set field so the protocol object can easily get factor instance. add ability to…

set field so the protocol object can easily get factor instance.  add ability to add observers for specific events and dispatch events to observers.  still more work needed there, since there is no relation between observers and what events are subscribed from freeswitch

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9528 d0543943-73ff-0310-b7d9-9358b9ac24b2

scripts/socket/freepy/fseventlistener.py

@@ -140,7 +140,7 @@ class FreeswitchEventListener(LineReceiver):
 
     def eventReceived(self, event_xml_str):
         """
-        should be overridden by subclasses
+        should be overridden by subclasses.
         """
         raise Exception("This is an abstract class, should be overridden "
                         "in a subclass")
@@ -153,6 +153,9 @@ class FreeswitchEventListenerFactory(ClientFactory):
                             should be a subclass of a FreeswitchEventListener
         """
 
+        # dictionary of observers.  key: event name, value: list of observers
+        self.event2observer = {}
+        
         self.protoclass=protoclass
         
         if host:
@@ -166,12 +169,33 @@ class FreeswitchEventListenerFactory(ClientFactory):
         self.connection_deferred = None
         self.num_attempts = 0
 
+    def addobserver(self, event_name, observer):
+        """
+        @param event_name, eg "CHANNEL_ANSWER"
+        @param observer (instance of object that has an eventReceived() method
+        """
+        observers = self.event2observer.get(event_name, [])
+        observers.append(observer)
+        self.event2observer[event_name] = observers
+
+    def dispatch2observers(self, event_name, event_xml_str, event_dom):
+        """
+        called back by the underlying protocol upon receiving an
+        event from freeswitch.  Currently subclasses must explicitly
+        call this method from their eventReceived method for observers
+        to get the message.  TODO: move this call to FreeswitchEventListener
+        and use observer pattern instead of any subclassing.
+        """
+        observers = self.event2observer.get(event_name, [])
+        for observer in observers:
+            observer.eventReceived(event_name, event_xml_str, event_dom)
+        
     def reset(self):
         self.protocol = None
         self.connection_deferred = None
         
     def connect(self):
-            
+
         if self.protocol:
             # if we have a protocol object, we are connected (since we always
             # null it upon any disconnection)
@@ -191,6 +215,7 @@ class FreeswitchEventListenerFactory(ClientFactory):
 
     def conncb(self, protocol):
         self.protocol = protocol
+        self.protocol.__dict__["factory"] = self
         deferred2callback = self.connection_deferred
         self.connection_deferred = None
         deferred2callback.callback(self.protocol)