Override jQuery functions

Question

Is there way to override jQuery\'s core functions ? Say I wanted to add an alert(this.length) in size: function() Instead of adding it in the source

size: f         


        

Answer 1

You almost had it, you need to set the this reference inside of the old size function to be the this reference in the override function, like this:

var oSize = jQuery.fn.size;
jQuery.fn.size = function() {
    alert(this.length);

    // Now go back to jQuery's original size()
    return oSize.apply(this, arguments);
};

The way this works is Function instances have a method called apply, whose purpose is to arbitrarily override the inner this reference inside of the function's body.

So, as an example:

var f = function() { console.log(this); }
f.apply("Hello World", null); //prints "Hello World" to the console