Document.onbeforescriptexecute

Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

Fired when the code in a <script> element declared in an HTML document is about to start executing. Does not fire if the element is added dynamically, eg with appendChild().

Syntax

document.onbeforescriptexecute = funcRef;

funcRef is a function reference, called when the event is fired. The event's target attribute is set to the script Element that is about to be executed.

Example

function starting(e) {
  logMessage("Starting script with ID: " + e.target.id);
}

document.addEventListener("beforescriptexecute", starting, true);

View Live Examples

Specification

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
onbeforescriptexecute
Non-standard
Chrome No support NoEdge No support NoFirefox Full support YesIE ? Opera ? Safari ? WebView Android No support NoChrome Android No support NoFirefox Android Full support YesOpera Android ? Safari iOS ? Samsung Internet Android No support No

Legend

Full support
Full support
No support
No support
Compatibility unknown
Compatibility unknown
Non-standard. Expect poor cross-browser support.
Non-standard. Expect poor cross-browser support.

See also