pub trait ExtractComponent<L, F = ()>: SyncComponent<L, F>where
L: AppLabel,{
type QueryData: ReadOnlyQueryData;
type QueryFilter: QueryFilter;
type Out: Bundle
where <Self::Out as DynamicBundle>::Effect: NoBundleEffect;
// Required method
fn extract_component(
item: <Self::QueryData as QueryData>::Item<'_, '_>,
) -> Option<Self::Out>;
}Expand description
Describes how a component gets extracted from the main app to a sub app.
Therefore the component is transferred from the “app world” into the “sub
world” in the ExtractSchedule step. This functionality is enabled by
adding ExtractComponentPlugin with the component type.
The Out type is defined in SyncComponent.
The marker type F is only used as a way to bypass the orphan rules. To
implement the trait for a foreign type you can use a local type as the
marker, e.g. the type of the plugin that calls ExtractComponentPlugin.
Required Associated Types§
Sourcetype QueryData: ReadOnlyQueryData
type QueryData: ReadOnlyQueryData
ECS ReadOnlyQueryData to fetch the components to extract.
Sourcetype QueryFilter: QueryFilter
type QueryFilter: QueryFilter
Filters the entities with additional constraints.
Sourcetype Out: Bundle
where
<Self::Out as DynamicBundle>::Effect: NoBundleEffect
type Out: Bundle where <Self::Out as DynamicBundle>::Effect: NoBundleEffect
The output from extraction, i.e. ExtractComponent::extract_component.
The output components won’t be removed automatically from the sub world if the implementing component is removed,
unless you set them in the SyncComponent::Target.
Required Methods§
Sourcefn extract_component(
item: <Self::QueryData as QueryData>::Item<'_, '_>,
) -> Option<Self::Out>
fn extract_component( item: <Self::QueryData as QueryData>::Item<'_, '_>, ) -> Option<Self::Out>
Defines how the component is transferred into the “sub world”.
Returning None based on the queried item will remove the SyncComponent::Target from the entity in
the sub world.
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.