rx_state_machine

Description:

rx state machine

A library for finite state machine realization in Dart. Inspired by Tinder StateMachine library.
How to use #
Define states, events and side effects:

abstract class State {}
class Open extends State {}
class Closed extends State {}


abstract class Event {}
class OnOpening extends Event {}
class OnClosing extends Event {}


abstract class SideEffect {
void call(State state, Event event);
}

class MakeSomeNoise extends SideEffect {
@override
void call(State state, Event event) => print("Ka-chunk-creeeeeeak-squeekie-squeekie");
}
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Initialize state machine and declare state transitions:
final RxStateMachine<State, Event, SideEffect> _stateMachine =
RxStateMachine<State, Event, SideEffect>.create((g) => g
..initialState(Open())
..state<Open>((b) => b
..on<OnClosing>((state, event) {
return b.transitionTo(Closed(), MakeSomeNoise());
}))
..state<Closed>((b) => b
..on<OnOpening>((state, event) {
return b.transitionTo(Open(), MakeSomeNoise());
}))
..onTransition((transition) {
if (transition is Valid) {
final item = transition as Valid;
print("Valid transition: from [${item.fromState}] to [${item.toState}] by [${item.event}]");
if(item.sideEffect is SideEffect) {
item.sideEffect(item.toState, item.event);
}
} else if (transition is Invalid) {
final item = transition as Invalid;
print("Invalid transition: from [${item.fromState}] by [${item.event}]");
}
})
);
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Observe the machine and react to changes.
_stateMachine.states.listen((state) {
if(state is Open && !_security.authenticated()) {
_security.alarm();
}
});
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Perform state transitions:
_stateMachine.transition(new OnClosing());
//...
_stateMachine.transition(new OnOpening());
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