OnEntityRemoved/Removing called when Component is removed doesn't allow accessing the removed component.

[acoppes]

When you remove a Component calling the manager.RemoveComponent(), the entity removing and remove are called to all groups interested in that component, however, they are called without that component.

I believe the system may want to react to the component being removed to remove data related to that component, in some cases with a reference to that data stored in the component itself or being used as identifier, etc.

To test it I am using the following code:

    class ListenerMock : IEntityAddedEventListener, IEntityRemovedEventListener, IEntityRemovingEventListener
    {
        public int addedCalls;

        public int removedCalls;

        public int removingCalls;

        public event Action<Entity> RemovedEvent;

        public event Action<Entity> RemovingEvent;

        #region IEntityAddedEventListener implementation
        public void OnEntityAdded (object sender, Entity entity)
        {
            addedCalls++;
        }

        public void OnEntityRemoved(object sender, Entity entity)
        {
            removedCalls++;
            if (RemovedEvent != null)
                RemovedEvent(entity);
        }

        public void OnEntityRemoving(object sender, Entity entity)
        {
            removingCalls++;
            if (RemovingEvent != null)
                RemovingEvent(entity);
        }
        #endregion

    }

    [Test]
    public void EntityRemovedCallbackShouldBeCalledWithComponents() {
        var entityManager = new EntityManager ();

        var group = entityManager.GetComponentGroup (typeof(Component1), typeof(Component2));

        var listenerMock = new ListenerMock ();
        group.SubscribeOnEntityAdded(listenerMock);
        group.SubscribeOnEntityRemoved (listenerMock);
        group.SubscribeOnEntityRemoving(listenerMock);

        var e = entityManager.CreateEntity ();

        entityManager.AddComponent (e, new Component1());
        entityManager.AddComponent (e, new Component2());

        Assert.That (listenerMock.addedCalls, Is.EqualTo (1));

        listenerMock.RemovingEvent += delegate (Entity e1) {
            Assert.True(entityManager.HasComponent<Component1>(e1));
            Assert.True(entityManager.HasComponent<Component2>(e1));
        };

        entityManager.RemoveComponentImmediate<Component1>(e);

        Assert.That (listenerMock.removingCalls, Is.EqualTo (1));
    }

It fails also using the normal remove:

    [Test]
    public void EntityRemovedCallbackShouldBeCalledWithComponents2() {
        var entityManager = new EntityManager ();

        var systemRoot = new SystemRoot<EntityManager>(entityManager);

        var group = entityManager.GetComponentGroup (typeof(Component1), typeof(Component2));

        var listenerMock = new ListenerMock ();
        // group.SubscribeOnEntityAdded(listenerMock);
        // group.SubscribeOnEntityRemoved (listenerMock);
        group.SubscribeOnEntityRemoving(listenerMock);

        // group.component

        var e = entityManager.CreateEntity ();

        entityManager.AddComponent (e, new Component1());
        entityManager.AddComponent (e, new Component2());

        // Assert.That (listenerMock.addedCalls, Is.EqualTo (1));

        // listenerMock.RemovedEvent += delegate (Entity e1) {
        //  Assert.True(entityManager.HasComponent<Component1>(e1));
        //  Assert.True(entityManager.HasComponent<Component2>(e1));
        // };

        listenerMock.RemovingEvent += delegate (Entity e1) {
            Assert.True(entityManager.HasComponent<Component1>(e1));
            Assert.True(entityManager.HasComponent<Component2>(e1));
        };

        entityManager.RemoveComponent<Component1>(e);
        // entityManager.RemoveComponentImmediate<Component1>(e);

        systemRoot.Update();

        Assert.That (listenerMock.removingCalls, Is.EqualTo (1));
    }

[Spy-Shifty]

Thank you I'll fix this

[Gotcab]

Is it fixed yet?

[dfraska]

I was able to address this by changing ComponentWrapper.cs lines 82 and 149 from: gameObjectEntity.EntityManager.RemoveComponent(gameObjectEntity.Entity); to: gameObjectEntity.EntityManager.RemoveComponentImmediate(gameObjectEntity.Entity);

I'm not 100% sure if this will have any other effects, but so far it has worked for me.

[dfraska]

The above fix causes issues with setting GameObjects inactive. I'm no longer seeing the original issue in my code... but I've made other bug fixes in my own non-public branch.