redux-little-router

redux-little-router is a tiny router for Redux applications that lets the URL do the talking.

The router follows three basic principles:

• The URL is just another member of the state tree.
• URL changes are just plain actions.
• Route matching should be simple and extendable.

While the core router does not depend on any view library, it provides flexible React bindings and components.

Why another router?

To understand why redux-little-router exists, check out our blog series, "Let the URL do the Talking":

Part 1 Part 2 Part 3

While React Router is a great, well-supported library, it hoards URL state within the view layer and makes certain Redux patterns difficult, if not impossible. This chart outlines a major issue in accessing URL state from outside of React Router.

react-router-redux is meant only to enable time-travel debugging in React Router and doesn't allow you to safely access URL state. redux-router, while allowing you to access URL state, is experimental, lags behind React Router releases, and recommends react-router-redux in its README.

redux-little-router makes URL state a first-class citizen of your Redux store and abstracts cross-browser navigation and routing into a pure Redux API.

Redux usage

To hook into Redux applications, redux-little-router uses a store enhancer that wraps the history module and adds current and previous router state to your store. The enhancer listens for location changes and dispatches rich actions containing the URL, parameters, and any custom data assigned to the route. redux-little-router also adds a middleware that intercepts navigation actions and calls their equivalent method in history.

Wiring up the boilerplate

The following is an example of a redux-little-router setup that works for browser-rendered applications. For a server rendering example, check out our advanced docs.

import { compose, createStore, applyMiddleware } from 'redux';
import { routerForBrowser } from 'redux-little-router';

import yourReducer from './your-app';

// Define your routes in a route-to-anything hash like below.
// The value of the route key can be any serializable data.
// This data gets attached to the `router` key of the state
// tree when its corresponding route is matched and dispatched.
// Useful for page titles and other route-specific data.

// Uses https://github.com/snd/url-pattern for URL matching
// and parameter extraction.
const routes = {
  '/messages': {
    title: 'Message'
  },
  '/messages/:user': {
    title: 'Message History'
  },
  // You can also define nested route objects!
  // Just make sure each route key starts with a slash.
  '/': {
    title: 'Home',
    '/bio': {
      title: 'Biographies',
      '/:name': {
        title: 'Biography for:'
      }
    }
  }
};

// Install the router into the store for a browser-only environment.
// routerForBrowser is a factory method that returns a store
// enhancer and a middleware.
const {
  routerEnhancer,
  routerMiddleware  
} = routerForBrowser({
  // The configured routes. Required.
  routes,
  // The basename for all routes. Optional.
  basename: '/example'
})

const clientOnlyStore = createStore(
  yourReducer,
  initialState,
  compose(
    routerEnhancer,
    applyMiddleware(routerMiddleware)
  )
);

Often, you'll want to update state or trigger side effects after loading the initial URL. To maintain compatibility with other store enhancers (particularly ones that handle side effects, like redux-loop or redux-saga), we require this optional initial dispatch to happen in userland code by doing the following:

import { initializeCurrentLocation } from 'redux-little-router';

// ...after creating your store
const initialLocation = store.getState().router;
if (initialLocation) {
  store.dispatch(initializeCurrentLocation(initialLocation));
}

Provided actions and state

On location changes, the store enhancer dispatches a LOCATION_CHANGED action that contains at least the following properties:

// For a URL matching /messages/:user
{
  pathname: '/messages/a-user-has-no-name',
  route: '/messages/:user',
  params: {
    user: 'a-user-has-no-name'
  },
  query: { // if your `history` instance uses `useQueries`
    some: 'thing'
  },
  result: {
    arbitrary: 'data that you defined in your routes object!'
    parent: { // for nested routes only
      // contains the result of the parent route,
      // which contains each other parent route's
      // result recursively
    }
  }
}

Your custom middleware can intercept this action to dispatch new actions in response to URL changes.

The reducer consumes this action and adds the following to the root of the state tree on the router property:

{
  pathname: '/messages/a-user-has-no-name',
  route: '/messages/:user',
  params: {
    user: 'a-user-has-no-name'
  },
  query: {
    some: 'thing'
  },
  result: {
    arbitrary: 'data that you defined in your routes object!',
    parent: { /* the parent route's result */ },
  },
  previous: {
    pathname: '/messages',
    route: '/messages',
    params: {},
    query: {},
    result: {
      more: 'arbitrary data that you defined in your routes object!'
      parent: { /* the parent route's result */ }
    }
  }
}

Your custom reducers or selectors can derive a large portion of your app's state from the URLs in the router property.

React bindings and usage

redux-little-router provides the following to make React integration easier:

• A <Fragment> component that conditionally renders children based on current route and/or location conditions.
• A <Link> component that sends navigation actions to the middleware when tapped or clicked. <Link> respects default modifier key and right-click behavior. A sibling component, <PersistentQueryLink>, persists the existing query string on navigation
• A provideRouter HOC that passes down everything <Fragment> and <Link> need via context.

redux-little-router assumes and requires that your root component is a direct or indirect child of <Provider> from react-redux. Both provideRouter and <RouterProvider> automatically connect() to updates from the router state.

