Where is the real implementation for commands.entity(id)?

[DasLixou]

Where is the real implementation for commands.entity(id)?

I can only find that it resolves in an EntityCommand that then adds the commands to the top command when i am understanding it right, but where is the actual logic for that? Im kinda new to rust and dont really understand this kind of project organization :D thanks :D

[bjorn3]

This is the full implementation of commands.entity(id):

bevy/crates/bevy_ecs/src/system/commands/mod.rs

Lines 249 to 254 in 7d9e864

	self.get_entity(entity).unwrap_or_else(|| {
	panic!(
	"Attempting to create an EntityCommands for entity {:?}, which doesn't exist.",
	entity
	)
	})

It calls get_entity which is defined at

bevy/crates/bevy_ecs/src/system/commands/mod.rs

Lines 283 to 285 in 7d9e864

	self.entities.contains(entity).then_some(EntityCommands {
	entity,
	commands: self,

EntityCommands has a bunch of methods which add a command to the commands on which .entity(id) was originally called and use the passed in entity. For example commands.entity(id).insert(my_component) is implemented at

bevy/crates/bevy_ecs/src/system/commands/mod.rs

Lines 567 to 571 in 7d9e864

	self.commands.add(Insert {
	entity: self.entity,
	component,
	});
	self

and pushes a Insert { entity: self.entity, component } to the commands queue. The actual implementation of Insert that inserts the component can be found at

bevy/crates/bevy_ecs/src/system/commands/mod.rs

Lines 792 to 803 in 7d9e864

	impl<T> Command for Insert<T>
	where
	T: Component,
	{
	fn write(self, world: &mut World) {
	if let Some(mut entity) = world.get_entity_mut(self.entity) {
	entity.insert(self.component);
	} else {
	panic!("error[B0003]: Could not add a component (of type `{}`) to entity {:?} because it doesn't exist in this World.", std::any::type_name::<T>(), self.entity);
	}
	}
	}

[DasLixou]

So i have to look at world.get_entity 😅