Hi,
This seems to me to be a good solution.
I applied the changes, and updated the test-file to reflect this.
I did comment the changes, so they can easily be reversed if shown they have
any negative effects, or a better solution is suggested.
At least now we can start using complex widgets again.
Great !
----- Original Message -----
From: "Joachim Lundgren" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, November 03, 2001 4:28 PM
Subject: Re: [Dynapi-Dev] Re: [Dynapi-Chat] Serious Event model bug
> I sent a fix for this ages ago (August, that is) to this list. That was
the mistake I did, it should have been to the bug/patches area. I simply
forgot it afterwards. And now I'm doing it again...
> (The kludge outlined below is NOT the same as the August kludge.)
>
> The problem is the objects share the same eventListener array [in the
example it can be verified with an
alert(scrollpane1.eventListeners===scrollpane2.eventListeners); line].
>
> (Because EventListeners are a rather fundamental aspect of the code it is
less of a kludge than it really is :-)
>
> In dynapi.js, make the DynObject function end with:
>
> // These aren't used unless listeners.js is included
> this.eventListeners = [];
> this.hasEventListeners = false;
> };
>
> and comment out or remove the first line in listeners.js:
> DynObject.prototype.addEventListener=function(listener) {
> // if(!this.eventListeners) { this.eventListeners = []; } // <-
remove this line (commented here)
> this.hasEventListeners = true;
> for (var i=0;i<this.eventListeners.length;i++) if
(this.eventListeners[i]==listener) return;
> this.eventListeners[this.eventListeners.length]=listener;
> }
>
> NB: This fixes the example and my own quick-and-dirty test-case, and I got
the desired results with these changes. Please check so it doesn't break
anything else! The August fix worked for the original bug submitter, and I
don't think the difference between my original fix and this version breaks
anything.
>
> /Lunna
>
>
> At 2001-11-02 03:01, you wrote:
> >Hi,
> >I added a testfile to the /tests directory in CVS or latest snapshot.
> >See:
> ><wrap>
>
>http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/~checkout~/dynapi/dynapi/tes
t
> >s/secondary_inheritance.html?rev=1.1&content-type=text/html
> >
> ></wrap>
> >Should make debugging this problem easier.
> >I would hope it is possible to debug this issue at it's core, instead of
> >changing the architecture of all the widgets.
> >
> >Cheers,
> >Richard.
> >
> >
> >----- Original Message -----
> >From: "Laszlo Teglas" <[EMAIL PROTECTED]>
> >To: <[EMAIL PROTECTED]>
> >Sent: Wednesday, October 31, 2001 4:42 PM
> >Subject: [Dynapi-Chat] Serious Event model bug
> >
> >
> >> After spending the better part of a day trying to track down a bug I
> >though
> >> I introduced into my code, when migrating from a November 2000 version
> >> DynAPI script to the current 2.55a version, I realized that something
more
> >> serious was causing my agony.
> >>
> >> After searching through the lists and bug reports, I came across what I
> >> think is the earliest mention of this problem. Bug number 425789
reported
> >on
> >> May 20, 2001.
> >>
> >> Basically any widget that does not inherit directly from DynLayer can
not
> >be
> >> used more than once on a single page, unless you only want one
> >EventListener
> >> for the whole lot (very unlikely).
> >>
> >> If you try to create multiple EventListeners (i.e. one for each widget
of
> >a
> >> class not derived directly from DynLayers), only the last EventListener
> >> assigned to one of this second generation widgets will fire. And it
will
> >> fire on all widgets that are instances of the same class.
> >>
> >> I have been mainly working with the ButtonImage class derived from
> >DynImage,
> >> but I believe this will affect List, PushPanel and any other second
> >> generation widget.
> >>
> >> Seeing that this problem has been around for some time, I imagine the
> >> solution will require a lot of work. A temporary solution would be to
> >> rewrite any second generation widget to inherit directly from DynLayer
and
> >> including any other inherited functions from it's former parent. I
realize
> >> this is redundant and counter to OOP, but at least we would have
complex
> >> widgets that work. There is no point in streamlining the core for
> >> performance if the core is broken. This would be a relatively simple
fix.
> >> And could be reversed easily once the event model is fixed. This would
> >also
> >> not require changes in code implementing these widgets, thus have
little
> >> effect on users other than performance due to redundancy.
> >>
> >> The other solution is to fix the problem in the event model. This will
> >take
> >> longer, but should be top priority. The whole purpose of DynAPI is to
have
> >> complex widgets, and a common API. For simple widgets anyone can create
> >> simple JavaScript that has less overhead than DynAPI. Therefore this
bug
> >> undermines the purpose of DynAPI.
> >>
> >> We did not have this bug in 2.0. What has changed so drastically since
2.0
> >> in the event model or in other parts of the core that introduced this
bug.
> >> Any idea?
> >>
> >>
> >> Laszlo
> >>
> >>
> >> _______________________________________________
> >> Dynapi-Chat mailing list
> >> [EMAIL PROTECTED]
> >> https://lists.sourceforge.net/lists/listinfo/dynapi-chat
> >>
> >
> >
> >_______________________________________________
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>
>
>
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