I am using next.js and I get the following error: "Warning: Expected server HTML to contain a matching nav in div".
Here is my code:
export default function Member() {
const router = useRouter();
const {
isAuthenticated,
authState,
profileState
} = useContext(AuthContext);
let profileArray = profileState.savedProfile;
const redirect = () => {
if (typeof window !== "undefined") {
router.push("/");
}
};
return (
<>
{!isAuthenticated() ? (
redirect()
) : (
<>
<Navigation />
<main className="main">
{{ /* Code that uses let profileArray */ }}
</main>
</>
)}
</>
);
}
I think the error occurs because of the React.Fragment - because when I replace the React.Fragments with f.ex. div, I get a different error "Warning: Expected server HTML to contain a matching div in div".
I just don't know how to solve this issue. I already tried to use useEffect, but then I get a server error.
Any suggestions? I'm new to next.js, so any help with code improvement is appreciated! Thanks a lot!
EDIT
A similar error occurs on other pages - only the warning differs f.ex. "Warning: Expected server HTML to contain a matching div in button". I think this is related to the AvatarDropdown, which is part of the Navigation. The code:
const AvatarDropdown = () => {
const node = useRef();
const { authState, isAuthenticated, logout } = useContext(AuthContext);
const [dropdownOpen, setDropdownOpen] = useState(false);
const router = useRouter();
const member = () => {
router.push("/member");
};
const dropdownItems = [
{ title: "My Account", onClick: () => member() },
{title: "Log Out", onClick: logout},
];
const handleClick = (e) => {
if (node.current && !node.current.contains(e.target)) {
setDropdownOpen(false);
}
};
useEffect(() => {
document.addEventListener("mousedown", handleClick);
return () => {
document.removeEventListener("mousedown", handleClick);
};
}, []);
return (
<div ref={node}>
{isAuthenticated() ? (
<button
onClick={() => setDropdownOpen(!dropdownOpen)}
>
<div>
<p>{authState.name}</p>
<ExpandMoreIcon />
</div>
</button>
) : (
<Link href="/login">
<button>
<p>LOGIN</p>
</button>
</Link>
)}
{dropdownOpen && (
<div>
<DropdownContent dropdownItems={dropdownItems} />
</div>
)}
</div>
);
};
redirect does not return any html node. Any side effect code should be executed in useEffect hook.
This is recommended. Try this..
export default function Member() {
const router = useRouter();
const {
isAuthenticated,
authState,
profileState
} = useContext(AuthContext);
let profileArray = profileState.savedProfile
React.useEffect(()=> {
if(!isAuthenticated()){
router.push('/')
}
},[])
if(!isAuthenticated()){
return <p>Loading..</p>
}
return (
<>
<Navigation / >
<main className = "main">
//code that uses let profileArray
</main>
</>
);
}
U can use Redirect component from 'react-router-dom'.
Related
I have 2 components, the Favorites component, makes a request to the api and maps the data to Card.
I also have a BtnFav button, which receives an individual item, and renders a full or empty heart according to a boolean.
Clicking on the BtnFav render removes a certain item from the favorites database.
What I need is that in the Favorites component, when I click on the BtnFavs component, the useEffect of Favorites is triggered again to bring the updated favorites.
How can i solve this? I have partially solved it with a global context(favoritesUser), but is there any other neater alternative?
The data flow for now would be something like this:
Favorites component fetches all the complete data and passes it to the Card component, the Card component passes individual data to the BtnFavs component.
Favorites Component:
const fetchWines = async () => {
try {
const vinos = await axios.get(`/api/favoritos/${id}`);
const arrVinos = vinos.data.map((vino) => {
return vino.product;
});
setVinosFavs(arrVinos);
} catch (err) {
console.error(err);
}
};
useEffect(() => {
fetchWines();
}, [favoritesUser]);
return (
<div>
<h1>Mis favoritos</h1>
<Card listWines={vinosFavs} />
</div>
);
BtnFavs:
const handleClickFav = (e) => {
if (!boton) {
axios.post("/api/favoritos/add", { userId, productId }).then((data) => {
setBoton(true);
return;
});
}
axios.put("/api/favoritos/delete ", { userId, productId }).then((data) => {
setBoton(false);
setFavoritesUser(data);
});
};
What I need is that in the Favorites component, when I click on the BtnFavs component, the useEffect of Favorites is triggered again to bring the updated favorites.
