The doSlide function was what I was referring to. I tried using TJ's 
suggestion of using this as the 2nd parameter, but the handler still wasn't 
getting called. You can find a prototype of what I am doing at 
http://andydaykin.com/Home. The slideshow (images obviously missing) is on 
the main page. The javascript file for the class is 
http://andydaykin.com/Home/public/js/Home.js

-Andy

--------------------------------------------------
From: "Daniel Rubin" <dru...@dimedis.de>
Sent: Friday, August 21, 2009 3:38 AM
To: <prototype-scriptaculous@googlegroups.com>
Subject: [Proto-Scripty] Re: this keyword inside of the map function

>
> Andy Daykin wrote:
>> I tried the first suggestion, but the function still isn't getting 
>> called.
> Exactly which function do you refer to? The map-iterator-func ("function
> (e) { ... }") or the click-handler (this.doSlide)?
>
> ----Daniel
>
>
>
>> TJ, can you explain more, or show an example of what the context param 
>> would
>> look like? Should I just put the doSlide function as the 2nd parameter?
>>
>> -Andy
>>
>> --------------------------------------------------
>> From: "T.J. Crowder" <t...@crowdersoftware.com>
>> Sent: Thursday, August 20, 2009 3:56 AM
>> To: "Prototype & script.aculo.us" 
>> <prototype-scriptaculous@googlegroups.com>
>> Subject: [Proto-Scripty] Re: this keyword inside of the map function
>>
>>> Hi,
>>>
>>> Rather than binding it, use the second parameter to map (aka collect
>>> [1]), that's what the second param ("context") is for.  You'll find
>>> that most of the Enumerable methods that take callbacks also take a
>>> context parameter so the callback can be a method.
>>>
>>> [1] http://prototypejs.org/api/enumerable/collect
>>>
>>> HTH,
>>> --
>>> T.J. Crowder
>>> tj / crowder software / com
>>> Independent Software Engineer, consulting services available
>>>
>>>
>>> On Aug 20, 8:34 am, Daniel Rubin <dru...@dimedis.de> wrote:
>>>> Andy Daykin wrote:
>>>>> Hello, I am having some difficulties writing a class, in my code I 
>>>>> have
>>>>> a class where I need to be able to bind event listeners to values. In
>>>>> my code I want the variable pointerIndex to be accessible outside of
>>>>> the initialize function, but right now it is not. If I make a global
>>>>> variable for pointerIndex I can solve the problem, but I would rather
>>>>> have a class variable using the this keyword.
>>>>> I am not positive, but I believe the problem is from my event 
>>>>> listeners
>>>>> on the line:
>>>>> Now: $(e).observe('click', this.doSlide.bind(featuresWrapper[i].id));
>>>>> Before: (working) $(e).observe('click',
>>>>> mySlide.doSlide.curry(featuresWrapper[i].id));
>>>>> With the new way of calling the doSlide function I can't even seem to
>>>>> be able to call the function, nothing happens when the function should
>>>>> get called. Before I was using the curry function to try and pass the
>>>>> values of the featuresWrapper array to the doSlide function. I was 
>>>>> able
>>>>> to get that to work, but I would rather just use bind and this to make
>>>>> the code more object oriented. Based on my alert statements I can tell
>>>>> that the this keyword is different inside and outside of the map
>>>>> function.
>>>> Hi Andy,
>>>>
>>>> the last observation is crucial.  Because this is not your expected
>>>> SlideShow instance when you do this.doSlide.bind (...), this.doSlide is
>>>> undefined and thus the call to this.doSlide.bind fails (there should be
>>>> an exception in the error console somewhere).
>>>>
>>>> You can solve it by bind()-ing the map function, too:
>>>>   $(parentDiv).childElements().map( (function(e) {
>>>>     $(e).observe('click',
>>>>                  this.doSlide.bind(this, featuresWrapper[i].id));
>>>>   }).bind (this) );
>>>>
>>>> (Note: Passing this as first arg to the inner bind call, as Kevin
>>>> suggested, is needed, too.)
>>>>
>>>> Have fun
>>>> ----Daniel
>>>>
>>>>
>>>>
>>>>> var SlideShow = Class.create({
>>>>> initialize: function(parentDiv) {
>>>>> this.pointerIndex = 0;
>>>>> //pointerIndex = 0;
>>>>> // Load the event listener for each section
>>>>> document.observe("dom:loaded", function() {
>>>>> var featuresWrapper = $('featuresWrapper').childElements();
>>>>> var i = 0;
>>>>> alert(this);
>>>>> $(parentDiv).childElements().map(function(e) {
>>>>> alert(this);
>>>>> $(e).observe('click', this.doSlide.bind(featuresWrapper[i].id));
>>>>> //$(e).observe('click', mySlide.doSlide.curry(featuresWrapper[i].id));
>>>>> i++;
>>>>> });
>>>>> slides = $$('.featureImage').map(function(e) {
>>>>> return e.id;
>>>>> });
>>>>> });
>>>>> },
>>>>> doSlide: function(slideClicked) {
>>>>> alert('here');
>>>>> if(active == 0) {
>>>>> active = 1;
>>>>> var yValCurrent = $(slides[this.pointerIndex]).viewportOffset().top;
>>>>> //var yValCurrent = $(slides[pointerIndex]).viewportOffset().top;
>>>>> var yValClick = $(slideClicked).viewportOffset().top;
>>>>> var yValDiff = yValClick - yValCurrent;
>>>>> var pointerShift = 0;
>>>>> if (Math.abs(yValDiff) == Math.abs(210)) {
>>>>> pointerShift = 70; // Change this to get the height as well as a few
>>>>> more
>>>>> }
>>>>> else {
>>>>> pointerShift = 140;
>>>>> }
>>>>> if (yValDiff > 0) {
>>>>> $$('.featureImage').map(function(e) {
>>>>> new Effect.Move(e, { y: -yValDiff, duration: .8, afterFinish:
>>>>> function(e) { active = 0; } });
>>>>> });
>>>>> new Effect.Move('featurePointer', { y: pointerShift });
>>>>> }
>>>>> else if (yValDiff < 0) {
>>>>> $$('.featureImage').map(function(e) {
>>>>> new Effect.Move(e, { y: -yValDiff, duration: .8, afterFinish:
>>>>> function(e) { active = 0; } });
>>>>> });
>>>>> new Effect.Move('featurePointer', { y: -pointerShift });
>>>>> }
>>>>> this.pointerIndex = slides.indexOf(slideClicked);
>>>>> }
>>>>> }
>>>>> });
>>>>> var slides;
>>>>> var active = 0;
>>>>> //var pointerIndex = 0;
>>>>> var mySlide = new SlideShow('featureList');
>
>
> >
> 

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