[whatwg] should we add beforeload/afterload events to the web platform?

[Boris Zbarsky]

On 1/10/12 3:40 PM, Adam Barth wrote:
>> Do they really need to block the load, or block processing of the response?
>
> Just block processing the response.

OK.  I have no serious problem with a "beforeprocess" event that fires 
before processing the response, esp. if "processing" is defined in a 
page-visible way (so e.g. you could still compile a script in the 
background before firing "beforeprocess"; you just couldn't run it).

> The actual element turns out to be useful tracking down and fixing
> these issues, at least in complicated web sites.

Fair.

> To be clear, I'm not the biggest fan of beforeload because dispatching
> synchronous events during loading is pretty tricky.

Exactly.  Also bad for the long-term evolution of the web, in my opinion.

> They are reasonably popular, however.

Except that every use case that's been brought up so far (except the 
not-really-working-anyway adblock use case) hasn't actually wanted what 
this event claims to provide but something slightly different... and 
just not had that better thing.

I do think there are good use cases here that we should address; a sync 
"before load" event is not the right way to address the ones I've seen 
so far.

-Boris