[whatwg] Fixing undo on the Web - UndoManager and Transaction

Ryosuke Niwa rniwa at webkit.org
Thu Aug 4 17:31:10 PDT 2011

On Wed, Aug 3, 2011 at 2:46 PM, Anne van Kesteren <annevk at opera.com> wrote:

> On Wed, 03 Aug 2011 23:40:27 +0200, Ryosuke Niwa <rniwa at webkit.org> wrote:
>> On Wed, Aug 3, 2011 at 2:36 PM, Anne van Kesteren <annevk at opera.com>
>> wrote:
>>> If they are identical I think it is even more clear we should remove the
>>> one on Document as it's redundant :-)
>> Mn... but I think it's more convenient to be able to access undoManager
>> from document.  Also, what if there were no body?  undoManager needs to
>> exist in such cases as well (e.g. designMode).
> <body> is not the root element. And if there is no root element there is
> nothing visible on the screen so I am not sure it matters if things are lost
> in that case. That is such an edge case and not really worth having an
> additional member on Document for.

Not sure.  This happens all the time in design mode.  We've had plenty of
crash reports that only reproduce when there are no document element.

It might also be hard to implement such a behavior in WebKit at least
because documents / frames have the undo stack managed by OS X or embedders
and having to fake non-existence of the undo stack might be tricky.

- Ryosuke

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