React Navigation

This guide covers how routing works in an app built with Ionic and React.

IonReactRouter uses the popular React Router library under the hood. With Ionic and React Router, you can create multi-page apps with rich page transitions.

Everything you know about routing using React Router carries over into Ionic React. Let's take a look at the basics of an Ionic React app and how routing works with it.

Routing in Ionic React

Here is a sample App component that defines a single route to the "/dashboard" URL. When you visit "/dashboard", the route renders the DashboardPage component.

App.tsx

const App: React.FC = () =>
  (
    <IonApp>
      <IonReactRouter>
        <IonRouterOutlet>
          <Route path="/dashboard" component={DashboardPage} />
          <Redirect exact from="/" to="/dashboard" />
        </IonRouterOutlet>
      </IonReactRouter>
    </IonApp>
  );

Directly after the Route, we define our default Redirect, which, when a user visits the root URL of the app ("/"), it redirects them to the "/dashboard" URL.

The redirect also has the exact prop set, which means the URL has to match the from prop (or the path prop if exact was used on a Route) precisely for this route to be a match. Without it, this redirect would render for every route, since every route begins with "/".

You can also programmatically redirect from a Route's render method based on a condition, like checking if a user is authed or not:

<Route
  exact
  path="/dashboard"
  render={props => {
    return isAuthed ? <DashboardPage {...props} /> : <LoginPage />;
  }}
/>

IonReactRouter

The IonReactRouter component wraps the traditional BrowserRouter component from React Router, and sets the app up for routing. Therefore, use IonReactRouter in place of BrowserRouter. You can pass in any props to IonReactRouter and they will be passed down to the underlying BrowserRouter.

Nested Routes

Inside the Dashboard page, we define more routes related to this specific section of the app:

DashboardPage.tsx

const DashboardPage: React.FC = () => {
  return (
    <IonRouterOutlet>
      <Route exact path="/dashboard" component={UsersListPage} />
      <Route path="/dashboard/users/:id" component={UserDetailPage} />
    </IonRouterOutlet>
  );
};

Here, there are a couple more routes defined to point to pages from within the dashboard portion of the app. Note, that we need to define the whole route in the path, and we can't leave off "/dashboard" even though we arrived to this page from that URL. React Router requires full paths, and relative paths are not supported.

However, we can use the match objects url property to provide the URL that was matched to render a component, which helps when working with nested routes:

const DashboardPage: React.FC<RouteComponentProps> = ({match}) => {
  return (
    <IonRouterOutlet>
      <Route exact path={match.url} component={UsersListPage} />
      <Route path={`${match.url}/users/:id`} component={UserDetailPage} />
    </IonRouterOutlet>
  );
};

Here, match.url contains the value of "/dashboard", since that was the URL used to render the DashboardPage.

These routes are grouped in an IonRouterOutlet, let's discuss that next.

IonRouterOutlet

The IonRouterOutlet component provides a container for Routes that render Ionic "pages". When a page is in an IonRouterOutlet, the container controls the transition animation between the pages as well as controls when a page is created and destroyed, which helps maintain the state between the views when switching back and forth between them.

The DashboardPage above shows a users list page and a details page. When navigating between the two pages, the IonRouterOutlet provides the appropriate platform page transition and keeps the state of the previous page intact so that when a user navigates back to the list page, it appears in the same state as when it left.

An IonRouterOutlet should only contain Routes or Redirects. Any other component should be rendered either as a result of a Route or outside of the IonRouterOutlet.

An IonRouterOutlet should also not be a descendant from another IonRouterOutlet.

Navigation

There are several options available when routing to different views in an Ionic React app. Here, the UsersListPage uses IonItem's href prop to specify the route to go to when the item is tapped/clicked:

UsersListPage.tsx

const UsersListPage: React.FC = () => {
  return (
    <IonPage>
      <IonHeader>
        <IonToolbar>
          <IonTitle>Users</IonTitle>
        </IonToolbar>
      </IonHeader>
      <IonContent>
        <IonList>
          <IonItem href="/dashboard/users/1">
            <IonLabel>User 1</IonLabel>
          </IonItem>
          <IonItem href="/dashboard/users/2">
            <IonLabel>User 2</IonLabel>
          </IonItem>
        </IonList>
      </IonContent>
    </IonPage>
  );
};

Outside of an IonItem, you can also use React Routers Link component to navigate between views:

<Link to="/dashboard/users/1">User 1</Link>

We recommend using one of the above methods whenever possible for routing. The advantage to these approaches is that they both render an anchor (<a>)tag, which is suitable for overall app accessibility.

A programmatic option for navigation is using the history prop that React Router provides to the components it renders via routes.

<IonButton
  onClick={e => {
    e.preventDefault();
    history.push('/dashboard/users/1');
  }}>
  Go to User 1
</IonButton>

Note: history is a prop.

URL Parameters

The second route defined in the Dashboard Page has a URL parameter defined (the ":id" portion in the path). URL parameters are dynamic portions of the path, and when the user navigates to a URL such as "/dashboard/users/1", the "1" is saved to a parameter named "id", which can be accessed in the component the route renders. Let's see how that's done.

UserDetailPage.tsx

interface UserDetailPageProps extends RouteComponentProps<{
  id: string;
}> {}

const UserDetailPage: React.FC<UserDetailPageProps> = ({match}) => {
  return (
    <IonPage>
      <IonHeader>
        <IonToolbar>
          <IonTitle>User Detail</IonTitle>
        </IonToolbar>
      </IonHeader>
      <IonContent>
        User {match.params.id}
      </IonContent>
    </IonPage>
  );
};

The match prop contains information about the matched route, including the URL params. We obtain the id param here and display it on the screen.

Note how we use a TypeScript interface to strongly type the props object. The interface gives us type safety and code completion inside of the component.

IonRouterOutlet in a Tabs View

When working in a tabs view, Ionic React needs a way to determine what views belong to which tabs. We accomplish this by taking advantage of the fact that the paths provided to a Route are regular expressions.

While the syntax looks a bit strange, it is reasonably straightforward once you understand it.

For example, the routes for a view with two tabs (sessions and speakers) can be set up as such:

<IonRouterOutlet>
  <Route path="/:tab(sessions)" component={SessionsPage} exact={true} />
  <Route path="/:tab(sessions)/:id" component={SessionDetail} />
  <Route path="/:tab(speakers)" component={SpeakerList} exact={true} />
</IonRouterOutlet>

If the navigated URL were "/sessions", it would match the first route and add a URL parameter named "tab" with the value of "sessions" to the resulting match object passed into SessionsPage.

When a user navigates to a session detail page ("/sessions/1" for instance), the second route adds a URL parameter named "tab" with a value of "sessions". When IonRouterOutlet sees that both pages are in the same "sessions" tab, it provides an animated page transition to the new view. If a user navigates to a new tab ("speakers" in this case), IonRouterOutlet knows not to provide the animation.

Switches in IonRouterOutlet

Since IonRouterOutlet takes over the job in determining which routes get rendered, using a Switch from React Router has no effect when used inside of an IonRouterOutlet. Switches still function as expected when used outside an IonRouterOutlet.

More Information

For more info on routing in React using React Router, check out their docs at https://reacttraining.com/react-router/web.

From the Community

Ionic 4 and React: Navigation - Paul Halliday