Re: Request For Feedback on Event Groups

On May 1, 2006, at 9:18 PM, Boris Zbarsky wrote:

>
> Doug Schepers wrote:
>> The WebAPI WG would like to solicit feedback about Event Groups,
>> particularly from implementors. Do Event Groups fill a current  
>> need? Are
>> they implemented in your UA, or are you planning to do so? Are  
>> they used by
>> authors in the wild? Basically, are there compelling reasons to  
>> either keep them or to get rid of
>> them?
>
> The only event groups Gecko implements at the moment are the  
> "normal" and "system" event groups.  The bubbling phase in the  
> "system" event group is when default actions take place.  This can  
> be used by authors of XBL bindings, for example (and is).  Note  
> that none of this requires actually exposing the system event group  
> per se; there's just an XBL syntax to add listeners in that group  
> instead of the "normal" one.

I think this concept of event groups is not the same as the DOM Level  
3 Events concept. Event groups in DOM3EV don't result in whole  
separate ordered capture and bubble phases. The main effect is that  
stopPropagation called in a listener in one group doesn't affect  
other groups. However, listeners on a given target all fire before  
proceeding to the next step of the bubble/capture phase. Also,  
relative ordering of listenrs in different groups are undefined.

Regards,
Maciej

Received on Tuesday, 2 May 2006 08:21:22 UTC