code: protected function injectComponents(
          array $pages,
          $routeMatch = null,
          $router = null,
          $request = null
      ) {
          if ($routeMatch) {
              /* @var RouteMatch|MvcRouter\RouteMatch $routeMatch */
              $routeName = $routeMatch->getMatchedRouteName();
  
              foreach ($pages as &$page) {
                  if (isset($page['active_on']) && in_array($routeName, (array) $page['active_on'])) {
                      $page['active'] = true;
                  }
              }
          }
  
          return parent::injectComponents($pages, $routeMatch, $router, $request);
      }
docs: Inject components into the pages.
  
  @internal
  Parses the pages options for the "active_on" property and
  sets the active flag if one of the routes match.
  
  {@inheritDoc}
  @since 0.30 add check, if $routeMatch is null