stevenpersia / wouter

⛸ A minimalistic ~1KB routing for React. Nothing else but HOOKS.

wouter

A tiny routing solution for modern React apps that relies on Hooks. A router you wanted so bad in your project!

• Zero dependency, only 1.11KB gzipped vs 17KB React Router.
• Supports both React and Preact! Read "Preact support" section for more details.
• No top-level <Router /> component, it is fully optional.
• Mimics React Router's best practices, however the library isn't a drop-in replacement.
• Only History API is supported out of the box, while customization is available via the <Router /> component.

How to get started?

Check out this demo app below in order to get started:

import { Link, Route } from "wouter";

const App = () => (
  <div>
    <Link href="/users/1">
      <a className="link">Profile</a>
    </Link>

    <Route path="/about">About Us</Route>
    <Route path="/users/:name">
      {params => <div>Hello, {params.name}!</div>}
    </Route>
    <Route path="/inbox" component={InboxPage} />
  </div>
);

This library comes untranspiled, please read this!

TL;DR Want to support IE11 → make sure you transpile node_modules.

The library is written in pure ES6 and doesn't come with transpiled sources. There is a big debate going on it the community on whether or not libraries should ship untranspiled code. Wouter was designed to be as small as possible and the decision to ship raw ES6 was made intentionally. We only use basic things like arrow functions and destructive assignment, so it should work fine in the majority of the browsers. If you'd like to aim platforms like IE11, please make sure you run Babel over your node_modules.

Wouter API

The power of HOOKS!

wouter relies heavily on React Hooks. Thus, it makes creating custom interactions such as route transitions or accessing router directly easier. You can check if a particular route matches the current location by using a useRoute hook:

import { useRoute } from "wouter";
import { Transition } from "react-transition-group";

const AnimatedRoute = () => {
  // `match` is boolean
  const [match, params] = useRoute("/users/:id");

  return <Transition in={match}>This is user ID: {params.id}</Transition>;
};

useLocation hook: working with the history

The low-level navigation in wouter is powered by the useLocation hook, which is basically a wrapper around the native browser location object. The hook rerenders when the location changes and you can also perform a navigation with it, this is very similar to how you work with values returned from the useState hook:

import { useLocation } from "wouter";

const CurrentLocation = () => {
  const [location, setLocation] = useLocation();

  return (
    <div>
      {`The current page is: ${location}`}
      <a onClick={() => setLocation("/somewhere")}>Click to update</a>
    </div>
  );
};

All the components including the useRoute rely on useLocation hook, so normally you only need the hook to perform the navigation using a second value setLocation. You can check out the source code of the Redirect component as a reference.

By default, wouter uses useLocation hook that reacts to pushState and replaceState navigation and observes the current pathname including the leading slash e.g. /users/12. If you do need a custom history observer, for example, for hash-based routing, you can implement your own hook and customize it in a <Router /> component:

import { useState, useEffect } from "react";
import { Router, Route } from "wouter";

const useCustomLocation = () => {
  const [location, update] = useState();

  // custom location logic
};

const App = () => (
  <Router hook={useCustomLocation}>
    <Route path="/about" component={About} />
    ...
  </Router>
);

Matching Dynamic Segments

Just like in React Router, you can make dynamic matches either with Route component or useRoute hook. useRoute returns a second parameter which is a hash of all dynamic segments matched. Similarily, the Route component passes these parameters down to its children via a function prop.

import { useRoute } from "wouter";

// /users/alex => [true, { name: "alex "}]
// /anything   => [false, null]
const [match, params] = useRoute("/users/:name");

// or with Route component
<Route path="/users/:name">
  {params => {
    /* { name: "alex" } */
  }}
</Route>;

wouter implements a limited subset of path-to-regexp package used by React Router or Express, and it supports the following patterns:

• Named dynamic segments: /users/:foo.
• Dynamic segments with modifiers: /foo/:bar*, /foo/baz? or /foo/bar+.

The library was designed to be as small as possible, so most of the additional matching features were left out (see this issue for more info). If you do need to have path-to-regexp-like functionality, you can customize a matcher function:

import { Router } from "wouter";
import createMatcher from "wouter/matcher";

import pathToRegexp from "path-to-regexp";

const App = () => (
  <Router matcher={createMatcher(pathToRegexp)}>
    {/* segment constraints aren't supported by wouter */}
    <Route path="/users/:id(\d+)" />}
  </Router>
);

FAQ and Code Recipes

How do I make a default/fallback route?

One of the common patterns in application routing is having a default route that will be shown as a fallback, in case no other route matches (for example, if you need to render 404 message). In wouter this can easily be done as a combination of <Switch /> component and catch-all route:

import { Switch, Route } from "wouter";

<Switch>
  <Route path="/about">...</Route>
  <Route path="/:rest*">404, not found!</Route>
</Switch>;

▶ Demo Sandbox

How do I make a link active for the current route?

There are cases when you need to highlight an active link, for example, in the navigation bar. While this functionality isn't provided out-of-the-box, you can easily write your own <Link /> wrapper and detect if the path is active by using the useRoute hook. The useRoute(pattern) hook returns a pair of [match, params], where match is a boolean value that tells if the pattern matches current location:

const [isActive] = useRoute(props.href);

return (
  <Link {...props}>
    <a className={isActive ? "active" : ""}>{props.children}</a>
  </Link>
);

▶ Demo Sandbox

Can I use wouter in my TypeScript project?

Yes! Although the project isn't written in TypeScript, there is a type definition package available through DefinitelyTyped. Simply add npm install --save-dev @types/wouter to your project and develop safely with types.

Preact support?

The Preact exports are available within the wouter/preact namespace:

- import { useRoute, Route, Switch } from "wouter";
+ import { useRoute, Route, Switch } from "wouter/preact";

You might need to ensure you have the latest version of Preact X with support for hooks.

Is there any support for server-side rendering (SSR)?

Yes! In order to render your app on a server, you'll need to tell the router that the current location comes from the request rather than the browser history. In wouter, you can achieve that by replacing the default useLocation hook with a static one:

import { renderToString } from "react-dom/server";
import { Router, Route } from "wouter";

// note: static location has a different import path,
// this helps to keep the wouter source as small as possible
import staticLocationHook from "wouter/static-location";

import App from "./app";

const handleRequest = (req, res) => {
  // The staticLocationHook function creates a hook that always
  // responds with a path provided
  const prerendered = renderToString(
    <Router hook={staticLocationHook(req.path)}>
      <App />
    </Router>
  );

  // respond with prerendered html
};

Make sure you replace the static hook with the real one when you hydrate your app on a client.

1KB is too much, I can't afford it!

We've got some great news for you! If you're a minimalist bundle-size nomad and you need a damn simple routing in your app, you can just use the useLocation hook which is only 241 bytes gzipped and manually match the current location with it:

import useLocation from "wouter/use-location";

const UsersRoute = () => {
  const [location] = useLocation();

  if (location !== "/users") return null;

  // render the route
};

Wouter's motto is "Minimalist-friendly".

Acknowledgements

Special thanks to Katya Vakulenko for creating a project logo.