How can i solve this? I have partially solved it with a global context(favoritesUser), but is there any other neater alternative?
The pattern you want is called a callback function, just like the onClick of a button. You pass a function to your components that get executed given a condition. If you want fetchWines to be called again, then just pass the function in as a prop.
Favorites Component:
<Card listWines={vinosFavs} refresh={fetchWines} />
Card Component
<BtnFavs onDelete={refresh} ... />
BtnFavs Component
onDelete();
You can name it whatever you want, but generally callbacks will be named like on<condition>.
If you really wanted useEffect to be triggered then you would pass a setState function that set one of the dependencies, but I don't see a point in this case.
I will share code, because this problem its normal for me, i really want to learn and improve that.
const Favorites = () => {
const { favoritesUser } = useFavoritesContext();
const user = useSelector((state) => state.user);
const id = user.id;
const [vinosFavs, setVinosFavs] = useState([]);
const fetchWines = async () => {
try {
const vinos = await axios.get(`/api/favoritos/${id}`);
const arrVinos = vinos.data.map((vino) => {
return vino.product;
});
setVinosFavs(arrVinos);
} catch (err) {
console.error(err);
}
};
useEffect(() => {
fetchWines();
}, [favoritesUser]);
return (
<div>
<h1>My favorits</h1>
<Grid listVinos={vinosFavs} />
</div>
);
};
export default Favorites
Grid
export default function Grid({ listVinos }) {
return (
<div>
<ul className={styles.layoutDeVinos}>
{listVinos?.map((element) => {
return <WineCard key={element.id} vino={element} />;
})}
</ul>
</div>
);
}
Card
export default function WineCard({ vino }) {
return (
<>
<div>
<Link to={`/products/${vino.id}`}>
<li>
<div className={styles.card}>
<div
className={styles.img1}
style={{
backgroundImage: `url(${vino.images})`,
}}
></div>
<div className={styles.text}>{vino.descripcion}</div>
<div className={styles.catagory}>
{vino.nombre}
<i className="fas fa-film"></i>
</div>
<div className={styles.views}>
{vino.bodega}
<i className="far fa-eye"></i>{" "}
</div>
</div>
</li>
</Link>
<div className="botonesUsuario">
<BtnFavs vino={vino} />
</div>
</div>
</>
);
}
BTN FAVS
export default function BtnFavs({ vino }) {
const { setFavoritesUser } = useFavoritesContext();
const [boton, setBoton] = useState(false);
const user = useSelector((state) => state.user);
const userId = user.id;
const productId = vino.id;
useEffect(() => {
axios
.post("/api/favoritos/verify", { userId, productId })
.then((bool) => setBoton(bool.data));
}, []);
const handleClickFav = (e) => {
if (!boton) {
axios.post("/api/favoritos/add", { userId, productId }).then((data) => {
setBoton(true);
return;
});
}
axios.put("/api/favoritos/delete ", { userId, productId }).then((data) => {
setBoton(false);
setFavoritesUser(data);
});
};
return (
<>
{!user.id ? (
<div></div>
) : boton ? (
<span
class="favIcons material-symbols-rounded"
onClick={handleClickFav}
>
favorite
</span>
) : (
<span className="material-symbols-rounded" onClick={handleClickFav}>
favorite
</span>
)}
</>
);
}
I am a beginner in react js programming. I'm trying to do the todo project, which is a classic project. When I delete or add an element from the list, the newly formed list appears on the screen by combining with the previous one, I will show it with a picture below. I did not understand the source of the eror so wanted to post it here to get some advices suggestions about why it is happening.Thank you.(I am getting and storing data in firebase firestore database)
Before Adding an element initial array state
After adding an element to the array.
