Develop Reference

How to detect matched route from a component outside of the <Route/> component that was matched using react-router?

I've got the following structure in my React app, using react-router-dom.
<Router>
<Header/>
<Main>
<AllRoutes> // THIS HANDLES THE SWITCH WITH ALL THE ROUTES
<Switch>
<Route exact path={ROUTES.HOME} component={Home}/>
<Route exact path={ROUTES.ABOUT} component={About}/>
<Route exact path={ROUTES.PRIVACY} component={Privacy}/>
// ETC
</Switch>
</AllRoutes>
</Main>
<Footer/> // <==== FOOTER NEEDS TO KNOW WHICH ROUTE HAS BEEN MATCH
<Router>
QUESTION
Footer needs to know what <Route/> has been match. What is the best pattern to achieve that?
OPTION #1
I found the useRouteMatch hook over on react router docs:
This would kind of work, but I don't think it is good enough for my situation. Because a URL string can match a route and still don't be a valid route at the same time.
For example:
Route: /:language/privacy
Valid route: /en/privacy
Not valid route that would also match: /notALanguage/privacy
Once a route has match, I usually need to check if it is valid before rendering a component page or the 404 page.
Like:
<Route exact path={"/:language/privacy"} render={(routeProps) => {
const possibleLanguage = routeProps.match.params.language;
if (possibleLanguage in LANGUAGES) {
return(
<PrivacyPage lang={possibleLanguage}/>
);
}
else {
return(
<Page404/>
);
}
}}/>
OPTION #2
What I'm thinking about doing is:
App.js calls useLocation. So it always re-render when there is a route change.
I could add a detectRoute function in App.js to do all the route checking beforehand.
And my AllRoutes component wouldn't need a component. I would implement a native JS switch and render the corresponding route.
This way I know upfront which <Route/> is going to match and I can pass it on to <Footer/> or any component that lives outside of the matched <Route/>.
Something like this:
SandBox Link
export default function App() {
console.log("Rendering App...");
const location = useLocation();
// THIS WOULD BE THE detectRoute FUNCTION
// I COULD EVEN USE THE useRouteMatch HOOK IN HERE
const matchedRoute =
location.pathname === ROUTE1
? "ROUTE1"
: location.pathname === ROUTE2
? "ROUTE2"
: "404";
return (
<div>
<div className="App">
<Link to={ROUTE1}>Route 1</Link>
<Link to={ROUTE2}>Route 2</Link>
<Link to={"/whatever"}>Route 404</Link>
</div>
<div>
<AllRoutes matchedRoute={matchedRoute} />
</div>
</div>
);
}
function AllRoutes(props) {
switch (props.matchedRoute) {
case "ROUTE1":
return <Route exact path={ROUTE1} component={Page1} />;
case "ROUTE2":
return <Route exact path={ROUTE2} component={Page2} />;
default:
return <Route exact path={"*"} component={Page404} />;
}
}
It works. But I would like to know if there's a proper way of doing this, 'cause this seems a bit weird and there might be something out there that was specifically designed for this.

Generally you want to either:
Wrap the components together
Create another switch to route them (and pass match params)
I put together a somewhat comprehensive example of the options. Hope that helps!
import React from "react";
import "./styles.css";
import { Switch, Link, Route, BrowserRouter } from "react-router-dom";
const hoc = (Component, value) => () => (
<>
<main>
<Component />
</main>
<Footer value={value} />
</>
);
const Wrapper = ({ component: Component, value }) => (
<>
<main>
<Component />
</main>
<Footer value={value} />
</>
);
const WrapperRoute = ({ component, value, ...other }) => (
<Route
{...other}
render={props => <Wrapper component={component} value={value} {...props} />}
/>
);
const Footer = ({ value }) => <footer>Footer! {value}</footer>;
const Header = () => <header>Header!</header>;
const Another = () => <Link to="/onemore">One More!</Link>;
const Home = () => <Link to="/other">Other!</Link>;
const OneMore = () => <Link to="/">Home!</Link>;
const Other = () => <Link to="/another">Another!</Link>;
export default () => (
<BrowserRouter>
<Header />
<Switch>
{/* You could inline it! */}
<Route
path="/another"
render={() => (
<>
<main>
<Another />
</main>
<Footer value="" />
</>
)}
/>
{/* You could use a custom route component (that uses an HOC or a wrapper) */}
<WrapperRoute
component={OneMore}
path="/onemore"
value="I got one more!"
/>
{/* You could use a Higher-Order Component! */}
<Route path="/other" component={hoc(Other, "I got other!")} />
{/* You could use a wrapper component! */}
<Route
path="/"
render={() => <Wrapper component={Home} value="I got home!" />}
/>
</Switch>
{/* You could have another switch for your footer (inline or within the component) */}
<Switch>
<Route
path="/another"
render={() => <Footer value="Switch footer another!" />}
/>
<Route
path="/other"
render={() => <Footer value="Switch footer other!" />}
/>
<Route
path="/onemore"
render={() => <Footer value="Switch footer onemore!" />}
/>
<Route path="/" render={() => <Footer value="Switch footer home!" />} />
</Switch>
</BrowserRouter>
);
Note the WrapperRoute would allow you to do validation on your match params before passing them through. You could do a Redirect if needed.

