| 'use strict'; |
| |
| var utils = require('../../utils/iframe') |
| , random = require('../../utils/random') |
| , browser = require('../../utils/browser') |
| , urlUtils = require('../../utils/url') |
| , inherits = require('inherits') |
| , EventEmitter = require('events').EventEmitter |
| ; |
| |
| var debug = function() {}; |
| if (process.env.NODE_ENV !== 'production') { |
| debug = require('debug')('sockjs-client:receiver:jsonp'); |
| } |
| |
| function JsonpReceiver(url) { |
| debug(url); |
| var self = this; |
| EventEmitter.call(this); |
| |
| utils.polluteGlobalNamespace(); |
| |
| this.id = 'a' + random.string(6); |
| var urlWithId = urlUtils.addQuery(url, 'c=' + encodeURIComponent(utils.WPrefix + '.' + this.id)); |
| |
| global[utils.WPrefix][this.id] = this._callback.bind(this); |
| this._createScript(urlWithId); |
| |
| // Fallback mostly for Konqueror - stupid timer, 35 seconds shall be plenty. |
| this.timeoutId = setTimeout(function() { |
| debug('timeout'); |
| self._abort(new Error('JSONP script loaded abnormally (timeout)')); |
| }, JsonpReceiver.timeout); |
| } |
| |
| inherits(JsonpReceiver, EventEmitter); |
| |
| JsonpReceiver.prototype.abort = function() { |
| debug('abort'); |
| if (global[utils.WPrefix][this.id]) { |
| var err = new Error('JSONP user aborted read'); |
| err.code = 1000; |
| this._abort(err); |
| } |
| }; |
| |
| JsonpReceiver.timeout = 35000; |
| JsonpReceiver.scriptErrorTimeout = 1000; |
| |
| JsonpReceiver.prototype._callback = function(data) { |
| debug('_callback', data); |
| this._cleanup(); |
| |
| if (this.aborting) { |
| return; |
| } |
| |
| if (data) { |
| debug('message', data); |
| this.emit('message', data); |
| } |
| this.emit('close', null, 'network'); |
| this.removeAllListeners(); |
| }; |
| |
| JsonpReceiver.prototype._abort = function(err) { |
| debug('_abort', err); |
| this._cleanup(); |
| this.aborting = true; |
| this.emit('close', err.code, err.message); |
| this.removeAllListeners(); |
| }; |
| |
| JsonpReceiver.prototype._cleanup = function() { |
| debug('_cleanup'); |
| clearTimeout(this.timeoutId); |
| if (this.script2) { |
| this.script2.parentNode.removeChild(this.script2); |
| this.script2 = null; |
| } |
| if (this.script) { |
| var script = this.script; |
| // Unfortunately, you can't really abort script loading of |
| // the script. |
| script.parentNode.removeChild(script); |
| script.onreadystatechange = script.onerror = |
| script.onload = script.onclick = null; |
| this.script = null; |
| } |
| delete global[utils.WPrefix][this.id]; |
| }; |
| |
| JsonpReceiver.prototype._scriptError = function() { |
| debug('_scriptError'); |
| var self = this; |
| if (this.errorTimer) { |
| return; |
| } |
| |
| this.errorTimer = setTimeout(function() { |
| if (!self.loadedOkay) { |
| self._abort(new Error('JSONP script loaded abnormally (onerror)')); |
| } |
| }, JsonpReceiver.scriptErrorTimeout); |
| }; |
| |
| JsonpReceiver.prototype._createScript = function(url) { |
| debug('_createScript', url); |
| var self = this; |
| var script = this.script = global.document.createElement('script'); |
| var script2; // Opera synchronous load trick. |
| |
| script.id = 'a' + random.string(8); |
| script.src = url; |
| script.type = 'text/javascript'; |
| script.charset = 'UTF-8'; |
| script.onerror = this._scriptError.bind(this); |
| script.onload = function() { |
| debug('onload'); |
| self._abort(new Error('JSONP script loaded abnormally (onload)')); |
| }; |
| |
| // IE9 fires 'error' event after onreadystatechange or before, in random order. |
| // Use loadedOkay to determine if actually errored |
| script.onreadystatechange = function() { |
| debug('onreadystatechange', script.readyState); |
| if (/loaded|closed/.test(script.readyState)) { |
| if (script && script.htmlFor && script.onclick) { |
| self.loadedOkay = true; |
| try { |
| // In IE, actually execute the script. |
| script.onclick(); |
| } catch (x) { |
| // intentionally empty |
| } |
| } |
| if (script) { |
| self._abort(new Error('JSONP script loaded abnormally (onreadystatechange)')); |
| } |
| } |
| }; |
| // IE: event/htmlFor/onclick trick. |
| // One can't rely on proper order for onreadystatechange. In order to |
| // make sure, set a 'htmlFor' and 'event' properties, so that |
| // script code will be installed as 'onclick' handler for the |
| // script object. Later, onreadystatechange, manually execute this |
| // code. FF and Chrome doesn't work with 'event' and 'htmlFor' |
| // set. For reference see: |
| // http://jaubourg.net/2010/07/loading-script-as-onclick-handler-of.html |
| // Also, read on that about script ordering: |
| // http://wiki.whatwg.org/wiki/Dynamic_Script_Execution_Order |
| if (typeof script.async === 'undefined' && global.document.attachEvent) { |
| // According to mozilla docs, in recent browsers script.async defaults |
| // to 'true', so we may use it to detect a good browser: |
| // https://developer.mozilla.org/en/HTML/Element/script |
| if (!browser.isOpera()) { |
| // Naively assume we're in IE |
| try { |
| script.htmlFor = script.id; |
| script.event = 'onclick'; |
| } catch (x) { |
| // intentionally empty |
| } |
| script.async = true; |
| } else { |
| // Opera, second sync script hack |
| script2 = this.script2 = global.document.createElement('script'); |
| script2.text = "try{var a = document.getElementById('" + script.id + "'); if(a)a.onerror();}catch(x){};"; |
| script.async = script2.async = false; |
| } |
| } |
| if (typeof script.async !== 'undefined') { |
| script.async = true; |
| } |
| |
| var head = global.document.getElementsByTagName('head')[0]; |
| head.insertBefore(script, head.firstChild); |
| if (script2) { |
| head.insertBefore(script2, head.firstChild); |
| } |
| }; |
| |
| module.exports = JsonpReceiver; |