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

     1  'use strict';
     2  
     3  // The simplest and most robust transport, using the well-know cross
     4  // domain hack - JSONP. This transport is quite inefficient - one
     5  // message could use up to one http request. But at least it works almost
     6  // everywhere.
     7  // Known limitations:
     8  //   o you will get a spinning cursor
     9  //   o for Konqueror a dumb timer is needed to detect errors
    10  
    11  var inherits = require('inherits')
    12    , SenderReceiver = require('./lib/sender-receiver')
    13    , JsonpReceiver = require('./receiver/jsonp')
    14    , jsonpSender = require('./sender/jsonp')
    15    ;
    16  
    17  function JsonPTransport(transUrl) {
    18    if (!JsonPTransport.enabled()) {
    19      throw new Error('Transport created when disabled');
    20    }
    21    SenderReceiver.call(this, transUrl, '/jsonp', jsonpSender, JsonpReceiver);
    22  }
    23  
    24  inherits(JsonPTransport, SenderReceiver);
    25  
    26  JsonPTransport.enabled = function() {
    27    return !!global.document;
    28  };
    29  
    30  JsonPTransport.transportName = 'jsonp-polling';
    31  JsonPTransport.roundTrips = 1;
    32  JsonPTransport.needBody = true;
    33  
    34  module.exports = JsonPTransport;