Re: Mutation Observers: a replacement for DOM Mutation Events

On 09/24/2011 12:16 AM, Adam Klein wrote:
>
> For each observer, if a registration exists which requests the
> matching mutation type and whose observed node set contains the target
> node of the mutation, a MutationRecord is appended to the observer's
> pending mutation queue. If multiple such registrations exist for a
> given observer, a single MutationRecord is delivered having the union
> of the information requested by all registrations (e.g.
> attributeOldValue).


This is actually still ambiguous.
What if attributeOldValue is first set to true for 
document.documentElement, and then false (implicitly or explicitly)
for document, should attribute values be reported?

Another problematic case is that if we have subtree A and B and both
are being observed by same observer but different options. Then some
node from A is moved to B. Which options should be used?

So, should we define that "union" means that 'true' values override
'false' values, and attributeFilter values are union'ed the usual way?

To make API somewhat more consistent, should we change
"Subsequent calls to the same MutationObserver made with the same 
|target| have the effect of resetting the options associated with the 
registration. " to follow the union-ing.

-Olli 

Received on Tuesday, 27 September 2011 20:13:10 UTC