doo1y / React-router-intro

Practice: React Router

You are going to practice using React Router v5. Although React Router v6 has been released, it is not yet in wide use, so knowing how to use v5 is still an important skill. Note that you will probably also want to get familiar with v6 at some point in your studies.

The ultimate goal of the React Router practices is to create a nav bar where you can choose Home, Stocks, and Movies components. You will be able to see the actual components and nested components based on the borders created in index.css. Ultimately, you will be able to navigate from one component to another by clicking on the links in the navbar. When you click on the Movies component you will see clickable movie titles. When you click on the titles you will then see the MovieDetails component showing the movie title, image and description.

For this first practice, you will learn how to setup a Router and create routes that will allow you to later navigate to different components.

Setup

Click the Download Project button at the bottom of this page to go to the starter repo, then load the repo into CodeSandbox.

Preparation

You should see a list of components for:

1. Home
2. Stocks
3. Movies

Note, in your package.json that you are using the react-router-dom version 5 package. This package gives you access to all of the components in React Router.

Take a look at the code that has already been created in the application. Notice the hierarchy of your components. Each component is represented by a folder that holds an index.js inside. This architecture enables you to import each component by using the relative path to the folder. (Create React App automatically looks for an index.js when a directory is specified as the import instead of a file.)

Router setup

You need to set up your Router to give you access to all of React Router's features. For this practice you will use BrowserRouter as your Router.

In src/index.js, import BrowserRouter from react-router-dom. Now wrap your entire application in this BrowserRouter component.

Instead of executing this inside the ReactDOM.render method, create a separate Root functional component that will return your BrowserRouter and nested App component:

const Root = () => {
  return (
    <BrowserRouter>
      <App />
    </BrowserRouter>
  );
};

Now replace the <App /> inside your ReactDOM call with the Root component.

You have now given router access to your entire application!

Route Matching

You now have the ability to create routes using the Route component. This component will mount your components when the correct path is chosen. The syntax for setting up a Route looks like this:

  <Route path='your chosen path'>
    <ComponentToRender />
  </Route>

Inside your App.js, import Route from the react-router-dom package.

Remove all of the components that are listed in the JSX. You will render these components using routes.

Next, inside the JSX below the h1 element, create a route for the Home component by using the Route component using the code snippet above as a guide. As you can see, the Route component takes an attribute called path. Using opening and closing Route tags, define your first Route component with a / for the path. Nest your Home component inside the opening and closing Route tags.

Now check your browser. You should only see the Home component being rendered at this point.

Next, do the same for the Stocks and Movies components, specifying paths of /stocks and /movies, respectively.

Take a look in your sandbox browser. In the address bar, append /stocks to the original URL and notice what you see. Now, replace /stocks with /movies. Notice that the Home component is always mounted? This is not the desired functionality.

To fix this, add the exact attribute inside the Route for the Home component. This will signify that the Home component should be rendered only when the exact path matches.

Now test again in the browser. Notice the difference?

Adding a Switch component

Below the other Route components, add another Route component with no path. Inside the opening and closing tags, add an <h1> tag with the text 'Page Not Found'.

Now test it in your sandbox browser by appending /movies or /stocks to the original URL.

Notice that 'Page Not Found' is always there no matter which component is being mounted? You cannot use exact in this instance because the Route has no path.

Instead, import the Switch component from react-router-dom. Now wrap all of your Route components with a single Switch component.

Test again in your sandbox browser. Notice that 'Page Not Found' does not show.

Now test the Page Not Found route. Try going to another route by appending /potato to the end of the original URL. Notice that the 'Page Not Found' text is now rendered.

What you have learned

Congratulations! In this practice you have learned how to

1. Use BrowserRouter to enable React Router in the entire application
2. Use the Route component to set up paths for components to be mounted
3. Nest components inside the Route component to be rendered based on the chosen path
4. Add the exact attribute to certain paths to enforce strict matching
5. Wrap the Route components in a Switch component so that React will stop at the first matching choice it finds