Prevent `useEffect` from looping - reactjs

I have a simple useEffect that I'm not sure how to stop from invoking endlessly. It keeps firing the first if conditional endlessly. I've been reading a lot about hooks and I assume (maybe erroneously) that each render of the component results in a new invocation of my useAuth() and useUser() hooks. Since they have new references in memory it's triggering the useEffect's deps since technically it's a new function that exists in the scope of this new component render?
Thats my thought at least, no clue how to fix that if that's indeed that case.
const RootPage = ({ Component, pageProps }): JSX.Element => {
const { logoutUser } = useAuth(); // imported
const { fetchUser } = useUser(); // imported
const router = useRouter();
useEffect(() => {
// authStatus();
const unsubscribe = firebaseAuth.onAuthStateChanged((user) => {
if (user) {
console.log(1);
return fetchUser(user.uid); // async function that fetches from db and updates redux
}
console.log(2);
return logoutUser(); // clears userData in redux
});
return () => unsubscribe();
}, [fetchUser, logoutUser]);
...
}
fetchUser
const fetchUser = async (uid) => {
try {
// find user doc with matching id
const response = await firebaseFirestore
.collection('users')
.doc(uid)
.get();
const user = response.data();
// update redux with user
if (response) {
return dispatch({
type: FETCH_USER,
payload: user,
});
}
console.log('no user found');
} catch (error) {
console.error(error);
}
};
logoutUser
const logoutUser = async () => {
try {
// logout from firebase
await firebaseAuth.signOut();
// reset user state in redux
resetUser();
return;
} catch (error) {
console.error(error);
}
};
when I refresh the page with this useEffect on this is output to the console:

useEffect(() => {
function onAuthStateChange() {
return firebaseAuth.onAuthStateChanged((user) => {
if (user) {
fetchUser(user.uid);
} else {
resetUser();
}
});
}
const unsubscribe = onAuthStateChange();
return () => {
unsubscribe();
};
}, [fetchUser, resetUser]);
Keeping everything the same && wrapping fetchUser and resetUser with a useCallback, this solution seems to be working correctly. I'm not entirely sure why at the moment.

Related

useEffect is re-rendering async promise again and again

I am trying to log currentUser details to console to see if user is logged in or not. But it is logging again n again and make a loop of currentUser in console.
Here is the code
const [currentUser, setCurrentUser] = useState(null);
const unSubscribeFromAuth = useRef(null);
useEffect(() => {
unSubscribeFromAuth.current = auth.onAuthStateChanged(async userAuth => {
if (userAuth) {
const userRef = await createUserProfileDocument(userAuth);
userRef.onSnapshot(snapShot => {
setCurrentUser({
id: snapShot.id,
...snapShot.data()
})
console.log(currentUser);
})
}
else {
setCurrentUser(userAuth);
}
})
return () => { unSubscribeFromAuth.current() };
}, [currentUser]);
and here is the function i am importing
export const createUserProfileDocument = async (userAuth, additionalData) => {
if (!userAuth) return;
const userRef = firestore.doc(`users/${userAuth.uid}`);
const snapShot = userRef.get();
console.log(snapShot);
if (!snapShot.exists) {
const { displayName, email } = userAuth;
const createdAt = new Date();
try {
await userRef.set({
displayName,
email,
createdAt,
...additionalData
})
}
catch (error) {
console.log('error creating user', error.message);
}
}
return userRef;
}
I tried to remove dependency but it says
React Hook useEffect has a missing dependency: 'currentUser'. Either include it or remove the dependency array
Since you are updating currentUser in the useEffect and the useEffect is triggered every time currentUser changes, you are seeing the infinite loop. You need to remove currentUser from the dependency array.
useEffect has a missing dependency is coming from console.log. If you remove it, it will go away.

