update

node_modules/engine.io-client/lib/transports/index.js

@@ -0,0 +1,53 @@
+/**
+ * Module dependencies
+ */
+
+var XMLHttpRequest = require('xmlhttprequest-ssl');
+var XHR = require('./polling-xhr');
+var JSONP = require('./polling-jsonp');
+var websocket = require('./websocket');
+
+/**
+ * Export transports.
+ */
+
+exports.polling = polling;
+exports.websocket = websocket;
+
+/**
+ * Polling transport polymorphic constructor.
+ * Decides on xhr vs jsonp based on feature detection.
+ *
+ * @api private
+ */
+
+function polling (opts) {
+  var xhr;
+  var xd = false;
+  var xs = false;
+  var jsonp = false !== opts.jsonp;
+
+  if (typeof location !== 'undefined') {
+    var isSSL = 'https:' === location.protocol;
+    var port = location.port;
+
+    // some user agents have empty `location.port`
+    if (!port) {
+      port = isSSL ? 443 : 80;
+    }
+
+    xd = opts.hostname !== location.hostname || port !== opts.port;
+    xs = opts.secure !== isSSL;
+  }
+
+  opts.xdomain = xd;
+  opts.xscheme = xs;
+  xhr = new XMLHttpRequest(opts);
+
+  if ('open' in xhr && !opts.forceJSONP) {
+    return new XHR(opts);
+  } else {
+    if (!jsonp) throw new Error('JSONP disabled');
+    return new JSONP(opts);
+  }
+}