Method navChanged

core/src/components/router/router.tsx:187–218

(direction: RouterDirection)

  /** @internal */
  @Method()
  async navChanged(direction: RouterDirection): Promise<boolean> {
    if (this.busy) {
      printIonWarning('[ion-router] - Router is busy, navChanged was cancelled.');
      return false;
    }
    const { ids, outlet } = await readNavState(window.document.body);
    const routes = readRoutes(this.el);
    const chain = findChainForIDs(ids, routes);
    if (!chain) {
      printIonWarning(
        '[ion-router] - No matching URL for',
        ids.map((i) => i.id)
      );
      return false;
    }

    const segments = chainToSegments(chain);
    if (!segments) {
      printIonWarning('[ion-router] - Router could not match path because some required param is missing.');
      return false;
    }

    // navChanged is an outlet-driven URL sync. Only keep the fragment when
    // the path is unchanged; on a real navigation it refers to an anchor on
    // the page being left and would be stale.
    const newPath = generatePath(segments);
    const fragment = newPath === this.previousPath ? this.getFragment() : undefined;
    this.setSegments(segments, direction, undefined, fragment);

    await this.safeWriteNavState(outlet, chain, ROUTER_INTENT_NONE, segments, null, ids.length);
    return true;
  }

  /** This handler gets called when a `ion-route-redirect` component is added to the DOM or if the from or to property of such node changes. */
  private onRedirectChanged() {