@dark-engine/web-router 🌖

The isomorphic Dark router designed for rendering universal web applications that work both on the client and on the server.

More about Dark

Features

🌳 Nested routes
🍩 Lazy loading
↪️ Redirects
🌠 Wildcards a.k.a Fallbacks
🔄 Combination wildcards and redirects
🔢 Parameters
📈 Hooks
💽 SSR
🔀 Concurrent transitions
✂️ No deps
📦 Small size (4 kB gzipped)

Installation

npm:

npm install @dark-engine/web-router

yarn:

yarn add @dark-engine/web-router

CDN:

<script src="https://unpkg.com/@dark-engine/web-router/dist/umd/dark-web-router.production.min.js"></script>

API

import {
  type Routes,
  type RouterRef,
  Router,
  Link,
  NavLink,
  useLocation,
  useHistory,
  useParams,
  useMatch,
  usePending,
  VERSION,
} from '@dark-engine/web-router';

Defining a basic route

const routes: Routes = [
  { path: 'first-component', component: FirstComponent },
  { path: 'second-component', component: SecondComponent },
];

const App = component(() => {
  return (
    <Router routes={routes}>
      {slot => {
        return (
          <>
            <header>
              <NavLink to='/first-component'>first-component</NavLink>
              <NavLink to='/second-component'>second-component</NavLink>
            </header>
            <main>{slot}</main> {/*<-- a route content will be placed here*/}
          </>
        );
      }}
    </Router>
  );
});

`<base href>`

You must add the element to the application's index.html for pushState routing to work.

<base href="/">

Also you must pass the baseUrl to Router if it is different from /.

<Router routes={routes} baseUrl={YOUR_BASE_URL}>{slot => slot}</Router>

Route order

The order of routes is important because the Router uses a first-match wins strategy when matching routes, so more specific routes should be placed above less specific routes. List routes with a static path first, followed by an empty path route, which matches the default route. The wildcard route comes last because it matches every URL and the Router selects it only if no other routes match first.

Getting route information

const FirstComponent = component(() => {
  const location = useLocation(); // url, protocol, host, pathname, search, key
  const match = useMatch(); // url prefix for links

  return <div>FirstComponent</div>;
});

Setting up wildcard routes

{ path: '**', component: ComponentName }

Displaying a 404 page

const routes: Routes = [
  { path: 'first-component', component: FirstComponent },
  { path: 'second-component', component: SecondComponent },
  { path: '**', component: PageNotFoundComponent },  // Wildcard route for a 404 page
];

Setting up redirects

const routes: Routes = [
  { path: 'first-component', component: FirstComponent },
  { path: 'second-component', component: SecondComponent },
  { path: '',   redirectTo: '/first-component', pathMatch: 'full' }, // redirect to `first-component`
  { path: '**', component: PageNotFoundComponent },  // Wildcard route for a 404 page
];

Nesting routes

const routes: Routes = [
  {
    path: 'first-component',
    component: FirstComponent, // The component receives children routes as slot
    children: [
      {
        path: 'child-a', 
        component: ChildAComponent,
      },
      {
        path: 'child-b',
        component: ChildBComponent,
      },
    ],
  },
];

Flat Nesting routes

const routes: Routes = [
  {
    path: 'first-component/child-a',
    component: ChildAComponent,
  },
   {
    path: 'first-component/child-b',
    component: ChildBComponent,
  },
  {
    path: 'first-component',
    component: FirstComponent, // In this case slot will be null
  },
];

Nested wildcards

const routes: Routes = [
 {
    path: 'first-component',
    component: FirstComponent,
    children: [
      {
        path: 'child-a', 
        component: ChildAComponent,
      },
      {
        path: 'child-b',
        component: ChildBComponent,
      },
      {
        path: '**',
        redirectTo: 'child-a',
      },
    ],
  },
];

const routes: Routes = [
 {
    path: 'first-component',
    component: FirstComponent,
    children: [
      {
        path: 'child-a', 
        component: ChildAComponent,
      },
      {
        path: 'child-b',
        component: ChildBComponent,
      },
      {
        path: '**',
        component: PageNotFoundComponent,
      },
    ],
  },
];

Navigation

via `Link` or `NavLink`

<Link to='/user/50'>Go to profile</Link>
<NavLink to='/home'>Home</NavLink>

NavLink internally uses Link, but at the same time provides a CSS class .active-link if the current URL is equal to or contains the to parameter of NavLink. NavLink can be used for headers and menus, which will continue to be on the page when it is clicked and the content is changed. Link means that it will disappear from the screen after you click it and go to another page. Of course you can create your own logic based on Link, using it as a base component.

via `history`

const SomeComponent = component(() => {
  const history = useHistory();

  useEffect(() => {
    history.push('/home'); // or history.replace('/home');
  }, []);

  return <div>SomeComponent</div>;
});

Parameters

Sometimes, a feature of your application requires accessing a part of a route, such as a parameter like id of something. You can define parameterized route like below.

const routes: Routes = [
  {
    path: 'first-component/:id',
    component: FirstComponent,
  },
  {
    path: 'second-component',
    component: SecondComponent,
  },
];

Then get access for parameter through hook

const FirstComponent = component(() => {
  const params = useParams();
  const id = Number(params.get('id'));

  return <div>FirstComponent: {id}</div>;
});

Lazy loading

You can configure your routes to lazy load modules, which means that Dark only loads modules as needed, rather than loading all modules when the application launches.

import { lazy } from '@dark-engine/core';

const Home = lazy(() => import('../components/home'));
const About = lazy(() => import('../components/about'));
const Contacts = lazy(() => import('../components/contacts'));

const routes: Routes = [
  {
    path: 'home',
    component: Home,
  },
  {
    path: 'about',
    component: About,
  },
  {
    path: 'contacts',
    component: Contacts,
  },
];

Imperative access to router

const App = component<AppProps>(({ url, routes }) => {
  const ref = useRef<RouterRef>(null);

  useEffect(() => {
    ref.current.navigateTo('/about');
  }, []);

  return (
    <Router ref={ref} routes={routes}>
      {slot => slot}
    </Router>
  );
});

Server-Side Rendering (SSR)

If you are rendering the application on the server, then you must pass the request URL to the router to emulate routing when rendering to a string.

server.get('*', async (req, res) => {
  const { url } = req;
  const app = await renderToString(Page({ title: 'My App', slot: App({ url }) }));
  const page = `<!DOCTYPE html>${app}`;

  res.statusCode = 200;
  res.send(page);
});

const App = component(({ url }) => {
  <Router routes={routes} url={url}>{slot => slot}</Router>
})

Full example SSR routing you can see in /examples.

Concurrent mode

In this mode, the router will automatically render through non-blocking transitions, using startTransition under the hood. To track the isPending flag and show the waiting UI you can use the special usePending hook.

<Router routes={routes} mode='concurrent'>
  {slot => slot}
</Router>

const Pending = component(() => {
  const isPending = usePending();

  // Makes the content on the screen a little transparent while the transition is in progress.
  return <Overlay isPending={isPending} />;
});