[apps/tidep0084.git] / example / iot-gateway / node_modules / engine.io-client / lib / transports / index.js
1 /**
2 * Module dependencies
3 */
5 var XMLHttpRequest = require('xmlhttprequest-ssl');
6 var XHR = require('./polling-xhr');
7 var JSONP = require('./polling-jsonp');
8 var websocket = require('./websocket');
10 /**
11 * Export transports.
12 */
14 exports.polling = polling;
15 exports.websocket = websocket;
17 /**
18 * Polling transport polymorphic constructor.
19 * Decides on xhr vs jsonp based on feature detection.
20 *
21 * @api private
22 */
24 function polling(opts){
25 var xhr;
26 var xd = false;
27 var xs = false;
28 var jsonp = false !== opts.jsonp;
30 if (global.location) {
31 var isSSL = 'https:' == location.protocol;
32 var port = location.port;
34 // some user agents have empty `location.port`
35 if (!port) {
36 port = isSSL ? 443 : 80;
37 }
39 xd = opts.hostname != location.hostname || port != opts.port;
40 xs = opts.secure != isSSL;
41 }
43 opts.xdomain = xd;
44 opts.xscheme = xs;
45 xhr = new XMLHttpRequest(opts);
47 if ('open' in xhr && !opts.forceJSONP) {
48 return new XHR(opts);
49 } else {
50 if (!jsonp) throw new Error('JSONP disabled');
51 return new JSONP(opts);
52 }
53 }