github.com/insionng/yougam@v0.0.0-20170714101924-2bc18d833463/themes/wind/static/libs/sockjs-client-1.1.0/lib/transport/xhr-polling.js (about)

     1  'use strict';
     2  
     3  var inherits = require('inherits')
     4    , AjaxBasedTransport = require('./lib/ajax-based')
     5    , XhrReceiver = require('./receiver/xhr')
     6    , XHRCorsObject = require('./sender/xhr-cors')
     7    , XHRLocalObject = require('./sender/xhr-local')
     8    ;
     9  
    10  function XhrPollingTransport(transUrl) {
    11    if (!XHRLocalObject.enabled && !XHRCorsObject.enabled) {
    12      throw new Error('Transport created when disabled');
    13    }
    14    AjaxBasedTransport.call(this, transUrl, '/xhr', XhrReceiver, XHRCorsObject);
    15  }
    16  
    17  inherits(XhrPollingTransport, AjaxBasedTransport);
    18  
    19  XhrPollingTransport.enabled = function(info) {
    20    if (info.nullOrigin) {
    21      return false;
    22    }
    23  
    24    if (XHRLocalObject.enabled && info.sameOrigin) {
    25      return true;
    26    }
    27    return XHRCorsObject.enabled;
    28  };
    29  
    30  XhrPollingTransport.transportName = 'xhr-polling';
    31  XhrPollingTransport.roundTrips = 2; // preflight, ajax
    32  
    33  module.exports = XhrPollingTransport;