I am using useState for array and using useEffect to get initial data
MainPage.js that contains form and the list components.
const MainPage = () => {
const [isLoading, setLoding] = useState(true);
const [array, setArray] = useState([]);
const sub = async (email) => {
var result = [];
await onSnapshot(doc(db, "users", email), (doc) => {
var data = doc.data().todos;
data.forEach((element) => {
Object.keys(element).map(() => {
result.push(element["title"]);
});
});
setArray(result);
setLoding(false);
});
};
useEffect(() => {
sub(auth.currentUser.email);
}, []);
const onAddToDo = (todoTitle) => {
setArray((prevAray) => {
return [...prevAray, todoTitle];
});
};
const onRemove = (title) => {
setArray((prevAray) => {
return [array.pop(array.indexOf(title))];
});
};
return (
<div>
{isLoading && <h1>Loading</h1>}
{!isLoading && (
<div>
<section>
<NavBar></NavBar>
<ToDoForm passData={onAddToDo} />
</section>
<section>
<CardList removeCards={onRemove} array={array} />
</section>
</div>
)}
</div>
);
};
export default MainPage;
Firebase.js that stores the firebase update methods
export const deleteItem = (title) => {
updateDoc(doc(db, "users", auth.currentUser.email), {
todos: arrayRemove({ title: title }),
});
};
export const addnewTodo = (title) => {
updateDoc(doc(db, "users", auth.currentUser.email), {
todos: arrayUnion({ title: title }),
});
};
TodoForm.js component
const ToDoForm = (props) => {
const [todoTitle, setTitle] = useState("");
const titleChangeHandler = (event) => {
setTitle(event.target.value);
};
const newTodoAdder = (event) => {
event.preventDefault();
addnewTodo(todoTitle);
props.passData(todoTitle);
};
return (
<div className="form_holder">
<div className="form_container">
<form onSubmit={newTodoAdder}>
<h3>Add Events</h3>
<label>Title</label>
<input
onChange={titleChangeHandler}
type="text"
placeholder="Title"
id="title"
></input>
<div className="holder">
<button type="sumbit">Add</button>
</div>
</form>
</div>
</div>
);
};
export default ToDoForm;
CardList.js component
const CardList = (props) => {
const array = props.array;
if (array.length === 0) {
return (
<div className="grid_container">
<h2>Found no todos</h2>
</div>
);
}
return (
<div className="grid_container">
{array.map((element, index) => {
return (
<Card
removeSelf={() => {
props.removeCards(element);
}}
key={index}
title={element}
/>
);
})}
</div>
);
};
export default CardList;
Card.js component
const Card = (props) => {
const handleRemove = (event) => {
event.preventDefault();
deleteItem(props.title);
props.removeSelf();
};
return (
<div className="card">
<h2 className="card__title">{props.title}</h2>
<button type="button" onClick={handleRemove}>
Delete
</button>
</div>
);
};
export default Card;
EDIT ;
Index.js file
import React from "react";
import ReactDOM from "react-dom/client";
import App from "./App";
import { BrowserRouter } from "react-router-dom";
const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(
<BrowserRouter>
<App />
</BrowserRouter>
);
SOLUTION
I fixed the issue by changing the add and remove functions that were inside of MainPage.js file You can see the new versions bellow. Hope someday it will help somebody.
Use effect was called once all I had to do get the data again after a change...
New Remove and Add functions
const onAddToDo = (todoTitle) => {
console.log(todoTitle + " Added");
sub(auth.currentUser.email);
};
const onRemove = (title) => {
console.log(title + " Deleted");
sub(auth.currentUser.email);
};
I am new to react. I'm trying to update the parent state from the child but i have an error on another component at the the same level of the child one.
that's my code.
RedirectPage.js (parent)
const RedirectPage = (props) => {
const [status, setStatus] = useState("Loading");
const [weather, setWeather] = useState(null);
const [location, setLocation] = useState(null)
const [showLoader, setShowLoader] = useState(true)
const [userId, setUserId] = useState(false)
const [isPlaylistCreated, setIsPlaylistCreated] = useState(false)
const headers = getParamValues(props.location.hash)
const getWeather = () =>{
//fetch data..
//...
//...
