Pass the Backplane channel ID to the server via JSONP

backplane_channel.js

(function() {
  if (typeof window.Backplane !== 'function' || parseInt(Backplane.version) !== 2)
    return;
 
  /**
   * Callback function to be executed on BP ready
   */
  function bp_ready_callback() {
    // Get the channel ID
    var bpChannel = Backplane.getChannelID();
    
    // Pass via JSONP to an endpoint "url"
    var script = document.createElement('script');
    script.type = "text/javascript";
    script.src = url
      + "&bp_channel=" + encodeURIComponent(bpChannel);
    document.getElementsByTagName('HEAD')[0].appendChild(script);
  }
 
  // Pass in function from above
  Backplane(bp_ready_callback);
})();