You can inspect the router state in any child component by using connect():

export default connect(state => ({
  router: state.router
}))(YourComponent);

<Fragment>

Think of <Fragment> as the midpoint of a "flexibility continuum" that starts with raw switch statements and ends with React Router's <Route> component. Fragments can live anywhere within the React tree, making split-pane or nested UIs easy to work with.

The simplest fragment is one that displays when a route is active:

<Fragment forRoute='/home/messages/:team'>
  <p>This is the team messages page!</p>
</Fragment>

You can also match a fragment against anything in the current location object:

<Fragment withConditions={location => location.query.superuser}>
  <p>Superusers see this on all routes!</p>
</Fragment>

You can use withConditions in conjunction with forRoute to set strict conditions for when a <Fragment> should display.

Two types of fragments exist: <RelativeFragment> (new to 9.0.0) and <AbsoluteFragment>. You can use either by doing the following:

import { RelativeFragment as Fragment } from 'redux-little-router';
// or
import { AbsoluteFragment as Fragment } from 'redux-little-router';

<RelativeFragment> lets you nest fragments to match your UI hierarchy to your route hierarchy, much like the <Route> component does in react-router. Given a URL of /home/bio/dat-boi, and the following elements:

<RelativeFragment forRoute='/home'>
  <h1>Home</h1>
  <RelativeFragment forRoute='/bio'>
    <h2>Bios</h2>
    <RelativeFragment forRoute='/dat-boi'>
      <h3>Dat Boi</h3>
      <p>Something something whaddup</p>
    </RelativeFragment>
  </RelativeFragment>
</RelativeFragment>

...React will render:

<div>
  <h1>Home</h1>
    <div>
      <h2>Bios</h2>
        <div>
          <h3>Dat Boi</h3>
          <p>Something something whaddup<p>
        </div>
    </div>
</div>

<RelativeFragment> makes basic component-per-page navigation easy:

<Fragment forRoute='/'>
  <Fragment forRoute='/home'><Home /></Fragment>
  <Fragment forRoute='/about'><About /></Fragment>
  <Fragment forRoute='/messages'><Messages /></Fragment>
  <Fragment forRoute='/feed'><Feed /></Fragment>
</Fragment>

<AbsoluteFragment>s do not communicate with their parent or child routes like <RelativeFragment>s do. The route you pass to forRoute must match an exact route in your routes configuration, and are analogous to absolute URLs (they are not "relative" to the forRoutes of any other fragment in the hierarchy).

<AbsoluteFragment> accepts an additional forRoutes prop that allows the fragment to display on multiple routes:

<Fragment forRoutes={['/home/messages', '/home']}>
  <p>This displays in a couple of places!</p>
</Fragment>

When in doubt, use <RelativeFragment>. <AbsoluteFragment> may be deprecated in a future release.

<Link>

Using the <Link> component is simple:

<Link className='anything' href='/yo'>
  Share Order
</Link>

Alternatively, you can pass in a location descriptor to href. This is useful for passing query objects:

<Link className='anything' href={{
  pathname: '/home/messages/a-team?test=ing',
  query: {
    test: 'ing'
  }
}}>
  Share Order
</Link>

<Link> takes an optional valueless prop, replaceState, that changes the link navigation behavior from pushState to replaceState in the History API.

provideRouter or <RouterProvider>

Like React Router's <Router> component, you'll want to wrap provideRouter around your app's top-level component like so:

import React from 'react';
import ReactDOM from 'react-dom';
import { provideRouter } from 'redux-little-router';
import YourAppComponent from './';

import createYourStore from './state';

const AppComponentWithRouter = provideRouter({
  store: createYourStore()
})(YourAppComponent);

ReactDOM.render(<AppComponentWithRouter />, document.getElementById('root');

This allows <Fragment> and <Link> to obtain their history and dispatch instances without manual prop passing.

If you'd rather use a plain component instead of a higher-ordered component, use <RouterProvider> like so:

import React from 'react';
import ReactDOM from 'react-dom';
import { RouterProvider } from 'redux-little-router';
import YourAppComponent from './';

import createYourStore from './state';

ReactDOM.render(
  <RouterProvider store={createYourStore()}>
    <YourAppComponent />
  </RouterProvider>,
  document.getElementById('root')
);

Environment

redux-little-router requires an ES5 compatible environment (no IE8).

Stability

We consider redux-little-router to be stable. Any API changes will be incremental.

Versioning

redux-little-router follows strict semver. Don't be alarmed by the high version number! Major version bumps represent any breaking change, no matter how small, and do not represent a major shift in direction. We strive to make breaking changes small and compartmentalized.