.then(response => {
var res = response.json();
return res;
})
.then(result => {
setWeather(result)
setShowLoader(false)
setStatus(null)
setLocation(result.name)
});
})
}
const changeStateFromChild = (value) => {
setIsPlaylistCreated(value)
}
useEffect(() => {
getWeather()
},[]);
return (
<div className="containerRedirectPage">
{showLoader ? (
<div className="wrapperLogo">
<img src={loader}className="" alt="logo" />
</div>)
: (
<div className="wrapperColonne">
<div className="firstRow">
<WeatherCard weatherConditions={weather}/>
</div>
{isPlaylistCreated ? (
<div className="secondRow">
<PlaylistCard />
</div>
) : (
<PlaylistButton userId={userId} headers={headers} weatherInfo={weather} playlistCreated={changeStateFromChild} />
)}
</div>
)}
</div>
)
};
export default RedirectPage;
PlaylistButton.js:
export default function PlaylistButton({userId, headers, weatherInfo, playlistCreated}) {
const buttonClicked = async () => {
// ...some code...
playlistCreated(true)
}
return (
<div className="button-container-1">
<span className="mas">CREA PLAYLIST</span>
<button onClick={buttonClicked} id='work' type="button" name="Hover">CREA PLAYLIST</button>
</div>
)
}
and that's the other component i'm getting the error when i click on button.
WeatherCard.js:
const WeatherCard = ({weatherConditions}) => {
const [weather, setWeather] = useState(null);
const [icon, setIcon] = useState(null);
const getTheIcon = () => {
// code to get the right icon
}
setIcon(x)
}
useEffect(() => {
getTheIcon()
},[]);
return (
<div className="weatherCard">
<div className="headerCard">
<h2>{weatherConditions.name}</h2>
<h3>{Math.floor(weatherConditions.main.temp)}°C</h3>
</div>
<div className="bodyCard">
<h5>{weatherConditions.weather[0].description}</h5>
<img className="weatherIcon" src={icon} alt="aa" />
</div>
</div>
)
};
export default WeatherCard;
the first time i load the redirect page WeatherCard component is right. When i click the button i get this error:
error
Can someone explain me why ?
What is the effect of the setting playlistCreated(true) ?
Does it affects the weatherCondition object ?
If weatherCondition could be undefined at some point you need to check it before using its properties (name, main.temp, and weather)
Update:
The error clearly state that it cannot read name from weather because it's undefined. You have to check it before using the weather object properties.
if (!weatherConditions) {
return <div>Loading...</div> // or something appropriate.
}
return (
<div className="weatherCard">
<div className="headerCard">
<h2>{weatherConditions.name}</h2>
{weatherConditions.main && <h3>{Math.floor(weatherConditions.main.temp)}°C</h3>}
</div>
<div className="bodyCard">
{weatherConditions.weather &&
{weatherConditions.weather.length > 0 &&
<h5>{weatherConditions.weather[0].description}</h5>}
....
)
I have 2 details tag, each has a control to toggle it on/off. Code snippet here. Clicking Control A should toggle on/off page A, clicking Control B should toggle on/off page B.
I did it with an if else if plus 2 useState, this would not be feasible when there are multiple details. How can I refactor the code such that maybe the if else if can be avoided and it detects which Control I click in a cleverer way?
Page.js
const Page = ({ name, isOpen, setIsOpen }) => {
return (
<>
<details
open={isOpen}
onToggle={(e) => {
setIsOpen(e.target.open);
}}
>
<summary>Page {name} title</summary>
<div>Page {name} contents</div>
</details>
</>
);
};
export default Page;
Control.js
const Control = ({ toggle }) => {
return (
<>
<a onClick={() => toggle("A")} href="#/">
Control A
</a>
<br />
<a onClick={() => toggle("B")} href="#/">
Control B
</a>
</>
);
};
App.js
export default function App() {
const [isOpenA, setIsOpenA] = useState(false);
const [isOpenB, setIsOpenB] = useState(false);
const toggle = (name) => {
if (name === "A") {
setIsOpenA((prevState) => !prevState);
} else if (name === "B") {
setIsOpenB((prevState) => !prevState);
}
};
return (
<div className="App">
<Control toggle={toggle} />
<Page name={"A"} isOpen={isOpenA} setIsOpen={setIsOpenA} />
<Page name={"B"} isOpen={isOpenB} setIsOpen={setIsOpenB} />
</div>
);
}
You can use an array to represent open ones
const [openPages, setOpenPages] = useState([])
And to toggle filter the array
const toggle = (name) => {
if(openPages.includes(name)){
setOpenPages(openPages.filter(o=>o!=name))
}else{
setOpenPages(pages=>{ return [...pages,name]}
}
}
I would personally use an object as a map for your toggles as in something like:
const [isOpen, _setIsOpen] = useState({});
const setIsOpen = (pageName,value) => _setIsOpen({
...isOpen,
[pageName]: value
});
const toggle = (name) => setIsOpen(name, !isOpen[name]);
and then in the template part:
<Page name={"A"} isOpen={isOpen["A"]} setIsOpen={toggle("A")} />
In this way you can have as many toggles you want and use them in any way you want
I think this would be quite cleaner, also you should put the various page names in an array and iterate over them as in
const pageNames = ["A","B"];
{
pageNames.map( name =>
<Page name={name} isOpen={isOpen[name]} setIsOpen={toggle(name)} />)
}
At least that's how I would go about it
Adithya's answer worked for me.
