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