If those functions (find, trigger, each, etc) all bind the "this" to
the object, what's the need for additionally passing it as the second
parameter?
On Jul 21, 1:54 am, Yehuda Katz <wyc...@gmail.com> wrote:
> On Mon, Jul 20, 2009 at 10:30 PM, David Flanagan
> <da...@davidflanagan.com>wrote:
>
>
>
> > What about the performance implications of creating those jQuery objects
> > for each call? Could you check the length property of the callback
> > function and only pass the jQuery object if it is actually declared to
> > expect 2 arguments?
>
> Yep! John and I had discussed this. I think it's the way to go.
>
>
>
> > What about modifying each() so that it passes three arguments to its
> > callback: the index, the element, and the wrapped element:
>
> > function(i, e, $e) { // e === $e[0] }
>
> > That avoids the compatibility problem, but loses the parallel with the
> > other methods, unless you pass both e and $e to their callback as well.
>
> Nah. If we do it, we need to do it right. I'd be ok with a jQuery.legacyEach
> = true, but John didn't like that ;)
>
>
>
>
>
>
>
> > David
>
> > John Resig wrote:
> > > A quick example:
>
> > > $(".msg").each(function(i, $this){
> > > $(".hide", this).click(function(){
> > > $this.hide();
> > > });
> > > });
>
> > > I actually proposed this set of changes to Yehuda on IM and then had a
> > > back and forth as to how to best implement them. I think they actually
> > > hold some promise. I like this since it's relatively pain-free which
> > > helping to reduce extra syntax (when dealing with closures in jQuery
> > > it's common that you'll need to declare references to the wrapped jQuery
> > > set - something that this avoids).
>
> > > The proposal is a set of 3 changes - each change is making the second
> > > argument of a callback function equal to $(this).
>
> > > - Modifying existing callbacks that have no second argument (like
> > > .filter, as Yehuda mentioned).
> > > - Modifying event callbacks to have a second argument be $(this)
> > > (which, can conflict with .trigger(event, data)).
> > > - Modifying each callbacks to have a second argument be $(this)
> > > (replacing the existing second argument of this).
>
> > > Obviously changing the second incoming argument to
> > > .each(function(i,$this)) is going to require a little bit of finesse. I
> > > did a quick search on Google Codesearch but didn't see any immediate
> > > warning signs:
> > >http://www.google.com/codesearch?hl=en&lr=&q=
> > > <http://www.google.com/codesearch?hl=en&lr=&q=
> > >\.each\%28\s*function\%28\s*\w%2B%2C\s*\w%2B\s*\%29+lang%3Ajavascript&sbtn=Search
>
> > > If we make a change like this I would like it to be an all-or-nothing
> > > proposition (having a half-baked API modification landing seems kind of
> > > lame) BUT it must be done in a way that we're sure won't break important
> > > code. (At the very least, a change like this would have to be done in a
> > > major 1.x release.)
>
> > > A quick note: It's probably important to use function(i, $this) in the
> > > examples (to help differentiate it from a "normal" self [which generally
> > > equates to var self = this;]).
>
> > > --John
>
> > > On Mon, Jul 20, 2009 at 11:14 PM, Yehuda Katz <wyc...@gmail.com
> > > <mailto:wyc...@gmail.com>> wrote:
>
> > > At the moment, traversal callbacks, like the ones passed to
> > > find/filter/etc. take a single "index" parameter. I'd like to
> > > propose that they are unified with .each as follows:
>
> > > $("div").filter(function(i, self) {
> > > // stuff
> > > });
>
> > > As a separate concern, I'd like to discuss changing the second
> > > parameter in both to be a jQuery object. Obviously, it would need to
> > > be done via slow deprecation for .each, but I don't think it'd break
> > > all that much code:
>
> > > $("div").filter(function(i, self) {
> > > // self == $(this)
> > > })
>
> > > Thoughts?
>
> > > --
> > > Yehuda Katz
> > > Developer | Engine Yard
> > > (ph) 718.877.1325
>
> --
> Yehuda Katz
> Developer | Engine Yard
> (ph) 718.877.1325- Hide quoted text -
>
> - Show quoted text -
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