backbone.js - Proper way of doing view mixins in Backbone

Question

I extend base backbone views all the time and have a base view per section so that I can extend on multiple levels. My question is, what's the most effective way of doing view mixins: reusable view partials that can be mixed in to any view. For example:

var BaseProfile = Backbone.View.extend({ ...});
var UserProfile = BaseProfile.extend({ ...});
var VideoSupport = Backbone.View.extend({ ...});

What's the best way to mixin VideoSupport view (an event object and a few methods) with UserProfile view?

Answer 1

The underscore.js library provides an extend method that does what you want. You can define functionality on any object, and then quite literally copy & paste all of the methods and attributes from that object to another.

Backbone's extend methods on Views, Models, and Routers are a wrapper around underscore's extend.

 var MyMixin = {
  foo: "bar",
  sayFoo: function(){alert(this.foo);}
}

var MyView = Backbone.View.extend({
 // ...
});

_.extend(MyView.prototype, MyMixin);

myView = new MyView();
myView.sayFoo(); //=> "bar"