Firebase database ref on not updating at first - javascript

I'm building a chat app with react native and firebase.
When the user sign in, previous messages have to load at first launch but it provides empty arrays to promise at first then when I connect again, it shows up...
I'm using snack and I have to change code to see the chat histroy(In order to update the device).
How can I load at first launch?
edit:
firebase structure
userName:
-rooms:
-otherUser:
-messages
-name
Code:
firebase.database().ref(`userName/rooms`).on('child_added', snapshot => callback(parse(snapshot)));;
const parse = snapshot => {
//console.log(snapshot);
const { name } = snapshot.val();
const { key: _id } = snapshot;
const rooms = {
_id,
name
};
return rooms;
};
And this is happening in my useEffect:
const loadRequiredMaterials = async () => {
return new Promise(async (resolve, reject) => {
//var loadedRooms = [...rooms]
var loadedRooms = []
await on(oldRooms => {
loadedRooms = [oldRooms, ...loadedRooms]
});
await resolve([loadedRooms]);
})
}
if (firebase.auth().currentUser) {
console.log(firebase.auth().currentUser)
loadRequiredMaterials()
.then((result)=> {
console.log(result)
setRooms(result[0]);
})
}

Related

Updating state with axios response data in reactjs

I am building a website using nextjs and axios. Users can apply to become a member and then be approved by admins. In the admin dashboard I initially load the users and the unapproved users and display them in a list.
When an admin clicks on a button the unapproved user should be approved. The functionality works. The only aspect I can't figure out is how to update the state.
Here is my code:
const AdminIndex = () => {
const [users, setUsers] = useState([])
const [unapprovedUsers, setUnapprovedUsers] = useState([])
useEffect(() => {
loadUnapprovedUsers()
loadUsers()
}, [])
const loadUnapprovedUsers = async () => {
const { data } = await axios.get('/api/admin/unapprovedUsers')
setUnapprovedUsers(data)
}
const loadUsers = async () => {
const { data } = await axios.get('/api/admin/users')
setUsers(data)
}
const approveUnapprovedUser = async (email) => {
try {
const { data } = await axios.put(
`/api/admin/approveUnapprovedUser/${email}`
)
setUnapprovedUsers([]) // only remove the approved user
setUsers(...data) // include the approved user into the array
} catch (err) {
console.log(err)
}
}
}
I am trying to remove the approved user from the unapprovedUsers array and try to add the user to the users array, hence updating the UI. The response returned by axios is an object, which doesn't make things easier.
I would be very thankful for any kind of help!
Just try to filter the unapprovedUsers with the users that don't have that email, also add the approved user to users state
const AdminIndex = () => {
const [users, setUsers] = useState([])
const [unapprovedUsers, setUnapprovedUsers] = useState([])
useEffect(() => {
loadUnapprovedUsers()
loadUsers()
}, [])
const loadUnapprovedUsers = async () => {
const { data } = await axios.get('/api/admin/unapprovedUsers')
setUnapprovedUsers(data)
}
const loadUsers = async () => {
const { data } = await axios.get('/api/admin/users')
setUsers(data)
}
const approveUnapprovedUser = async (email) => {
try {
const { data } = await axios.put(
`/api/admin/approveUnapprovedUser/${email}`
)
setUnapprovedUsers(prev => prev.filter(user => user.email !== email)) // only remove the approved user
setUsers(prev => [...prev, data]) // include the approved user into the array
} catch (err) {
console.log(err)
}
}
}

