Develop Reference

Map Components not rerendered after navigate back

i have a page with the following code:
// Homepage
return (
<>
<div>HELLO BE YOu</div>
{list.map((video) => {
return <VideoPreview key={video._id} video={video</VideoPreview>
});}
{list.map((video) => {
return <div>TEST</div>
})}
</>
);
VideoPreview is an imported component:
export const VideoPreview = ({video}) => {
const navigate = useNavigate();
function handleClick(){
navigate('/video');
}
return <div onClick={handleClick}>video</div>
}
When a user clicks on <VideoPreview/>, they will be directed to another page which has been defined in App.js to be
<BrowserRouter forceRefresh={true}>
<Routes>
<Route path="/" element={<Homepage />} />
<Route path="/video" element={<Videopage />} />
</Routes>
</BrowserRouter>
The bug is that when the user attempts to go back to "/" path from "/video" path, the HomePage component does not render properly.
The items inside the list map do not render. (Other element outside of list.map eg, <div>HELLO BE YOu</div> was rendered properly though). I have verified that list is not empty and when i place console.log statements within the map function, those logs gets printed out.
{list.map((video) => {
return <VideoPreview key={video._id} video={video}></VideoPreview>
});}
{list.map((video) => {
return <div>TEST</div>
})}
May i get some help in resolving this problem? Thank you.

React-Router render : Functions are not valid as a React child

I have created a HOC "ProtectedRoute" to restrict paths for unauthenticated users. I have used "react-router-dom" for routing in the application.
I am able to route the users based on their token but I am receiving a warning in the console and I am unable to access routerprops such as "history", "location", "match" in rendered component. Below is the ProtectedRoute component implementation.
const ProtectedRoute = ({component:Component, ...rest}) => {
const [isLoggedIn, setLoggedIn] = useState({loggedIn:false, loaded:false})
useEffect(async () => {
const userStatus = await validateUserLoggedIn(); # returns true if user is authenticated
setLoggedIn((prevState) => {return {loggedIn:userStatus, loaded:true}})
}, [])
return(
<Route {...rest} render={(routerProps) => {
return isLoggedIn.loaded ?
isLoggedIn.loggedIn ? <Component {...routerProps} {...rest} /> : <Redirect to={{pathname:'/login'}} :
<h1>Loading Page</h1>
}} />
)
}
ProtectedRoute in main routing component:
<Switch>
<ProtectedRoute exact path="/admin" component={Admin} />
</Switch>
Error Message "Functions are not valid as a React child. This may happen if you return a Component instead of from render. Or maybe you meant to call this function rather than return it".
Any suggestion is appreciated.

Ok so there a few things wrong.
You should not return something inside a component, you are doing this inside your <Route /> component. This is causing the warning: Functions are not valid as a React child. This may happen if you return a Component instead of from render.
Your <Redirect /> component was missing a /> at the end of it, leaving it open will cause an error.
These fixes should also solve your problem where you couldn't access the route props.
<Route
{...rest}
render={(routerProps) => {
isLoggedIn.loaded ? (
isLoggedIn.loggedIn ? (
<Component {...routerProps} {...rest} />
) : (
<Redirect to={{ pathname: '/login' }} />
)
) : (
<h1>Loading Page</h1>
);
}}
/>;

ReactRouterDom, AuthRoute returns react render functions are not valid as react child warning

My Router is a simple component containing public and private routes. I have created an AuthRoute referring to the great tutorial from here
So, my Router looks like:
<Router>
<div>
<Navigation />
<Route exact path={ROUTES.LANDING} component={Landing} />
<Route path={ROUTES.SIGN_UP} component={SignUp} />
<Route path={ROUTES.SIGN_UP_SUCCESS} component={SignUpSuccess} />
<AuthenticationRoute path={ROUTES.HOME} component={Home} />
</div>
</Router>
and my AuthenticationRoute looks like this:
export const AuthenticationRoute = ({ component: Component, ...rest }) => {
const [authChecking, setAuthChecking] = useState(true);
const [{ isAuth }, dispatch] = useStateValue();
useEffect(() => {
checkLoggedIn().then(res => {
setAuthChecking(false);
dispatch({
op: 'auth',
type: 'toggleSessionAuth',
toggleSessionAuth: res
});
});
}, [])
if(authChecking)
return null;
if(!isAuth) {
return <Redirect to='/' />;
}
return <Route {...rest} render={(props) => (
<Component {...props} />
)
} />
}
Everything looks fine, however, my console returns such warning:
Warning: Functions are not valid as a React child. This may happen if you return a Component instead of <Component /> from the render. Or maybe you meant to call this function rather than return it.
I have tried different solutions using component/render etc, however, I could not find a solution to this problem and I have no idea what I am doing wrong.
For testing purposes, instead of rendering Component, I tried to render simple <div>test</div> and it worked fine. However, when I am passing a JSX component in props, it returns the warning shown above.
Implementation oh Home Component (Home.js):
export const Home = () => {
const [{ user }, dispatch] = useStateValue();
const { history } = useReactRouter();
const moveTo = path => {
dispatch({
op: 'other',
type: 'setView',
setView: path
});
history.push(path);
}
return (
<div className="pageMenuWrapper">
<h1 className="homeTitle">Hi {() => user ? `, ${user.username}` : ``}.</h1>
<div className="wrapper">
<Tile image={leagueico} alt="text" onClick={() => moveTo(ROUTES.TEST)}/>
<Tile comingSoon />
</div>
</div>
);
}
export default Home;
Could anyone help me solve this little problem?

