[whatwg] onerror

[Anne van Kesteren]

On Sat, 17 Jan 2009 04:04:19 +0100, Jonas Sicking <jonas at sicking.cc> wrote:
> Not sure if I should be posting this to the whatwg list or the webapps
> list, given that the spec is in process of transitioning between the
> two groups. So I'm posting to both in the hope that this thread won't
> generate too much related traffic. So please stay on topic :)
>
> Currently the webapps spec define that the onerror property should
> start out as undefined, rather than other onX properties which start
> out as null. The reason for this is parity with the window object
> where the onerror property behaves the same.
>
> However there is very little parity anyway between the window onerror
> and the worker onerror. The former isn't a normal event handler but
> rather a special function that receives 3 arguments and returns a
> special value to suppress the error. The latter is a normal event
> handler which receives an error event and suppresses the error by
> calling .preventDefault() on the event.
>
> Further, the fact that onerror is undefined at the start is to prevent
> breaking existing scripts, of which there are none for workers.
>
> So I think it'd be nicer to have parity with other onX properties,
> than to have parity on this one aspect with window.onerror.

Will you be changing Firefox for the other onX attributes then?

I.e.,

http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0D%0A...%3Cscript%3E%20w(document.body.onclick)%20%3C%2Fscript%3E

gives "null" in Opera 9.6+ and Internet Explorer 6, but "undefined" in  
Firefox 3.2a1pre.


(Replying just to the WHATWG list as my question is only relevant to HTML5  
for now.)


-- 
Anne van Kesteren
<http://annevankesteren.nl/>
<http://www.opera.com/>