Struct bevy_ecs::system::RemovedComponents [−][src]
pub struct RemovedComponents<'a, T: Component> { /* fields omitted */ }
Expand description
A SystemParam
that grants access to the entities that had their T
Component
removed.
Note that this does not allow you to see which data existed before removal.
If you need this, you will need to track the component data value on your own,
using a regularly scheduled system that requests Query<(Entity, &T), Changed<T>>
and stores the data somewhere safe to later cross-reference.
If you are using bevy_ecs
as a standalone crate,
note that the RemovedComponents
list will not be automatically cleared for you,
and will need to be manually flushed using World::clear_trackers
For users of bevy
itself, this is automatically done in a system added by MinimalPlugins
or DefaultPlugins
at the end of each pass of the game loop.
Examples
Basic usage:
fn react_on_removal(removed: RemovedComponents<MyComponent>) {
removed.iter().for_each(|removed_entity| println!("{:?}", removed_entity));
}
Implementations
Trait Implementations
type Fetch = RemovedComponentsState<T>
Auto Trait Implementations
impl<'a, T> !RefUnwindSafe for RemovedComponents<'a, T>
impl<'a, T> Send for RemovedComponents<'a, T>
impl<'a, T> Sync for RemovedComponents<'a, T>
impl<'a, T> Unpin for RemovedComponents<'a, T> where
T: Unpin,
impl<'a, T> !UnwindSafe for RemovedComponents<'a, T>
Blanket Implementations
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