Overwritten “this” variable problem or how to call a member function?

Question

I have this class where I am using a combination of jQuery and Prototype:

var MyClass = Class.create({
    initElements: function(sumEl) {
       this.sumEl          


        

Answer 1

Totally untested suggestion:

sumEl.keyup(this.updateSumHandler.bind(this));

.bind() gives back a new function where the first parameter of bind is closured for you as the function's this context. It can also closure parameters, check out the documentation.

To me, Function.bind() is the single best function ever written in JavaScript :)