Redirect to login page in react router 4

I usually create a PrivateRoute component that checks if the user is logged in (via prop, redux, localstorage or something).

Something like:

const PrivateRoute = ({ isLoggedIn, ...props }) =>
  isLoggedIn
    ? <Route { ...props } />
    : <Redirect to="/login" />

In the router I then use it for my, well, private routes :)

<Switch>
  <PrivateRoute isLoggedIn={ this.state.loggedIn } path="/protected" component={Protected} />
  <Route path="/login" component={Login}/>
</Switch>