In Javascript, can you extend the DOM?

Question

In Javascript, you can extend existing classes by using its prototype object:

String.prototype.getFirstLetter = function() {     return this[0]; }; 

Is it possible to use this method to extend DOM elements?

Answer 1

I found the answer just as I was writing the question, but thought I'd post anyway to share the info.

The object you need to extend is Element.prototype.

Element.prototype.getMyId = function() {     return this.id; }; 

Answer 2

you can extend the DOM by using the Element's prototype. However, this does not work in IE7 and earlier. You will need to extend the specific element, one at a time. The Prototype library does this. I recommend looking through the source to see exactly how it's done.