What's Changed

Minor Changes

• React Router now supports an alternative way to define your route element and errorElement fields as React Components instead of React Elements. You can instead pass a React Component to the new Component and ErrorBoundary fields if you choose. There is no functional difference between the two, so use whichever approach you prefer 😀. You shouldn't be defining both, but if you do Component/ErrorBoundary will "win". (#10045)

  Example JSON Syntax

  // Both of these work the same:
  const elementRoutes = [{
    path: '/',
    element: <Home />,
    errorElement: <HomeError />,
  }]
  
  const componentRoutes = [{
    path: '/',
    Component: Home,
    ErrorBoundary: HomeError,
  }]
  
  function Home() { ... }
  function HomeError() { ... }

  Example JSX Syntax

  // Both of these work the same:
  const elementRoutes = createRoutesFromElements(
    <Route path='/' element={<Home />} errorElement={<HomeError /> } />
  );
  
  const componentRoutes = createRoutesFromElements(
    <Route path='/' Component={Home} ErrorBoundary={HomeError} />
  );
  
  function Home() { ... }
  function HomeError() { ... }

• Introducing Lazy Route Modules! (#10045)

  In order to keep your application bundles small and support code-splitting of your routes, we've introduced a new lazy() route property. This is an async function that resolves the non-route-matching portions of your route definition (loader, action, element/Component, errorElement/ErrorBoundary, shouldRevalidate, handle).

  Lazy routes are resolved on initial load and during the loading or submitting phase of a navigation or fetcher call. You cannot lazily define route-matching properties (path, index, children) since we only execute your lazy route functions after we've matched known routes.

  Your lazy functions will typically return the result of a dynamic import.

  // In this example, we assume most folks land on the homepage so we include that
  // in our critical-path bundle, but then we lazily load modules for /a and /b so
  // they don't load until the user navigates to those routes
  let routes = createRoutesFromElements(
    <Route path="/" element={<Layout />}>
      <Route index element={<Home />} />
      <Route path="a" lazy={() => import("./a")} />
      <Route path="b" lazy={() => import("./b")} />
    </Route>
  );

  Then in your lazy route modules, export the properties you want defined for the route:

  export async function loader({ request }) {
    let data = await fetchData(request);
    return json(data);
  }
  
  // Export a `Component` directly instead of needing to create a React Element from it
  export function Component() {
    let data = useLoaderData();
  
    return (
      <>
        <h1>You made it!</h1>
        <p>{data}</p>
      </>
    );
  }
  
  // Export an `ErrorBoundary` directly instead of needing to create a React Element from it
  export function ErrorBoundary() {
    let error = useRouteError();
    return isRouteErrorResponse(error) ? (
      <h1>
        {error.status} {error.statusText}
      </h1>
    ) : (
      <h1>{error.message || error}</h1>
    );
  }

  An example of this in action can be found in the examples/lazy-loading-router-provider directory of the repository. For more info, check out the lazy docs.

  🙌 Huge thanks to @rossipedia for the Initial Proposal and POC Implementation.

Patch Changes

• Improve memoization for context providers to avoid unnecessary re-renders (#9983)
• Fix generatePath incorrectly applying parameters in some cases (#10078)
• [react-router-dom-v5-compat] Add missed data router API re-exports (#10171)

Full Changelog: https://github.com/remix-run/react-router/compare/react-router@6.8.2...react-router@6.9.0