I've programmed a modal with a TinyMCE editor inside, where it's value is saved via ajax, but when leaving the page there's still the warning Changes you made may not be saved.
Is there a function or some sort of flag I can configure to avoid the alert?
The popup is caused by a bound onbeforeunload event that is being added via the autosave plugin. To completely disable it;
var editor = window.Joomla.editors.instances['{editor}'];
editor.instance.plugins.autosave = {};
Replace {editor} with the id of the editor.
Addendum (2022-09-15):
This code now throws an error during the onbeforeunload event. I've found a fix already:
var editor = window.Joomla.editors.instances['{editor}'];
editor.instance.plugins.autosave = {storeDraft:function(){editor.instance.setDirty(false)}};