Struct SubApp

pub struct SubApp {
    pub update_schedule: Option<Interned<dyn ScheduleLabel>>,
    /* private fields */
}

A secondary application with its own World. These can run independently of each other.

These are useful for situations where certain processes (e.g. a render thread) need to be kept separate from the main application.

Example

#[derive(Resource, Default)]
struct Val(pub i32);

#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, AppLabel)]
struct ExampleApp;

// Create an app with a certain resource.
let mut app = App::new();
app.insert_resource(Val(10));

// Create a sub-app with the same resource and a single schedule.
let mut sub_app = SubApp::new();
sub_app.insert_resource(Val(100));

// Setup an extract function to copy the resource's value in the main world.
sub_app.set_extract(|main_world, sub_world| {
    sub_world.resource_mut::<Val>().0 = main_world.resource::<Val>().0;
});

// Schedule a system that will verify extraction is working.
sub_app.add_systems(Main, |counter: Res<Val>| {
    // The value will be copied during extraction, so we should see 10 instead of 100.
    assert_eq!(counter.0, 10);
});

// Add the sub-app to the main app.
app.insert_sub_app(ExampleApp, sub_app);

// Update the application once (using the default runner).
app.run();

Fields

update_schedule: Option<Interned<dyn ScheduleLabel>>

The schedule that will be run by update.

Implementations

impl SubApp

pub fn new() -> SubApp

Returns a default, empty SubApp.

pub fn world(&self) -> &World

Returns a reference to the World.

pub fn world_mut(&mut self) -> &mut World

Returns a mutable reference to the World.

pub fn run_default_schedule(&mut self)

Runs the default schedule.

Does not clear internal trackers used for change detection.

pub fn update(&mut self)

Runs the default schedule and updates internal component trackers.

pub fn extract(&mut self, world: &mut World)

Extracts data from world into the app’s world using the registered extract method.

Note: There is no default extract method. Calling extract does nothing if set_extract has not been called.

pub fn set_extract<F>(&mut self, extract: F) -> &mut SubApp

where F: Fn(&mut World, &mut World) + Send + 'static,

Sets the method that will be called by extract.

The first argument is the World to extract data from, the second argument is the app World.

pub fn insert_resource<R>(&mut self, resource: R) -> &mut SubApp

where R: Resource,

See App::insert_resource.

pub fn init_resource<R>(&mut self) -> &mut SubApp

where R: Resource + FromWorld,

See App::init_resource.

pub fn add_systems<M>( &mut self, schedule: impl ScheduleLabel, systems: impl IntoSystemConfigs<M>, ) -> &mut SubApp

See App::add_systems.

pub fn register_system<I, O, M>( &mut self, system: impl IntoSystem<I, O, M> + 'static, ) -> SystemId<I, O>

where I: SystemInput + 'static, O: 'static,

See App::register_system.

pub fn configure_sets( &mut self, schedule: impl ScheduleLabel, sets: impl IntoSystemSetConfigs, ) -> &mut SubApp

See App::configure_sets.

pub fn add_schedule(&mut self, schedule: Schedule) -> &mut SubApp

See App::add_schedule.

pub fn init_schedule(&mut self, label: impl ScheduleLabel) -> &mut SubApp

See App::init_schedule.

pub fn get_schedule(&self, label: impl ScheduleLabel) -> Option<&Schedule>

See App::get_schedule.

pub fn get_schedule_mut( &mut self, label: impl ScheduleLabel, ) -> Option<&mut Schedule>

See App::get_schedule_mut.

pub fn edit_schedule( &mut self, label: impl ScheduleLabel, f: impl FnMut(&mut Schedule), ) -> &mut SubApp

See App::edit_schedule.

pub fn configure_schedules( &mut self, schedule_build_settings: ScheduleBuildSettings, ) -> &mut SubApp

See App::configure_schedules.

pub fn allow_ambiguous_component<T>(&mut self) -> &mut SubApp

where T: Component,

See App::allow_ambiguous_component.

pub fn allow_ambiguous_resource<T>(&mut self) -> &mut SubApp

where T: Resource,

See App::allow_ambiguous_resource.

pub fn ignore_ambiguity<M1, M2, S1, S2>( &mut self, schedule: impl ScheduleLabel, a: S1, b: S2, ) -> &mut SubApp

where S1: IntoSystemSet<M1>, S2: IntoSystemSet<M2>,

See App::ignore_ambiguity.

pub fn add_event<T>(&mut self) -> &mut SubApp

where T: Event,

See App::add_event.

pub fn add_plugins<M>(&mut self, plugins: impl Plugins<M>) -> &mut SubApp

See App::add_plugins.

pub fn is_plugin_added<T>(&self) -> bool

where T: Plugin,

See App::is_plugin_added.

pub fn get_added_plugins<T>(&self) -> Vec<&T>

where T: Plugin,

See App::get_added_plugins.

pub fn plugins_state(&mut self) -> PluginsState

Return the state of plugins.

pub fn finish(&mut self)

Runs Plugin::finish for each plugin.

pub fn cleanup(&mut self)

Runs Plugin::cleanup for each plugin.

pub fn register_type<T>(&mut self) -> &mut SubApp

where T: GetTypeRegistration,

See App::register_type.

pub fn register_type_data<T, D>(&mut self) -> &mut SubApp

where T: Reflect + TypePath, D: TypeData + FromType<T>,

See App::register_type_data.

Trait Implementations

impl Debug for SubApp

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for SubApp

fn default() -> SubApp

Returns the “default value” for a type.

impl RegisterDiagnostic for SubApp

fn register_diagnostic(&mut self, diagnostic: Diagnostic) -> &mut SubApp

Register a new Diagnostic with an App.