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| 1 | +/* Simple JavaScript Inheritance |
| 2 | + * By John Resig http://ejohn.org/ |
| 3 | + * MIT Licensed. |
| 4 | + */ |
| 5 | +// Inspired by base2 and Prototype |
| 6 | +(function(){ |
| 7 | + var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/; |
| 8 | + |
| 9 | + // The base Class implementation (does nothing) |
| 10 | + this.Class = function(){}; |
| 11 | + |
| 12 | + // Create a new Class that inherits from this class |
| 13 | + Class.extend = function(prop) { |
| 14 | + var _super = this.prototype; |
| 15 | + |
| 16 | + // Instantiate a base class (but only create the instance, |
| 17 | + // don't run the init constructor) |
| 18 | + initializing = true; |
| 19 | + var prototype = new this(); |
| 20 | + initializing = false; |
| 21 | + |
| 22 | + // Copy the properties over onto the new prototype |
| 23 | + for (var name in prop) { |
| 24 | + // Check if we're overwriting an existing function |
| 25 | + prototype[name] = typeof prop[name] == "function" && |
| 26 | + typeof _super[name] == "function" && fnTest.test(prop[name]) ? |
| 27 | + (function(name, fn){ |
| 28 | + return function() { |
| 29 | + var tmp = this._super; |
| 30 | + |
| 31 | + // Add a new ._super() method that is the same method |
| 32 | + // but on the super-class |
| 33 | + this._super = _super[name]; |
| 34 | + |
| 35 | + // The method only need to be bound temporarily, so we |
| 36 | + // remove it when we're done executing |
| 37 | + var ret = fn.apply(this, arguments); |
| 38 | + this._super = tmp; |
| 39 | + |
| 40 | + return ret; |
| 41 | + }; |
| 42 | + })(name, prop[name]) : |
| 43 | + prop[name]; |
| 44 | + } |
| 45 | + |
| 46 | + // The dummy class constructor |
| 47 | + function Class() { |
| 48 | + // All construction is actually done in the init method |
| 49 | + if ( !initializing && this.init ) |
| 50 | + this.init.apply(this, arguments); |
| 51 | + } |
| 52 | + |
| 53 | + // Populate our constructed prototype object |
| 54 | + Class.prototype = prototype; |
| 55 | + |
| 56 | + // Enforce the constructor to be what we expect |
| 57 | + Class.prototype.constructor = Class; |
| 58 | + |
| 59 | + // And make this class extendable |
| 60 | + Class.extend = arguments.callee; |
| 61 | + |
| 62 | + return Class; |
| 63 | + }; |
| 64 | +})(); |
| 65 | + |
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