Question

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

var MyClass = Class.create({     initElements: function(sumEl) {        this.sumEl = sumEl;        sumEl.keyup(this.updateSumHandler);     },      updateSumHandler: function(event) {        // Throws error here: 'this.updateSum is not a function'        this.updateSum();     },      updateSum: function() {        // does something here     } }); 

How can I call this.updateSum() after all?

Answer 1

You need to use closures.

 initElements: function(sumEl) {         this.sumEl = sumEl;         var ref = this;         sumEl.keyup( function(){ref.updateSumHandler();});  },