Fix generated stateMixin class to properly implement overridable transition methods instead of messing with getattr; allows use of `super().transition_name()` in classes that subclass from the Mixin

2 files changed, 7 insertions, 9 deletions

diff --git a/examples/statemachine/libraryBookDemo.py b/examples/statemachine/libraryBookDemo.py
index 95e5996..5e73f07 100644
--- a/examples/statemachine/libraryBookDemo.py
+++ b/examples/statemachine/libraryBookDemo.py
@@ -24,9 +24,9 @@ class RestrictedBook(Book):
     # specialized checkout to check permission of user first
     def checkout(self, user=None):
         if user in self._authorized_users:
-            self._state = self._state.checkout()
+            super().checkout()
         else:
-            raise Exception("{0} could not check out restricted book".format((user, "anonymous")[user is None]))
+            raise Exception("{0} could not check out restricted book".format(user if user is not None else "anonymous"))
 
 
 def run_demo():
diff --git a/examples/statemachine/statemachine.py b/examples/statemachine/statemachine.py
index f4244a5..7e4de86 100644
--- a/examples/statemachine/statemachine.py
+++ b/examples/statemachine/statemachine.py
@@ -219,17 +219,15 @@ def expand_named_state_definition(source, loc, tokens):
         "    def state(self):",
         "        return self._state",
 
-        "    # get behavior/properties from current state",
-        "    def __getattr__(self, attrname):",
-        "        attr = getattr(self._state, attrname)",
-        "        if attrname in {baseStateClass}.transition_names:".format(baseStateClass=baseStateClass),
-        "            return lambda x=self: setattr(x, '_state', attr())",
-        "        return attr",
-
         "    def __str__(self):",
         "       return '{0}: {1}'.format(self.__class__.__name__, self._state)"
     ])
 
+    # define transition methods to be delegated to the _state instance variable
+    statedef.extend(
+        "    def {tn_name}(self): self._state = self._state.{tn_name}()".format(tn_name=tn)
+        for tn in transitions
+    )
     return indent + ("\n" + indent).join(statedef) + "\n"
 
 namedStateMachine.setParseAction(expand_named_state_definition)