Function ngswAppInitializer

packages/service-worker/src/provider.ts:32–122

()

);

export function ngswAppInitializer(): void {
  if (typeof ngServerMode !== 'undefined' && ngServerMode) {
    return;
  }

  const options = inject(SwRegistrationOptions);

  if (!('serviceWorker' in navigator && options.enabled !== false)) {
    return;
  }

  const script = inject(SCRIPT);
  const ngZone = inject(NgZone);
  const appRef = inject(ApplicationRef);

  // Set up the `controllerchange` event listener outside of
  // the Angular zone to avoid unnecessary change detections,
  // as this event has no impact on view updates.
  ngZone.runOutsideAngular(() => {
    // Wait for service worker controller changes, and fire an INITIALIZE action when a new SW
    // becomes active. This allows the SW to initialize itself even if there is no application
    // traffic.
    const sw = navigator.serviceWorker;
    const onControllerChange = () => sw.controller?.postMessage({action: 'INITIALIZE'});

    sw.addEventListener('controllerchange', onControllerChange);

    appRef.onDestroy(() => {
      sw.removeEventListener('controllerchange', onControllerChange);
    });
  });

  // Run outside the Angular zone to avoid preventing the app from stabilizing (especially
  // given that some registration strategies wait for the app to stabilize).
  ngZone.runOutsideAngular(() => {
    let readyToRegister: Promise<void>;

    const {registrationStrategy} = options;
    if (typeof registrationStrategy === 'function') {
      readyToRegister = new Promise((resolve) => registrationStrategy().subscribe(() => resolve()));
    } else {
      const [strategy, ...args] = (registrationStrategy || 'registerWhenStable:30000').split(':');

      switch (strategy) {
        case 'registerImmediately':
          readyToRegister = Promise.resolve();
          break;
        case 'registerWithDelay':
          readyToRegister = delayWithTimeout(+args[0] || 0);
          break;
        case 'registerWhenStable':
          readyToRegister = Promise.race([appRef.whenStable(), delayWithTimeout(+args[0])]);
          break;
        default:
          // Unknown strategy.
          throw new RuntimeError(
            RuntimeErrorCode.UNKNOWN_REGISTRATION_STRATEGY,
            (typeof ngDevMode === 'undefined' || ngDevMode) &&