React unsubscribe a listener from anywhere in the app

I need help extracting a database listener function into its own callable function so I can unsubscribe from it. Here is what I have:
const reroute = (user) => {
// A function to route user based on its state values
};
export function AuthenticateUser() {
const user = useStore((state) => state.user);
const setUser = useStore((state) => state.setUser);
useEffect(() => {
let unsubscribe;
function setupUser(userDetails) {
Analytics.setUserId(userDetails!.id);
setUser(userDetails);
}
if (!user) {
// LISTENER 1 : Authenticate user. We unsubscribe from this listener in the cleanup function.
unsubscribe = firebase.auth().onAuthStateChanged((authenticatedUser) => {
if (authenticatedUser) {
const uid = authenticatedUser.uid;
const db = firebase.firestore();
// LISTENER 2: This is the listener I need to be able to unsubscribe from wherever I need.
const unsubscribeUserUpdates = db.collection("users").doc(uid)
.onSnapshot(
async (doc) => {
// onSnapshot listener will fire this whenever something updates on the server
const documentData = doc.data();
const userData = {
id: doc.id,
...documentData,
};
setupUser(userData);
setLoadingUser(false);
reroute(userData);
},
(error) => {
console.log("error", error);
alertMessage("danger", "User authentication failed", error.message);
reportError("GQL_getOrCreateUser", error);
}
);
} else {
// No authenticated user
setLoadingUser(false);
reroute(null);
}
});
}
return () => {
unsubscribe?.();
// unsubscribeUserUpdates?.(); << If I run this, then the listener will be terminated, but I don't want to terminate it here.
};
}, [GQL_getOrCreateUser, setLoadingUser, setUser, user]);
}
I load AuthenticateUser into my react navigation index.ts
export default function Navigation() {
AuthenticateUser();
return (
<NavigationContainer>
...
I have a Sign Out function here which fires on button click that should sign the user out and terminate the unsubscribeUserUpdates listener
export default function AccountNavigator() {
const setUser = useStore((state) => state.setUser);
function signOut() {
setUser(null);
firebase.auth().signOut();
}
return (
<AccountStack.Navigator>
...
I want to be able to terminate the unsubscribeUserUpdates listener, but I think that for that I need to have it as a callable function. I tried extracting it to a useCallback hook, but got errors.
Could someone please let me know, with code example, what to do to be able to load the listener in AuthenticateUser and stop it anywhere I need?
You can make a new useEffect for unmounting purpose. Empty dependencies make the useEffect work as componentDidMount and returning that makes it componentWillUnmount
useEffect(() => {
const unsubscribe = someAuthStuff();
return () => {
unsubscribe();
};
}, []);
You should initialize a variable
on useEffect try this:
mounted = true
...
mounted && fun();
return () => (mounted = false);

Can't update react state, even component is not unmounted

Description
I have component which shows data that get from server and display it on the table using the state, tableData and it must be set when Redux action is dispatched.
I've use action listener library which uses Redux middleware which consisting of 63 lines of code. redux-listeners-qkreltms.
For example when I register a function on analysisListIsReady({}).type which is ANALYSISLIST_IS_READY then when the action is dispatched, the function is called.
Issue
The issue is that react throws sometimes the error: Can't update react state... for setTableData so response data is ignored to be set. I want to figure it out when it happens.
I've assumed that it's because of unmounting of component, so I printed some logs, but none of logs are printed and also ComponentA is not disappeared.
It's not throing any error when I delete getAnalysisJsonPathApi and getResource, so I tried to reporuduce it, but failed... link
It's not throing any error when I delete listenMiddleware.addListener see: #2
#1
// ComponentA
const [tableData, setTableData] = useState([])
useEffect(() => {
return () => {
console.log("unmounted1")
}}, [])
useEffect(() => {
listenMiddleware.addListener(analysisListIsReady({}).type, (_) => {
try {
getAnalysisJsonPathApi().then((res) => {
//...
getResource(volumeUrl)
.then((data: any) => {
// ...
setTableData(data)
})
})
} catch (error) {
warn(error.message)
}
})
return () => {
console.log("unmounted2")
}
}, [])
export const getAnalysisJsonPathApi = () => {
return api
.post('/segment/volume')
.then(({ data }) => data)
export const getResource = async (src: string, isImage?: boolean): Promise<ArrayBuffer> =>
api
.get(src)
.then(({ data }) => data)
#2
// ComponentA
const [tableData, setTableData] = useState([])
useEffect(() => {
return () => {
console.log("unmounted1")
}}, [])
useEffect(() => {
if (steps.step2a) {
try {
getAnalysisJsonPathApi().then((res) => {
//...
getResource(volumeUrl)
.then((data: any) => {
// ...
setTableData(data)
})
})
} catch (error) {
warn(error.message)
}
}
return () => {
console.log("unmounted2")
}
}, [steps.step2a])
Well, its as you said:
because of unmounting of component
In your UseEffect() function, you need to check if the componenet is mounted or not, in other words, you need to do the componentDidMount & componentDidUpdate (if needed) logics:
const mounted = useRef();
useEffect(() => {
if (!mounted.current) {
// do componentDidMount logic
console.log('componentDidMount');
mounted.current = true;
} else {
// do componentDidUpdate logic
console.log('componentDidUpdate');
}
});
i didn't go to your question code detail, but my hint might help you, usually this error happens in fetchData function,
suppose you have a fetchData function like below:
fetchData(){
...
let call = await service.getData();
...
--->setState(newItems)//Here
}
so when api call end and state want to be updated, if component been unmounted, there is no state to be set,
you can use a bool variable and set it false when component will unmount:
let stillActive= true;
fetchData(){
active = true;
...
let call = await service.getData();
...
if(stillActive)
setState(newItems)//Here
}
}
componentWillUnmount(){
active = false;
}
I've found out it's because of redux-listeners-qkreltms, Redux middleware.
It keeps function when component is mounted into listener, but never changes its functions even component is unmounted.
middleware.addListener = (type, listener) => {
for (let i = 0; i < listeners.length; i += 1) {
if (listeners[i].type === type) {
return;
}
}
listeners.push(createListener(type, listener));
};

