/* Simple JavaScript Inheritance * By John Resig http://ejohn.org/ * MIT Licensed. */ // Inspired by base2 and Prototype (function(){ var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/; // The base Class implementation (does nothing) this.Class = function(){}; // Create a new Class that inherits from this class Class.extend = function(prop) { var _super = this.prototype; // Instantiate a base class (but only create the instance, // don't run the init constructor) initializing = true; var prototype = new this(); initializing = false; // Copy the properties over onto the new prototype for (var name in prop) { // Check if we're overwriting an existing function prototype[name] = typeof prop[name] == "function" && typeof _super[name] == "function" && fnTest.test(prop[name]) ? (function(name, fn){ return function() { var tmp = this._super; // Add a new ._super() method that is the same method // but on the super-class this._super = _super[name]; // The method only need to be bound temporarily, so we // remove it when we're done executing var ret = fn.apply(this, arguments); this._super = tmp; return ret; }; })(name, prop[name]) : prop[name]; } // The dummy class constructor function Class() { // All construction is actually done in the init method if ( !initializing && this.init ) this.init.apply(this, arguments); } // Populate our constructed prototype object Class.prototype = prototype; // Enforce the constructor to be what we expect Class.prototype.constructor = Class; // And make this class extendable Class.extend = arguments.callee; return Class; }; })(); if(!(typeof exports === 'undefined')) { exports.Class = Class; } //========================================================================= var Person = Class.extend( { init: function() { console.log('Created Person'); }, speak: function() { console.log('Person Speaking'); } }); var p = new Person(); p.speak(); var Guy = Person.extend({ init: function() { this._super(); console.log( 'Create Guy'); }, speak: function() { this._super(); console.log( "I'm a Guy!" ); } }); var bob = new Guy(); bob.speak(); var Girl = Person.extend( { init: function() { console.log( "Created Girl" ); }, speak: function() { console.log( "I'm a Girl!" ); } }); var jill = new Girl(); jill.speak();