Transiflow

A C# implementation of a generic, flexible state machine with support for validating and handling state transitions, as well as custom entrance and exit actions for each state.

Features

Generic implementation to support any state, event, and context types.
Extensible transition handling with custom actions.
Entrance and exit actions for each state.
Easy integration with dependency injection and extensibility through IServiceProvider.

Getting Started

Install the required dependencies:

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Transiflow;

2-Include the provided state machine and related interfaces in your project.

3-Create your state, event, and context classes that implement IState, IEvent, and IContext<TState, TStateTag> interfaces, respectively.

4-Implement the necessary ITransitionHandler<TContext, TState, TEvent, TNewState>, IStateEntranceHandler<TContext, TState>, and IStateExistHandler<TContext, TState> classes for your state machine.

5-Set up your state machine configuration

var services = new ServiceCollection();
ServiceCollection.AddScoped<ICodec<Context>, ContextCodec>
var serviceProvider = services.BuildServiceProvider();

var stateMachine = new StateMachine<TState, TStateTag, TEvent, TEventTag, TContext>(serviceProvider)
.AddTransition<TCurrentState, TTriggerEvent, TNewState>(sourceStateTag, eventTag, (sp, ctx) => new TransitionHandler());

6-Create a service instance for your state machine:

var stateMachineService = stateMachine.CreateService(context);

7-Use the SendEvent method to trigger state transitions:

stateMachineService.SendEvent(new TEvent());

Custom Entrance and Exit Actions

TransiFlow supports executing custom entrance and exit actions for each state by implementing the IStateEntranceHandler<TContext, TState> and IStateExistHandler<TContext, TState> interfaces, respectively.

IStateEntranceHandler

Implement this interface to define custom actions that should be executed when entering a specific state.

public class CustomStateEntranceHandler : IStateEntranceHandler<TContext, TState>
{
    public async Task HandleEntrance(TContext context, TState state)
    {
        // Your custom entrance action logic here
    }
}

IStateExistHandler

Implement this interface to define custom actions that should be executed when exiting a specific state.

public class CustomStateExitHandler : IStateExitHandler<TContext, TState>
{
    public async Task HandleExit(TContext context, TState state)
    {
        // Your custom exit action logic here
    }
}

Register your custom entrance and exit handlers with the dependency injection container to ensure they are executed during the state transitions.

var serviceCollection = new ServiceCollection();

serviceCollection
    .AddSingleton<IStateExistHandler<TContext, TState>, CustomStateExitHandler>()
    .AddSingleton<IStateEntranceHandler<TContext, TState>, CustomStateEntranceHandler>();

var serviceProvider = serviceCollection.BuildServiceProvider();

Examples

Check the unit tests provided in the project for examples of setting up state machines and using them in various scenarios.

License

This project is licensed under the MIT License.

TheFo2sh/Transiflow