For future reference, I put the full working code here. The onToggle attribute in Page.js is not needed. All required is passing correct true/false to open={isOpen} in Page.js.
App.js:
export default function App() {
const [openPages, setOpenPages] = useState([]);
const toggle = (name) => {
if (openPages.includes(name)) {
setOpenPages(openPages.filter((o) => o !== name));
} else {
setOpenPages((pages) => {
return [...pages, name];
});
}
};
return (
<div className="App">
<Control toggle={toggle} />
<Page name={"A"} isOpen={openPages.includes("A")} />
<Page name={"B"} isOpen={openPages.includes("B")} />
<Page name={"C"} isOpen={openPages.includes("C")} />
</div>
);
}
Page.js
const Page = ({ name, isOpen }) => {
return (
<>
<details open={isOpen}>
<summary>Page {name} title</summary>
<div>Page {name} contents</div>
</details>
</>
);
};
Control.js remains the same.
I have a parent and a child component, child component has a button, which I'd like to disable it after the first click. This answer works for me in child component. However the function executed on click now exists in parent component, how could I pass the attribute down to the child component? I tried the following and it didn't work.
Parent:
const Home = () => {
let btnRef = useRef();
const handleBtnClick = () => {
if (btnRef.current) {
btnRef.current.setAttribute("disabled", "disabled");
}
}
return (
<>
<Card btnRef={btnRef} handleBtnClick={handleBtnClick} />
</>
)
}
Child:
const Card = ({btnRef, handleBtnClick}) => {
return (
<div>
<button ref={btnRef} onClick={handleBtnClick}>Click me</button>
</div>
)
}
In general, refs should be used only as a last resort in React. React is declarative by nature, so instead of the parent "making" the child disabled (which is what you are doing with the ref) it should just "say" that the child should be disabled (example below):
const Home = () => {
const [isButtonDisabled, setIsButtonDisabled] = useState(false)
const handleButtonClick = () => {
setIsButtonDisabled(true)
}
return (
<>
<Card isDisabled={isButtonDisabled} onButtonClick={handleButtonClick} />
</>
)
}
const Card = ({isDisabled, onButtonClick}) => {
return (
<div>
<button disabled={isDisabled} onClick={onButtonClick}>Click me</button>
</div>
)
}
Actually it works if you fix the typo in prop of Card component. Just rename hadnlBtnClick to handleBtnClick
You don't need to mention each prop/attribute by name as you can use javascript Object Destructuring here.
const Home = () => {
const [isButtonDisabled, setIsButtonDisabled] = useState(false)
const handleButtonClick = () => {
setIsButtonDisabled(true)
}
return (
<>
<Card isDisabled={isButtonDisabled} onButtonClick={handleButtonClick} />
</>
)
}
const Card = (props) => {
return (
<div>
<button {...props}>Click me</button>
</div>
)
}
You can also select a few props and use them differently in the child components. for example, see the text prop below.
const Home = () => {
const [isButtonDisabled, setIsButtonDisabled] = useState(false)
const handleButtonClick = () => {
setIsButtonDisabled(true)
}
return (
<>
<Card text="I'm a Card" isDisabled={isButtonDisabled} onButtonClick={handleButtonClick} />
</>
)
}
const Card = ({text, ...restProps}) => {
return (
<div>
<button {...restProps}>{text}</button>
</div>
)
}