Function EventInterface

src/js/constructors/EventInterface/EventInterface.ts:34–79

( Splide?: Splide )

 * @return A collection of interface functions.
 */
export function EventInterface( Splide?: Splide ): EventInterfaceObject {
  /**
   * The document fragment for internal events.
   * Provide the Splide instance to share the bus.
   */
  const bus = Splide ? Splide.event.bus : document.createDocumentFragment();

  /**
   * An event binder object.
   */
  const binder = EventBinder();

  /**
   * Listens to an internal event or events.
   *
   * @param events   - An event name or names separated by spaces. Use a dot(.) to add a namespace.
   * @param callback - A callback function to register.
   */
  function on( events: string | string[], callback: AnyFunction ): void {
    binder.bind( bus, toArray( events ).join( ' ' ), e => {
      callback.apply( callback, isArray( e.detail ) ? e.detail : [] );
    } );
  }

  /**
   * Triggers callback functions.
   * This accepts additional arguments and passes them to callbacks.
   *
   * @param event - An event name.
   */
  function emit( event: string ): void {
    // eslint-disable-next-line prefer-rest-params, prefer-spread
    binder.dispatch( bus, event, slice( arguments, 1 ) );
  }

  if ( Splide ) {
    Splide.event.on( EVENT_DESTROY, binder.destroy );
  }

  return assign( binder, {
    bus,
    on,
    off: apply( binder.unbind, bus ),
    emit,
  } );
}