What I've ended up doing:
Since I'm using Redux, I added a piece of global state to keep track of the matched route.
And I dispatch actions to update that state from the render prop from the <Route/>'s component.
<Switch>
<Route key={index} exact path={"/some-route"} render={(routeProps) => {
// HERE I DISPATCH AN ACTION TO CHANGE THE STATE FOR THE CURRENT ROUTE
dispatch({
type: UPDATE_CURRENT_ROUTE,
payload: { name: "SOME_ROUTE_NAME" }
});
return (
<PrivacyPage
{...routeProps}
/>
);
}}/>
</Switch>
And now I can do on Footer.js:
function Footer() {
const currentRoute = useSelector((state) => state.currentRoute);
// RENDER FOOTER ACCORDINGLY TO THE CURRENT ROUTE
}

React Router path var with other paths as well, React cant tell the difference

I am setting up react router for different link in my project but the problem is I need react router to tell the difference between a user username variable and other paths.
For example:
baseUrl/admin
baseUrl/daniel
React doesnt know the difference. I will have a list of usernames in a db and would return an error if the user doesnt exist then that means the page does not exist.
This is my code:
class App extends Component{
render(){
return (
<Router>
<Route exact path="/" render={props => (
<React.Fragment>
<h1>Hey</h1>
</React.Fragment>
)}
/>
<Route exact path="/admin" render={props => (
<React.Fragment>
<h1>admin</h1>
</React.Fragment>
)}
/>
<Route path="/:user" component={UserComponent}
/>
</Router>
);
}
}

You can use the match.url property to choose which component render, for example:
<Route path="/:user" render={props => {
if(props.match.url === '/admin') {
return (
<React.Fragment>
<h1>Hey</h1>
</React.Fragment>
)
} else return (<UserComponent {...props} />)
}} />

How to change NavBar text on login/logout in React.JS?

I have a Navigation bar in my project which I call from inside App.js. Based on if I am logged in or not, I want to render different views of NavBar. If logged in, I want the NavBar to have a logout button. And if logged out, I want the NavBar to have login button. I use a token in localStorage to check if I am logged in or not. When logged in, token is present in localStorage. On logout/before login, there is no token key in localStorage. I pass this token as a state to NavBar as shown:
export default function App() {
const [loggedIn, setLoggedIn] = useState(localStorage.getItem("token"));
return (
<div>
<Router>
<Navbar isAuth={loggedIn} />
<Route exact path="/" exact component={Home} />
<Route path="/login" component={Login} />
<PrivateRoute path="/dashboard" component={Dashboard} />
</Router>
</div>
);
}
Now from NavBar component, I use this prop to render different views of NavBar as shown below:
const NavBar = props => {
const classes = useStyles();
if (props.isAuth !== null) {
return (
<div className={classes.root}>
<AppBar position="static">
<Toolbar>
<Typography variant="h6" className={classes.title}>
<Link
href="/"
style={{ textDecoration: "none", color: "white" }}
>
Timetracker
</Link>
</Typography>
<Link href="/" style={{ color: "white" }}>
<Button color="inherit" onClick={auth.logout}>
Logout
</Button>
</Link>
</Toolbar>
</AppBar>
</div>
);
} else {
return (
<div className={classes.root}>
<AppBar position="static">
<Toolbar>
<Typography variant="h6" className={classes.title}>
<Link
href="/"
style={{ textDecoration: "none", color: "white" }}
>
Timetracker
</Link>
</Typography>
<Link href="/login" style={{ color: "white" }}>
<Button color="inherit">Login</Button>
</Link>
</Toolbar>
</AppBar>
</div>
);
}
};
export default NavBar;
The problem is that, the NavBar does not update itself as soon as I login. I have to manually refresh the page in order to render the new NavBar. Similarly on logout too, It does not update itself and updates only on manual refresh. What is the issue and how to solve this?

