Some Style question I guess?

[eterlan]

Take some times ues the amazing project, great works! 😆
Just wondering, why in the tutorial and samples, author prefer to cache the context reference in the system but not use the Contexts.sharedInstance? It might be trivial, just curious.

[sschmid]

Hi, do you have some links to examples that you mean?

[eterlan]

Hi, do you have some links to examples that you mean?

Yes sir. What I mean is why you guys prefer caching context and group in the constructor?

public sealed class BoardSystem : ReactiveSystem<GameEntity>, IInitializeSystem
{
    readonly Contexts _contexts;
    readonly IGroup<GameEntity> _pieces;

    public BoardSystem(Contexts contexts) : base(contexts.game)
    {
        _contexts = contexts;
        _pieces = contexts.game.GetGroup(AllOf(Piece, Position));
    }
    ...   
}
Is there any problem to use these things in execute method? Sounds like not what ECS suggest, but I guess it's not a big deal right?

[sschmid]

You can use both directly in the execute if you want and in some cases this can be better, e.g. when your game support some sort of soft-reboot where contexts re-created.

However, for me that's never the case and by caching the groups you basically avoid a dictionary lookup. References to groups like _pieces are always up to date, so it's fine to store them in a field like this