var Class = function(){};
var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/;
// Create a new Class that inherits from this class
Class.extend = function(props) {
var _super = this.prototype;
// Instantiate a base class (but only create the instance,
// don't run the init constructor)
initializing = true;
var proto = new this();
initializing = false;
// Copy the properties over onto the new prototype
for (var name in props) {
if(typeof props[name] === "function"){
// Check if we're overwriting an existing function
proto[name] = typeof props[name] == "function" &&
typeof _super[name] == "function" && fnTest.test(props[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, props[name]) :
props[name];
}
}
// The dummy class constructor
function Class() {
// All construction is actually done in the init method via the spawn function
// Trying to instantiate this Class with the new keyword will throw an error
if(!initializing) throw "Don't use the new keyword to create this object. Instead use the 'spawn' function.";
}
// Populate our constructed prototype object
Class.prototype = proto;
// Enforce the constructor to be what we expect
Class.constructor = Class;
Class.spawn = function(propValues, skipInit){
// Martial values onto property definitions
var finalProps = {};
for(var key in props){
if(typeof props[key] !== "function"){
finalProps[key] = props[key];
finalProps[key].value = propValues[key];
}
}
// Create, initialize and return the new object
var newObject = Object.create(Class.prototype,finalProps);
if(newObject.init && !skipInit)newObject.init();
return newObject;
};
// And make this class extensible
Class.extend = (function(fn){
return function(childProps){
//If the parent has properties not defined by the child, copy them on
for(var key in props){
if(!childProps[key]) childProps[key] = props[key];
}
return fn.call(this,childProps);
}
})(arguments.callee);
return Class;
};
if (typeof exports !== "undefined") { // CommonJS module support
exports.Class = Class;
}