rsbhsm 
Hierarchical state machine with RSB support based on transitions (version >= 0.4.0).
Features include:
- full lifecycle state management
- automatic listener management for transitions
- and much more
The basic usage of rsbhsm does not differ much from other transition state machines.
from rsbhsm import RSBHierarchicalStateMachine as Machine
class Model(object):
def well_trained():
return True
model = Model()
states = ['stand', 'walk', 'run'] # state as strings
transitions = [
['acc', 'stand', 'walk'], # array transition
{'trigger':'acc', 'source':'walk', 'dest': 'run'}, # or dictionary
# with conditions and/or unless
{'trigger': 'spring', 'source':'stand', 'dest': 'run', 'conditions':'well_trained'},
# also direct function pointers
{'trigger': 'break_required', 'source':'run', 'dest': 'stand', 'unless':model.well_trained},
# chained processing; since previous transitions fails, this one will be executed
{'trigger': 'break_required', 'source':'run', 'dest': 'walk'}
]
machine = Machine(model, states=states, transitions=transitions)Added features
The additional keyword for RSBState is action:
states = [
{'name': 'run', 'action':'my.action.class'}
]
If an RSBState is entered, an object of 'my.action.class' is created and destroyed whenever it is exited.
This class must implement an enter and exit method which will be called according to the event.
A minimal action can look like this:
class BaseAction(object):
def __init__(self, *args, **kwargs):
self.model = kwargs['model']
def enter(self, *args, **kwargs):
pass
def exit(self, *args, **kwargs):
passThe additional keywords for RSBTransition are scope and type:
transitions = [
{'trigger':'acc', 'source':'stand', 'dest':'walk', 'scope':'/foo/bar/baz', 'type': 'rst.generic.Value'}
]scope defines the RSB scope and type the RST
message type as a string. If a native type is required, use 'type':str or similar.
A listener on this scope will be created if and only if the transition is possible from the current state.
Additionally, the listener will be destroyed if the transition is no longer valid.
