Bug 81712 – "this" argument for MutationCallbacks should be the MutationObserver

• Status: RESOLVED
• Resolution: FIXED
• Component: DOM

[Adam Klein]

"this" argument for MutationCallbacks should be the MutationObserver

[Adam Klein]

Created attachment 133097 [details]
Patch

[Adam Klein]

Add some bindings experts.

[Adam Barth]

Comment on attachment 133097 [details]
Patch

Do other callbacks have this problem?  Why is this code custom and not autogenerated.

[Adam Klein]

(In reply to comment #3)
> (From update of attachment 133097 [details])
> Do other callbacks have this problem?  Why is this code custom and not autogenerated.

It's specified to be the observer by DOM4 (see step 4):

http://dvcs.w3.org/hg/domcore/raw-file/tip/Overview.html#concept-mo-invoke

Note that WebIDL lets specifications define this on a per-callback basis:

http://dev.w3.org/2006/webapi/WebIDL/#dfn-callback-this-value

I think there probably should be some codegen perl here, but I'm not sure exactly what it should look like, so I'd like to land this for now and wait to see if we have other users of this WebIDL feature.

[Erik Arvidsson]

Comment on attachment 133097 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=133097&action=review

LGTM

It is really silly to pass the mutation observer as the second argument to the callback but that is a topic for the spec and not for this patch.

> LayoutTests/fast/mutation/callback-this-argument.html:4
> +if (window.layoutTestController) {

Can you use js-test-pre?

> LayoutTests/fast/mutation/callback-this-argument.html:9
> +function mutationCallback(mutations) {

Should we also test arguments[1]?

[Adam Klein]

Comment on attachment 133097 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=133097&action=review

>> LayoutTests/fast/mutation/callback-this-argument.html:9
>> +function mutationCallback(mutations) {
> 
> Should we also test arguments[1]?

Will combine with callback-second-argument.html and use js-test-pre.

[Adam Klein]

Created attachment 133115 [details]
Patch for landing

[WebKit Review Bot]

Comment on attachment 133115 [details]
Patch for landing

Clearing flags on attachment: 133115

Committed r111611: <http://trac.webkit.org/changeset/111611>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.