I found a simple solution:
use a componentDidMount() or useEffect() function which will render automatically upon loading the NavBar page.
Inside this function, use a setInterval() function to continually retrieve the auth status (say, an interval of 5000). This will continually refresh the NavBar, and change the button immediately.
I imagine you would have to put the auth check in the NavBar component itself, instead of using props. I put the specific buttons I wanted to change in a separate component called NavBarUser, which changes 'login | signup' to 'logout' and contains a user avatar. I then inserted this component into the NavBar itself at the appropriate place.
This is what my code looks like:
```
import React, { useState, useEffect } from 'react';
import Avatar from './Avatar';
import { BrowserRouter as Router, Link } from 'react-router-dom';
const NavBarUser = () => {
const [user, setUser] = useState({});
useEffect(() => {
{ /*
setInterval was used in order to refresh the page constantly
in order to have the "logout" button show immediately in place of
"login", as soon as user logs out.
*/}
setInterval(() => {
const userString = localStorage.getItem("user");
const user = JSON.parse(userString);
setUser(user);
}, [])
}, 5000);
const logout = () => {
return localStorage.removeItem("user");
}
if (!user) {
return (
<div className="navbar-nav ml-auto">
<Link to="/login" className="nav-item nav-link">Login</Link> <span
className="nav-item nav-link">|</span> <Link to="/SignUp" className="nav-item nav-
link">Sign Up</Link>
</div>
)
}
if (user) {
return (
<div className="navbar-nav ml-auto">
<Link to="/" className="nav-item nav-link" onClick={logout}>Logout</Link>
<Avatar img="/images/Eat-healthy.jpg" />
</div>
)
}
}
export default NavBarUser;
```

You need to add <Switch> as well. From the documentation:
Renders the first child or that matches the location.
<Switch> is unique in that it renders a route exclusively. In contrast, every <Route> that matches the location renders inclusively.
Just like the following:
<Router>
<Switch>
<Navbar isAuth={loggedIn} />
<Route exact path="/" exact component={Home} />
<Route path="/login" component={Login} />
<PrivateRoute path="/dashboard" component={Dashboard} />
</Switch>
</Router>
Read further here: Router
I hope that helps!

Your app's state won't update if you change the value of the token in localStorage.
You need to make sure you update the state, I've added a sandbox if it helps.

Here's how I solved this issue:
To start, I created a isLoggedIn state in my App class. I gave it a componentDidMount() method that would fetch the login state from a cookie on app start. Then I created globalLogin and globalLogout methods as arrow functions, which set the isLoggedIn state to true or false accordingly. I passed my Nav component the isLoggedIn state as a prop and passed the Login and Nav routes the globalLogin and globalLogout methods. These methods can then be called from Login or Nav with this.props.globalLogout(); or this.props.globalLogin();.
This is a simplified version of my App.js.
class App extends Component {
constructor(props){
super(props);
this.state = {
isLoggedIn: false,
}
}
componentDidMount() {
const token = Cookie.get("token") ? Cookie.get("token") : null;
if (token) {
this.setState({ "isLoggedIn": true });
}
}
globalLogin = () => {
this.setState({ "isLoggedIn": true });
}
globalLogout = () => {
this.setState({ "isLoggedIn": false });
}
render() {
return (
<Router>
<div className="App">
<Nav isLoggedIn={this.state.isLoggedIn} globalLogout={this.globalLogout}/>
<Switch>
<Route path="/" exact component={Home} />
<Route path="/login" exact>
<Login globalLogin={this.globalLogin}/>
</Route>
</Switch>
</div>
</Router>
);
}
}
EDIT: using history.push didn't work in login module above so I added an intermediate to handle props
render() {
const LoginIntermediate = (props) => {
return (
<Login {...props} globalLogin={this.globalLogin}/>
)
}
return (
<Router>
<div className="App">
<Nav isLoggedIn={this.state.isLoggedIn} globalLogout={this.globalLogout}/>
<Switch>
<Route path="/" exact component={Home} />
<Route path="/login" exact component={LoginIntermediate} />
</Switch>
</div>
</Router>
);
}

