| <!-- |
| @license |
| Copyright (c) 2015 The Polymer Project Authors. All rights reserved. |
| This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt |
| The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt |
| The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt |
| Code distributed by Google as part of the polymer project is also |
| subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt |
| --> |
| <link rel="import" href="../polymer/polymer.html"> |
| |
| <script> |
| (function() { |
| "use strict"; |
| /** |
| * `Polymer.IronJsonpLibraryBehavior` loads a jsonp library. |
| * Multiple components can request same library, only one copy will load. |
| * |
| * Some libraries require a specific global function be defined. |
| * If this is the case, specify the `callbackName` property. |
| * |
| * You should use an HTML Import to load library dependencies |
| * when possible instead of using this element. |
| * |
| * @hero hero.svg |
| * @demo demo/index.html |
| * @polymerBehavior |
| */ |
| Polymer.IronJsonpLibraryBehavior = { |
| |
| properties: { |
| /** |
| * True if library has been successfully loaded |
| */ |
| libraryLoaded: { |
| type: Boolean, |
| value: false, |
| notify: true, |
| readOnly: true |
| }, |
| /** |
| * Not null if library has failed to load |
| */ |
| libraryErrorMessage: { |
| type: String, |
| value: null, |
| notify: true, |
| readOnly: true |
| } |
| // Following properties are to be set by behavior users |
| /** |
| * Library url. Must contain string `%%callback%%`. |
| * |
| * `%%callback%%` is a placeholder for jsonp wrapper function name |
| * |
| * Ex: https://maps.googleapis.com/maps/api/js?callback=%%callback%% |
| * @property libraryUrl |
| */ |
| /** |
| * Set if library requires specific callback name. |
| * Name will be automatically generated if not set. |
| * @property callbackName |
| */ |
| /** |
| * name of event to be emitted when library loads. Standard is `api-load` |
| * @property notifyEvent |
| */ |
| /** |
| * event with name specified in `notifyEvent` attribute |
| * will fire upon successful load2 |
| * @event `notifyEvent` |
| */ |
| }, |
| |
| observers: [ |
| '_libraryUrlChanged(libraryUrl)' |
| ], |
| |
| _libraryUrlChanged: function(libraryUrl) { |
| // can't load before ready because notifyEvent might not be set |
| if (this._isReady && this.libraryUrl) |
| this._loadLibrary(); |
| }, |
| |
| _libraryLoadCallback: function(err, result) { |
| if (err) { |
| Polymer.Base._warn("Library load failed:", err.message); |
| this._setLibraryErrorMessage(err.message); |
| } |
| else { |
| this._setLibraryErrorMessage(null); |
| this._setLibraryLoaded(true); |
| if (this.notifyEvent) |
| this.fire(this.notifyEvent, result, {composed: true}); |
| } |
| }, |
| |
| /** loads the library, and fires this.notifyEvent upon completion */ |
| _loadLibrary: function() { |
| LoaderMap.require( |
| this.libraryUrl, |
| this._libraryLoadCallback.bind(this), |
| this.callbackName |
| ); |
| }, |
| |
| ready: function() { |
| this._isReady = true; |
| if (this.libraryUrl) |
| this._loadLibrary(); |
| } |
| }; |
| |
| /** |
| * LoaderMap keeps track of all Loaders |
| */ |
| var LoaderMap = { |
| apiMap: {}, // { hash -> Loader } |
| |
| /** |
| * @param {Function} notifyCallback loaded callback fn(result) |
| * @param {string} jsonpCallbackName name of jsonpcallback. If API does not provide it, leave empty. Optional. |
| */ |
| require: function(url, notifyCallback, jsonpCallbackName) { |
| |
| // make hashable string form url |
| var name = this.nameFromUrl(url); |
| |
| // create a loader as needed |
| if (!this.apiMap[name]) |
