Method navigateToSyncWithBrowser

packages/router/src/router.ts:311–357

* Schedules a router navigation to synchronize Router state with the browser state. * * This is done as a response to a popstate event and the initial navigation. These * two scenarios represent times when the browser URL/state has been updated and * the Router needs to respond to ensure

(
    url: string,
    source: NavigationTrigger,
    state: RestoredState | null | undefined,
    extras: NavigationExtras,
    hasUAVisualTransition?: boolean,
  )

   * the Router needs to respond to ensure its internal state matches.
   */
  private navigateToSyncWithBrowser(
    url: string,
    source: NavigationTrigger,
    state: RestoredState | null | undefined,
    extras: NavigationExtras,
    hasUAVisualTransition?: boolean,
  ) {
    // TODO: restoredState should always include the entire state, regardless
    // of navigationId. This requires a breaking change to update the type on
    // NavigationStart’s restoredState, which currently requires navigationId
    // to always be present. The Router used to only restore history state if
    // a navigationId was present.

    // The stored navigationId is used by the RouterScroller to retrieve the scroll
    // position for the page.
    const restoredState = state?.navigationId ? state : null;

    // When `browserUrl` was used during the original navigation, the actual route URL
    // was stored in history state as `ɵrouterUrl`. Use it for route matching and
    // preserve the browser URL as the displayed URL.
    const routerUrl = state?.ɵrouterUrl ?? url;
    if (state?.ɵrouterUrl) {
      extras = {...extras, browserUrl: url};
    }

    // Separate to NavigationStart.restoredState, we must also restore the state to
    // history.state and generate a new navigationId, since it will be overwritten
    if (state) {
      const stateCopy = {...state} as Partial<RestoredState>;
      delete stateCopy.navigationId;
      delete stateCopy.ɵrouterPageId;
      delete stateCopy.ɵrouterUrl;
      if (Object.keys(stateCopy).length !== 0) {
        extras.state = stateCopy;
      }
    }

    const urlTree = this.parseUrl(routerUrl);
    this.scheduleNavigation(urlTree, source, restoredState, extras, hasUAVisualTransition).catch(
      (e) => {
        if (this.disposed) {
          return;
        }
        this.injector.get(ɵINTERNAL_APPLICATION_ERROR_HANDLER)(e);
      },
    );
  }

  /** The current URL. */
  get url(): string {