javascript/safari-driver/dom.js

// Copyright 2012 Selenium committers
// Copyright 2012 Software Freedom Conservancy
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

goog.provide('safaridriver.dom');

goog.require('goog.array');


/**
 * Invokes the native definition of a DOM function using the object's
 * constructor. This attempts to protect against pages that redefine DOM
 * functions (e.g. window.postMessage or window.dispatchEvent) from interfering
 * with the SafariDriver's functionality. We're out of luck if the page
 * redefines the function on the constructor prototype.
 * @param {!(Document|Element|Window)} obj The object to use.
 * @param {string} name The name of the function to retrieve.
 * @param {...} var_args The function arguments.
 * @return {*} The function result.
 */
safaridriver.dom.call = function(obj, name, var_args) {
  // Safari does not let you override the constructor property of document
  // or an element, so we can access those directly. The constructor property
  // for Window can be hidden by defining a global with the same name, so we
  // have to use some trickery for Window.
  var ctor = obj.constructor;
  if (obj.window === obj) {
    try {
      var saved = obj.constructor;
      delete obj.constructor;
      ctor = obj.constructor;
      obj.constructor = saved;
    } catch (ex) {
    }
  }
  return ctor.prototype[name].apply(obj, goog.array.slice(arguments, 2));
};