extendscript-es5-shim/Object/create.js

a collection of useful es5-shims for Extendscript

if (!Object.create) {
  // Production steps of ECMA-262, Edition 5, 15.2.3.5
  // Reference: http://es5.github.io/#x15.2.3.5
  Object.create = (function() {
    // To save on memory, use a shared constructor
    function Temp() {}

    // make a safe reference to Object.prototype.hasOwnProperty
    var hasOwn = Object.prototype.hasOwnProperty;

    return function(O) {
      // 1. If Type(O) is not Object or Null throw a TypeError exception.
      if (Object(O) !== O && O !== null) {
        throw TypeError('Object prototype may only be an Object or null');
      }

      // 2. Let obj be the result of creating a new object as if by the
      //    expression new Object() where Object is the standard built-in
      //    constructor with that name
      // 3. Set the [[Prototype]] internal property of obj to O.
      Temp.prototype = O;
      var obj = new Temp();
      Temp.prototype = null; // Let's not keep a stray reference to O...

      // 4. If the argument Properties is present and not undefined, add
      //    own properties to obj as if by calling the standard built-in
      //    function Object.defineProperties with arguments obj and
      //    Properties.
      if (arguments.length > 1) {
        // Object.defineProperties does ToObject on its first argument.
        var Properties = Object(arguments[1]);
        for (var prop in Properties) {
          if (hasOwn.call(Properties, prop)) {
            var descriptor = Properties[prop];
            if (Object(descriptor) !== descriptor) {
              throw TypeError(prop + 'must be an object');
            }
            if ('get' in descriptor || 'set' in descriptor) {
              throw new TypeError('getters & setters can not be defined on this javascript engine');
            }
            if ('value' in descriptor) {
              obj[prop] = Properties[prop].value;
            }

          }
        }
      }

      // 5. Return obj
      return obj;
    };
  })();
}