| // Copyright 2015 The Closure Library Authors. All Rights Reserved. |
| // |
| // 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. |
| |
| /** |
| * @fileoverview Wrapper for URL and its createObjectUrl and revokeObjectUrl |
| * methods that are part of the HTML5 File API. |
| */ |
| |
| goog.provide('goog.fs.url'); |
| |
| |
| /** |
| * Creates a blob URL for a blob object. |
| * Throws an error if the browser does not support Object Urls. |
| * |
| * @param {!Blob} blob The object for which to create the URL. |
| * @return {string} The URL for the object. |
| */ |
| goog.fs.url.createObjectUrl = function(blob) { |
| return goog.fs.url.getUrlObject_().createObjectURL(blob); |
| }; |
| |
| |
| /** |
| * Revokes a URL created by {@link goog.fs.url.createObjectUrl}. |
| * Throws an error if the browser does not support Object Urls. |
| * |
| * @param {string} url The URL to revoke. |
| */ |
| goog.fs.url.revokeObjectUrl = function(url) { |
| goog.fs.url.getUrlObject_().revokeObjectURL(url); |
| }; |
| |
| |
| /** |
| * @typedef {{createObjectURL: (function(!Blob): string), |
| * revokeObjectURL: function(string): void}} |
| */ |
| goog.fs.url.UrlObject_; |
| |
| |
| /** |
| * Get the object that has the createObjectURL and revokeObjectURL functions for |
| * this browser. |
| * |
| * @return {goog.fs.url.UrlObject_} The object for this browser. |
| * @private |
| */ |
| goog.fs.url.getUrlObject_ = function() { |
| var urlObject = goog.fs.url.findUrlObject_(); |
| if (urlObject != null) { |
| return urlObject; |
| } else { |
| throw Error('This browser doesn\'t seem to support blob URLs'); |
| } |
| }; |
| |
| |
| /** |
| * Finds the object that has the createObjectURL and revokeObjectURL functions |
| * for this browser. |
| * |
| * @return {?goog.fs.url.UrlObject_} The object for this browser or null if the |
| * browser does not support Object Urls. |
| * @private |
| */ |
| goog.fs.url.findUrlObject_ = function() { |
| // This is what the spec says to do |
| // http://dev.w3.org/2006/webapi/FileAPI/#dfn-createObjectURL |
| if (goog.isDef(goog.global.URL) && |
| goog.isDef(goog.global.URL.createObjectURL)) { |
| return /** @type {goog.fs.url.UrlObject_} */ (goog.global.URL); |
| // This is what Chrome does (as of 10.0.648.6 dev) |
| } else if ( |
| goog.isDef(goog.global.webkitURL) && |
| goog.isDef(goog.global.webkitURL.createObjectURL)) { |
| return /** @type {goog.fs.url.UrlObject_} */ (goog.global.webkitURL); |
| // This is what the spec used to say to do |
| } else if (goog.isDef(goog.global.createObjectURL)) { |
| return /** @type {goog.fs.url.UrlObject_} */ (goog.global); |
| } else { |
| return null; |
| } |
| }; |
| |
| |
| /** |
| * Checks whether this browser supports Object Urls. If not, calls to |
| * createObjectUrl and revokeObjectUrl will result in an error. |
| * |
| * @return {boolean} True if this browser supports Object Urls. |
| */ |
| goog.fs.url.browserSupportsObjectUrls = function() { |
| return goog.fs.url.findUrlObject_() != null; |
| }; |