Created
February 1, 2012 00:07
-
-
Save gryzzly/1714086 to your computer and use it in GitHub Desktop.
Backbone's extend self-propagating function
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Helper function to correctly set up the prototype chain, for subclasses. | |
// Similar to `goog.inherits`, but uses a hash of prototype properties and | |
// class properties to be extended. | |
var inherits = function(parent, protoProps, staticProps) { | |
var child; | |
// The constructor function for the new subclass is either defined by you | |
// (the "constructor" property in your `extend` definition), or defaulted | |
// by us to simply call the parent's constructor. | |
if (protoProps && protoProps.hasOwnProperty('constructor')) { | |
child = protoProps.constructor; | |
} else { | |
child = function(){ parent.apply(this, arguments); }; | |
} | |
// Inherit class (static) properties from parent. | |
_.extend(child, parent); | |
// Set the prototype chain to inherit from `parent`, without calling | |
// `parent`'s constructor function. | |
ctor.prototype = parent.prototype; | |
child.prototype = new ctor(); | |
// Add prototype properties (instance properties) to the subclass, | |
// if supplied. | |
if (protoProps) _.extend(child.prototype, protoProps); | |
// Add static properties to the constructor function, if supplied. | |
if (staticProps) _.extend(child, staticProps); | |
// Correctly set child's `prototype.constructor`. | |
child.prototype.constructor = child; | |
// Set a convenience property in case the parent's prototype is needed later. | |
child.__super__ = parent.prototype; | |
return child; | |
}; | |
// The self-propagating extend function that Backbone classes use. | |
var extend = function (protoProps, classProps) { | |
var child = inherits(this, protoProps, classProps); | |
child.extend = this.extend; | |
return child; | |
}; | |
// Set up inheritance for the model, collection, and view. | |
Backbone.Model.extend = Backbone.Collection.extend = | |
Backbone.Router.extend = Backbone.View.extend = extend; |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment