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React Native - Variable does not update correctly when retrieving data from AsyncStorage

I'm trying to store and get data that I fetch from an API. The user is supposed to get a token on the login screen, and the token will be shown in an Alert dialog on home screen when the user press a button. But the token is not shown in the Alert dialog. the token is shown after I reload(not refresh the app. I used Live Server extension) the screen three times.
Login.js
const _userLogin = () => {
fetch(URLs._login, {
method: "POST",
headers, body,
})
}).then((response) => response.json())
.then((result) => {
if(result.message !== "Unauthorized / Access Token Expired" && result.message !== "The given data was invalid."){
storeData(result.access_token, result.token_type);
navigation.navigate('HomeScreen');
} else {
Alert.alert("Error", result.message);
}
});
};
const storeData = async (accessToken, tokenType) => {
try {
await AsyncStorage.setItem('#access_token', accessToken);
await AsyncStorage.setItem('#token_type', tokenType);
await AsyncStorage.setItem('#user_auth', tokenType + " " + accessToken);
} catch (e) {
console.log(e);
}
}
Home.js [UPDATE]
const [inputs, setInputs] = React.useState({
userToken: '',
userPointsBalance: '',
expiringOn: '',
});
useEffect (() => {
_dashboard();
})
const getToken = async () => {
inputs.userToken = await AsyncStorage.getItem('#user_auth');
}
const _dashboard = () => {
getToken();
fetch(URLs._dashboard, {
method: "GET",
headers: {
'Authorization': inputs.userToken,
'Content-Type': 'application/json',
},
}).then((response) => response.json())
.then(async (result) => {
storeData(result.code, result.name, result.member_name, result.user_points_balance, result.expiring_on, result.status, result.token_id);
getData();
});
};
const storeData = async (code, name, memberName, userPointsBalance, expiringOn, status, tokenId) => {
try {
await AsyncStorage.setItem('#user_points_balance', userPointsBalance.toString());
await AsyncStorage.setItem('#expiring_on', expiringOn.toString());
} catch (e) {
console.log(e);
}
}
const getData = async () => {
const userPointsBalance = await AsyncStorage.getItem('#user_points_balance');
const expiringOn = await AsyncStorage.getItem('#expiring_on');
setInputs({userPointsBalance: userPointsBalance, expiringOn: expiringOn});
}
return (
<Text>{inputs.expiringOn}<Text>
)

i hope it works
.then(async(result) => {
if(result.message !== "Unauthorized / Access Token Expired" && result.message !== "The given data was invalid."){
await storeData(result.access_token, result.token_type)
.then(res=>
navigation.navigate('HomeScreen')
)
} else {
Alert.alert("Error", result.message);
}
});

Use Effect doesn't run on websocket ON

I am working on a websocket project in react. But when I send a message, the websocket does reload to display new messages. I have to reload my page manually to show the changes.
Here's my use Effect Hook
useEffect(() => {
if (socket.current) {
socket.current.on('msgSent', ({ newMsg }) => {
console.log('MESSAGE SENT', newMsg)
if (newMsg.receiver === openChatId.current) {
setMessages((prev) => [...prev, newMsg])
setChats((prev) => {
const previousChat = prev.find(
(chat) => chat.messagesWith === newMsg.receiver
)
previousChat.lastMessage = newMsg.msg
previousChat.date = newMsg.date
return [...prev]
})
}
})
}
}, [])
When I remove the useEffect dependency (i.e []), It works but it renders the message multiple times on the screen.
Here's the rest of my frontend client code
const openChatId = useRef('')
const auth = useContext(AuthContext)
const queryMessage = new URLSearchParams(search).get('message')
useEffect(() => {
if (!socket.current) {
socket.current = io(process.env.REACT_APP_API)
}
if (socket.current) {
socket.current.emit('join', { userId: auth.user._id })
socket.current.on('connectedUsers', ({ users }) => {
users.length > 0 && setConnectedUsers(users)
})
}
if (chats.length > 0 && !queryMessage) {
history.push(`/messages?message=${chats[0].messagesWith}`, undefined, {
shallow: true,
})
}
return () => {
if (socket.current) {
socket.current.emit('logout')
socket.current.off()
}
}
}, [chats])
useEffect(() => {
const getAllChats = async (token) => {
try {
setLoading(true)
const res = await getChats(token)
if (res) {
setChats(res)
setLoading(false)
}
} catch (err) {
console.log(err)
setLoading(false)
}
}
getAllChats(auth.token)
}, [])
useEffect(() => {
const loadMessages = () => {
socket.current.emit('loadMessages', {
userId: auth.user._id,
messagesWith: queryMessage,
})
socket.current.on('messagesLoaded', async ({ chat }) => {
setMessages(chat.messages)
setBannerData({
firstName: chat.messagesWith.firstName,
lastName: chat.messagesWith.lastName,
profilePicUrl: chat.messagesWith.profilePicUrl,
})
openChatId.current = chat.messagesWith._id
})
socket.current.on('noChatFound', async () => {
const { firstName, lastName, profilePicUrl } = await ChatGetUserInfo(
queryMessage,
auth.token
)
setBannerData({ firstName, lastName, profilePicUrl })
setMessages([])
openChatId.current = queryMessage
})
}
if (socket.current) {
loadMessages()
}
}, [queryMessage])
const sendMsg = (msg) => {
if (socket.current) {
socket.current.emit('sendNewMsg', {
userId: auth.user._id,
msgSendToUserId: openChatId.current,
msg,
})
}
}
The backend works very well. U think my problem is with the useEffect

I fixed it. I was missing the [chats] dependency

React Redux Thunk with callback to another function -- TypeError: Cannot read property 'then' of undefined

I am using react+redux.
I have a modal form with data and images and on success I need to close the modal else display error returned from redux. In the dispatch function I have 1 more callback function to store images to S3. I am returning promise from the redux-thunk but I keep getting "TypeError: Cannot read property 'then' of undefined".
Component
handleSubmit = e => {
e.preventDefault();
if(this.isFieldEmpty()){
this.setState({ message: "All fields are mandatory with at least 1 pic" });
return;
} else {
this.setState({ message: "" });
}
const data = {
name: this.state.name,
description : this.state.description,
points : this.state.points,
attributes : this.state.attributes,
images : this.state.images,
created_by: localStorage.getItem('id'),
}
this.props.createItem(data).then(() => {
this.hideModal();
})
}
const mapDispatchToProps = dispatch => {
return {
createItem: data => {
return dispatch(createItem(data))
},
};
};
Action
const saveItemImages = (images,successcb, failurecb) => {
if(images.length > 0){
const formData = new FormData();
for(var x = 0; x<images.length; x++) {
formData.append('image', images[x])
}
const token = localStorage.getItem('token');
fetch(`${backendUrl}/upload/item-images/`, {
method: "POST",
headers: {
'Authorization': `Bearer ${token}`
},
credentials: 'include',
body: formData
})
.then(res => {
if(res.status === 200){
res.json().then(resData => {
successcb(resData.imagesUrl);
});
}else{
res.json().then(resData => {
failurecb(resData.message);
})
}
})
.catch(err => {
console.log(err);
});
} else {
successcb([]);
}
}
export const createItem = data => { return (dispatch) => {
saveItemImages(data.images, imagesUrl => {
data.images = imagesUrl;
return fetch(`${backendUrl}/admin/createItem`, {
method: 'POST',
headers: {
'Accept': 'application/json, text/plain, */*',
'Content-Type': 'application/json',
'Authorization': `Bearer ${data.token}`
},
credentials: 'include',
body: JSON.stringify(data)
})
.then(res => {
if(res.status === 200){
res.json().then(resData => {
dispatch({
type: ADMIN_CREATE_ITEM_SUCCESS,
payload: resData
})
return true;
});
}else{
console.log("Save failed");
res.json().then(resData => {
dispatch({
type: ADMIN_CREATE_ITEM_FAILED,
payload: {
message: resData.message
}
})
})
}
})
.catch(err => {
dispatch({
type: ADMIN_CREATE_ITEM_FAILED,
payload: {
message: `Internal Error -- ${err}`
}
})
});
}, failedMessage => {
let payload = {responseMessage: failedMessage}
dispatch({
type: ADMIN_CREATE_ITEM_FAILED,
payload: payload
})
});
};
};
Thanks in advance for any help

You should return a Promise to create async flow for the action like this:
export const createItem = data => dispatch => new Promise((resolve, reject) => {
// do something was a success
resolve();
// do something was a fail
reject();
});

React Redux promise error - (...).then is not a function

Had a look for this in the questions that offered but this was the closest and it didnt really address my problem.
I have a code block (detailed a little way down the page) as part of a larger fetch block.. it gets to this codeblock and also runs fine if this code block is commented out i.e it carrys out a successful fetch etc and returns a JWT no problem but... add this block in and i get the following error:
TypeError: (0 , _localStorageDropDowns.confirmSelectDataExistance)(...).then is not a function
It is referring to this function in another folder (imported correctly)..
export const confirmSelectDataExistance = () => {
const companyStateShortNameJson = localStorage.getItem(COMPANYSTATESHORTNAME)
const statesJson = localStorage.getItem(STATES)
const suburbLocationsJson = localStorage.getItem(LOCATIONS)
if (companyStateShortNameJson || statesJson || suburbLocationsJson) {
console.log('something exists in localstorage')
return true
}
console.log('nothing in localstorage')
return false
}
simple function - returns true or false.
and here is the code block -its failing on the first line:
return confirmSelectDataExistance().then(isConfirmed => {
if (!isConfirmed) {
dispatch({ type: REQUEST_SELECT_DATA })
console.log('gets here!', isConfirmed)
const token = getJwt()
const headers = new Headers({
'Authorization': `Bearer ${token}`
})
const retrieveSelectData = fetch('/api/SelectData/SelectData', {
method: 'GET',
headers: {
'Content-Type': 'application/json;charset=UTF-8'
},
})
.then(handleErrors)
.then(response => response.json())
.then(selectData => {
dispatch({ type: RECEIVE_SELECT_DATA, payload: selectData })
saveSelectData(selectData)
});
return saveSelectData(selectData);
}
})
From my limited experience the "confirmSelectDataExistance" is a function so why is it saying that its not?
Finally here is the whole action in its entirety so you can see how it that block is called.. as I said - comment the block out and it works perfectly..
export const requestLoginToken = (username, password) =>
(dispatch, getState) => {
dispatch({ type: REQUEST_LOGIN_TOKEN, payload: username })
const payload = {
userName: username,
password: password,
}
const task = fetch('/api/jwt', {
method: 'POST',
body: JSON.stringify(payload),
headers: {
'Content-Type': 'application/json;charset=UTF-8'
},
})
.then(handleErrors)
.then(response => response.json())
.then(data => {
dispatch({ type: RECEIVE_LOGIN_TOKEN, payload: data })
saveJwt(data)
return confirmSelectDataExistance().then(isConfirmed => {
if (!isConfirmed) {
dispatch({ type: REQUEST_SELECT_DATA })
console.log('gets here!', isConfirmed)
const token = getJwt()
const headers = new Headers({
'Authorization': `Bearer ${token}`
})
const retrieveSelectData = fetch('/api/SelectData/SelectData', {
method: 'GET',
headers: {
'Content-Type': 'application/json;charset=UTF-8'
},
})
.then(handleErrors)
.then(response => response.json())
.then(selectData => {
dispatch({ type: RECEIVE_SELECT_DATA, payload: selectData })
saveSelectData(selectData)
});
return saveSelectData(selectData);
}
})
})
.catch(error => {
clearJwt()
console.log('ERROR - LOGIN!',error)
})
addTask(task)
return task
}
EDIT
I have finally got this to work after hacking away for hours.. Here is the finished action:
export const requestLoginToken = (username, password) =>
(dispatch, getState) => {
dispatch({ type: REQUEST_LOGIN_TOKEN, payload: username })
const payload = {
userName: username,
password: password,
}
const task = fetch('/api/jwt', {
method: 'POST',
body: JSON.stringify(payload),
headers: {
'Content-Type': 'application/json;charset=UTF-8'
},
})
.then(handleErrors)
.then(response => response.json())
.then(data => {
dispatch({ type: RECEIVE_LOGIN_TOKEN, payload: data })
saveJwt(data)
// Now check local storage for dropdown data..
if (!confirmSelectDataExistance()) {
dispatch({ type: REQUEST_SELECT_DATA })
const token = JSON.stringify(data)
const headers = new Headers({
'Authorization': `Bearer ${token}`
})
const retrieveSelectData = fetch('/api/SelectData/SelectData', {
method: 'GET',
headers: {
'Content-Type': 'application/json;charset=UTF-8'
},
})
.then(handleErrors)
.then(response => response.json())
.then(selectData => {
dispatch({ type: RECEIVE_SELECT_DATA, payload: selectData })
saveSelectData(selectData)
});
}
})
.catch(error => {
clearJwt()
console.log('ERROR - LOGIN!', error)
})
addTask(task)
return task
}
and here is the function it calls:
export const confirmSelectDataExistance = () => {
const companyStateShortNameJson = localStorage.getItem(COMPANYSTATESHORTNAME)
const statesJson = localStorage.getItem(STATES)
const suburbLocationsJson = localStorage.getItem(LOCATIONS)
if (companyStateShortNameJson || statesJson || suburbLocationsJson) {
console.log('something exists in localstorage')
return true
}
console.log('nothing in localstorage')
return false
}
The one thing I changed from the other attempts is that I used "data" instead of calling "getJwt()". I then used the line:
const token = JSON.stringify(data)
to obtain the JWT I just got.
In the end I used #Karin s answer and ran with that. (upvoted by me)

