Vielzeug

Appearance

Page Titles from Meta ​

Problem ​

Setting document.title inside individual handlers is repetitive and misses back/forward navigation driven by the browser's own history buttons.

Solution ​

Store title hints in route meta and update document.title in a single subscribe() callback.

ts
import { createRouter } from '@vielzeug/wayfinder';

type Meta = { title?: string };

const router = createRouter({
  routes: {
    home: {
      path: '/',
      meta: { title: 'Home' } satisfies Meta,
    },
    users: {
      path: '/users',
      meta: { title: 'Users' } satisfies Meta,
    },
    userDetail: {
      path: '/users/:id',
      meta: { title: 'User Detail' } satisfies Meta,
      data: async ({ params }) => fetchUser(params.id),
    },
  },
  notFound: {
    meta: { title: 'Not Found' } satisfies Meta,
    component: NotFoundPage,
  },
});

// Wait for initial routing before reading the first snapshot, then update on later state changes.
const applyTitle = (state: ReturnType<typeof router.getSnapshot>) => {
  const m = state.matches.at(-1)?.meta as Meta | undefined;
  document.title = m?.title ? `${m.title} — My App` : 'My App';
};

await router.ready;
applyTitle(router.getSnapshot());
router.subscribe(applyTitle);

Pitfalls ​

  • router.subscribe() does not synchronously emit the current snapshot. Await router.ready, then apply the current snapshot before subscribing.
  • For nested routes, use all entries in state.matches (not just the leaf) to build breadcrumb-style titles from root to leaf.