Listeners and Scope

[J.B]

Hi All,

I am trying to fire an event in my JS file to a listener rendered by lazy-initialization code, but the two don't want to talk to each other. Do I need to define a specific scope? They are both rendered on the same page..

JS

	this.addEvents({'checkactive': true});

        .....

	this.grid.on('rowclick',  function(grid, index, e) {		
		if (sm.getCount() > 0) {
			this.fireEvent('checkactive', 'enabled');						
		} else { 
			this.fireEvent('checkactive', 'disabled');						
		}
	}, this);

In my JSON lazy initialization code:

	buttons: [{
		"text": "Submit",
		"type": "button",
		"scope": this,
		"handler": function(){ submit(); },
		"listeners": {
	  			 "checkactive": function(isenabled) {
						alert(isenabled);				
				},
				scope:this
		}
           .....

I've checked in FireBug and the fireEvent is run, but the listener never gets executed.

Any ideas?

Thanks

[Animal]

this.grid.on('rowclick'....

You bind that handler function to whatever "this" is at that time. That is then what the 'checkactive' event is fire on.

[J.B]

Thanks Animal, what could it be binded to other than 'this'? I am not familiar with using different scoping definitions...

Thanks again

[Animal]

If you don't need it, don't use it.

But if you are writing "function soup" rather than a set of discrete Classes which manage their own internal state individually, then you are storing up trouble.

[J.B]

Thanks. I'm assuming by removing the scope on an event it would work across the dom of the active page? That would solve the problem I am having.

I have removed the scrope from the listener but how can I make the event global, currently this.fireEvent.... still does not execute the listener which is without scope.

Thanks

John

[Animal]

this.grid.on('rowclick',  function(grid, index, e) {		
		if (sm.getCount() > 0) {
			this.fireEvent('checkactive', 'enabled');						
		} else { 
			this.fireEvent('checkactive', 'disabled');						
		}
	}, this)

The things in red are the same. You have specified a rowclick handler to run, and passed this as the scope. So that is what the this in the handler will be.