Add some comments for future details, as well as partial of on_message

DecisionSystem/CentralisedDecision/ballotvoter.py

@@ -1,20 +1,34 @@
 import paho.mqtt.client as mqtt
+import umsgpack
 
 class BallotVoter:
     def __init__(self):
         self.client = mqtt.Client()
-        self.client.connect('172.16.43.2')
+        # id is generated automatically.
+        self.client.connect('172.16.13.128')
 
     def on_connect(self, client, userdata, flags, rc):
         print("Connected with result code " + str(rc))
-        if rc == 0:
-            global connected
-            connected = True
 
         self.client.subscribe('swarm1/voters', qos=1)
 
-    def on_message(self, client, userdata, message):
+        # Create the message to send that it is now part of the swarm.
 
+        # Need to set a will as well to broadcast on unexpected disconnection, so commander
+        # knows it is no longer part of the set of voters. 
+        # Leaving this until core centralised system is working.
+        #will_message = {"type": "UDisconnect"}
+
+        # Send a connected message to let any commanders know that 
+        # it is available. 
+        self.client.publish("swarm/commander", "connect," + self.client._client_id)
+
+    def on_message(self, client, userdata, message):
+        messageDict = umsgpack.unpackb(message)
+        if "type" in messageDict.keys:
+            # Ok message.
+        else:
+            # Bad message.
 
     def submit_vote(self):
         self.client.publish('swarm1/')