arcade2d
Class

AbstractWorldObjectComponent

world/abstract-world-object-component.ts:52

Extends AbstractComponent<WorldObject>

Implements WorldObjectComponent<TDeps>

Abstract base class for components attached to a WorldObject.

The recommended way to implement the WorldObjectComponent contract. Supplies the boilerplate every per-object system would otherwise write by hand:

  • The AbstractComponent.host reference, typed as WorldObject.
  • A AbstractWorldObjectComponent.world accessor that hops through the host to the parent World — the short-hand for the very common this.host.world.findOneByTag(...) / this.host.world.camera.shake(...) patterns.
  • A AbstractWorldObjectComponent.game accessor that hops one further through the world to the Game — the single-step way to reach page-scoped services like the keyboard or mouse samplers from inside per-object behaviour code.
  • No-op default implementations of the required lifecycle hooks (onAdded, onUpdate, onDestroy) so subclasses only override the ones they actually use.

Subclasses that take additional constructor arguments must define their own constructor and forward host via super(host).

Example

class WASDController extends AbstractWorldObjectComponent {
  public onUpdate(update: WorldUpdate): void {
    const keys = this.game.getKeyboardState();
    const speed = 0.2 * update.deltaMilliseconds;

    if (keys.isDown('KeyW')) this.host.position.y -= speed;
    if (keys.isDown('KeyS')) this.host.position.y += speed;
    if (keys.isDown('KeyA')) this.host.position.x -= speed;
    if (keys.isDown('KeyD')) this.host.position.x += speed;
  }
}

Constructors

#
constructor(host: WorldObject): AbstractWorldObjectComponent<TDeps>

Parameters

Properties

#
enabled: boolean

Per-component gate on the three update hooks (onPreUpdate, onUpdate, onPostUpdate). When explicitly false, the engine skips all three for this component during the host's tick — useful for temporarily pausing behaviour (e.g. a freeze powerup) without removing the component and losing its internal state.

Does not gate onAdded or onDestroy; those always fire so a host can never end up with a half-attached component.

readonly #
host: WorldObject

The host this component is attached to. Stored read-only; subclasses access it as this.host directly, or through the tier-appropriate aliases (this.world, this.game) on the per-tier abstract bases.

Accessors

readonly #
game: Game

The Game the host's world belongs to. Always non-null — the world's game field is a mandatory construction argument, not an option.

readonly #
world: World

The World the host WorldObject lives in. Shorthand for this.host.world.

Methods

#
onAdded(_deps: TDeps): void

Lifecycle hook that is called when the component is added to the host object. Should not be called directly.

Parameters

  • _deps TDeps

Returns

void
#
onDestroy(_deps: TDeps): void

Lifecycle hook that is called when the host object is destroyed. Should not be called directly.

Parameters

  • _deps TDeps

Returns

void
#
onUpdate(_update: WorldUpdate, _deps: TDeps): void

Lifecycle hook for the main update phase. Called once per world tick, after every component's onPreUpdate and before any onPostUpdate.

Parameters

Returns

void
ESC