Switch.md

<Switch>

Renders the first child <Route> or <Redirect> that matches the location.

How is this different than just using a bunch of <Route>s?

<Switch> is unique in that it renders a route exclusively. In contrast, every <Route> that matches the location renders inclusively. Consider these routes:

import { Route } from "react-router";

let routes = (
  <div>
    <Route path="/about">
      <About />
    </Route>
    <Route path="/:user">
      <User />
    </Route>
    <Route>
      <NoMatch />
    </Route>
  </div>
);

If the URL is /about, then <About>, <User>, and <NoMatch> will all render because they all match the path. This is by design, allowing us to compose <Route>s into our apps in many ways, like sidebars and breadcrumbs, bootstrap tabs, etc.

Occasionally, however, we want to pick only one <Route> to render. If we're at /about we don't want to also match /:user (or show our "404" page). Here's how to do it with Switch:

import { Route, Switch } from "react-router";

let routes = (
  <Switch>
    <Route exact path="/">
      <Home />
    </Route>
    <Route path="/about">
      <About />
    </Route>
    <Route path="/:user">
      <User />
    </Route>
    <Route>
      <NoMatch />
    </Route>
  </Switch>
);

Now, if we're at /about, <Switch> will start looking for a matching <Route>. <Route path="/about"/> will match and <Switch> will stop looking for matches and render <About>. Similarly, if we're at /michael then <User> will render.

This is also useful for animated transitions since the matched <Route> is rendered in the same position as the previous one.

let routes = (
  <Fade>
    <Switch>
      {/* there will only ever be one child here */}
      <Route />
      <Route />
    </Switch>
  </Fade>
);

let routes = (
  <Fade>
    {/* there will always be two children here,
        one might render null though, making transitions
        a bit more cumbersome to work out */}
    <Route />
    <Route />
  </Fade>
);

location: object

A location object to be used for matching children elements instead of the current history location (usually the current browser URL).

children: node

All children of a <Switch> should be <Route> or <Redirect> elements. Only the first child to match the current location will be rendered.

<Route> elements are matched using their path prop and <Redirect> elements are matched using their from prop. A <Route> with no path prop or a <Redirect> with no from prop will always match the current location.

When you include a <Redirect> in a <Switch>, it can use any of the <Route>'s location matching props: path, exact, and strict. from is just an alias for the path prop.

If a location prop is given to the <Switch>, it will override the location prop on the matching child element.

import { Redirect, Route, Switch } from "react-router";

let routes = (
  <Switch>
    <Route exact path="/">
      <Home />
    </Route>

    <Route path="/users">
      <Users />
    </Route>
    <Redirect from="/accounts" to="/users" />

    <Route>
      <NoMatch />
    </Route>
  </Switch>
);