simplifying binding anonymous javascript functions to class

Question

I have a rather large set of javascript functions that I am working on refactoring into a set of classes using Prototype.

I was wondering if there was a way I could make binding anonymous functions to the class simpler? I keep forgetting to add the bind this at the end. Or is this just the way it is done all the time?

 var arr = this.getSomeArray();
 arr.each(function(t) {
     t.update(val);
     this.updateJSValue(t);
 }.bind(this));

Answer 1

Your options are basically to call some function (bind, addMethods or another function you write) or use a local variable rather than this:

var self=this;
arr.each(function(t) {
     t.update(val);
     self.updateJSValue(t);
});

If you've a large number of functions, the local variable requires the least typing For just a few functions, there isn't too much difference.

function ThingMixin(self) {
    self.foo = function(arr) {
        arr.each(function(t) {
             t.update(val);
             self.updateJSValue(t);
        });
    };
    ...
};
...
ThingMixin(Ralph.prototype);

// or an anonymous function:
(function (self){
    self.foo = function(arr) {
        arr.each(function(t) {
             t.update(val);
             self.updateJSValue(t);
        });
    };
    ...
})(Ralph.prototype);