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Re: WebApps-ISSUE-178 (empty string and null event types): Implementations and DOM Core allow empty string and null event types [DOM3 Events]

From: Olli Pettay <Olli.Pettay@helsinki.fi>
Date: Tue, 10 May 2011 14:14:28 +0300
Message-ID: <4DC91E14.4060603@helsinki.fi>
To: Jonas Sicking <jonas@sicking.cc>
CC: Simon Pieters <simonp@opera.com>, Jacob Rossi <Jacob.Rossi@microsoft.com>, "www-dom@w3.org" <www-dom@w3.org>, "annevk@opera.com" <annevk@opera.com>
On 05/10/2011 12:57 PM, Jonas Sicking wrote:
> On Tue, May 10, 2011 at 2:19 AM, Simon Pieters<simonp@opera.com>  wrote:
>> On Tue, 10 May 2011 09:53:36 +0200, Jonas Sicking<jonas@sicking.cc>  wrote:
>>> On Monday, May 9, 2011, Jacob Rossi<Jacob.Rossi@microsoft.com>  wrote:
>>>> Hi folks,
>>>> In recognition that implementations support null and empty string event
>>>> types and that DOM Core allows this, we accepted the change to D3E to remove
>>>> this restriction. I have removed the spec text in the exceptions section
>>>> which required
>>>>   an exception be thrown in these cases.
>>> Hmm. I only vaguely remember the tail end of this discussion, but
>>> wasn't the conclusion that it was better to let empty string signify
>>> an uninitialized event?
There certainly wasn't such conclusion.
Gecko now throws an exception if non-initialized event is dispatched,
but it doesn't matter what the event type string contain.

> Thus making empty string a not allowed name.
>>> The alternative is to force the event to hold some hidden state which
>>> indicates if it has been initialized or not. This is worse both from
>>> an implementation complexity aspect, as well as removes the ability
>>> for pages to check if an event has been initialized (I don't have any
>>> use cases for the latter, but it's a nice free bonus)
>> Some argued for that but DOM Core was then changed to have a flag -
>> http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#initialized-flag
> Why? What was the advantage with that approach?
The advantage is to keep event.type a separate thing which
doesn't affect event dispatch.

  I'd rather not head
> down a path that'll make us add extra API
What extra API? The flag is an internal thing.


> just to check the
> initialized flag if someone comes up with a use case a couple of years
> down the road.
> / Jonas
Received on Tuesday, 10 May 2011 11:15:18 UTC

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