Handling auth with React Hooks

I've been chasing my tail for hours now trying to figure out how to handle auth on my component using firebase and react hooks.
I've created a custom useAuth hook that is intended to handle all the auth behaviors. My thought was to put a useEffect on the root of my component tree that would trigger if the firebase.auth.onAuthStateChanged() ever changed (ie, user is now logged out / logged in.) But, at this point after making a million unsuccessful changes I really don't know what I'm doing anymore.
Here is the code that I have...
RootPage component
const RootPage = ({ Component, pageProps }): JSX.Element => {
const { logoutUser, authStatus } = useAuth();
const router = useRouter();
useEffect(() => {
authStatus();
}, [authStatus]);
...
}
my thought was ok, lets trigger authStatus on mount, but that ends up with me lying about my dependencies. So, in an effort to not lie about my deps, I added authStatus to the deps. Logging out and then logging in results in this:
useAuth hook
const useAuth = () => {
const { fetchUser, resetUser, userData } = useUser();
const { currentUser } = firebaseAuth;
const registerUser = async (username, email, password) => {
try {
const credentials = await firebaseAuth.createUserWithEmailAndPassword(
email,
password
);
const { uid } = credentials.user;
await firebaseFirestore
.collection('users')
.doc(credentials.user.uid)
.set({
username,
points: 0,
words: 0,
followers: 0,
following: 0,
created: firebase.firestore.FieldValue.serverTimestamp(),
});
fetchUser(uid);
console.log('user registered', credentials);
} catch (error) {
console.error(error);
}
};
const loginUser = async (email, password) => {
try {
// login to firebase
await firebaseAuth.signInWithEmailAndPassword(email, password);
// take the current users id
const { uid } = firebaseAuth.currentUser;
// update the user in redux
fetchUser(uid);
} catch (error) {
console.error(error);
}
};
const logoutUser = async () => {
try {
// logout from firebase
await firebaseAuth.signOut();
// reset user state in redux
resetUser();
return;
} catch (error) {
console.error(error);
}
};
const authStatus = () => {
firebaseAuth.onAuthStateChanged((user) => {
if (user) {
console.log('User logged in.');
// On page refresh, if user persists (but redux state is lost), update user in redux
if (userData === initialUserState) {
console.log('triggered');
// update user in redux store with data from user collection
fetchUser(user.uid);
}
return;
}
console.log('User logged out.');
});
};
return { currentUser, registerUser, loginUser, logoutUser, authStatus };
};
export default useAuth;
I'm relatively certain that react hooks are only meant for reusable pieces of logic, so if the purpose of your hook is to contact firebase in every single component you're using it, along with rerendering and refreshing state every time that component is updated, then it's fine, but you can't use hooks for storing global auth state, which is how auth should be stored.
You're looking for react context instead.
import React, {createContext, useContext, useState, useEffect, ReactNode} from 'react'
const getJwt = () => localStorage.getItem('jwt') || ''
const setJwt = (jwt: string) => localStorage.setItem('jwt', jwt)
const getUser = () => JSON.parse(localStorage.getItem('user') || 'null')
const setUser = (user: object) => localStorage.setItem('user', JSON.stringify(user))
const logout = () => localStorage.clear()
const AuthContext = createContext({
jwt: '',
setJwt: setJwt,
user: {},
setUser: setUser,
loading: false,
setLoading: (loading: boolean) => {},
authenticate: (jwt: string, user: object) => {},
logout: () => {},
})
export const useAuth = () => useContext(AuthContext)
const Auth = ({children}: {children: ReactNode}) => {
const auth = useAuth()
const [jwt, updateJwt] = useState(auth.jwt)
const [user, updateUser] = useState(auth.user)
const [loading, setLoading] = useState(false)
useEffect(() => {
updateJwt(getJwt())
updateUser(getUser())
}, [])
const value = {
jwt: jwt,
setJwt: (jwt: string) => {
setJwt(jwt)
updateJwt(jwt)
},
user: user,
setUser: (user: object) => {
setUser(user)
updateUser(user)
},
loading: loading,
setLoading: setLoading,
authenticate: (jwt: string, user: object) => {
setJwt(jwt)
updateJwt(jwt)
setUser(user)
updateUser(user)
},
logout: () => {
localStorage.removeItem('jwt')
localStorage.removeItem('user')
updateJwt('')
updateUser({})
setLoading(false)
},
}
return <AuthContext.Provider value={value}>
{children}
</AuthContext.Provider>
}
export default Auth
...
// app.tsx
import Auth from './auth'
...
<Auth>
<Router/>
</Auth>
// or something like that
...
import {useAuth} from './auth'
// in any component to pull auth from global context state
You can change that according to whatever you need.
I know the issue why its happening but don't know the solution...But i am not fully sure...Look how react works is if any parents re render it also cause re render the children..ok?Its mean if any reason your apps is re rendering and the useAuth keep firing...so for this there to much console log.But i am not sure that it will work or not..give me your repo i will try on my local computer
const RootPage = ({ Component, pageProps }): JSX.Element => {
const { logoutUser, authStatus,currentUser } = useAuth();
const router = useRouter();
useEffect(() => {
authStatus();
}, [currentUser]);
//only fire when currentUser change
...
}
Update your useEffect hook like so:
useEffect(() => {
const unsub = firebaseAuth.onAuthStateChanged((user) => {
if (user) {
console.log('User logged in.');
// On page refresh, if user persists (but redux state is lost), update user in redux
if (userData === initialUserState) {
console.log('triggered');
// update user in redux store with data from user collection
fetchUser(user.uid);
}
} else {
console.log('User logged out.');
}
});
return ()=> unsub;
},[])

