Display a simple loading indicator between routes in react router

Question

I'm coming from AngularJS world and start some days ago writing my first React App with react-router, in AngularJS I do:

app.directive('Loading', function($rootScope, $timeout) {
    return {
        restrict: 'E',
        replace: true,
        template: '<p>Loading</p>'
        link: function(scope, element) {
            $rootScope.$on('$routeChangeStart', function(event, currentRoute, previousRoute) {
                element.removeClass('ng-hide');
            });

            $rootScope.$on('$routeChangeSuccess', function() {
                element.addClass('ng-hide');
            });
        }
    };
});

and then I just add <Loading></Loading>. So now in my React App I have:

class App extends Component {
  render() {
    return (
       <Router>
        <div>
          <ul>
            <li><Link to="/">Home</Link></li>
            <li><Link to="/about">About</Link></li>
          </ul>

          <hr/>

          <Route exact path="/" component={Home}/>
          <Route path="/about" component={About}/>

        </div>
      </Router>


    );
  }
}

and my two components are simple:

class Home extends Component {
    render() {
        return (
            <h1>Home</h1>
        );
    }
}
class About extends Component {
    render() {
        return (
            <h1>About</h1>
        );
    }
}

Can I do this without using reduxJS?

Answer 1

you can use a High Order Component in react to do this in a generic way.

Look is a example:

https://github.com/thejameskyle/react-loadable

Answer 2

If you fetching some data I made a small package react-router-loading that allows you to show loading indicator and load some data before switching the screen.

Just use Switch and Route from this package instead of react-router-dom:

import { Switch, Route } from "react-router-loading";

Add loading props to the Route where you want to wait something:

<Route path="/about" component={About} loading/>

And then somewhere at the end of fetch logic in About component add loadingContext.done();:

import { LoadingContext } from "react-router-loading";
const loadingContext = useContext(LoadingContext);

const loading = async () => {
    //loading some data

    //call method to indicate that loading is done and we are ready to switch
    loadingContext.done();
};