Adds support for custom message sending.

Messages can now be sent to only one Observer if needed.

Observer.py

@@ -24,7 +24,6 @@ Simply copy/paste this file and import Observer to start using it.
  """
 
 import json
-from StringIO import StringIO
 
 
 class Observer():
@@ -51,7 +50,6 @@ class Observer():
         A notification updates message value
         """
         ut = ObsUtility()
-        mess = json.loads(message)
 
         if ut.is_json_valid(message):
             self.message = message
@@ -87,7 +85,6 @@ class Observable():
         """
         Adds observer to notification list.
         """
-        # FIXME: Check name unique
         if not isinstance(observer, Observer):
             raise TypeError("Subscriber must be Observer")
 
@@ -110,9 +107,12 @@ class Observable():
         """
         Sends notification message to all subscribed observer
         """
+        # sends message only to those needed
+        dest = json.loads(mess)["name"]
+
         for observer in self.obs_collection:
-            #print "sent %s to %s" % (mess, str(observer))
-            observer.update(mess)
+            if (len(dest) == 0 ) or (observer.name == dest):
+                observer.update(mess)
 
     def set_val(self, val):
         """
@@ -126,7 +126,7 @@ class Observable():
         else:
             raise TypeError("Expecting a valid JSon Object")
 
-        self.message = val
+        self.message = val  # saves last message sent
         self.__notify(self.message)
 
 
@@ -146,8 +146,8 @@ class ObsUtility():
         # Cheks for the presence of tags
         try:
             #simply access all
-            expected = sorted(["name", "group", "type", "data"]) # should be placed somewhere else
+            expected = sorted(["name", "group", "type", "data"])  # should be placed somewhere else
             got = sorted(mess.keys())
             return (expected == got)
         except KeyError:
-            return False
+            return False

testObserver.py

@@ -38,8 +38,6 @@ class TestObserver(unittest.TestCase):
 
         self.myObservable = obs.Observable()
 
-        self.default_mess = "message"
-
         self.name1 = "myObserver1"
         self.myObserver1 = obs.Observer(self.name1)
         self.name2 = "myObserver2"
@@ -69,7 +67,6 @@ class TestObserver(unittest.TestCase):
         self.assertRaises(TypeError, lambda: self.myObserver1.update([4, 2]))
         self.assertRaises(TypeError, lambda: self.myObserver1.update(None))
 
-
     ## Observable
     def testIsJsonValid(self):
         self.assertEquals(True, self.ut.is_json_valid('{"name": "Bob","group": "","type": "","data": 42}'))
@@ -113,18 +110,22 @@ class TestObserver(unittest.TestCase):
         self.myObservable.subscribe(self.myObserver1)
         self.myObservable.subscribe(self.myObserver2)
 
-        test = '{"name": "R2D2","group": "","type": "","data": 42}'
+        test = '{"name": "","group": "","type": "R2D2","data": 42}'
         self.myObservable.set_val(test)
         self.assertEquals(self.myObserver1.message, test)
         self.assertEquals(self.myObserver2.message, test)
 
-
         self.myObservable.unsubscribe(self.myObserver1)
-        test2 = '{"name": "C3PO","group": "","type": "","data": 42}'
-        self.myObservable.set_val(test2 )
+        test2 = '{"name": "","group": "C3PO","type": "","data": 42}'
+        self.myObservable.set_val(test2)
         self.assertEquals(self.myObserver1.message, test)
         self.assertEquals(self.myObserver2.message, test2)
 
+        self.myObservable.subscribe(self.myObserver1)
+        test3 = '{"name": "myObserver1","group": "C3PO","type": "","data": 42}'
+        self.myObservable.set_val(test3)
+        self.assertEquals(self.myObserver1.message, test3)
+        self.assertEquals(self.myObserver2.message, test2)
 
 if __name__ == '__main__':
-    unittest.main()
+    unittest.main()