Trait DelayedCommandsExt 

pub trait DelayedCommandsExt<'w> {
    // Required method
    fn delayed(&mut self) -> DelayedCommands<'w, '_>;
}

Extension trait for Commands that provides delayed command functionality.

Required Methods

fn delayed(&mut self) -> DelayedCommands<'w, '_>

Returns a DelayedCommands instance that can be used to queue commands to be submitted at a later point in time.

When dropped, the DelayedCommands submits spawn commands that will spawn DelayedCommandQueue entities. The entities are checked by the check_delayed_command_queues system, and their queues are submitted when the specified time has elapsed.

Usage

fn my_system(mut commands: Commands) {
    // Spawn an entity after one second
    commands.delayed().secs(1.0).spawn_empty();
}

Entity allocation happens immediately even if the spawn command is delayed. This allows you to queue delayed commands on an entity that hasn’t been spawned yet.

fn my_system(mut commands: Commands) {
    let mut delayed = commands.delayed();
    // spawn an entity after 1 second, then despawn it a second later
    let entity = delayed.secs(1.0).spawn_empty().id();
    delayed.secs(2.0).entity(entity).despawn();
}

Timing

Delayed commands are currently checked against the default clock in the PreUpdate schedule. There’s currently no way to specify different clocks for different delayed commands - this is a limitation of the system and if you need this behavior you’ll likely have to implement your own delay system.

Implementors

impl<'w, 's> DelayedCommandsExt<'w> for Commands<'w, 's>