More than one SideEffect?

[franciscoaleixo]

Hi, so I was wondering if there's a recommended way to have more than one SideEffect for a transition? Is it simply repeating a transitionTo to the destination state but with different SideEffects?

And yes, I realize I could just simply have unique SideEffects for each transition, but that would lead to a lot of repeated code in my case. If I'm missing anything please let me know. Thanks!

For example (see // THIS comments):

val stateMachine = StateMachine.create<State, Event, SideEffect> {
    initialState(State.Solid)
    state<State.Solid> {
        on<Event.OnMelted> {
            transitionTo(State.Liquid, SideEffect.LogMelted)
            transitionTo(State.Liquid, SideEffect.LogOtherLiquidInfo) // THIS
        }
    }
    state<State.Liquid> {
        on<Event.OnFroze> {
            transitionTo(State.Solid, SideEffect.LogFrozen)
        }
        on<Event.OnVaporized> {
            transitionTo(State.Gas, SideEffect.LogVaporized)
        }
    }
    state<State.Gas> {
        on<Event.OnCondensed> {
            transitionTo(State.Liquid, SideEffect.LogCondensed)
            transitionTo(State.Liquid, SideEffect.LogOtherLiquidInfo)  // THIS
        }
    }
    onTransition {
        val validTransition = it as? StateMachine.Transition.Valid ?: return@onTransition
        when (validTransition.sideEffect) {
            SideEffect.LogMelted -> logger.log(ON_MELTED_MESSAGE)
            SideEffect.LogFrozen -> logger.log(ON_FROZEN_MESSAGE)
            SideEffect.LogVaporized -> logger.log(ON_VAPORIZED_MESSAGE)
            SideEffect.LogCondensed -> logger.log(ON_CONDENSED_MESSAGE)
            SideEffect.LogOtherLiquidInfo-> logger.log(ON_OTHER_LIQUID_INFO)  // THIS
        }
    }
}

[franciscoaleixo]

Oh, nevermind. In this case we could simply check the destination state, i.e. validTransition.toState == State.Liquid in the transition. So I guess this would be:

val stateMachine = StateMachine.create<State, Event, SideEffect> {
    initialState(State.Solid)
    state<State.Solid> {
        on<Event.OnMelted> {
            transitionTo(State.Liquid, SideEffect.LogMelted)
        }
    }
    state<State.Liquid> {
        on<Event.OnFroze> {
            transitionTo(State.Solid, SideEffect.LogFrozen)
        }
        on<Event.OnVaporized> {
            transitionTo(State.Gas, SideEffect.LogVaporized)
        }
    }
    state<State.Gas> {
        on<Event.OnCondensed> {
            transitionTo(State.Liquid, SideEffect.LogCondensed)
        }
    }
    onTransition {
        val validTransition = it as? StateMachine.Transition.Valid ?: return@onTransition
        if (validTransition.toState == State.Liquid) {
            logger.log(ON_OTHER_LIQUID_INFO)
        }
        when (validTransition.sideEffect) {
            SideEffect.LogMelted -> logger.log(ON_MELTED_MESSAGE)
            SideEffect.LogFrozen -> logger.log(ON_FROZEN_MESSAGE)
            SideEffect.LogVaporized -> logger.log(ON_VAPORIZED_MESSAGE)
            SideEffect.LogCondensed -> logger.log(ON_CONDENSED_MESSAGE)
        }
    }
}