| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| /** |
| * Alias for document.getElementById. |
| * @param {string} id The ID of the element to find. |
| * @return {HTMLElement} The found element or null if not found. |
| */ |
| function $(id) { |
| return document.getElementById(id); |
| } |
| |
| /** |
| * Creates a new URL which is the old URL with a GET param of key=value. |
| * Copied from ui/webui/resources/js/util.js. |
| * @param {string} url The base URL. There is not sanity checking on the URL so |
| * it must be passed in a proper format. |
| * @param {string} key The key of the param. |
| * @param {string} value The value of the param. |
| * @return {string} The new URL. |
| */ |
| function appendParam(url, key, value) { |
| var param = encodeURIComponent(key) + '=' + encodeURIComponent(value); |
| |
| if (url.indexOf('?') == -1) |
| return url + '?' + param; |
| return url + '&' + param; |
| } |
| |
| /** |
| * Creates a new URL by striping all query parameters. |
| * @param {string} url The original URL. |
| * @return {string} The new URL with all query parameters stripped. |
| */ |
| function stripParams(url) { |
| return url.substring(0, url.indexOf('?')) || url; |
| } |
| |
| /** |
| * Extract domain name from an URL. |
| * @param {string} url An URL string. |
| * @return {string} The host name of the URL. |
| */ |
| function extractDomain(url) { |
| var a = document.createElement('a'); |
| a.href = url; |
| return a.hostname; |
| } |