/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @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 {!File|!Blob|!MediaSource|!MediaStream} obj The object for which
* to create the URL.
* @return {string} The URL for the object.
*/
goog.fs.url.createObjectUrl = function(obj) {
'use strict';
return goog.fs.url.getUrlObject_().createObjectURL(obj);
};
/**
* 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.
* @return {void}
*/
goog.fs.url.revokeObjectUrl = function(url) {
'use strict';
goog.fs.url.getUrlObject_().revokeObjectURL(url);
};
/**
* @record
* @private
*/
goog.fs.url.UrlObject_ = function() {};
/**
* @param {!File|!Blob|!MediaSource|!MediaStream} arg
* @return {string}
*/
goog.fs.url.UrlObject_.prototype.createObjectURL = function(arg) {};
/**
* @param {string} s
* @return {void}
*/
goog.fs.url.UrlObject_.prototype.revokeObjectURL = function(s) {};
/**
* 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() {
'use strict';
const urlObject = goog.fs.url.findUrlObject_();
if (urlObject != null) {
return urlObject;
} else {
throw new 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() {
'use strict';
// This is what the spec says to do
// http://dev.w3.org/2006/webapi/FileAPI/#dfn-createObjectURL
if (goog.global.URL !== undefined &&
goog.global.URL.createObjectURL !== undefined) {
return /** @type {!goog.fs.url.UrlObject_} */ (goog.global.URL);
// This is what the spec used to say to do
} else if (goog.global.createObjectURL !== undefined) {
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() {
'use strict';
return goog.fs.url.findUrlObject_() != null;
};