WIP - add extractor, generate snippet_data

node_modules/sockjs-client/lib/transport/iframe.js

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+'use strict';
+
+// Few cool transports do work only for same-origin. In order to make
+// them work cross-domain we shall use iframe, served from the
+// remote domain. New browsers have capabilities to communicate with
+// cross domain iframe using postMessage(). In IE it was implemented
+// from IE 8+, but of course, IE got some details wrong:
+//    http://msdn.microsoft.com/en-us/library/cc197015(v=VS.85).aspx
+//    http://stevesouders.com/misc/test-postmessage.php
+
+var inherits = require('inherits')
+  , JSON3 = require('json3')
+  , EventEmitter = require('events').EventEmitter
+  , version = require('../version')
+  , urlUtils = require('../utils/url')
+  , iframeUtils = require('../utils/iframe')
+  , eventUtils = require('../utils/event')
+  , random = require('../utils/random')
+  ;
+
+var debug = function() {};
+if (process.env.NODE_ENV !== 'production') {
+  debug = require('debug')('sockjs-client:transport:iframe');
+}
+
+function IframeTransport(transport, transUrl, baseUrl) {
+  if (!IframeTransport.enabled()) {
+    throw new Error('Transport created when disabled');
+  }
+  EventEmitter.call(this);
+
+  var self = this;
+  this.origin = urlUtils.getOrigin(baseUrl);
+  this.baseUrl = baseUrl;
+  this.transUrl = transUrl;
+  this.transport = transport;
+  this.windowId = random.string(8);
+
+  var iframeUrl = urlUtils.addPath(baseUrl, '/iframe.html') + '#' + this.windowId;
+  debug(transport, transUrl, iframeUrl);
+
+  this.iframeObj = iframeUtils.createIframe(iframeUrl, function(r) {
+    debug('err callback');
+    self.emit('close', 1006, 'Unable to load an iframe (' + r + ')');
+    self.close();
+  });
+
+  this.onmessageCallback = this._message.bind(this);
+  eventUtils.attachEvent('message', this.onmessageCallback);
+}
+
+inherits(IframeTransport, EventEmitter);
+
+IframeTransport.prototype.close = function() {
+  debug('close');
+  this.removeAllListeners();
+  if (this.iframeObj) {
+    eventUtils.detachEvent('message', this.onmessageCallback);
+    try {
+      // When the iframe is not loaded, IE raises an exception
+      // on 'contentWindow'.
+      this.postMessage('c');
+    } catch (x) {
+      // intentionally empty
+    }
+    this.iframeObj.cleanup();
+    this.iframeObj = null;
+    this.onmessageCallback = this.iframeObj = null;
+  }
+};
+
+IframeTransport.prototype._message = function(e) {
+  debug('message', e.data);
+  if (!urlUtils.isOriginEqual(e.origin, this.origin)) {
+    debug('not same origin', e.origin, this.origin);
+    return;
+  }
+
+  var iframeMessage;
+  try {
+    iframeMessage = JSON3.parse(e.data);
+  } catch (ignored) {
+    debug('bad json', e.data);
+    return;
+  }
+
+  if (iframeMessage.windowId !== this.windowId) {
+    debug('mismatched window id', iframeMessage.windowId, this.windowId);
+    return;
+  }
+
+  switch (iframeMessage.type) {
+  case 's':
+    this.iframeObj.loaded();
+    // window global dependency
+    this.postMessage('s', JSON3.stringify([
+      version
+    , this.transport
+    , this.transUrl
+    , this.baseUrl
+    ]));
+    break;
+  case 't':
+    this.emit('message', iframeMessage.data);
+    break;
+  case 'c':
+    var cdata;
+    try {
+      cdata = JSON3.parse(iframeMessage.data);
+    } catch (ignored) {
+      debug('bad json', iframeMessage.data);
+      return;
+    }
+    this.emit('close', cdata[0], cdata[1]);
+    this.close();
+    break;
+  }
+};
+
+IframeTransport.prototype.postMessage = function(type, data) {
+  debug('postMessage', type, data);
+  this.iframeObj.post(JSON3.stringify({
+    windowId: this.windowId
+  , type: type
+  , data: data || ''
+  }), this.origin);
+};
+
+IframeTransport.prototype.send = function(message) {
+  debug('send', message);
+  this.postMessage('m', message);
+};
+
+IframeTransport.enabled = function() {
+  return iframeUtils.iframeEnabled;
+};
+
+IframeTransport.transportName = 'iframe';
+IframeTransport.roundTrips = 2;
+
+module.exports = IframeTransport;