Entity is in the world although it is deleted, the Contains function should also include delayRemoval entities.

[AnderWoche]

entity.remove()
if(entity in world) // should be false
becouse the in funktion ignore the delayRemoval entities

[Quillraven]

Hm but that is contradicting because it is actually still in the world, hence delayRemoval ;)
Also, the only scenario where this can happen is if you delete an entity inside your system and check if it is in the world. I think there is no other case.

Can you provide your scenario where this is an issue?

[AnderWoche]

I am trying to build a parent child structure.

I have built a state system inspired by React which changes/rebuilds the UI depending on the state change, so if more than one state is changed per frame I have to rebuild the whole parent child structure several times.

To make the project clearer I thought I could outsource individual logics into components.

class ParentComponent(var parent: Entity) : Component<ParentComponent> {

    //[...]

    //If the entity is deleted, it should automatically remove itself from the parent.
    override fun World.onRemove(entity: Entity) {
        parent.getOrNull(ChildrenComponent)?.children?.minusAssign(entity)
    }
}

as soon as I want to rebuild everything from one point I assumed that entity.remove() works immediately and executes the logic of the onRemove of the component.

    private fun removeEntityAndChildrenTree(entity: Entity) {
        val children = entity.getOrNull(ChildrenComponent)?.children
        if (children != null) {
            for (i in children.size - 1 downTo 0) {
                removeEntityAndChildrenTree(children[i])
            }
        }
        println("delte entity ${entity.id}")
        //a solution would be to call children.clear() here.
        entity.remove()
    }

after long debugging I realized that the entities may only be removed later.

But because I already explicitly called remove, I thought that the entity would no longer be in the world.

if (family.contains(entity)) {
        if (entity[StateComponent].boundStates.contains(stateID)) {
            if(entity in world) { // I have called remove sometime before but the entity is still in the parent's CHildrenComponent. hence the check if it is still in the world/or has been marked as remove.
                doReInit(entity)
            }
            return
        }
}

Your point that you mentioned makes sense, that at that time the entity is really not deleted, but then I would like to have a method to check if the entity is marked as removeLater.

[Quillraven]

in is just a special syntax for contains. What about a contains(includeDelay: Boolean = false) default implementation of this method? When you set the parameter to true, then it will also check for delay removals. Or do you want a separate method like entity.isMarkedForRemoval()? Whatever you prefer :)

[AnderWoche]

Normally I would prefer that
contains(includeDelay: Boolean = false)
but I think to avoid confusion with the in syntax would use the other one.

this: entity.isMarkedForRemoval()

[Quillraven]

@AnderWoche: I just made the change in the master: 3c0ece2

Should be available in the Snapshot soon. Please let me know, if that solves your problem :)

Thanks!

Edit: I broke something. Will need to have a look tomorrow, sorry.

[Quillraven]

Snapshot should be available now soon

[AnderWoche]

@AnderWoche: I just made the change in the master: 3c0ece2

Should be available in the Snapshot soon. Please let me know, if that solves your problem :)

Thanks!

Edit: I broke something. Will need to have a look tomorrow, sorry.

Everything solved 👍