react-router

What is react-router?

The react-router npm package is a declarative routing library for React, allowing you to add navigation functionality to your React applications. It enables you to handle URL routing, match routes to your React components, and manage navigation state in a single-page application (SPA) environment.

What are react-router's main functionalities?

Basic Routing

This code demonstrates how to set up basic routing in a React application using react-router. It includes navigation links and route components that render different components based on the URL path.

import { BrowserRouter as Router, Route, Link } from 'react-router-dom';

function App() {
  return (
    <Router>
      <div>
        <nav>
          <ul>
            <li>
              <Link to='/'>Home</Link>
            </li>
            <li>
              <Link to='/about'>About</Link>
            </li>
          </ul>
        </nav>

        <Route exact path='/' component={Home} />
        <Route path='/about' component={About} />
      </div>
    </Router>
  );
}

function Home() {
  return <h2>Home</h2>;
}

function About() {
  return <h2>About</h2>;
}

Dynamic Routing

This code snippet shows how to implement dynamic routing with path parameters. The User component will render with the appropriate user ID based on the URL.

import { BrowserRouter as Router, Route, Link } from 'react-router-dom';

function App() {
  return (
    <Router>
      <div>
        <ul>
          <li>
            <Link to='/users/1'>User 1</Link>
          </li>
          <li>
            <Link to='/users/2'>User 2</Link>
          </li>
        </ul>

        <Route path='/users/:id' component={User} />
      </div>
    </Router>
  );
}

function User({ match }) {
  return <h2>User ID: {match.params.id}</h2>;
}

Nested Routing

Nested routing allows you to create routes within routes. This example shows a Layout component with a nested Dashboard route.

import { BrowserRouter as Router, Route, Link, Switch } from 'react-router-dom';

function App() {
  return (
    <Router>
      <Route path='/' component={Layout} />
    </Router>
  );
}

function Layout({ match }) {
  return (
    <div>
      <nav>
        <Link to={`${match.url}dashboard`}>Dashboard</Link>
      </nav>
      <Switch>
        <Route path={`${match.path}dashboard`} component={Dashboard} />
      </Switch>
    </div>
  );
}

function Dashboard() {
  return <h2>Dashboard</h2>;
}

Protected Routes

Protected routes are used to restrict access to certain parts of your application. This example shows a route that renders a component only if the user is authenticated, otherwise it redirects to a login page.

import { BrowserRouter as Router, Route, Redirect } from 'react-router-dom';

function App() {
  return (
    <Router>
      <Route path='/protected' render={() => (
        isAuthenticated() ? (
          <ProtectedComponent />
        ) : (
          <Redirect to='/login' />
        )
      )} />
    </Router>
  );
}

function isAuthenticated() {
  // Authentication logic here
  return true;
}

function ProtectedComponent() {
  return <h2>Protected</h2>;
}

Other packages similar to react-router

vue-router

Vue-router is the official router for Vue.js. It provides similar functionalities for Vue applications as react-router does for React applications, including nested routes, dynamic segments, and navigation guards. However, it is designed to work seamlessly with Vue's reactivity system.

reach-router

Reach Router is another routing library for React, which aims to be more accessible and simpler to use than react-router. It has a smaller API surface area and focuses on accessibility by managing focus after route transitions. However, as of my knowledge cutoff in 2023, Reach Router has been officially merged with React Router, and its features have been integrated into React Router v6.

README

React Router

A complete routing library for React.

Docs

• Guide: Overview
• API

Important Notes

SemVer

Before our 1.0 release, breaking API changes will cause a bump to 0.x. For example, 0.4.1 and 0.4.8 will have the same API, but 0.5.0 will have breaking changes.

Please refer to the upgrade guide and changelog when upgrading.

Installation

npm install react-router
# or
bower install react-router

This library is written with CommonJS modules. If you are using browserify, webpack, or similar, you can consume it like anything else installed from npm.

There is also a global build available on bower, find the library on window.ReactRouter.

The library is also available on the popular CDN cdnjs.

Features

• Nested views mapped to nested routes
• Modular construction of route hierarchy
• Sync and async transition hooks
• Transition abort / redirect / retry
• Dynamic segments
• Query parameters
• Links with automatic .active class when their route is active
• Multiple root routes
• Hash or HTML5 history (with fallback) URLs
• Declarative Redirect routes
• Declarative NotFound routes
• Browser scroll behavior with transitions

Check out the examples directory to see how simple previously complex UI and workflows are to create.

What's it look like?

var routes = (
  <Route handler={App} path="/">
    <DefaultRoute handler={Home} />
    <Route name="about" handler={About} />
    <Route name="users" handler={Users}>
      <Route name="recent-users" path="recent" handler={RecentUsers} />
      <Route name="user" path="/user/:userId" handler={User} />
      <NotFoundRoute handler={UserRouteNotFound}/>
    </Route>
    <NotFoundRoute handler={NotFound}/>
    <Redirect from="company" to="about" />
  </Route>
);

Router.run(routes, function (Handler) {
  React.render(<Handler/>, document.body);
});

// Or, if you'd like to use the HTML5 history API for cleaner URLs:

Router.run(routes, Router.HistoryLocation, function (Handler) {
  React.render(<Handler/>, document.body);
});

See more in the overview guide.

Benefits of this Approach

1. Incredible screen-creation productivity - There is only one use-case when a user visits a route: render something. Every user interface has layers (or nesting) whether it's a simple navbar or multiple levels of master-detail. Coupling nested routes to these nested views gets rid of a ton of work for the developer to wire all of it together when the user switches routes. Adding new screens could not get faster.

2. Immediate understanding of application structure - When routes are declared in one place, developers can easily construct a mental image of the application. It's essentially a sitemap. There's not a better way to get so much information about your app this quickly.

3. Code tractability - When a developer gets a ticket to fix a bug at as specific url they simply 1) look at the route config, then 2) go find the handler for that route. Every entry point into your application is represented by these routes.

4. URLs are your first thought, not an after-thought - With React Router, you don't get UI on the page without configuring a url first. Fortunately, it's wildly productive this way, too.

Related Modules

• rnr-constrained-route - validate paths and parameters on route handlers.
• react-router-bootstrap - Integration with react-bootstrap components.
• react-router-proxy-loader - A Webpack loader to dynamically load react-router components on-demand

Contributing

Please see CONTRIBUTING

Thanks, Ember

This library is highly inspired by the Ember.js routing API. In general, it's a translation of the Ember router api to React. Huge thanks to the Ember team for solving the hardest part already.