Fixing Nested Route Rendering Issues in React Router v6

A common challenge when working with React Router v6 is getting nested routes to render correctly. The v6 API introduced significant changes to how nested routes work compared to v5.

The Problem (Common Mistakes)

// ❌ Wrong approaches that break nested routing
<Route path="/users" element={<Users />}>
  {/* Children won't render properly */}
  <Route path="profile" element={<Profile />} />
</Route>

// ❌ Missing Outlet in parent
function Users() {
  return <div>User List</div>; // No place for children to render
}

// ❌ Absolute paths in nested routes
<Route path="/users" element={<Users />}>
  <Route path="/profile" element={<Profile />} /> {/* Won't match */}
</Route>

Correct Solutions

1. Basic Nested Routes

// ✅ Correct nested route configuration
<Routes>
  <Route path="/users" element={<Users />}>
    <Route path=":id" element={<UserProfile />} />
    <Route path="list" element={<UserList />} />
  </Route>
</Routes>

// Users component must render an Outlet
function Users() {
  return (
    <div>
      <h1>Users</h1>
      <Outlet /> {/* This renders the nested routes */}
    </div>
  );
}

2. Multiple Layout Levels

<Routes>
  <Route path="/admin" element={<AdminLayout />}>
    <Route index element={<AdminDashboard />} />
    <Route path="users" element={<UsersLayout />}>
      <Route index element={<UserList />} />
      <Route path=":id" element={<UserDetail />} />
    </Route>
  </Route>
</Routes>

// AdminLayout.jsx
function AdminLayout() {
  return (
    <div className="admin">
      <AdminSidebar />
      <main>
        <Outlet /> {/* Nested admin routes appear here */}
      </main>
    </div>
  );
}

// UsersLayout.jsx
function UsersLayout() {
  return (
    <div className="users">
      <UserManagementHeader />
      <Outlet /> {/* User-specific routes appear here */}
    </div>
  );
}

3. Index Routes

<Routes>
  <Route path="/blog" element={<BlogLayout />}>
    <Route index element={<BlogPosts />} /> {/* Renders at /blog */}
    <Route path=":slug" element={<BlogPost />} />
  </Route>
</Routes>

Key Concepts for Nested Routes

1. Outlet Component: Renders matched child routes
2. Relative Paths: Child paths are relative to parent
3. Index Routes: Default child for parent path
4. Layout Components: Should render an Outlet

Common Mistakes to Avoid

1. Forgetting the Outlet:

   function Parent() {
     return <div>No Outlet - children won't render</div>;
   }

2. Absolute paths in nested routes:

   <Route path="users">
     <Route path="/profile" /> {/* ❌ Should be "profile" */}
   </Route>

3. Mixing v5 and v6 patterns:

   <Route path="users" component={Users}> {/* ❌ v5 syntax */}
     <Route path=":id" element={<Profile />} />
   </Route>

4. Duplicate path segments:

   <Route path="users">
     <Route path="users/:id" /> {/* ❌ Results in /users/users/123 */}
   </Route>

Best Practices

1. Use relative paths for nested routes
2. Create layout components that render Outlet
3. TypeScript users – Add type safety:

   interface LayoutProps {
     children?: ReactNode; // For v5-like usage
   }

   function Layout({ children }: LayoutProps) {
     return (
       <div>
         <Header />
         {children || <Outlet />} {/* Support both patterns */}
       </div>
     );
   }

4. Test route matching with the useMatch hook:

   const match = useMatch('/parent/child');

Advanced Patterns

1. Pathless Layout Routes

<Routes>
  <Route element={<AuthLayout />}>
    <Route path="/login" element={<Login />} />
    <Route path="/register" element={<Register />} />
  </Route>
</Routes>

function AuthLayout() {
  return (
    <div className="auth-layout">
      <AuthHeader />
      <Outlet />
      <AuthFooter />
    </div>
  );
}

2. Dynamic Breadcrumbs

function useBreadcrumbs() {
  const matches = useMatches();
  return matches.map(match => ({
    path: match.pathname,
    title: match.handle?.title // From route definitions
  }));
}

function Breadcrumbs() {
  const crumbs = useBreadcrumbs();
  return (
    <nav>
      {crumbs.map(crumb => (
        <Link key={crumb.path} to={crumb.path}>{crumb.title}</Link>
      ))}
    </nav>
  );
}

3. Route-Based Analytics

function TrackPageViews() {
  const location = useLocation();

  useEffect(() => {
    analytics.trackView(location.pathname);
  }, [location]);

  return null;
}

// Usage in root route
<Route element={<TrackPageViews />}>
  {/* All other routes */}
</Route>

Remember: Nested routes in v6 are powerful but require:

1. Proper Outlet placement in parent components
2. Relative path definitions
3. Clear route hierarchy
4. Layout component organization

Always test your nested routes by:

• Verifying all levels render correctly
• Checking active link highlighting
• Testing navigation between routes
• Validating dynamic parameter matching