Method constructor

packages/service-worker/worker/src/driver.ts:161–225

(
    private scope: ServiceWorkerGlobalScope,
    private adapter: Adapter,
    private db: Database,
  )

  private controlTable: Promise<Table>;

  constructor(
    private scope: ServiceWorkerGlobalScope,
    private adapter: Adapter,
    private db: Database,
  ) {
    this.controlTable = this.db.open('control');
    this.ngswStatePath = this.adapter.parseUrl('ngsw/state', this.scope.registration.scope).path;

    // Set up all the event handlers that the SW needs.

    // The install event is triggered when the service worker is first installed.
    this.scope.addEventListener('install', (event) => {
      // SW code updates are separate from application updates, so code updates are
      // almost as straightforward as restarting the SW. Because of this, it's always
      // safe to skip waiting until application tabs are closed, and activate the new
      // SW version immediately.
      event!.waitUntil(this.scope.skipWaiting());
    });

    // The activate event is triggered when this version of the service worker is
    // first activated.
    this.scope.addEventListener('activate', (event) => {
      event!.waitUntil(
        (async () => {
          // As above, it's safe to take over from existing clients immediately, since the new SW
          // version will continue to serve the old application.
          await this.scope.clients.claim();
        })(),
      );

      // Rather than wait for the first fetch event, which may not arrive until
      // the next time the application is loaded, the SW takes advantage of the
      // activation event to schedule initialization. However, if this were run
      // in the context of the 'activate' event, waitUntil() here would cause fetch
      // events to block until initialization completed. Thus, the SW does a
      // postMessage() to itself, to schedule a new event loop iteration with an
      // entirely separate event context. The SW will be kept alive by waitUntil()
      // within that separate context while initialization proceeds, while at the
      // same time the activation event is allowed to resolve and traffic starts
      // being served.
      if (this.scope.registration.active !== null) {
        this.scope.registration.active.postMessage({action: 'INITIALIZE'});
      }
    });

    // Handle the fetch, message, push, notificationclick,
    // notificationclose, pushsubscriptionchange, messageerror, rejectionhandled,
    // and unhandledrejection events.
    this.scope.addEventListener('fetch', (event) => this.onFetch(event!));
    this.scope.addEventListener('message', (event) => this.onMessage(event!));
    this.scope.addEventListener('push', (event) => this.onPush(event!));
    this.scope.addEventListener('notificationclick', (event) => this.onClick(event));
    this.scope.addEventListener('notificationclose', (event) => this.onClose(event));
    this.scope.addEventListener('pushsubscriptionchange', (event) =>
      this.onPushSubscriptionChange(event),
    );
    this.scope.addEventListener('messageerror', (event) => this.onMessageError(event));
    this.scope.addEventListener('unhandledrejection', (event) => this.onUnhandledRejection(event));