Can't perform a React state update on an unmounted component. Problem with React, redux and useEffect

I have a React component using hooks like this:
const myComponent = (props) => {
useEffect(() => {
FetchData()
.then(data => {
setState({data: data});
}
// some other code
}, []);
//some other code and render method...
}
fetchData is in charge to use axios and get the data from an API:
const FetchData = async () => {
try {
res = await myApiClient.get('/myEndpoint);
} catch (err) {
console.log('error in FetchData');
res = err.response
}
}
and finally myApiClient is defined externally. I had to use this setup in order to be able to use different APIs...
import axios from "axios";
axios.defaults.headers.post["Content-Type"] = "application/json";
const myApiClient = axios.create({
baseURL: process.env.REACT_APP_API1_BASEURL
});
const anotherApiClient = axios.create({
baseURL: process.env.REACT_APP_API2_BASEURL
});
export {
myApiClient,
anotherApiClient
};
with this setup I am getting the warning
Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.
I googled a bit and I saw some suggestions on how to clean up requests from useEffect, like this, but my axios is defined externally. So how can I send the cancellation using this setup?
Also, the application is using redux, not sure if it is in some way involved.
Any other suggestion to avoid the error is welcome.
You can use defer from rxjs for this:
const FetchData = () => {
try {
return myApiClient.get("/myEndpoint");
} catch (err) {
console.log("error in FetchData");
return err.response;
}
};
const myComponent = (props) => {
useEffect(() => {
const subscription = defer(FetchData()).subscribe({
next: ({
data
}) => {
setState({
data: data
});
},
error: () => {
// error handling
},
complete: () => {
// cancel loading state etc
}
});
return () => subscription.unsubscribe();
}, []);
}
Alway check if you are dealing with fetch or any long operations.
let _isMounted = false;
const HooksFunction = props => {
const [data, setData] = useState({}); // data supposed to be object
const fetchData = async ()=> {
const res = await myApiClient.get('/myEndpoint');
if(_isMounted) setData(res.data); // res.data supposed to return an object
}
useEffect(()=> {
_isMounted = true;
return ()=> {
_isMounted = false;
}
},[]);
return (
<div>
{/*....*/}
<div/>
);
}

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