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.
The Document.onafterscriptexecute property references a
function that fires when a static <script> element finishes executing
its script. It does not fire if the element is added dynamically, such as with
appendChild().
Syntax
document.onafterscriptexecute = funcRef;
funcRef is a function reference, called when the event is fired. The event's
target attribute is set to the <script> element that just
finished executing.
Example
function finished(e) {
logMessage(`Finished script with ID: ${e.target.id}`);
}
document.addEventListener('afterscriptexecute', finished, true);
Specifications
Browser compatibility
BCD tables only load in the browser