react-router: Setup Tutorial

Introduction

Developers cannot build more than one-page web application in React because React is a single-page application (SPA). Therefore, a web application that is built in React will not reload the page. How we can make more than one page then? react-router is the answer to this question. react-router gives us the flexibility to render components dynamically based on the route in the URL. These are the steps how you can set up your react-router in react application.

Installation

As usual, we need to install the package by running this command in the terminal.

npm install react-router-dom

// or

yarn add react-router-dom

Primary Components

According to react-router documentation, there are three main categories of components in react-router (routers, route matchers, and navigation).

• routers -> <BrowserRouter> and <HashRouter>
• route matchers -> <Route> and <Switch>
• navigation -> <Link>, <NavLink>, and <redirect>

Routers

The difference between <BrowserRouter> and <HashRouter> is the URL link. <HashRouter> could store a hash in the link http://example.com/#/your/page, and usually, we use it to refer to several sections in the page.

We must put a router in the top hierarchy component. I usually place the <BrowserRouter> in the index.js and wrap the <App/> component.

// ./src/index.js
// ...
import { BrowserRouter as Router } from 'react-router-dom';

ReactDOM.render(
  <React.StrictMode>
    <Router>
      <App />
    </Router>
  </React.StrictMode>,
  document.getElementById('root')
);

Route Matchers

The idea of route matchers is to declare the conditional rendering components corresponding with the URL. I might say <Route> is similar to "if statement", and <Switch> is similar to switch statement. Take a look at the snippets below.

Using Route

// ./src/App.js
// ...
import { Route } from 'react-router-dom';

function App() {
  return (
    <div className="App">
      <Nav /> {/* I will show this components in the next section */}
      <Route path="/about">
        <About />
      </Route>
      <Route path="/portfolio">
        <Portfolio />
      </Route>
      <Route path="/contact">
        <Contact />
      </Route>
      <Route path="/">
          <Home />
      </Route>
    </div>
  );
}

If we are not using <Switch>, it will render <About /> and <Home /> components at the same time when users go to the localhost:3000/about link. It renders two components at the same time because /about matches with "/about" and "/" paths.

We can solve more than one component at the same time by adding the exact attribute.

<Route exact path="/about">
  <About />
</Route>
<Route exact path="/portfolio">
  <Portfolio />
</Route>
<Route exact path="/contact">
  <Contact />
</Route>
<Route exact path="/">
  <Home />
</Route>

or we can use the <Switch> component like this snippet below.

Using Switch

// ./src/App.js
// ...
import { Switch, Route } from 'react-router-dom';

function App() {
  return (
    <div className="App">
      <Nav /> {/* I will show this components in the next section */}
      <Switch>
        <Route path="/about">
          <About />
        </Route>
        <Route path="/portfolio">
          <Portfolio />
        </Route>
        <Route path="/contact">
          <Contact />
        </Route>
        <Route path="/">
          <Home />
        </Route>
      </Switch>
    </div>
  );
}

a quick note about why I put path="/" in the last of Route. If I put path="/" in the beginning, other Route will not render at all. When users go to localhost:3000/about, it will match with '/' first, and others will be ignored.

Navigation

Navigation components allow the website to create a new link in the URL without reloading the page like using an anchor tag (<a>). Whenever we are using the anchor tag, the page will be reloaded, and we cannot do that in SPA.

// ./src/components/Navbar/Navbar.js
// ...
import { Link } from 'react-router-dom';

const Nav = () => {
  return (
    <nav className={styles.wrapper}>
      <Link to="/">Home</Link>
      <Link to="/about">About</Link>
      <Link to="/portfolio">Portfolio</Link>
      <Link to="/contact">Contact</Link>
    </nav>
  );
};

export default Nav;

NavLink

The main difference between <Navlink> and <Link> is styling purposes. If we want to give a style when the link is active we can use <NavLink> like the snippet below

<NavLink to="/contact" activeClassName="active">
  Contact
</NavLink>

It will be rendered to be HTML like this if the users visit /contact.

<a href="/contact" className="active">React</a>

Redirect

If this component renders, it will force to redirect to corresponding with the to prop.

<Redirect to="/login" />

Conclusion

These three primary categories of react-router components are the basis of how we can apply react-router to our project. If we understand these three kinds of categories, it will be easier to implement react-router. I will share another advanced topic about react-router in the next blog.