Getting total Number of User Items in Firebase Realtime database in javascript

I have been trying to get amount of users that have same "referralId" in my firebase Realtime database,
users {
AY35bkc5cbkufik8gfe3vjbmgr {
email: james #gmail.com
verify: none
referralid: AY35ja35
}
B16fty9jDchfNgdx7Fxnjc5nxf5v {
email: mobilewisdom #gmail.com
verify: none
referralid: AY35ja35
}
}
How can I use JavaScript to count the amount of account with referralid:AY35ja35
I tried:
const query = ref.orderByChild('referralid').equalTo('AY35ja35');
query.get().then((results) => {
console.log(Object.keys(results.val()).length);
results.forEach((snapshot) => {
console.log(snapshot.key, snapshot.val());
});
});
But am getting this error in my console:
Uncaught TypeError: query.get is not a function
In v8/namespaced syntax that'd be:
const ref = firebase.database().ref('users');
const query = ref.orderByChild('referralid').equalTo('AY35ja35');
const results = await query.get();
console.log(Object.keys(results.val()).length);
results.forEach((snapshot) => {
console.log(snapshot.key, snapshot.val());
});
Or if you're in an environment where await doesn't work:
const ref = firebase.database().ref('users');
const query = ref.orderByChild('referralid').equalTo('AY35ja35');
query.get().then((results) => {
console.log(Object.keys(results.val()).length);
results.forEach((snapshot) => {
console.log(snapshot.key, snapshot.val());
});
});
In v9/modular syntax the equivalent would be:
const ref = ref(getDatabase(), 'users');
const query = query(ref, orderByChild('referralid'), equalTo('AY35ja35'));
const results = await get(query);
console.log(Object.keys(results.val()).length);
results.forEach((snapshot) => {
console.log(snapshot.key, snapshot.val());
});
Or if you're in an environment where await doesn't work:
const ref = ref(getDatabase(), 'users');
const query = query(ref, orderByChild('referralid'), equalTo('AY35ja35'));
get(query).then((results) => {
console.log(Object.keys(results.val()).length);
results.forEach((snapshot) => {
console.log(snapshot.key, snapshot.val());
});
});
Firstly you will have to run a query to get the data from firebase using either firebase package, axios or fetch
Your data is fetched in form of Object containing different objects. You can either user for .. in .. loop to iterate through the object.
var count = 0
for (const user in users) {
if (user.referralid==="AY35ja35") {
count++
}
}
Or use Object.values(object) function to get array of users. Now you can use a JavaScript array function such as map or filter.
by using map. you can do it like this:
var count=0
user.map(user=>{if(user.referralid==="AY35ja35"){count++})
or by using filter
const matchedUsers = user.filter(user=>(user.referralid==="AY35ja35"))
const count = matchedUsers.length
Hope this helps :)

How do I get user details in Firebase Storage?

I'm a new programmer and very new to firebase and I'm trying to get the current user files info to display on the screen, it seems that my problem is that I can get the URL and the metadata separately, how do I combine them? how can I take everything at once?
I need to show the file name, date, time, link to download.
const getUserFiles = async () => {
if (!userUID) {
return null;
}
let listRef = storageRef.child(userUID);
listRef.listAll().then(res => {
// res.prefixes.forEach((item) => {
// });
res.items.forEach(item => {
item.getMetadata().then(item => {
var file = {
name: item.name.toString(),
timeCreated: item.timeCreated.toString(),
link: '',
};
myFiles.push(file);
});
});
res.items.forEach(item => {
let counter = 0;
item.getDownloadURL().then(url => {
myFiles[counter].link = url.toString();
});
});
});
console.log(myFiles);
};
the current method don't work! and notice that the userUID its only the uid without the user (local state)
Thanks!
The problem is with the asynchronous calls. You're making an async call in forEach and forEach expects a synchronous function.
You can change the logic to use for-of instead.
See below:
const getUserFiles = async () => {
if (!userUID) {
return null;
}
let listRef = storageRef.child(userUID);
const res = await listRef.listAll();
for (const itemRef of res.items) {
const itemMetadata = await itemRef.getMetadata();
const url = await itemRef.getDownloadUrl();
var file = {
name: itemMetadata.name.toString(),
timeCreated: itemMetadata.timeCreated.toString(),
link: url,
};
myFiles.push(file);
}
console.log(myFiles);
}

