fix inheritance of status codes attached to state functions

secop/states.py

@@ -27,30 +27,27 @@ handles status depending on statemachine state
 
 
 from secop.core import BUSY, IDLE, ERROR, Parameter, Command, Done
-from secop.errors import ProgrammingError
 from secop.lib.newstatemachine import StateMachine, Retry, Finish, Start, Stop
 
 
-class status_code:
+def status_code(code, text=None):
-    """decorator for state methods"""
+    """decorator, attaching a status to a state function
-    def __init__(self, code, text=None):
-        self.code = code
-        self.text = text
 
-    def __set_name__(self, owner, name):
+    :param code: the first element of the secop status tuple
-        if not issubclass(owner, HasStates):
+    :param text: the second element of the secop status tuple. if not given,
-            raise ProgrammingError('when using decorator "status_code", %s must inherit HasStates' % owner.__name__)
+                 the name of the state function is used (underscores replaced by spaces)
-        self.cls = owner
+    :return: the decorator function
-        self.name = name
-        if 'statusMap' not in owner.__dict__:
-            # we need a copy on each inheritance level
-            owner.statusMap = owner.statusMap.copy()
-        owner.statusMap[name] = self.code, name.replace('_', ' ') if self.text is None else self.text
-        setattr(owner, name, self.func)  # replace with original method
 
-    def __call__(self, func):
+    if a state function has not attached status and is a method of the module running
-        self.func = func
+    the state machine, the status is inherited from an overridden method, if available
-        return self
+
+    a state function without attached status does not change the status, or, if it is
+    used as the start function, BUSY is taken as default status code
+    """
+    def wrapper(func):
+        func.status = code, func.__name__.replace('_', ' ') if text is None else text
+        return func
+    return wrapper
 
 
 class HasStates:
@@ -58,7 +55,7 @@ class HasStates:
     all_status_changes = False  # when true, send also updates for status changes within a cycle
     _state_machine = None
     _status = IDLE, ''
-    statusMap = {}
+    statusMap = None
 
     def init_state_machine(self, **kwds):
         self._state_machine = StateMachine(
@@ -71,6 +68,7 @@ class HasStates:
 
     def initModule(self):
         super().initModule()
+        self.statusMap = {}
         self.init_state_machine()
 
     def state_transition(self, sm, newstate):
@@ -97,7 +95,22 @@ class HasStates:
             status = self._state_machine.idle_status or (ERROR, 'Finish was returned without final status')
         else:
             name = statefunc.__name__
-            status = self.statusMap.get(name)
+            try:
+                # look up in statusMap cache
+                status = self.statusMap[name]
+            except KeyError:
+                # try to get status from method or inherited method
+                cls = type(self)
+                for base in cls.__mro__:
+                    try:
+                        status = getattr(base, name, None).status
+                        break
+                    except AttributeError:
+                        pass
+                else:
+                    status = None
+                # store it in the cache for all further calls
+                self.statusMap[name] = status
             if status is None and default_code is not None:
                 status = default_code, name.replace('_', ' ')
         return status
@@ -108,8 +121,7 @@ class HasStates:
             return Done
         return sm.status
 
-    def doPoll(self):
+    def cycle_machine(self):
-        super().doPoll()
         sm = self._state_machine
         sm.cycle()
         if sm.statefunc is None:
@@ -118,6 +130,10 @@ class HasStates:
                 self.setFastPoll(False)
         self.read_status()
 
+    def doPoll(self):
+        super().doPoll()
+        self.cycle_machine()
+
     def on_cleanup(self, sm):
         if isinstance(sm.cleanup_reason, Exception):
             return self.on_error(sm)