BlackMali.StateMachine 1.1.3

StateMachine

State machine implementation in C#.

Advantages:

• DI ready
• Async Pattern
• Safe programming with nullable types
• Works without constants and enums
• Builder for state machine creation
• Configuration of states and transitions
• Strict (default) and open transitions
• more than 95% code coverage

Compatible target frameworks

NuGet

You should install BlackMali.StateMachine with NuGet:

Install-Package BlackMali.StateMachine.Autofac

Or via the .NET Core command line interface:

dotnet add package BlackMali.StateMachine.Autofac

Registration

Autofac

var builder = new ContainerBuilder();
builder.RegisterModule<StateMachineModule>();
builder.RegisterType<LockState>().AsSelf();

Configuration

public class SlotMachine
{
	private readonly IStateMachine _stateMachine;

	public SlotMachine(IStateMachineBuilder builder)
	{
		// With DI registration -> AddState<LockState>()
		builder.AddState<LockState>()
			.AddStartTransition();
			.AddInStateTransition()
			.AddTransition<UnLockState>()
			.AddTransition<EndState>();

		// Without DI registration -> AddState(new UnLockState())
		builder.AddState(new UnLockState())
			.AddInStateTransition()
			.AddTransition<LockState>()
			.AddTransition<EndState>();

		// Create state machine
		_stateMachine = builder.Build();
	}
}

State change

// Perform state change
await _stateMachine.Transmit<LockState>();

// Or with Event
await _stateMachine.Transmit<LockState>(new StateMachineEvent());

// Or safe with exception handling
_stateMachine.OnError += (sender, args) => { };
await _stateMachine.TryTransmit<LockState>(new StateMachineEvent());

Event publishing with Post

// Posts an event to the current status
await _stateMachine.Post(new StateMachineEvent());

// Safe posting
await _stateMachine.TryPost(new StateMachineEvent());

State implementation

internal class LockState 
	: State // you can also use the interface IState without overrides
{
	// optional:
	public override async Task OnEnter(IStateMachineContext context)
	{
		await base.OnEnter(context);

		Console.WriteLine("Please insert coin");
	}

	// optional:
	public override async Task<IState?> OnTransmitted(IStateMachineContext context, StateMachineEvent @event)
	{
		var unLockEvent = @event as UnLockEvent;
		if (unLockEvent == null)
			return null;

		// No state change...
		if (unLockEvent.Coin == null)
			return null;

		// State change to UnLockState
		return await context.GetState<UnLockState>();
	}

	// optional:
	public override async Task OnExit(IStateMachineContext context)
	{
		// Do something...

		await Task.CompletedTask;
	}
}

Solution Packages

Unit-Tests:

• XUnit
• XUnit.Runner.VisualStudio
• Autofac.Extras.Moq
• Moq
• Coverlet.Collector

IDE

Implemented with Microsoft Visual Studio Community 2022

• Markdown Editor
• Fine Code Coverage