Array.map() doesn't render anything in React

I'm trying to make a list in my react app. I have retrieved data from my database, and pushed it into a list. I have doublechecked that the data shows up correctly in the console, and it does, but array.map() returns nothing. I think the problem might be that array.map() runs two times. I don't know why it runs two times.
function Dashboard() {
const user = firebase.auth().currentUser;
const [teams, setTeams] = useState([])
const history = useHistory();
useEffect(() => {
getTeams()
if (user) {
} else {
history.push("/")
}
}, [])
function Welcome() {
if (user) {
return <h1>Welcome, {user.displayName}</h1>
} else {
}
}
const getTeams = () => {
firebase.firestore().collectionGroup('members').where('user', '==', user.uid).get().then((snapshot) => {
const docList = []
snapshot.forEach((doc) => {
docList.push({
teamId: doc.data().teamId,
})
})
const teamslist = []
docList.forEach((data) => {
firebase.firestore().collection('teams').doc(data.teamId).get().then((doc) => {
teamslist.push({
name: doc.data().name,
teamId: doc.id,
})
})
})
setTeams(teamslist)
})
}
const openTeam = (data) => {
console.log(data.teamId)
}
return (
<div>
<Welcome />
<div>
<ul>
{console.log(teams)}
{teams.map((data) => {
return (
<li onClick={() => openTeam(data)} key={data.teamId}>
<h1>{data.name}</h1>
<p>{data.teamId}</p>
</li>
)
})}
</ul>
</div>
</div>
)
}
export default Dashboard
The getTeams function has a bug where it isn't waiting for the firebase.firestore().collection('teams').doc(data.teamId).get().then promises to finish before calling setTeams, so it is called with an empty array, causing React to trigger a render with the empty array.
As the promises for fetching each team resolve they will be pushed to the same array reference, but this won't trigger a rerender in React since you're not calling setTeams again when the array changes.
Try this code, which won't call setTeams until each team promise generated from docList has been resolved.
const getTeams = () => {
firebase.firestore().collectionGroup('members').where('user', '==', user.uid).get().then((snapshot) => {
const docList = []
snapshot.forEach((doc) => {
docList.push({
teamId: doc.data().teamId,
})
})
const teamslist = [];
Promise.all(docList.map((data) => {
return firebase
.firestore()
.collection('teams')
.doc(data.teamId)
.get()
.then((doc) => {
teamslist.push({
name: doc.data().name,
teamId: doc.id,
})
})
}))
.then(() => setTeams(teamslist));
})
}
A smaller edit would be to call setTeams after each separate team promise resolves, which will trigger a React render each time a new team is resolved:
.then((doc) => {
teamslist.push({
name: doc.data().name,
teamId: doc.id,
});
// create a new array, since using the same array
// reference won't cause react to rerender
setTeams([...teamslist]);
})
Many thanks to #martinstark who provided you an answer while I was unavailable.
However, there are some more things that need to be covered.
User State
In your current component, you pull the current user from Firebase Authentication, but don't handle the state changes of that user - signing in, signing out, switching user. If a user is signed in and they were to navigate directly to your dashboard, firebase.auth().currentUser could be momentarily null while it resolves the user's login state, which would incorrectly send them off to your login page.
This can be added using:
const [user, setUser] = useState(() => firebase.auth().currentUser || undefined);
const userLoading = user === undefined;
useEffect(() => firebase.auth().onAuthStateChanged(setUser), []);
Next, in your first useEffect call, you call getTeams() whether the user is signed in or not - but it should depend on the current user.
useEffect(() => {
if (userLoading) {
return; // do nothing (yet)
} else if (user === null) {
history.push("/");
return;
}
getTeams()
.catch(setError);
}, [user]);
// This getTeams() is a () => Promise<void>
const getTeams = async () => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', user.uid)
.get();
const docList = []
membersQuerySnapshot.forEach((doc) => {
docList.push({
teamId: doc.get("teamId"), // better perfomance than `doc.data().teamId`
});
});
const teamDataList = [];
await Promise.all(docList.map((data) => {
return firebase.firestore()
.collection('teams')
.doc(data.teamId)
.get()
.then(doc => teamDataList.push({
name: doc.get("name"),
teamId: doc.id
}));
}));
setTeams(teamDataList);
}
Optimizing getTeams() - Network Calls
