React Router Hooks - How To Use Them

#react #todayisearched #javascript

I know I'm a little behind the ball, but a few months ago React-Router released a new update that introduced hooks to their API.

This update now allows users access to the state of the router and the ability to perform navigation from inside components by using the useHistory, useParams, useLocation, and useRouteMatch hooks.

Today, I'll be giving you a brief overview of each of the hooks and how they've changed the way we write routes.

`useHistory`

The useHistory hook gives you access to the history object that you can use to navigate routes.

import { useHistory } from "react-router-dom"

const Homepage = () => {
  let history = useHistory()

  function goBack(){
    history.goBack()
  }

  function goHome(){
    history.push('/')
  } 

  return(
    <div>
      <button onClick={goBack}>Previous</button>
      <button onClick={goHome}>Home</button>
    </div>
 )
}

export default Homepage

The history object will give us access to the following properties and methods:

length - (number) The number of entries in the history stack
action - (string) The current action (PUSH, REPLACE, or POP)
location - (object) The current location. May have the following properties:
- pathname - (string) The path of the URL
- search - (string) The URL query string
- hash - (string) The URL hash fragment
- state - (object) location-specific state that was provided to e.g. push(path, state) when this location was pushed onto the stack. Only available in browser and memory history.
push(path, [state]) - (function) Pushes a new entry onto the history stack
replace(path, [state]) - (function) Replaces the current entry on the history stack
go(n) - (function) Moves the pointer in the history stack by n entries
goBack() - (function) Equivalent to go(-1)
goForward() - (function) Equivalent to go(1)
block(prompt) - (function) Prevents navigation

`useParams`

The useParams hook gives you access to the params of the given route. Params are just parameters on a given URL that is dynamically set.

Before the useParams hook was introduced by React-Router you had to access the params through props that were passed down to the component like so

import React from "react"
import ReactDOM from "react-dom"
import {
  BrowserRouter as Router,
  Switch,
  Route
} from "react-router-dom"

function Post(props) {
  let { id } = props.match.params
  return <div>Now showing post {id}</div>
}

function App(){
  return(
   <div className='app'>
    <Router>
      <Switch>
        <Route exact path="/" component={Homepage} />
        <Route 
          path="/blog/:id"
          render={routerProps => (
           <Post {...routerProps}/>
          )}
          />
      </Switch>
    </Router>
   </div>
 )
}

Now all you need to do is call the useParams hook to have access to the params.

import React from "react"
import ReactDOM from "react-dom"
import {
  BrowserRouter as Router,
  Switch,
  Route,
  useParams
} from "react-router-dom"

function Post(props) {
  let { id } = useParams()
  return <div>Now showing post {id}</div>
}

function App(){
  return(
   <div className='app'>
    <Router>
      <Switch>
        <Route exact path="/" />
          <Homepage />
        </Route>
        <Route path="/blog/:id">
          <Post />
        </Route>
      </Switch>
    </Router>
   </div>
 );
}

`useLocation`

Another hook that now ships with the React-Router update is the useLocation hook.

This hook will give you access to the location object that represents the current URL. The official documentation said that you can view the useLocation hook as useState that returns a new location every time the URL is updated.

import React from "react"
import ReactDOM from "react-dom"
import {
  BrowserRouter as Router,
  Switch,
  useLocation
} from "react-router-dom"

const LearnMore = () => {
  let location = useLocation()
  return(
    <div>
      You are currently at the following path {location.pathname}
    </div>
  )
 }

function App(){
 return(
  <div className='app'>
    <Router>
     <ul>
        <li>
            <Link to='/'>Home</Link>
        </li>
        <li>
            <Link to='/learn-more'>Learn More</Link>
        </li>
     </ul>
     <Switch>
       <Route exact path='/'>
          <HomePage />
       </Route>
       <Route path='/learn-more'>
          <LearnMore />
       </Route>
     </Switch>
    </Router>
  </div>
 )
}

`useRouteMatch`

Finally, the useRouteMatch hook will give you access to the match property without actually rendering a <Route> component.

Previously you had to use the render prop function to handle this like so

import { Route } from "react-router-dom"

function AnimalCard() {
  return (
    <Route
      path="/animal/:id"
      render={({ match }) => {
        // Do some stuff with your match...
        return <div />
      }}
    />
  );
}

Now you can just import the hook and render elements once the route matches

import { useRouteMatch } from "react-router-dom"

function AnimalCard() {
  let match = useRouteMatch("/animal/:id")

  // Do some stuff with your match...
  return <div />;
}