Mapping actions example.cs

// -------------------------------
// Common action invoker interface

public interface IActionInvoker
{
	string InvokingActionType { get; }
	void Execute(Contexts contexts);
}
// -------------------------------

// -------------------------------
// Action component itself
using Entitas;

[Game]
public class ActionComponent : IComponent
{
	public string type;
}
// -------------------------------

// -------------------------------
// An Entitas component for it (entitas as a DI container)
using Entitas;
using Entitas.CodeGeneration.Attributes;

[Game]
public class ActionInvokerComponent : IComponent
{
	[EntityIndex]
	public string type;
	public IActionInvoker handler;
}
// -------------------------------

// -------------------------------
// Action implementation example
using Entitas;

public class SelectNextCarButtonHandler : IActionInvoker
{
	public string InvokingActionType { get { return ActionTypes.SelectNextCar; } }

	public void Execute(Contexts contexts)
	{
		var currentSelectedCarIndex = contexts.game.selectedCarId.value;
		currentSelectedCarIndex += 1;
		currentSelectedCarIndex %= contexts.game.GetEntities(GameMatcher.RuntimeCarData).Length;
		contexts.game.ReplaceSelectedCarId(currentSelectedCarIndex);
	}
}
// -------------------------------

// -------------------------------
// Invoking system with an optional Timer parameter
using System.Collections.Generic;
using Entitas;

public class InvokeActionsSystem : ReactiveSystem<GameEntity>
{
	private Contexts _contexts;

	public InvokeActionsSystem(Contexts contexts) : base(contexts.game)
	{
		_contexts = contexts;
	}

	protected override ICollector<GameEntity> GetTrigger(IContext<GameEntity> context)
	{
		return context.CreateCollector(GameMatcher.Timer.Removed(), GameMatcher.Action.Added());
	}

	protected override bool Filter(GameEntity entity)
	{
		return entity.hasAction && !entity.hasTimer;
	}

	protected override void Execute(List<GameEntity> entities)
	{
		foreach (var buttonPressEntity in entities)
		{
			var handlers = _contexts.game.GetEntitiesWithActionInvoker(buttonPressEntity.action.type);
			foreach (var handler in handlers)
			{
				handler.actionInvoker.handler.Execute(_contexts);
			}
			buttonPressEntity.isDestroyed = true;
		}
	}
}
// -------------------------------

// -------------------------------
// Action registration system that registers all invokers on startup
// Reflection can be easily replaced with a code generator that runs that loop offline and creates an array of implementing types
using System;
using System.Reflection;
using Entitas;

public class InitializeActionInvokersSystem : IInitializeSystem
{
	private Contexts _contexts;

	public InitializeActionInvokersSystem(Contexts contexts)
	{
		_contexts = contexts;
	}

	public void Initialize()
	{
		var assembly = Assembly.GetAssembly(typeof(IActionInvoker));
		var types = assembly.GetTypes();
		foreach (var type in types)
		{
			if (type.IsClass && !type.IsAbstract && typeof(IActionInvoker).IsAssignableFrom(type))
			{
				var handler = (IActionInvoker) Activator.CreateInstance(type);
				var handledType = handler.InvokingActionType;
				var entity = _contexts.game.CreateEntity();
				entity.AddActionInvoker(handledType, handler);
			}
		}
	}
}