The getTeams function in your question calls setTeams with the array [], which will be empty at the time of calling it as covered in #martinstark's answer. The "get team data" operations are asyncronous and you aren't waiting for them to resolve before updating your state and triggering a new render. While you are pushing data to them after the component has rendered, modifying the array won't trigger a new render.
While you could fetch the data for each team using db.collection("teams").doc(teamId).get(), each of these is requests is a network call, and you can only make a limited number of these in parallel. So instead of fetching 1 team per network call, you could fetch up to 10 teams per network call instead using the in operator and FieldPath.documentId().
Assuming the collectionGroup("members") targets the collections of documents at /teams/{aTeamId}/members which contain (at least):
"/teams/{aTeamId}/members/{memberUserId}": {
teamId: aTeamId,
user: memberUserId, // if storing an ID here, call it "uid" or "userId" instead
/* ... */
}
// this utility function lives outside of your component near the top/bottom of the file
function chunkArr(arr, n) {
if (n <= 0) throw new Error("n must be greater than 0");
return Array
.from({length: Math.ceil(arr.length/n)})
.map((_, i) => arr.slice(n*i, n*(i+1)))
}
// This getTeams() is a () => Promise<void>
const getTeams = async () => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', user.uid)
.get();
const teamIDList = []
membersQuerySnapshot.forEach((doc) => {
teamIDList.push(doc.get("teamId")); // better perfomance than `doc.data().teamId`
})
const chunkedTeamIDList = chunkArr(teamIDList, 10) // split into batches of 10
const teamsColRef = firebase.firestore().collection('teams');
const documentId = firebase.firestore.FieldPath.documentId(); // used with where() to target the document's ID
const foundTeamDocList = await Promise
.all(chunkedTeamIDList.map((chunkOfTeamIDs) => {
// fetch each batch of IDs
return teamsColRef
.where(documentId, 'in', chunkOfTeamIDs)
.get();
}))
.then((arrayOfQuerySnapshots) => {
// flatten results into a single array
const allDocsList = [];
arrayOfQuerySnapshots.forEach(qs => allDocsList.push(...qs.docs));
return allDocsList;
});
const teamDataList = foundTeamDocList
.map((doc) => ({ name: doc.get("name"), teamId: doc.id }));
// sort by name, then by ID
teamDataList.sort((aTeam, bTeam) =>
aTeam.name.localeCompare(bTeam.name) || aTeam.teamId.localeCompare(bTeam.teamId)
)
// update state & trigger render
setTeams(teamDataList);
}
You can also make use of this utility function to simplify & optimize the code a bit. Which gives:
// This getTeams() is a () => Promise<void>
const getTeams = async () => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', user.uid)
.get();
const teamIDList = []
membersQuerySnapshot.forEach((doc) => {
teamIDList.push(doc.get("teamId")); // better perfomance than `doc.data().teamId`
})
const teamsColRef = firebase.firestore().collection('teams');
const teamDataList = [];
await fetchDocumentsWithId(
teamsColRef,
teamIDList,
(doc) => teamDataList.push({ name: doc.get("name"), teamId: doc.id })
);
// sort by name, then by ID
teamDataList.sort((aTeam, bTeam) =>
aTeam.name.localeCompare(bTeam.name) || aTeam.teamId.localeCompare(bTeam.teamId)
)
// update state & trigger render
setTeams(teamDataList);
}
Optimizing getTeams() - Function Definition
As part of the last optimization, you could pull it out of your component or place it in its own file so that it's not redefined with every render:
// define at top/bottom of the file outside your component
// This getTeams() is a (userId: string) => Promise<{ name: string, teamId: string}[]>
async function getTeams(userId) => {
const membersQuerySnapshot = await firebase.firestore()
.collectionGroup('members')
.where('user', '==', userId)
.get();
const teamIDList = []
membersQuerySnapshot.forEach((doc) => {
teamIDList.push(doc.get("teamId")); // better perfomance than `doc.data().teamId`
})
const teamsColRef = firebase.firestore().collection('teams');
const teamDataList = [];
await fetchDocumentsWithId(
teamsColRef,
teamIDList,
(doc) => teamDataList.push({ name: doc.get("name"), teamId: doc.id })
);
// sort by name, then by ID
teamDataList.sort((aTeam, bTeam) =>
aTeam.name.localeCompare(bTeam.name) || aTeam.teamId.localeCompare(bTeam.teamId)
)
// return the sorted teams
return teamDataList
}
and update how you use it:
useEffect(() => {
if (userLoading) {
return; // do nothing
} else if (user === null) {
history.push("/");
return;
}
getTeams(user.uid)
.then(setTeams)
.catch(setError);
}, [user]);

