Name: Rendering a Sidebar or Breadcrumbs with React Router v4
Rating: 1.3 (3065 reviews)
Author: tylermcginnis

When building an app with React Router, often you'll want to implement a sidebar or breadcrumb navbar. In this post you'll learn how that's done with React Router by breaking down the Sidebar example from the React Router documentation.

A common UI pattern is to have a sidebar or breadcrumb navbar in your app. Because React Router allows you to render and match more than one Route per page, implementing this pattern is pretty straight forward. The goal of this post is to show how you can, by rendering multiple Routes, render separate components at separate parts of your page based on the path (like a sidebar).

The first thing we'll do, and really the secret to this post, is to create a routes array. Each item in the array is going to contain all the information about the specific route, and also which component should be rendered.

const routes = [
  { path: '/',
    exact: true,
    sidebar: () => <div>home!</div>,
    main: () => <h2>Home</h2>
  },
  { path: '/bubblegum',
    sidebar: () => <div>bubblegum!</div>,
    main: () => <h2>Bubblegum</h2>
  },
  { path: '/shoelaces',
    sidebar: () => <div>shoelaces!</div>,
    main: () => <h2>Shoelaces</h2>
  }
]

Now, because we've abstracted our routes to this array, whenever we want to render any Routes we can map over it and specify which component should be rendered (main or sidebar). To show how that's done, let's first build out the basic skeleton for our app.

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

const routes = [
  { path: '/',
    exact: true,
    sidebar: () => <div>home!</div>,
    main: () => <h2>Home</h2>
  },
  { path: '/bubblegum',
    sidebar: () => <div>bubblegum!</div>,
    main: () => <h2>Bubblegum</h2>
  },
  { path: '/shoelaces',
    sidebar: () => <div>shoelaces!</div>,
    main: () => <h2>Shoelaces</h2>
  }
]

class App extends React.Component {
  render() {
    return (
      <Router>
        <div style={{ display: 'flex' }}>
          <div style={{
            padding: '10px',
            width: '40%',
            background: '#f0f0f0'
          }}>
            <ul style={{ listStyleType: 'none', padding: 0 }}>
              <li><Link to="/">Home</Link></li>
              <li><Link to="/bubblegum">Bubblegum</Link></li>
              <li><Link to="/shoelaces">Shoelaces</Link></li>
            </ul>

          </div>
        </div>
      </Router>
    )
  }
}

export default App

Now remember the goal here is to render multiple components in different places of the app, based on the path. We already have our routes array, so wherever we want to render some Routes we can just map over it. First, let's add some Routes to the sidebar (inside of our nav).

render() {
  return (
    <Router>
      <div style={{ display: 'flex' }}>
        <div style={{
          padding: '10px',
          width: '40%',
          background: '#f0f0f0'
        }}>
          <ul style={{ listStyleType: 'none', padding: 0 }}>
            <li><Link to="/">Home</Link></li>
            <li><Link to="/bubblegum">Bubblegum</Link></li>
            <li><Link to="/shoelaces">Shoelaces</Link></li>
          </ul>
          {routes.map((route) => (
            <Route
              key={route.path}
              path={route.path}
              exact={route.exact}
              component={route.sidebar}
            />
          ))}
        </div>
      </div>
    </Router>
  )
}

The biggest thing to notice is that we've passed in route.sidebar to Routes component prop. This is the crux of the example and shows the importance of the routes array we created earlier. Now whenever the location matches the path, the sidebar component will be rendered. However, we don't just want to stop there. We also want to render a component in the main body of our app when the location matches the path. To do that, we'll map over routes again but instead of passing component route.sidebar, we'll pass it route.main.

render() {
  return (
    <Router>
      <div style={{ display: 'flex' }}>
        <div style={{
          padding: '10px',
          width: '40%',
          background: '#f0f0f0'
        }}>
          <ul style={{ listStyleType: 'none', padding: 0 }}>
            <li><Link to="/">Home</Link></li>
            <li><Link to="/bubblegum">Bubblegum</Link></li>
            <li><Link to="/shoelaces">Shoelaces</Link></li>
          </ul>
          {routes.map((route) => (
            <Route
              key={route.path}
              path={route.path}
              exact={route.exact}
              component={route.sidebar}
            />
          ))}
        </div>

        <div style={{ flex: 1, padding: '10px' }}>
          {routes.map((route) => (
            <Route
              key={route.path}
              path={route.path}
              exact={route.exact}
              component={route.main}
            />
          ))}
        </div>
      </div>
    </Router>
  )
}

🕺. Now, because React Router allows us to render and match more than one Route on a page, and because we abstracted our routes to an array, we can render different components at different sections of our page whenever the location matches the Routes path.

This was originally published at TylerMcGinnis.com and is part of their React Router course.