epimeth
Joined: 29 May 2008
Posts: 1
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 Posted: Thu May 29, 2008 4:33 pm Post subject: self = this ... or how I learned to continue worrying but lo |
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so here's a *greatly simplified* snippet:
it uses the YUI event handler functions... if you don't know them then suffice it to say that:
YAHOO.util.Event.on ( el , sType , fn , obj , override )
Appends an event handler
Parameters:
el <String|HTMLElement|Array|NodeList> An id, an element reference, or a collection of ids and/or elements to assign the listener to.
sType <String> The type of event to append
fn <Function> The method the event invokes
obj <Object> An arbitrary object that will be passed as a parameter to the handler
override <Boolean|object> If true, the obj passed in becomes the execution scope of the listener. If an object, this object becomes the execution scope.
| Code: |
function TopLevel() {
function MyProblematicClass() {
// here is why it is problematic:
var self = null;
var myObjectHandler = function(action, args) {
var myProblematicFunction() {
var myDiv = document.createElement('div');
// here is where I use 'self' because 'this' did not work
YAHOO.util.Event.on(myDiv, 'click', function() {
this.someFunction();
}, null, self);
return myDiv;
}
switch(action) {
case 'myAction':
//here I define 'self' to be 'this'
self = this;
// here (the same scope as above!), 'this' *does* work
this.someOtherFunction(myProblematicFunction());
break;
default:
}
}
return new objectThatDefines_someFunction_and_someOtherFunction({
objectHandler: myObjectHandler
});
}
var myObj = new MyProblematicClass();
myObj.callToThingWhichFiresTheHandler();
}
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the call to myObj.callToThingWhichFiresTheHandler() doesn't actually occur where I placed it, but I think this is enough to post my question.
I can only assume that my problem lies in the fact that I instead of keeping to standard closure procedure I decided to return a reference to some newly created object. However, the code *does* work, so I really don't understand what the problem is.
If you want to get into slightly deeper specifics, the objectThatDefines_someFunction_and_someOtherFunction
is actually the ycarousel component found at http://www.billwscott.com/carousel/
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