What's the difference between "IGroup.OnEntityAdded" and ReativeSystem when using?

[atkdefender]

I write some code below. Found that they looks like doing the same thing. If they are totally equal, I will write the shorter one ;)

public sealed class MoveReactiveSystem : ReactiveSystem<GameEntity>,IInitializeSystem
{
    readonly Contexts _contexts;
    public MoveReactiveSystem(Contexts contexts) : base(contexts.game)
    {
        _contexts = contexts;
    }

    public void Initialize()
    {
        _contexts.game.GetGroup(GameMatcher.Moveable).OnEntityAdded += (group, entity, index, component) => {
            Debug.Log("GroupTrigger [" + entity.creationIndex + "]:" + entity.isMoveable);
        };
    }
    protected override ICollector<GameEntity> GetTrigger(IContext<GameEntity> context)
    => context.CreateCollector(GameMatcher.Moveable.Added());

    protected override bool Filter(GameEntity entity) => entity.isMoveable;

    protected override void Execute(List<GameEntity> entities)
    {
        foreach(var entity in entities)
        {
            Debug.Log("ReactiveSys [" + entity.creationIndex + "]:" + entity.isMoveable);
        }
    }
}

[rglobig]

The difference is that the OnEntityAdded method is called immediately after the change happened. The Execute method of the Reactive System is relative to the execution order you do yourself with Systems or Feature. I suggest to only use the group events if you really need it. More infos: https://github.com/sschmid/Entitas-CSharp/wiki/Systems

[atkdefender]

The difference is that the OnEntityAdded method is called immediately after the change happened. The Execute method of the Reactive System is relative to the execution order you do yourself with Systems or Feature. I suggest to only use the group events if you really need it. More infos: https://github.com/sschmid/Entitas-CSharp/wiki/Systems

Ah...I forget ReactiveSys can react in order. Thx for reminding, before I went wrong.