Refactor FSMBase to subclass transitions.Machine

lib/tfw/components/fsm_managing_event_handler.py

@@ -1,8 +1,6 @@
 # Copyright (C) 2018 Avatao.com Innovative Learning Kft.
 # All Rights Reserved. See LICENSE file for details.
 
-from collections import defaultdict
-
 from tfw import BroadcastingEventHandler
 from tfw.config.logs import logging
 
@@ -13,7 +11,6 @@ class FSMManagingEventHandler(BroadcastingEventHandler):
     def __init__(self, key, fsm_type):
         super().__init__(key)
         self.fsm = fsm_type()
-        self.fsm_manager = FSMManager(self.fsm)
         self._fsm_updater = FSMUpdater(self.fsm)
 
         self.command_handlers = {
@@ -30,7 +27,7 @@ class FSMManagingEventHandler(BroadcastingEventHandler):
             LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)
 
     def handle_trigger(self, data):
-        self.fsm_manager.trigger(data['value'])
+        self.fsm.step(data['value'])
         return self.with_fsm_update(data)
 
     def with_fsm_update(self, data):
@@ -43,35 +40,6 @@ class FSMManagingEventHandler(BroadcastingEventHandler):
         return self.with_fsm_update(data)
 
 
-class FSMManager:
-    def __init__(self, fsm):
-        self.fsm = fsm
-        self.trigger_predicates = defaultdict(list)
-
-    def trigger(self, trigger):
-        predicate_results = [
-            predicate()
-            for predicate in self.trigger_predicates[trigger]
-        ]
-
-        # TODO: think about what could we do when this prevents triggering
-        if all(predicate_results):
-            try:
-                self.fsm.trigger(trigger)
-            except AttributeError:
-                LOG.debug('FSM failed to execute nonexistent trigger: "%s"', trigger)
-
-    def subscribe_predicate(self, trigger, *predicates):
-        self.trigger_predicates[trigger].extend(predicates)
-
-    def unsubscribe_predicate(self, trigger, *predicates):
-        self.trigger_predicates[trigger] = [
-            predicate
-            for predicate in self.trigger_predicates[trigger]
-            not in predicates
-        ]
-
-
 class FSMUpdater:
     def __init__(self, fsm):
         self.fsm = fsm
@@ -80,7 +48,7 @@ class FSMUpdater:
         state = self.fsm.state
         valid_transitions = [
             {'trigger': trigger}
-            for trigger in self.fsm.machine.get_triggers(self.fsm.state)
+            for trigger in self.fsm.get_triggers(self.fsm.state)
         ]
         return {
             'current_state': state,

lib/tfw/fsm_base.py

@@ -1,14 +1,17 @@
 # Copyright (C) 2018 Avatao.com Innovative Learning Kft.
 # All Rights Reserved. See LICENSE file for details.
 
-from typing import List
+from collections import defaultdict
 
 from transitions import Machine
 
 from tfw.mixins import CallbackMixin
+from tfw.config.logs import logging
+
+LOG = logging.getLogger(__name__)
 
 
-class FSMBase(CallbackMixin):
+class FSMBase(Machine, CallbackMixin):
     """
     A general FSM base class you can inherit from to track user progress.
     See linear_fsm.py for an example use-case.
@@ -18,10 +21,12 @@ class FSMBase(CallbackMixin):
     """
     states, transitions = [], []
 
-    def __init__(self, initial: str = None, accepted_states: List[str] = None):
+    def __init__(self, initial=None, accepted_states=None):
         self.accepted_states = accepted_states or [self.states[-1]]
-        self.machine = Machine(
-            model=self,
+        self.trigger_predicates = defaultdict(list)
+
+        Machine.__init__(
+            self,
             states=self.states,
             transitions=self.transitions,
             initial=initial or self.states[0],
@@ -34,4 +39,27 @@ class FSMBase(CallbackMixin):
         self._execute_callbacks(event_data.kwargs)
 
     def is_solved(self):
-        return self.state in self.accepted_states # pylint: disable=no-member
+        return self.state in self.accepted_states  # pylint: disable=no-member
+
+    def subscribe_predicate(self, trigger, *predicates):
+        self.trigger_predicates[trigger].extend(predicates)
+
+    def unsubscribe_predicate(self, trigger, *predicates):
+        self.trigger_predicates[trigger] = [
+            predicate
+            for predicate in self.trigger_predicates[trigger]
+            not in predicates
+        ]
+
+    def step(self, trigger):
+        predicate_results = [
+            predicate()
+            for predicate in self.trigger_predicates[trigger]
+        ]
+
+        # TODO: think about what could we do when this prevents triggering
+        if all(predicate_results):
+            try:
+                self.trigger(trigger)
+            except AttributeError:
+                LOG.debug('FSM failed to execute nonexistent trigger: "%s"', trigger)