Appropriate handling of DOMContentLoaded event

[arvgta]

When using Ajaxify, the DOMContentLoaded event is not fired every time around i.e. only on initial load.

Lots of sites that translate e.g. the old jQuery ready() event to native JavaScript use the DOMContentLoaded event instead. In order to assist such porting, we have introduced the following piece of code...

... which is suspected to be buggy:

$.intevents = () => {
    let iFn = function (a, b, c = false) { 
        if ((this === document || this === window) && a=="DOMContentLoaded") 
            setTimeout(b); // if "DOMContentLoaded" - execute function, 
        else this.ael(a,b,c); //else - call original event listener
    };

    EventTarget.prototype.ael = EventTarget.prototype.addEventListener; // store original method
    EventTarget.prototype.addEventListener = iFn; // start intercepting event listener addition
}

At the very least the setTimeout(b) bit seems dodgy, because the b handler is being called at the time of registering the handler, which can cause timing problems, that have been reported on some sites.

The above logic is enabled by default (intevents: true)

• Has anyone observed any peculiar behaviour?

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A different and possibly cleaner approach might be to programmatically trigger DOMContentLoaded, in case the user wants that?

Something like this:

document.dispatchEvent(new Event('DOMContentLoaded'))

• What would you think of that?

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• Here's a proposed draft of the new code...

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Now that I made the transition, the next problem is how to avoid duplicate attaching of any event handlers?

If necessary, I would like to ensure that the handlers are only triggered once by using the modern { once: true } technique:

• as described here - please see bottom of the article

[arvgta]

Just for the sake of completeness - this approach has been discarded in the course of some testing...

[arvgta]

Our partner AllMediaLab has reported, that there are still issues with DOMContentLoaded handling - thus reopening

[arvgta]

Our partner AllMediaLab has reported, that this is not an issue with DOMContentLoaded handling after all - thus closing again