How to display 404 when URL doesn't match any route and when the URL contains /#/ using ReactJS

Question

This is my first time using ReactJS and is not my project however, I am trying to redirect any non-existent routes to a 404 page that I have made. My 404 page is currently displaying as intended when any URL that doesn't match a route is entered apart from when the URL contains /#/.

For example, this URL will redirect to my 404 page:

http://localhost:8080/non-existent-url

But this URL will only load my app's default route (homepage):

http://localhost:8080/#/non-existent-url

I don't know what the /#/ is for and it appears that the app will display pages with valid routes with or without it.

Stripped down routes file:

import React from "react";
import { Router, Route, IndexRoute, browserHistory, hashHistory, Redirect } from "react-router/es";
import willTransitionTo from "./routerTransition";
import App from "./App";
import DashboardContainer from "./components/Dashboard/DashboardContainer";
import DashboardAccountsOnly from "./components/Dashboard/DashboardAccountsOnly";
import NotFound from './components/NotFound';

const history = __HASH_HISTORY__ ? hashHistory : browserHistory;

class Auth extends React.Component {
    render() {return null; }
}

const routes = (
    <Route path="/" component={App} onEnter={willTransitionTo}>
        <IndexRoute component={DashboardContainer}/>
        <Route path="/auth/:data" component={Auth}/>
        <Route path="/dashboard" component={DashboardContainer}/>

        <Route path='*' exact={true} component={NotFound} />
    </Route>
);

export default class Routes extends React.Component {
    render() {
        return <Router history={history} routes={routes} />;
    }
}

404 (NotFound) component:

import React from 'react';
import {Link} from "react-router/es";
import Translate from "react-translate-component";

var image = require("assets/404.png");

const NotFound = () =>

    <div className="grid-block main-content wrap regular-padding">
        <div className="grid-content small-12" style={{marginTop:"200px"}}>
            <div style={{ textAlign:"center"}}>
                <img style={{marginBottom:"1.2rem"}} src={image} />
                <h3>404 page not found</h3>
                <p>This page does not exist.</p>
                <Link className="button" to={"/dashboard"}>
                    <Translate style={{color:"#fff"}} content="account.home" />
                </Link>
            </div>
        </div>
    </div>

export default NotFound;

How can I redirect users to my 404 page when a URL doesn't match any route and when the URL contains /#/?

Answer 1

For react-router < 4.0

If you want to display an error page and not change the path

<Route path='*' exact={true} component={errorcomponent} />

If you want to display an error page and change the path

<Route path='/error' component={errorcomponent} />
 // use redirect to  change the Url
<Redirect from='*' to='/error' />

For react-router 4

Keep the path

<Switch>
    <Route exact path="/" component={component} />
    <Route component={errorcomponent} />
 </Switch>

change Url.

 <Switch>
    <Route path="/comp" component={component} />
   <Redirect to="/error" />
 </Switch>

the redirect tag has to be put whereever you place a route tag insde a switch.

Answer 2

Based on what I'm seeing in your code, trying to switch between hash history and browser history just isn't going to work. The moment you hit '/#' in anything it's going to break and always hit your generic '/' route.

Hash URLs are an older way of handling things that shouldn't be an issue anymore. See this SO question and its accepted answer for more details.

Doing links like Twitter, Hash-Bang #! URL's

So yeah, unless you have some crazy reason to still support hashes in URLs, drop hash history and simply use browser history. Then your routes as defined in your provided code sample should work.