The error is not saying that confirmSelectDataExistance is not a function, it's saying that then isn't a function on what is returned from it, which is a boolean (it would be equivalent to false.then(...), which doesn't work).
If seems like you're trying to use then as a conditional. In that case a simple if statement should work:
if (confirmSelectDataExistance()) {
// do things if it returns true
} else {
// do things if it returns false
}

export const confirmSelectDataExistance = () => {
return new Promise(function (resolve, reject) {
const companyStateShortNameJson = localStorage.getItem(COMPANYSTATESHORTNAME)
const statesJson = localStorage.getItem(STATES)
const suburbLocationsJson = localStorage.getItem(LOCATIONS)
if (companyStateShortNameJson || statesJson || suburbLocationsJson) {
console.log('something exists in localstorage')
resolve(true)
}
console.log('nothing in localstorage')
reject(false)
})
}

Try something like this:
export const confirmSelectDataExistance = new Promise((resolve, reject) => {
const companyStateShortNameJson = localStorage.getItem(COMPANYSTATESHORTNAME);
const statesJson = localStorage.getItem(STATES);
const suburbLocationsJson = localStorage.getItem(LOCATIONS);
if (companyStateShortNameJson || statesJson || suburbLocationsJson) {
console.log('something exists in localstorage');
resolve(true);
}
console.log('nothing in localstorage');
reject(false); // or resolve(false) if you want handle this situation inside then block also
});

How catch error from async action with redux?

I have fetch, it throws error:
fetchAuthorization(username, password) {
return fetch(`https://api.github.com/user`, {
method: 'GET',
headers: {
"Accept": 'application/json',
"Content-Type": 'application/json',
"Authorization": "Basic " + btoa(`${username}:${password}`)
},
})
.then(res => {
if(res.status !== 200) {
throw Error("Bad validation");
}
return res.json();
});
},
then this async action (redux):
export const onSignInAction = (username, password) => {
return dispatch => {
return api.fetchAuthorization(username, password)
.then( res => {
dispatch(signInAction(username, password, res));
})
.catch(err => console.log(err));
}
}
next:
handleSignIn = (username, password) => {
const { onSignInAction } = this.props;
onSignInAction(username, password);
}
And now I want catch Error from my fetch :
handleSignIn = () => {
const { onSignIn } = this.props;
const { errorMessage, open } = this.state;
const username = this.usernameField.getValue();
const password = this.passwordField.getValue();
try {
onSignIn(username, password);
}
catch (Error) {
this.setState({
errorMessage: 'Incorrect username or password'
});
}
}
How to catch it correctly? My code doesn't do this stuff. Thanks!

You can throw error from .catch(), substitute Promise.prototype.catch() for try..catch
var onSignInAction = () => {
return Promise.reject(new Error("Bad validation")).catch(e => {
console.log("catch 1", e.message);
throw e
});
}
onSignInAction()
.catch(err => {
console.log("catch 2:", {
errorMessage: 'Incorrect username or password'
}, err.message);
});