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How do i pass an argument to an eventListener in a quick easy way?

Posted on 2011-09-27
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Last Modified: 2012-05-12
Hi

I'm trying to solve this thing with passing variables with eventListeners..
Why is it so hard? Seriously?

currentObject is null when i'm trying to alert this and I've come to understand that it has something with closure to do. But isn't there som way to get the variables in there anyway?

I just want a way to pass arguments to a function that i call when i press an html-object.
It would probably work with setting ahref to the object,, or perhaps giving the html-object a attribute (nr), and then use .this to get it's attribute. But is this really neccessary?


function outerFunction() {
	var currentObject = g.objectHandler.first;
	var newObjectTitle;
	var newTextNode;
	
	while(currentObject != null) {

		newObjectTitle = document.createElement('p');
		newTextNode = document.createTextNode(currentObject.title);
		newObjectTitle.appendChild(newTextNode);
		newScrollBox.appendChild(newObjectTitle);

		newObjectTitle.addEventListener('click', function(){innerFunction(currentObject.nr)},false);
		
		////////////////////////////////////////
		
		currentObject = currentObject.next;		
	}
}


function innerFunction(nr) {
	alert(nr);
}

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Question by:walkman69
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3 Comments
 
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Expert Comment

by:JPJ78
ID: 36715037
Maybe you can use.

newObjectTitle.addEventListener('click', function(){ eval("innerFunction(" + currentObject.nr + ");");}, false);
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Accepted Solution

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mattjp88 earned 500 total points
ID: 36715761
use anonymous functions:

newObjectTitle.addEventListener('click', function(co){  return function(){  innerFunction(co.nr)  } }(currentObject),false);

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It's all about scope.  The function(co) function will take in the object you are referencing and then return a new function that will get called when the event triggers.

-Matt
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Author Closing Comment

by:walkman69
ID: 37123492
Nice.. thanx! =)
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