migratingToV5.md

Migrating to Version 5

In Version 5, we split the state machine usage into three distinct steps:

• Define the state machine
• Create a state machine from the definition
• Run the state machine

State machines can now be quickly created from an existing definition.

An example state machine prior to version 5:

var machine = new PassiveStateMachine<States, Events>("my state machine");

machine
    .In(States.Off)
    .On(Events.TurnOn)
        .Goto(States.On)
        .Execute(SayHello);

machine
    .In(States.On)
    .On(Events.TurnOff)
        .Goto(States.Off)
        .Execute(SayBye);

machine
    .Initialize(States.Off);

machine
    .Start();

In version 5, the same state machine looks like this:

// create a definition builder
var builder = new StateMachineDefinitionBuilder<States, Events>();

builder
    .In(States.Off)
    .On(Events.TurnOn)
        .Goto(States.On)
        .Execute(SayHello);

builder
    .In(States.On)
    .On(Events.TurnOff)
        .Goto(States.Off)
        .Execute(SayBye);

builder
    .WithInitialState(States.Off); // the initial state is now set during definition time

// create the definition to later spawn state machines from it
var definition = builder
    .Build();

// create as many state machines as you need from the same definition
var machine =    
    .CreatePassiveStateMachine("my state machine"); // you can also create an active state machine

machine
    .Start();

Make sure you use the correct StateMachineDefinitionBuilder:

• from namespace Appccelerate.StateMachine.Machine for state machines without async/await support
• from namespace Appccelerate.StateMachine.AsyncMachine for state machines with async/await support

Changes in extension API

The extension API is changed in version 5, too. Instead of mutable states, the state definition is passed to the extensions.