2006 React-Router-Prework.md

React Router Prework

This gist contains a short assignment I'd like everyone to complete before our formal lesson. The prework involves reading some of the React Router documentation, and will allow us to keep the lesson more hands on.

Instructions

1. Fork this gist
2. On your own copy, go through the listed readings and answer associated questions
3. Comment a link to your forked copy on the original gist

Questions / Readings

Router Overview

React Router is a library that allows us to make our single page React applications mimic the behavior of multipage apps. It provides the ability to use browser history, allowing users to navigate with forward / back buttons and bookmark links to specific views of the app. Most modern sites use some form of routing. React Router exposes this functionality through a series of components. Let's start by looking at the overall structure of an app using router:

1. Take a look at the quick start page of the React Router docs. Take note of the syntax and organization of the page. No worries if this looks unclear right now! (nothing to answer here)

2. What package do we need to install to use React Router?

npm install react-router-dom

Router Components

React Router provides a series of helpful components that allow our apps to use routing. These can be split into roughly 3 categories:

• Routers
• Route Matcher
• Route Changers

Routers

Any code that uses a React-Router-provided component must be wrapped in a router component. There are lots of router components we can use, but we'll focus on one in particular. Let's look into the docs to learn more.

3. What is a <BrowserRouter />?

   <BrowserRouter /> is a <Router> that uses the HTML5 history API (pushState, replaceState & the pop state event) to keep UI in sync with the URL

4. Why would we use <BrowserRouter /> in our apps?

   <BrowserRouter> allows us to build single page web applications with navigation without the page refreshing as the user navigates. By preventing a page refresh, the flash of a blank page is prevented. It also allows the user to utilize the back button & refresh the page while maintaining the correct application view.

Route Matchers

5. What does the <Route /> component do?

   The route component renders certain UI when its path matches the current URL.

6. How does the <Route /> component check whether it should render something?

The <Route /> component checks whether it should render something by checking if the <Route>’s path matches the URL & rendering its children. Basically, if the path matches then render the component & if the path doesn’t match, don’t render it.

7. What does the <Switch /> component do?

The <Switch> component will only render the first matched child, it will render only one component that matches the path & then will stop looking.

8. How does it decide what to render?

It will render exact matches & only the exact match.

Route Changers

9. What does the <Link /> component do? How does a user interact with it?

The <Link> component creates links in the application. Wherever it is used, an <a> will be rendered in the HTML document. <Link> will navigate a user, changing the URL without reloading the page. It connects the route path with the React component that should appear on the page.

10. What does the <NavLink /> component do? How does a user interact with it?

The <NavLink> component is similar to the <Link> component, but it allows you to add styling attributes to the rendered element when it matches the current URL.

11. What does the <Redirect /> component do?

The <Redirect> component navigates to a new location that overrides the current location in the history stack.