frappe/webnotes/public/js/wn/class.js

// Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
// MIT License. See license.txt

/*

Inheritence "Class"
-------------------
see: http://ejohn.org/blog/simple-javascript-inheritance/
To subclass, use:

	var MyClass = Class.extend({
		init: function
	})

*/

/* Simple JavaScript Inheritance
 * By John Resig http://ejohn.org/
 * MIT Licensed.
 */
// Inspired by base2 and Prototype

; /* otherwise causes a concat bug? */

(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
			this._type = "instance";
			if ( !initializing && this.init )
				this.init.apply(this, arguments);
		}
		
		// Populate our constructed prototype object
		Class.prototype = prototype;
		Class._type = "class";
		
		// Enforce the constructor to be what we expect
		Class.prototype.constructor = Class;

		// And make this class extendable
		Class.extend = arguments.callee;
		
		return Class;
	};
})();