GoScrobble/web/node_modules/sockjs-client/lib/iframe-bootstrap.js

'use strict';

var urlUtils = require('./utils/url')
  , eventUtils = require('./utils/event')
  , JSON3 = require('json3')
  , FacadeJS = require('./facade')
  , InfoIframeReceiver = require('./info-iframe-receiver')
  , iframeUtils = require('./utils/iframe')
  , loc = require('./location')
  ;

var debug = function() {};
if (process.env.NODE_ENV !== 'production') {
  debug = require('debug')('sockjs-client:iframe-bootstrap');
}

module.exports = function(SockJS, availableTransports) {
  var transportMap = {};
  availableTransports.forEach(function(at) {
    if (at.facadeTransport) {
      transportMap[at.facadeTransport.transportName] = at.facadeTransport;
    }
  });

  // hard-coded for the info iframe
  // TODO see if we can make this more dynamic
  transportMap[InfoIframeReceiver.transportName] = InfoIframeReceiver;
  var parentOrigin;

  /* eslint-disable camelcase */
  SockJS.bootstrap_iframe = function() {
    /* eslint-enable camelcase */
    var facade;
    iframeUtils.currentWindowId = loc.hash.slice(1);
    var onMessage = function(e) {
      if (e.source !== parent) {
        return;
      }
      if (typeof parentOrigin === 'undefined') {
        parentOrigin = e.origin;
      }
      if (e.origin !== parentOrigin) {
        return;
      }

      var iframeMessage;
      try {
        iframeMessage = JSON3.parse(e.data);
      } catch (ignored) {
        debug('bad json', e.data);
        return;
      }

      if (iframeMessage.windowId !== iframeUtils.currentWindowId) {
        return;
      }
      switch (iframeMessage.type) {
      case 's':
        var p;
        try {
          p = JSON3.parse(iframeMessage.data);
        } catch (ignored) {
          debug('bad json', iframeMessage.data);
          break;
        }
        var version = p[0];
        var transport = p[1];
        var transUrl = p[2];
        var baseUrl = p[3];
        debug(version, transport, transUrl, baseUrl);
        // change this to semver logic
        if (version !== SockJS.version) {
          throw new Error('Incompatible SockJS! Main site uses:' +
                    ' "' + version + '", the iframe:' +
                    ' "' + SockJS.version + '".');
        }

        if (!urlUtils.isOriginEqual(transUrl, loc.href) ||
            !urlUtils.isOriginEqual(baseUrl, loc.href)) {
          throw new Error('Can\'t connect to different domain from within an ' +
                    'iframe. (' + loc.href + ', ' + transUrl + ', ' + baseUrl + ')');
        }
        facade = new FacadeJS(new transportMap[transport](transUrl, baseUrl));
        break;
      case 'm':
        facade._send(iframeMessage.data);
        break;
      case 'c':
        if (facade) {
          facade._close();
        }
        facade = null;
        break;
      }
    };

    eventUtils.attachEvent('message', onMessage);

    // Start
    iframeUtils.postMessage('s');
  };
};