BINANCE API - How to get Account info with User Data Stream

I'm using Node and the ws npm package to work with WebSockets. Got the listenKey as stated in the docs (below), but I'm unable to get my account info using User Data Stream. I'd prefer to use a stream to read my most current account info (balances, etc) since using the Rest API to do it incurs a penalty (WEIGHT: 5) each time.
I've tried doing ws.send('outboundAccountInfo') but no joy.
DOCS: https://github.com/binance-exchange/binance-official-api-docs/blob/master/user-data-stream.md
Full code example - does not return any data:
import request from 'request'
import WebSocket from 'ws'
import { API_KEY } from '../../assets/secrets'
const DATA_STREAM_ENDPOINT = 'wss://stream.binance.com:9443/ws'
const BINANCE_API_ROOT = 'https://api.binance.com'
const LISTEN_KEY_ENDPOINT = `${BINANCE_API_ROOT}/api/v1/userDataStream`
const fetchAccountWebsocketData = async() => {
const listenKey = await fetchListenKey()
console.log('-> ', listenKey) // valid key is returned
let ws
try {
ws = await openWebSocket(`${DATA_STREAM_ENDPOINT}/${listenKey}`)
} catch (err) {
throw(`ERROR - fetchAccountWebsocketData: ${err}`)
}
// Nothing returns from either
ws.on('message', data => console.log(data))
ws.on('outboundAccountInfo', accountData => console.log(accountData))
}
const openWebSocket = endpoint => {
const p = new Promise((resolve, reject) => {
const ws = new WebSocket(endpoint)
console.log('\n-->> New Account Websocket')
ws.on('open', () => {
console.log('\n-->> Websocket Account open...')
resolve(ws)
}, err => {
console.log('fetchAccountWebsocketData error:', err)
reject(err)
})
})
p.catch(err => console.log(`ERROR - fetchAccountWebsocketData: ${err}`))
return p
}
const fetchListenKey = () => {
const p = new Promise((resolve, reject) => {
const options = {
url: LISTEN_KEY_ENDPOINT,
headers: {'X-MBX-APIKEY': API_KEY}
}
request.post(options, (err, httpResponse, body) => {
if (err)
return reject(err)
resolve(JSON.parse(body).listenKey)
})
})
p.catch(err => console.log(`ERROR - fetchListenKey: ${err}`))
return p
}
export default fetchAccountWebsocketData
Was stuggling too .... for hours !!!
https://www.reddit.com/r/BinanceExchange/comments/a902cq/user_data_streams_has_anyone_used_it_successfully/
The binance user data stream doesn't return anything when you connect
to it, only when something changes in your account. Try running your
code, then go to binance and place an order in the book, you should
see some data show up*

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