Trait bevy_ecs::system::EntityCommand
source · pub trait EntityCommand<Marker = ()>: Send + 'static {
// Required method
fn apply(self, id: Entity, world: &mut World);
// Provided method
fn with_entity(self, id: Entity) -> WithEntity<Marker, Self>
where Self: Sized { ... }
}
Expand description
A Command
which gets executed for a given Entity
.
§Examples
use bevy_ecs::system::EntityCommand;
#[derive(Resource, Default)]
struct Counter(i64);
/// A `Command` which names an entity based on a global counter.
fn count_name(entity: Entity, world: &mut World) {
// Get the current value of the counter, and increment it for next time.
let mut counter = world.resource_mut::<Counter>();
let i = counter.0;
counter.0 += 1;
// Name the entity after the value of the counter.
world.entity_mut(entity).insert(Name::new(format!("Entity #{i}")));
}
// App creation boilerplate omitted...
fn setup(mut commands: Commands) {
commands.spawn_empty().add(count_name);
commands.spawn_empty().add(count_name);
}
fn assert_names(named: Query<&Name>) {
// We use a HashSet because we do not care about the order.
let names: HashSet<_> = named.iter().map(Name::as_str).collect();
assert_eq!(names, HashSet::from_iter(["Entity #0", "Entity #1"]));
}
Required Methods§
Provided Methods§
sourcefn with_entity(self, id: Entity) -> WithEntity<Marker, Self>where
Self: Sized,
fn with_entity(self, id: Entity) -> WithEntity<Marker, Self>where
Self: Sized,
Returns a Command
which executes this EntityCommand
for the given Entity
.