Scoping problem with Javascript callback

Question

I am having some trouble getting a callback function to work. Here is my code:

SomeObject.prototype.refreshData = function()
{
  var read_obj = new SomeAjaxCall         


        

Answer 1

Well the most straightforward thing to do is to just wrap "this.readSuccess" in another function:

SomeObject.prototype.refreshData = function()
{
  var obj = this;
  var read_obj = new SomeAjaxCall("read_some_data", { }, 
    function() { obj.readSuccess(); }, function() { obj.readFail(); });
}

Some Javascript frameworks provide a utility to "bind" a function to an object, which simply means that it creates one of those little functions for you. Note that the variable "obj" will be "remembered" by those little functions, so when your handlers are called the "this" reference will be to the object that was used to call "refreshData".