| this.apiMap[name] = new Loader(name, url, jsonpCallbackName); |
| |
| // ask for notification |
| this.apiMap[name].requestNotify(notifyCallback); |
| }, |
| |
| nameFromUrl: function(url) { |
| return url.replace(/[\:\/\%\?\&\.\=\-\,]/g, '_') + '_api'; |
| } |
| }; |
| |
| /** @constructor */ |
| var Loader = function(name, url, callbackName) { |
| this.notifiers = []; // array of notifyFn [ notifyFn* ] |
| |
| // callback is specified either as callback name |
| // or computed dynamically if url has callbackMacro in it |
| if (!callbackName) { |
| if (url.indexOf(this.callbackMacro) >= 0) { |
| callbackName = name + '_loaded'; |
| url = url.replace(this.callbackMacro, callbackName); |
| } else { |
| this.error = new Error('IronJsonpLibraryBehavior a %%callback%% parameter is required in libraryUrl'); |
| // TODO(sjmiles): we should probably fallback to listening to script.load |
| return; |
| } |
| } |
| this.callbackName = callbackName; |
| window[this.callbackName] = this.success.bind(this); |
| this.addScript(url); |
| }; |
| |
| Loader.prototype = { |
| |
| callbackMacro: '%%callback%%', |
| loaded: false, |
| |
| addScript: function(src) { |
| var script = document.createElement('script'); |
| script.src = src; |
| script.onerror = this.handleError.bind(this); |
| var s = document.querySelector('script') || document.body; |
| s.parentNode.insertBefore(script, s); |
| this.script = script; |
| }, |
| |
| removeScript: function() { |
| if (this.script.parentNode) { |
| this.script.parentNode.removeChild(this.script); |
| } |
| this.script = null; |
| }, |
| |
| handleError: function(ev) { |
| this.error = new Error("Library failed to load"); |
| this.notifyAll(); |
| this.cleanup(); |
| }, |
| |
| success: function() { |
| this.loaded = true; |
| this.result = Array.prototype.slice.call(arguments); |
| this.notifyAll(); |
| this.cleanup(); |
| }, |
| |
| cleanup: function() { |
| delete window[this.callbackName]; |
| }, |
| |
| notifyAll: function() { |
| this.notifiers.forEach( function(notifyCallback) { |
| notifyCallback(this.error, this.result); |
| }.bind(this)); |
| this.notifiers = []; |
| }, |
| |
| requestNotify: function(notifyCallback) { |
| if (this.loaded || this.error) { |
| notifyCallback( this.error, this.result); |
| } else { |
| this.notifiers.push(notifyCallback); |
| } |
| } |
| }; |
| })(); |
| </script> |
| |
| <!-- |
| Loads specified jsonp library. |
| |
| Example: |
| |
| <iron-jsonp-library |
| library-url="https://apis.google.com/js/plusone.js?onload=%%callback%%" |
| notify-event="api-load" |
| library-loaded="{{loaded}}"></iron-jsonp-library> |
| |
| Will emit 'api-load' event when loaded, and set 'loaded' to true |
| |
| Implemented by Polymer.IronJsonpLibraryBehavior. Use it |
| to create specific library loader elements. |
| |
| @demo |
| --> |
| <script> |
| Polymer({ |
| |
| is: 'iron-jsonp-library', |
| |
| behaviors: [ Polymer.IronJsonpLibraryBehavior ], |
| |
| properties: { |
| /** |
| * Library url. Must contain string `%%callback%%`. |
| * |
| * `%%callback%%` is a placeholder for jsonp wrapper function name |
| * |
| * Ex: https://maps.googleapis.com/maps/api/js?callback=%%callback%% |
| */ |
| libraryUrl: String, |
| /** |
| * Set if library requires specific callback name. |
| * Name will be automatically generated if not set. |
| */ |
| callbackName: String, |
| /** |
| * event with name specified in 'notifyEvent' attribute |
| * will fire upon successful load |
| */ |
| notifyEvent: String |
| /** |
| * event with name specified in 'notifyEvent' attribute |
| * will fire upon successful load |
| * @event `notifyEvent` |
| */ |
| |
| } |
| }); |
| |
| </script> |