Hi, Jonas-
Jonas Sicking wrote (on 7/18/08 2:51 PM):
Well, I'd start by asking what the rationale is for mutation events at
all :) They seem to only solve the very simple cases where all parties
that mutate the page cooperate nicely with each other and with the
parties that listen to mutation events. But I would have expected that
in those cases the parties that mutate the DOM could instead have
notified the listening parties directly.
I admit I've used mutation events only sparingly in my own projects, so
I'm not the most qualified to answer. However, many authors I've talked
to or read from speak of them glowingly, so I will defer to the notion
that they are useful.
I know you deal a lot with the more complex mashup cases, but are those
really the most common case? I suspect that even today, the very simple
case where only one site is involved are the more common. Or does "all
parties" also mean cases where people are using script frameworks like dojo?
In mozilla we have never implemented DOMNodeRemovedFromDocument or
DOMNodeInsertedIntoDocument due to its high cost. Likewise I doubt that
we'll implement DOMDescendantRemovedFromDocument. I'm not sure what
other vendors have done about the old event or feel about the new.
I am very reluctant to specify something that browser vendors won't
implement. Unless other vendors feel strongly about including it, or
Mozilla changes their mind and decides to include it, I'm not going to
waste everyone's time by adding this. The only reason to add a feature
is to make sure that authors can use it interoperably, in my mind. As
an author, I was (and am!) always bitter and disappointed when I read
about *exactly* the feature I need in a spec, but it's not implemented
at all, or not implemented interoperably enough to use. I have no
intention of building up authors expectations like that if it will be
futile.
If possible, I prefer to keep looking for a solution that fits the use
cases and will be widely implemented.
But I want to resolve this soon. This specification is at the awkward
point where it's too established to change it much, and too unstable to
rely on it. That sucks for everyone.
I understand that having the distinction means that you could filter
on the level of depth to fire events on, but I'm asking if this is
useful and necessary.
I take it you are asking under the general assumption that mutation
events are useful at all? :)
That is the general tenor of the authors, who, along with users, are my
chief constituents.
Do note that there is still nothing that defines when these events
should fire. I.e. if you do foo.textContent = '', does that fire a
DOMNodeRemoved on all elements before any of them are removed, or does
it fire the event on each of them as they are removed.
Though it might not be needed to be defined if the events get deprecated
anyway...
No, I intend to define that regardless of whether or not we deprecate it.
Regards-
-Doug Schepers
W3C Team Contact, WebApps, SVG, and CDF
