this resolves #134

also fixes an issue with positionally passing data to callbacks
(positional passing had not been covered by tests before)

README.md

@@ -210,12 +210,14 @@ lump.state
 lump.evaporate()
 lump.state
 >>> 'gas'
-lump.ionize()
+lump.trigger('ionize')
 lump.state
 >>> 'plasma'
 ```
 
 Notice the shiny new methods attached to the `Matter` instance (`evaporate()`, `ionize()`, etc.). Each method triggers the corresponding transition. You don't have to explicitly define these methods anywhere; the name of each transition is bound to the model passed to the `Machine` initializer (in this case, `lump`).
+Additionally, there is a method called `trigger` now attached to your model.
+This method lets you execute transitions by name in case dynamic triggering is required.
 
 ### <a name="states"></a>States
 
@@ -532,6 +534,7 @@ Note that condition-checking methods will passively receive optional arguments a
 
 ```python
 lump.heat(temp=74)
+# equivalent to lump.trigger('heat', temp=74)
 ```
 
 ... would pass the `temp=74` optional kwarg to the `is_flammable()` check (possibly wrapped in an `EventData` instance). For more on this, see the [Passing data](#passing-data) section below.
@@ -627,7 +630,8 @@ lump = Matter()
 machine = Machine(lump, ['solid', 'liquid'], initial='solid')
 machine.add_transition('melt', 'solid', 'liquid', before='set_environment')
 
-lump.melt(45)  # positional arg
+lump.melt(45)  # positional arg; 
+# equivalent to lump.trigger('melt', 45)
 lump.print_temperature()
 >>> 'Current temperature is 45 degrees celsius.'
 

tests/test_core.py

@@ -240,8 +240,9 @@ def test_send_event_data_callbacks(self):
             trigger='advance', source='A', dest='B', before='set_message')
         s.advance(message='Hallo. My name is Inigo Montoya.')
         self.assertTrue(s.message.startswith('Hallo.'))
-        # Make sure callbacks handle arguments properly
-        s.to_B()
+        s.to_A()
+        s.advance('Test as positional argument')
+        self.assertTrue(s.message.startswith('Test as'))
         # Now wrap arguments in an EventData instance
         m.send_event = True
         m.add_transition(
@@ -599,3 +600,17 @@ def test_multiple_models(self):
         # for backwards compatibility model should return a model instance
         # rather than a list
         self.assertNotIsInstance(m.model, list)
+
+    def test_string_trigger(self):
+        def return_value(value):
+            return value
+
+        self.stuff.machine.add_transition('do', '*', 'C')
+        self.stuff.trigger('do')
+        self.assertTrue(self.stuff.is_C())
+        self.stuff.machine.add_transition('maybe', 'C', 'A', conditions=return_value)
+        self.assertFalse(self.stuff.trigger('maybe', value=False))
+        self.assertTrue(self.stuff.trigger('maybe', value=True))
+        self.assertTrue(self.stuff.is_A())
+        with self.assertRaises(AttributeError):
+            self.stuff.trigger('not_available')

tests/test_reuse.py

@@ -89,7 +89,7 @@ def test_blueprint_remap(self):
 
         new_states = ['A', 'B', {'name': 'C', 'children':
                       [counter, {'name': 'X', 'children': ['will', 'be', 'filtered', 'out']}],
-                       'remap': {'finished': 'A', 'X': 'A'}}]
+                      'remap': {'finished': 'A', 'X': 'A'}}]
         new_transitions = [
             {'trigger': 'forward', 'source': 'A', 'dest': 'B'},
             {'trigger': 'forward', 'source': 'B', 'dest': 'C%s1' % State.separator},

transitions/core.py

@@ -23,6 +23,13 @@ def listify(obj):
         return obj if isinstance(obj, (list, tuple, type(None))) else [obj]
 
 
+def get_trigger(model, trigger_name, *args, **kwargs):
+    func = getattr(model, trigger_name, None)
+    if func:
+        return func(*args, **kwargs)
+    raise AttributeError("Model has no trigger named %s" % trigger_name)
+
+
 class State(object):
 
     def __init__(self, name, on_enter=None, on_exit=None,
@@ -97,7 +104,8 @@ def check(self, event_data):
                 model attached to the current machine which is used to invoke
                 the condition.
             """
-            predicate = getattr(event_data.model, self.func)
+            predicate = getattr(event_data.model, self.func) if isinstance(self.func, string_types) else self.func
+
             if event_data.machine.send_event:
                 return predicate(event_data) == self.target
             else:
@@ -368,6 +376,9 @@ def __init__(self, model=None, states=None, initial=None, transitions=None,
         if ordered_transitions:
             self.add_ordered_transitions()
 
+        for model in self.models:
+            model.trigger = partial(get_trigger, model)
+
     @staticmethod
     def _create_transition(*args, **kwargs):
         return Transition(*args, **kwargs)
@@ -497,7 +508,7 @@ def add_transition(self, trigger, source, dest, conditions=None,
         if trigger not in self.events:
             self.events[trigger] = self._create_event(trigger, self)
             for model in self.models:
-                trig_func = partial(self.events[trigger].trigger, model=model)
+                trig_func = partial(self.events[trigger].trigger, model)
                 setattr(model, trigger, trig_func)
 
         if isinstance(source, string_types):

transitions/extensions/locking.py

@@ -19,7 +19,7 @@ class LockedEvent(Event):
 
     def trigger(self, model, *args, **kwargs):
         with self.machine.rlock:
-            super(LockedEvent, self).trigger(model, *args, **kwargs)
+            return super(LockedEvent, self).trigger(model, *args, **kwargs)
 
 
 class LockedMachine(Machine):