How to get route params in navbar in React 18, React-Router 6

Question

I have a React frontend. The code follows below. My problem is that I need to get route information outside <Routes>, in navigation menu and I can't use useParams(). On the other hand, I tried to move <Routes> outside <NavMenu> but I get an error:

Error: [default] is not a <Route> component. All component children of <Routes> must be a <Route> or <React.Fragment>

Before React 18 I could use this.props.location.pathname.split... but even that was a workaround. Also withRouter is not available anymore in react-router-dom@6.

The code, much simplified:

index.tsx

ReactDOM.createRoot(document.getElementById('react-hook'))
    .render(
        <Provider store={store}>
            <BrowserRouter>
                <App />
            </BrowserRouter>
        </Provider>
    );

app.tsx

export default () => (
    <Layout>
        <Routes>
            <Route path='/:auxParam/site/foo/:startIndex?' Component={Extra} />
        </Routes>
    </Layout>
);

layout.tsx

export default (props: { children?: React.ReactNode }) => (
    <React.Fragment>
        <NavMenu />
        <Container tag="main">
            {props.children}
        </Container>
    </React.Fragment>
);

navmenu.tsx

class NavMenu extends React.PureComponent<NavMenuProps, { isOpen: boolean }> {
  public render() {
    const auxParam: string = ...?...; // how to get it?
    return (
      <header>
        <Navbar>
          <Container>
            <NavbarBrand tag={Link} to="/">My site (React)</NavbarBrand>
            <ul>
              <NavItem>
                <NavLink tag={Link} to={`/${aux}/site/foo`}>Extra</NavLink>
              </NavItem>
            </ul>
          </Container>
        </Navbar>
      </header>
    );
  }
}
export default NavMenu;

Answer 1

Update Layout to be a layout route component, e.g. it renders an Outlet component instead of the children prop.

Example:

Layout.tsx

import { Outlet } from 'react-router-dom';

export default () => (
  <React.Fragment>
    <NavMenu />
    <Container tag="main">
      <Outlet />
    </Container>
  </React.Fragment>
);

App.tsx

Render Extra on the element prop. The Component prop is only useful in Data routers.

export default () => (
  <Routes>
    <Route element={<Layout />}>
      <Route path='/:auxParam/site/foo/:startIndex?' element={<Extra />} />
    </Route>
  </Routes>
);

NavMenu.tsx

Convert this component to a React function component so that it can use the useParams hook.

import { Link, useParams } from 'react-router-dom';
...

const NavMenu () => {
  const { auxParam } = useParams();

  return (
    <header>
      <Navbar>
        <Container>
          <NavbarBrand tag={Link} to="/">My site (React)</NavbarBrand>
          <ul>
            <NavItem>
              <NavLink tag={Link} to={`/${aux}/site/foo`}>
                Extra
              </NavLink>
            </NavItem>
          </ul>
        </Container>
      </Navbar>
    </header>
  );
}

export default NavMenu;