React Router 4 passing props through Route render doesn't work

This question has been asked, but other answers aren't solving this for me. I want to pass the signInWithEmail handler function from my <App /> component down through <Layout /> and then to the <SignIn /> component via a <Route />.
The way to do this is apparently via the render attribute on the Route, but for me it just renders ignores my onSubmit. In React dev tools I just see the default Route props, even though I can see my handler function(s) in the <Layout /> element showing up as props.signInWithEmail. They don't make it to the <SignIn /> element.
What am I missing? Thanks.
const Layout = (props) => (
// i can console.log(props) here and see props.signInWithEmail
<div className="layout">
// header etc...
<main>
<Switch>
// ... other routes
<Route
path="/signin"
render= {(props) => <SignIn onSubmit={props.signInWithEmail} />}
/>
</Switch>
</main>
// footer etc...
</div>
)}
render part of App:
render() {
return (
<div className="App">
<BrowserRouter>
<Layout
signInWithEmail={this.signInWithEmail}
signUpWithEmail={this.signUpWithEmail}
signOut={this.signOut}
state={this.state}
/>
</BrowserRouter>
</div>
);
}

It happens because you overriding props within arrow function.
Try to destructure Layout prop like that:
const Layout = ({signInWithEmail}) => (
// i can console.log(props) here and see props.signInWithEmail
<div className="layout">
// header etc...
<main>
<Switch>
// ... other routes
<Route
path="/signin"
render= {() => <SignIn onSubmit={signInWithEmail} />}
/>
</Switch>
</main>
// footer etc...
</div>
)}

Routes inside component previously routed

I am using react-router-dom 4.2. I have my App.js with Authenticated components inside. This components are created by me and add a little of business logic, create the component via React.createElement, and route them via Route component. Nothing unusual.
The App.js:
// ...
const App = props => (
<BrowserRouter>
<Fragment>
<Switch location={location}>
<Route
exact
path={URLS.ROOT}
render={() => <Redirect to={URLS.DASHBOARD} />}
/>
<Authenticated
{...props}
resource={ResourcesCode.DASHBOARD}
patent={PatentsCode.VIEW}
path={URLS.DASHBOARD}
component={Dashboard}
/>
<Authenticated
{...props}
resource={ResourcesCode.SUBSCRIBE}
patent={PatentsCode.VIEW}
path={URLS.SUBSCRIBE}
component={Subscribe}
/>
</Fragment>
</BrowserRouter>
// ...
Inside of the component Subscribe (mentioned above in the 2nd Authenticated component), I have more routes as you can see below:
// ...
<Route
path={URLS.SUBSCRIBE}
exact
render={() => (
//...
)}
/>
<Route
path={URLS.SUBSCRIBETWO}
exact
render={() => (
//...
)}
/>
// ...
The point is that this routes on the child component (Subscribe) are ignored.
Why are them ignored? How can I solve it?
I really need this routes inside the child component. I don't want to move them to App.js
IMPORTANT EDIT:
The second route is ignored, I realized that the first doesn't. In other words, The Route component with path={URLS.SUBSCRIBE} is working, but the component with path={URLS.SUBSCRIBETWO} is ignored, so here is the problem to solve.
EDIT:
For if you need, the Authenticated component:
// ...
}) => (
<Route
path={path}
exact={exact}
render={route => {
if (!authenticated) {
if (loggingIn) {
return '';
}
return <Redirect to={URLS.LOGIN} />;
}
if (!roleSubReady) {
return '';
}
if (path !== URLS.SUBSCRIBE && user.pendingSubscription) {
if (isLoading) {
return '';
}
return <Redirect to={URLS.SUBSCRIBE} />;
}
if (path === URLS.SUBSCRIBE && !user.pendingSubscription) {
if (isLoading) {
return '';
}
return <Redirect to={URLS.DASHBOARD} />;
}
if (resource && !checkPermission(user, resource, patent)) {
return <NotAuthorized history={route.history} />;
}
return (
<React.Fragment>
<Menu user={user} path={path} isLoading={isLoading} />
<Header show={showHeaderAndFooter} user={user} path={path} />
<MainContent>
{React.createElement(component, {
user,
resource,
...route,
})}
<Footer show={showHeaderAndFooter} />
</MainContent>
</React.Fragment>
);
}}/>
);