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.
- Fork this gist
- On your own copy, go through the listed readings and answer associated questions
- Comment a link to your forked copy on the original gist
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:
-
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)
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What package do we need to install to use React Router?
We need to install
react-router-dom
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
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.
- What is a
<BrowserRouter />?
A
<BrowserRouter />is a router component which should wrap the root<App />element, and uses regular URL paths to identify which page view to render (requiring that the server be properly configured for these paths to work).
- Why would we use
<BrowserRouter />in our apps?
This is the router component which ultimately keeps the UI in sync with the current URL, and will enable our app to 'route' to the different page views depending on specified paths, creating the experience similar to a multipage application.
- What does the
<Route />component do?
The
<Route />components specify each path, wrapping all of the different components (passing in the relevant props, if a component may perhaps be re-used and rendered differently according to different paths) which may be rendered when directed to that given path.
- How does the
<Route />component check whether it should render something?
As each
<Route />specifies a path, the paths for each are checked in turn and the first which contains a path matching the current given will render all of the child components wrapped by that<Route />component.
- What does the
<Switch />component do?
The
<Switch />component wraps all of the<Route />components together and searches through those child elements to determine which components to render based on a given URL.
- How does it decide what to render?
the
<Switch />component is what looks for and directs to render the first child<Route />(or<Redirect />) component whose path matches the current given URL. Using an 'exact path' will require a complete rather than partial match for a<Route />to be rendered. Renders<Route />s exclusively instead of inclusively
- What does the
<Link />component do? How does a user interact with it?
A
<Link />component uses a friendlier syntax to create an html anchor tag under the hood, so a user may click on this link ('s innerText) to be directed to the path specified in the<Link />.
- What does the
<NavLink />component do? How does a user interact with it?
Similarly, a
<NavLink />is a special kind of<Link />component which automatically adds active styling properties (a className) when targeted by its prop (indicated path) exactly matching the current path.
- What does the
<Redirect />component do?
A
<Redirect />is rendered to force navigation to a new location (again specifying a path as a prop), which will override the current location in the history stack