I get this message when loading a typical page on my browser:
Use of Mutation Events is deprecated. Use MutationObserver instead.
Line Number where this message happens to be thrown is given as: jquery-3.2.1.js:5062:6
Looking at jQuery source, this is the code it contains, where the offending line is elem.addEventListener( type, eventHandle );
// Init the event handler queue if we're the first
if ( !( handlers = events[ type ] ) ) {
handlers = events[ type ] = [];
handlers.delegateCount = 0;
// Only use addEventListener if the special events handler returns false
if ( !special.setup ||
special.setup.call( elem, data, namespaces, eventHandle ) === false ) {
if ( elem.addEventListener ) {
elem.addEventListener( type, eventHandle );
# ^^^^^ the line that throws the Mutation Observer message
}
}
}
How do I find out the code responsible for triggering this message?
Per comments under the question:
Search your codebase for the deprecated DOM events, i.e the regex of:
DOMAttrModified|DOMAttributeNameChanged|DOMCharacterDataModified|DOMElementNameChanged|DOMNodeInserted|DOMNodeInsertedIntoDocument|DOMNodeRemoved|DOMNodeRemovedFromDocument|DOMSubtreeModified
It will show you offending lines that trigger deprecated events.