports (supported) xsl:apply-templates (supported) xsl:attribute (supported) xsl:attribute-set (supported) xsl:call-template (supported) xsl:choose (supported) xsl:comment (supported) xsl:copy (supported) xsl:copy-of (supported) xsl:decimal-format (supported) xsl:element (supported) xsl:fallback (not supported) xsl:for-each (supported) xsl:if (supported) xsl:import (mostly supported) xsl:include (supported) xsl:key (supported) xsl:message (supported) xsl:namespace-alias (not supported) xsl:number (partially supported) xsl:otherwise (supported) xsl:output (partially supported) xsl:param (supported) xsl:preserve-space (supported) xsl:processing-instruction xsl:sort (supported...