subject class extended to support callbacks

vban_cmd/subject.py

@@ -1,15 +1,14 @@
 import logging
 
+logger = logging.getLogger(__name__)
+
 
 class Subject:
-    """Adds support for observers"""
-
-    logger = logging.getLogger("subject.subject")
-
     def __init__(self):
-        """list of current observers"""
+        """Adds support for observers and callbacks"""
 
         self._observers = list()
+        self.logger = logger.getChild(self.__class__.__name__)
 
     @property
     def observers(self) -> list:
@@ -17,38 +16,57 @@ class Subject:
 
         return self._observers
 
-    def notify(self, modifier=None):
+    def notify(self, event):
         """run callbacks on update"""
 
-        [o.on_update(modifier) for o in self._observers]
+        for o in self._observers:
+            if hasattr(o, "on_update"):
+                o.on_update(event)
+            else:
+                if o.__name__ == f"on_{event}":
+                    o()
 
     def add(self, observer):
-        """adds an observer to _observers"""
+        """adds an observer to observers"""
 
-        if observer not in self._observers:
-            self._observers.append(observer)
-            self.logger.info(f"{type(observer).__name__} added to event observers")
-        else:
-            self.logger.error(
-                f"Failed to add {type(observer).__name__} to event observers"
-            )
+        try:
+            iterator = iter(observer)
+            for o in iterator:
+                if o not in self._observers:
+                    self._observers.append(o)
+                    self.logger.info(f"{o} added to event observers")
+                else:
+                    self.logger.error(f"Failed to add {o} to event observers")
+        except TypeError:
+            if observer not in self._observers:
+                self._observers.append(observer)
+                self.logger.info(f"{observer} added to event observers")
+            else:
+                self.logger.error(f"Failed to add {observer} to event observers")
 
     register = add
 
     def remove(self, observer):
-        """removes an observer from _observers"""
+        """removes an observer from observers"""
 
         try:
-            self._observers.remove(observer)
-            self.logger.info(f"{type(observer).__name__} removed from event observers")
-        except ValueError:
-            self.logger.error(
-                f"Failed to remove {type(observer).__name__} from event observers"
-            )
+            iterator = iter(observer)
+            for o in iterator:
+                try:
+                    self._observers.remove(o)
+                    self.logger.info(f"{o} removed from event observers")
+                except ValueError:
+                    self.logger.error(f"Failed to remove {o} from event observers")
+        except TypeError:
+            try:
+                self._observers.remove(observer)
+                self.logger.info(f"{observer} removed from event observers")
+            except ValueError:
+                self.logger.error(f"Failed to remove {observer} from event observers")
 
     deregister = remove
 
     def clear(self):
-        """clears the _observers list"""
+        """clears the observers list"""
 
         self._observers.clear()