Question

I was just curious if I could pass a function as a variable. For example:
I have a function

$('#validate').makeFloat({x:671,y:70,limitY:700});

I would like to do something like this:

$('#validate').makeFloat({x:function(){ return $("#tabs").offset().left+$("#tabs").width();},y:70,limitY:700});

This does not work, but ideally every time the variable was accessed it would compute the new value. So if the window was resized it would automatically adjust as opposed to a variable passed in being static. I realize I can implement this directly inside the function\widget, but I was wondering if there was some way to do something like the above.

The concept of this is independent of the plugin. I am talking about the function being “cast” as a variable.

Answer 1

Yes, you can pass an object which will invoke some function when its property is read (this is called a getter), but it is not cross-browser compatible. For example, this will (probably) work in IE9:

var o = {y:70, limitY:700};
Object.defineProperty(o, 'x', {get: function() {return 671;}});
$('#validate').makeFloat(o);

There are other syntaxes for other browsers such as __defineGetter__ for Firefox, and some browsers don’t have this functionality at all. So it is practically useless unless you can fully control the environment where your code runs.