/** * Simplified version of es5-sham#Object-create that also works around a bug * in the actual es5-sham: https://github.com/es-shims/es5-shim/issues/252 * * Does not: * - Support empty inheritance via `Object.create(null)`. * - Support getter and setter accessors via `Object.create( .., properties )`. * - Support custom property descriptor (e.g. writable, configurtable, enumerable). * - Leave behind an enumerable "__proto__" all over the place. * * @author Timo Tijhof, 2014 */ // ES5 15.2.3.5 // http://es5.github.com/#x15.2.3.5 if ( !Object.create ) { ( function () { var hasOwn = Object.hasOwnProperty, // https://developer.mozilla.org/en-US/docs/ECMAScript_DontEnum_attribute#JScript_DontEnum_Bug // http://whattheheadsaid.com/2010/10/a-safer-object-keys-compatibility-implementation isEnumBug = !{ valueOf: 0 }.propertyIsEnumerable( 'valueOf' ); // Reusable constructor function for Object.create function Empty() {} function defineProperty( object, key, property ) { if ( hasOwn.call( property, 'value' ) ) { object[ key ] = property.value; } else { object[ key ] = property; } } Object.create = function create( prototype, properties ) { var object, key; if ( prototype !== Object( prototype ) ) { throw new TypeError( 'Called on non-object' ); } Empty.prototype = prototype; object = new Empty(); if ( properties !== undefined ) { if ( !isEnumBug ) { for ( key in properties ) { if ( hasOwn.call( properties, key ) ) { defineProperty( object, key, properties[ key ] ); } } } else { Object.keys( properties ).forEach( function ( key ) { defineProperty( object, key, properties[ key ] ); } ); } } return object; }; }() ); }