spincycle/example/app/elements/message-router/message-router.html

A reactive message router and object manager that lets clients subscribe to object property changes on the server

<link rel="import" href="../../bower_components/polymer/polymer.html">
<link rel="import" href="../../bower_components/iron-signals/iron-signals.html">

<link rel="import" href="../../elements/message-router/message-router.html">

<polymer-element name="message-router" attributes="io">
  <template>
    <iron-signals on-iron-signal-register="{{registerListener}}"></iron-signals>
    <iron-signals on-iron-signal-objectsubscribe="{{registerObjectSubscriber}}"></iron-signals>
    <iron-signals on-iron-signal-emit="{{emitMessage}}"></iron-signals>
  </template>
  <script>
    (function ()
    {
      Polymer(
        {
            subscribers: [],
            objsubscribers: [],
            outstandingMessages: [],

          ready: function ()
          {
            console.log('message-router is ready');
          },

          registerListener: function(e, detail, sender)
          {
            //console.dir(arguments);
            //console.log("message-router registering listener for message '"+detail.message+"'");
            var subscribers = this.subscribers[detail.message] || [];
            subscribers.push(detail.callback);
            this.subscribers[detail.message] = subscribers;
          },

          registerObjectSubscriber: function(e, detail, sender)
          {
            //console.dir(arguments);
            console.log("message-router registering subscriber for object '"+detail.obj.id+"' type "+detail.obj.type);
            var subscribers = this.objsubscribers[detail.obj.id] || [];
            subscribers.push(detail.callback);
            this.objsubscribers[detail.obj.id] = subscribers;
            this.io.emit('message', JSON.stringify({target:'registerForUpdatesOn', messageId: UUID.generate(), obj: detail.obj}))
          },

          emitMessage: function(e, detail, sender)
          {
            console.log("emitMessage called");
            console.dir(detail);
              detail.messageId = UUID.generate();
              this.outstandingMessages.push(detail);
              this.io.emit('message', JSON.stringify(detail));
          },

          ioChanged: function()
          {
            if(this.io)
            {
              this.setupSockets(this.io)
            }
          },

          setupSockets: function(io)
          {
            console.log("message-router setupSockets called");
            console.dir(io);

            this.subscribers['OBJECT_UPDATE'] =
            [
              function(obj)
              {
                console.log("+++++++++++ obj update message router got obj");
                //console.dir(obj);
                var subscribers = this.objsubscribers[obj.id] || [];
                if(subscribers.length === 0)
                {
                  console.log("* OH NOES! * No subscribers for object update on object "+obj.id);
                  console.dir(this.objsubscribers);
                }
                else
                {
                  subscribers.forEach(function(subscriber) { subscriber(obj) } );
                }
              }.bind(this)
            ];

            io.on('message', function(reply)
            {
                var status    = reply.status;
                var message   = reply.payload;
                var info      = reply.info;

                console.log("got reply id "+reply.messageId+" status "+status+", info "+info+" data "+message);
                console.dir(reply);

                var index = -1;
                if(reply.messageId)
                {
                    for(var i = 0; i < this.outstandingMessages.length; i++)
                    {
                        var detail = this.outstandingMessages[i];
                        if (detail.messageId == reply.messageId)
                        {
                            detail.callback(message);
                            index = i;
                            break;
                        }
                    }
                    if(index > 0)
                    {
                        this.outstandingMessages.splice(index, 1);
                    }
                }
                else
                {
                    var subscribers = this.subscribers[info];
                    if(subscribers)
                    {
                        subscribers.forEach(function(listener)
                        {
                            //console.log("sending reply to listener");
                            listener(message)
                        });
                    }
                    else
                    {
                        console.log("no subscribers for message "+message);
                        console.dir(reply);
                    }
                }
            }.bind(this));
          }
        });
    })();
  </script>
</polymer-element>