gistfile1.js

if (Meteor.isClient) {
  function joinRoom (roomName) {
    // Update joinedRooms on successful subscription.
    var publishCallbacks = {
      onReady: function () {
        Meteor.call("updateRoomsJoined", roomName);
        Session.set('currentRoom', roomName);
        $('#joined-rooms').val(roomName);
      },
      onError: function () {
      
      }
    }
    // Check if room exists, create one if not, otherwise subscribe.
    if (Rooms.find({name: roomName}).count() === 0) {
      Meteor.call('createAndPublishRoom', roomName, function (error, result) {
        if (!error) {
          Meteor.subscribe(roomName, publishCallbacks);
        }
      });
    } else {
      Meteor.subscribe(roomName, publishCallbacks);
    }
  }