[react-router-v4] How to listen to route changes in react router v4?

I have a couple of buttons that acts as routes. Everytime the route is changed, I want to make sure the button that is active changes.

Is there a way to listen to route changes in react router v4?

In some cases you might use render attribute instead of component, in this way:

class App extends React.Component {

    constructor (props) {
        super(props);
    }

    onRouteChange (pageId) {
        console.log(pageId);
    }

    render () {
        return  <Switch>
                    <Route path="/" exact render={(props) => { 
                        this.onRouteChange('home');
                        return <HomePage {...props} />;
                    }} />
                    <Route path="/checkout" exact render={(props) => { 
                        this.onRouteChange('checkout');
                        return <CheckoutPage {...props} />;
                    }} />
                </Switch>
    }
}

Notice that if you change state in onRouteChange method, this could cause 'Maximum update depth exceeded' error.

withRouter, history.listen, and useEffect (React Hooks) works quite nicely together:

import React, { useEffect } from 'react'
import { withRouter } from 'react-router-dom'

const Component = ({ history }) => {
    useEffect(() => history.listen(() => {
        // do something on route change
        // for my example, close a drawer
    }), [])

    //...
}

export default withRouter(Component)

The listener callback will fire any time a route is changed, and the return for history.listen is a shutdown handler that plays nicely with useEffect.

For functional components try useEffect with props.location.

import React, {useEffect} from 'react';

const SampleComponent = (props) => {

      useEffect(() => {
        console.log(props.location);
      }, [props.location]);

}

export default SampleComponent;

I just dealt with this problem, so I'll add my solution as a supplement on other answers given.

The problem here is that useEffect doesn't really work as you would want it to, since the call only gets triggered after the first render so there is an unwanted delay.
If you use some state manager like redux, chances are that you will get a flicker on the screen because of lingering state in the store.

What you really want is to use useLayoutEffect since this gets triggered immediately.

So I wrote a small utility function that I put in the same directory as my router:

export const callApis = (fn, path) => {
    useLayoutEffect(() => {
      fn();
    }, [path]);
};

Which I call from within the component HOC like this:

callApis(() => getTopicById({topicId}), path);

path is the prop that gets passed in the match object when using withRouter.

I'm not really in favour of listening / unlistening manually on history. That's just imo.

import React, { useEffect } from 'react';
import { useLocation } from 'react-router';

function MyApp() {

  const location = useLocation();

  useEffect(() => {
      console.log('route has been changed');
      ...your code
  },[location.pathname]);

}

with hooks

With the useEffect hook it's possible to detect route changes without adding a listener.

import React, { useEffect }           from 'react';
import { Switch, Route, withRouter }  from 'react-router-dom';
import Main                           from './Main';
import Blog                           from './Blog';


const App  = ({history}) => {

    useEffect( () => {

        // When route changes, history.location.pathname changes as well
        // And the code will execute after this line

    }, [history.location.pathname]);

    return (<Switch>
              <Route exact path = '/'     component = {Main}/>
              <Route exact path = '/blog' component = {Blog}/>
            </Switch>);

}

export default withRouter(App);

To expand on the above, you will need to get at the history object. If you are using BrowserRouter, you can import withRouter and wrap your component with a higher-order component (HoC) in order to have access via props to the history object's properties and functions.

import { withRouter } from 'react-router-dom';

const myComponent = ({ history }) => {

    history.listen((location, action) => {
        // location is an object like window.location
        console.log(action, location.pathname, location.state)
    });

    return <div>...</div>;
};

export default withRouter(myComponent);

The only thing to be aware of is that withRouter and most other ways to access the history seem to pollute the props as they de-structure the object into it.

v5.1 introduces the useful hook useLocation

https://reacttraining.com/blog/react-router-v5-1/#uselocation

import { Switch, useLocation } from 'react-router-dom'

function usePageViews() {
  let location = useLocation()

  useEffect(
    () => {
      ga.send(['pageview', location.pathname])
    },
    [location]
  )
}

function App() {
  usePageViews()
  return <Switch>{/* your routes here */}</Switch>
}

With hooks:

import { useEffect } from 'react'
import { withRouter } from 'react-router-dom'
import { history as historyShape } from 'react-router-prop-types'

const DebugHistory = ({ history }) => {
  useEffect(() => {
    console.log('> Router', history.action, history.location])
  }, [history.location.key])

  return null
}

DebugHistory.propTypes = { history: historyShape }

export default withRouter(DebugHistory)

Import and render as <DebugHistory> component

You should to use history v4 lib.

Example from there

history.listen((location, action) => {
  console.log(`The current URL is ${location.pathname}${location.search}${location.hash}`)
  console.log(`The last navigation action was ${action}`)
})

import { useHistory } from 'react-router-dom';

const Scroll = () => {
  const history = useHistory();

  useEffect(() => {
    window.scrollTo(0, 0);
  }, [history.location.pathname]);

  return null;
}

With react Hooks, I am using useEffect

  const history = useHistory()
  const queryString = require('query-string')
  const parsed = queryString.parse(location.search)
  const [search, setSearch] = useState(parsed.search ? parsed.search : '')

  useEffect(() => {
    const parsedSearch = parsed.search ? parsed.search : ''
    if (parsedSearch !== search) {
      // do some action! The route Changed!
    }
  }, [location.search])