| 'use strict'; | 
|   | 
| var inherits = require('inherits') | 
|   , AjaxBasedTransport = require('./lib/ajax-based') | 
|   , XhrReceiver = require('./receiver/xhr') | 
|   , XHRCorsObject = require('./sender/xhr-cors') | 
|   , XHRLocalObject = require('./sender/xhr-local') | 
|   ; | 
|   | 
| function XhrPollingTransport(transUrl) { | 
|   if (!XHRLocalObject.enabled && !XHRCorsObject.enabled) { | 
|     throw new Error('Transport created when disabled'); | 
|   } | 
|   AjaxBasedTransport.call(this, transUrl, '/xhr', XhrReceiver, XHRCorsObject); | 
| } | 
|   | 
| inherits(XhrPollingTransport, AjaxBasedTransport); | 
|   | 
| XhrPollingTransport.enabled = function(info) { | 
|   if (info.nullOrigin) { | 
|     return false; | 
|   } | 
|   | 
|   if (XHRLocalObject.enabled && info.sameOrigin) { | 
|     return true; | 
|   } | 
|   return XHRCorsObject.enabled; | 
| }; | 
|   | 
| XhrPollingTransport.transportName = 'xhr-polling'; | 
| XhrPollingTransport.roundTrips = 2; // preflight, ajax | 
|   | 
| module.exports = XhrPollingTransport; |