bevy/release-content/migration-guides/static-bundle-split.md

title	pull_requests
`StaticBundle` has been split off from `Bundle`	19491

The StaticBundle trait has been split off from the Bundle trait to avoid conflating the concept of a type whose values can be inserted into an entity (Bundle) with the concept of a statically known set of components (StaticBundle). This required the update of existing APIs that were using Bundle as a statically known set of components to use StaticBundle instead.

Changes for most users will be zero or pretty minimal, since #[derive(Bundle)] will automatically derive StaticBundle and most types that implemented Bundle will now also implement StaticBundle. The main exception will be generic APIs or types, which now will need to update or add a bound on StaticBundle. For example:

// 0.16
#[derive(Bundle)]
struct MyBundleWrapper<T: Bundle> {
    inner: T
}

fn my_register_bundle<T: Bundle>(world: &mut World) {
    world.register_bundle::<T>();
}


// 0.17
#[derive(Bundle)]
struct MyBundleWrapper<T: Bundle + StaticBundle> { // Add a StaticBundle bound
    inner: T
}

fn my_register_bundle<T: StaticBundle>(world: &mut World) { // Replace Bundle with StaticBundle
    world.register_bundle::<T>();
}

The following APIs now require the StaticBundle trait instead of the Bundle trait:

• World::register_bundle, which has been renamed to World::register_static_bundle
• the B type parameter of EntityRefExcept and EntityMutExcept
• EntityClonerBuilder::allow and EntityClonerBuilder::deny
• EntityCommands::clone_components and EntityCommands::move_components
• EntityWorldMut::clone_components and EntityWorldMut::move_components
• the B type parameter of IntoObserverSystem, Trigger, App::add_observer, World::add_observer, Observer::new, Commands::add_observer, EntityCommands::observe and EntityWorldMut::observe
• EntityWorldMut::remove_recursive and Commands::remove_recursive
• EntityCommands::remove, EntityCommands::remove_if, EntityCommands::try_remove_if, EntityCommands::try_remove, EntityCommands::remove_with_requires, EntityWorldMut::remove and EntityWorldMut::remove_with_requires
• EntityWorldMut::take
• EntityWorldMut::retain and EntityCommands::retain

The following APIs now require the StaticBundle trait in addition to the Bundle trait:

• Commands::spawn_batch, Commands::insert_batch, Commands::insert_batch_if_new, Commands::try_insert_batch, Commands::try_insert_batch_if_new, bevy::ecs::command::spawn_batch, bevy::ecs::command::insert_batch, World::spawn_batch, World::insert_batch, World::insert_batch_if_new, World::try_insert_batch and World::try_insert_batch_if_new
• ReflectBundle::new, impl FromType<B> for ReflectBundle and #[reflect(Bundle)]
• ExtractComponent::Out

Moreover, some APIs have been renamed:

• World::register_bundle has been renamed to World::register_static_bundle
• the DynamicBundle trait has been renamed to ComponentsFromBundle