myblog/node_modules/uberproto/lib/proto.js

/* global define */
/**
 * A base object for ECMAScript 5 style prototypal inheritance.
 *
 * @see https://github.com/rauschma/proto-js/
 * @see http://ejohn.org/blog/simple-javascript-inheritance/
 * @see http://uxebu.com/blog/2011/02/23/object-based-inheritance-for-ecmascript-5/
 */
(function (root, factory) {
	if (typeof define === 'function' && define.amd) {
		define([], factory);
	} else if (typeof exports === 'object') {
		module.exports = factory();
	} else {
		root.Proto = factory();
	}
}(this, function () {

	function makeSuper(_super, old, name, fn) {
		return function () {
			var tmp = this._super;

			// Add a new ._super() method that is the same method
			// but either pointing to the prototype method
			// or to the overwritten method
			this._super = (typeof old === 'function') ? old : _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;
		};
	}

	function legacyMixin(prop, obj) {
		var self = obj || this;
		var fnTest = /\b_super\b/;
		var _super = Object.getPrototypeOf(self) || self.prototype;
		var _old;

		// Copy the properties over
		for (var name in prop) {
			// store the old function which would be overwritten
			_old = self[name];

			// Check if we're overwriting an existing function
			if(
					((
						typeof prop[name] === 'function' &&
						typeof _super[name] === 'function'
					) || (
						typeof _old === 'function' &&
						typeof prop[name] === 'function'
					)) && fnTest.test(prop[name])
			) {
				self[name] = makeSuper(_super, _old, name, prop[name]);
			} else {
				self[name] = prop[name];
			}
		}

		return self;
	}

	function es5Mixin(prop, obj) {
		var self = obj || this;
		var fnTest = /\b_super\b/;
		var _super = Object.getPrototypeOf(self) || self.prototype;
		var descriptors = {};
		var proto = prop;
		var processProperty = function(name) {
			if(!descriptors[name]) {
				descriptors[name] = Object.getOwnPropertyDescriptor(proto, name);
			}
		};

		// Collect all property descriptors
		do {
			Object.getOwnPropertyNames(proto).forEach(processProperty);
    } while((proto = Object.getPrototypeOf(proto)) && Object.getPrototypeOf(proto));
		
		Object.keys(descriptors).forEach(function(name) {
			var descriptor = descriptors[name];

			if(typeof descriptor.value === 'function' && fnTest.test(descriptor.value)) {
				descriptor.value = makeSuper(_super, self[name], name, descriptor.value);
			}

			Object.defineProperty(self, name, descriptor);
		});

		return self;
	}

	return {
		/**
		 * Create a new object using Object.create. The arguments will be
		 * passed to the new instances init method or to a method name set in
		 * __init.
		 */
		create: function () {
			var instance = Object.create(this);
			var init = typeof instance.__init === 'string' ? instance.__init : 'init';

			if (typeof instance[init] === 'function') {
				instance[init].apply(instance, arguments);
			}
			return instance;
		},
		/**
		 * Mixin a given set of properties
		 * @param prop The properties to mix in
		 * @param obj [optional] The object to add the mixin
		 */
		mixin: typeof Object.defineProperty === 'function' ? es5Mixin : legacyMixin,
		/**
		 * Extend the current or a given object with the given property
		 * and return the extended object.
		 * @param prop The properties to extend with
		 * @param obj [optional] The object to extend from
		 * @returns The extended object
		 */
		extend: function (prop, obj) {
			return this.mixin(prop, Object.create(obj || this));
		},
		/**
		 * Return a callback function with this set to the current or a given context object.
		 * @param name Name of the method to proxy
		 * @param args... [optional] Arguments to use for partial application
		 */
		proxy: function (name) {
			var fn = this[name];
			var args = Array.prototype.slice.call(arguments, 1);

			args.unshift(this);
			return fn.bind.apply(fn, args);
		}
	};

}));