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
}

Organizing React routes into separate components

I'm trying to find a way to organize my routes to assist the dev who might be taking over my work in the future. I thought of separating my <Route /> entries into separate components and then just load those into a main component similar to how users are assigned groups.
The issue is that when using more than one component only the first one works. This might not be the most react way of doing this so I'm also open to alternatives.
Original route arrangement
const AllRoutes = () => {
return (
<Switch>
{/* public routes*/}
<Route path={'/about'} component={AboutView} />
<Route path={'/project'} component={ProjectView} />
<Route path={'/contact'} component={ContactView} />
{/* auth routes */}
<Route path={'/login'} component={LoginView} />
<Route path={'/logout'} component={LogoutView} />
<Route component={Error404View} />
</Switch>
)
}
Separating the public routes from the auth ones:
const PublicRouteGroup = () => {
return (
<>
<Route path={'/about'} component={AboutView} />
<Route path={'/project'} component={ProjectView} />
<Route path={'/contact'} component={ContactView} />
</>
)
}
const AuthRouteGroup = () => {
return (
<>
<Route path={'/login'} component={LoginView} />
<Route path={'/logout'} component={LogoutView} />
</>
)
}
This way I can use it as such:
const AllRoutes = () => {
return (
<Switch>
<PublicRouteGroup /> {/* This works */}
<AuthRouteGroup /> {/* This doesn't */}
{/* This 404 is not a route group */}
<Route component={Error404View} />
</Switch>
)
}
Flipping <PublicRouteGroup /> and <AuthRouteGroup /> only changes the order:
const AllRoutes = () => {
return (
<Switch>
<AuthRouteGroup /> {/* This works */}
<PublicRouteGroup /> {/* This doesn't */}
{/* This 404 is not a route group */}
<Route component={Error404View} />
</Switch>
)
}
Update #1
This is thanks to #skyboyer. By moving the <Switch> to the child components and removing it from the AllRoutes component each component started to show. It appears adding the <Switch> in AllRoutes is allowing only the first hit to show which is as <Switch> does. But now by removing it it shows the 404 at the end of each page as well.
Basically, it looks like this:
const AllRoutes = () => {
return (
<>
<Route component={AuthRouteGroup} /> {/* This works */}
<Route component={PublicRouteGroup} /> {/* This also works */}
{/* This 404 is not a route group */}
<Route component={Error404View} /> {/* Always shown at the bottom */}
{/* Even putting the 404 in its own RouteGroup yields the same issue */}
</>
)
}

It appears this current set up of treating components like OOP classes you can extend from is the wrong approach. I've instead made use of arrays since these can be acted upon by the spread operator. It still accomplishes the same goal of organizing routes across an infinite number of groups which was what I was after.
Create the array for each group
const public_route_group = [
{path: '/about', component: AboutView},
{path: '/project', component: ProjectView},
{path: '/contact', component: ContactView},
]
const auth_route_group = [
{path: '/login', component: LoginView},
{path: '/logout', component: LogoutView},
]
const error_route_group = [
{component: Error404View} // No path required
]
const user_routes = [
...public_route_group,
...auth_route_group,
...error_route_group
]
Create the routes
const AllRoutes = () => {
return (
<Switch>
{user_routes.map((route, idx) => {
return <Route key={idx} {...route} />
})}
</Switch>
)
}
I figure this can also be modified further if you're using nested objects in your array.
I'd like to thank #skyboyer for providing an insight into this problem.

How about having it without Swtich at top-level
<Route component={PublicRouteGroup} />
<Route component={AuthRouteGroup} />
so they are rendered unconditionally. And then having extra Switch in your components like
const AuthRouteGroup = () => {
return (
<Switch>
<Route path={'/login'} component={LoginView} />
<Route path={'/logout'} component={LogoutView} />
<Switch/>
)
}
But why id did not work?
The reason is how Switch works:
React.Children.forEach(this.props.children, child => {
if (match == null && React.isValidElement(child)) {
element = child;
const path = child.props.path || child.props.from;
match = path
? matchPath(location.pathname, { ...child.props, path })
: context.match;
}
});
See, even if AuthRouteGroup is not a Route, Switch anyway looks to its props.path. And once undefined for props.path matches any path and Switch renders only first matching Route you are getting only first component rendered.
[UPD] "does-not-match-any-route" View will work only at top level of Switch. Also there are no way to know if some nested children of sibling element has matched current route or not. So only way I see is listing all routes in single place.
Alternative that looks rather poor is having special route "/error404" and redirect user to it from inside of other components(but who should decide? and where? and when?).