We Keep Coding

How to get all documents in Firestore (v9) sub collection

I'm trying to get all documents in all sub-collection with Firebase V9, so I used collectionGroup to retrieve the data.
Here is my Firestore architecture :
bots (collection)
| id (doc ID)
| order_history (sub collection)
| id (doc ID)
createdBy: uid (user uid)
And this is how I try to get documents :
const [orders, setOrders] = useState([]);
const { user } = useAuth();
const getOrders = async () => {
const orders = await getDocs(query(collectionGroup(db, 'order_history'), where('createdBy', '==', user.uid)));
setOrders(orders.docs.map((doc) => ({
...doc.data()
})))
}
useEffect(() => {
getOrders();
console.log('orders ', orders); // return []
}, []);
This code returns an empty array.
Did I do something wrong?

I think your getOrders function is asynchronus function.
If you want debug log I think you should waiting for getOrders completed then orders had been updated.
Ex:
useEffect(() => {
console.log('orders ', orders);
}, [orders]);

Your getOrders anonymous method execution requires an explicit return statement if there's more than 1 statement. Implicit returns work when only a single statement exists (and after some testing, return await X doesn't appear to work either).
const getOrders = async () => {
const orders = await getDocs(...);
setOrders(orders.docs.map(...))
}
Needs to be
const getOrders = async () => {
const orders = await getDocs(...);
return setOrders(orders.docs.map(...))
}

Trouble returning the customer object with stripe queries

I am playing around with stripe queries and in the documentation this is the example that is given:
const stripe = require('stripe')('some-api-key');
const customer = await stripe.customers.search({
query: 'metadata[\'foo\']:\'bar\'',
});
so naturally I tried this:
const stripe = require('stripe')('some-api-key');
const customer = async () => await stripe.customers.search({
query: 'metadata[\'foo\']:\'bar\'',
});
console.log(customer)
but all I get back is this in the console:
customer() {
return _ref.apply(this, arguments);
}
and when I try this I just get promise pending:
console.log(customer().then(data => console.log(data)));
what am I doing wrong here?

If you are doing this:
const customer = async () => await stripe.customers.search({
query: 'metadata[\'foo\']:\'bar\'',
});
Then customer is an async function. So you have two ways to log the result: console.log(await customer()) or customer().then(res => console.log(res)).

How to await admin.auth().getUser() method within a forEach loop?

I am trying to iterate over an array of comments and need to grab the commenter's uid for each comment. I am a beginner to JavaScript and need a little bit of help with the following use case:
I need to grab the uid for each comment and then run a .getUser() method which will return the user's email address that is associated with the user's uid. Since .getUser() returns a promise (method reference link), I need to await somewhere in this loop. How to do so? Is this even a good approach?
(Note: My end goal is to eventually attach the email addresses to a to property in a msg object where I will then send out email notifications.)
Example data for comments:
[
{
id: 1,
uid: 'RGaBbiui'
},
{
id: 2,
uid: 'ladfasdflal'
},
{
id: 3,
uid: 'RGaBbiui'
},
{
id: 4,
uid: 'RGaBbiui'
},
{
id: 5,
uid: 'ladfasdflal'
},
{
id: 6,
uid: 'ladfasdflal'
}
]
Cloud function example:
export const sendCommentNotification = functions.firestore
.document('users/{uid}/posts/{postId}/comments/{commentId}')
.onCreate(async (snapshot, context) => {
try {
const commentsQuery = await admin
.firestore()
.collection(
`users/${context.params.uid}/posts/${context.params.postId}/comments`
)
.get()
const commentsArr = []
commentsQuery.forEach((documentSnapshot) =>
commentsArr.push(documentSnapshot.data())
)
const commentsArrUids = new Set(commentsArr.map((c) => c.uid))
console.log(commentsArrUids)
const emailAddresses = []
commentsArrUids.forEach((uid) =>
emailAddresses.push(admin.auth().getUser(uid)) // how to use await here?
)
...
const msg = {
to: //TO DO..put email addresses here..
...

You cannot use await in a forEach loop. You could use await in a for-loop but they won't run simultaneously as in Promise.all().
You can just await all the promises at once using Promise.all():
Returned values will be in order of the Promises passed, regardless of completion order.
const emailAddresses = []
commentsArrUids.forEach((uid) => {
emailAddresses.push(admin.auth().getUser(uid))
})
const data = await Promise.all(emailAddresses)
Data will be an array of UserRecord.
Then you can use the .map() method to get an array of all the emails.
const emails = data.map((user) => user.email)
The code can be written like this to make it easier:
const commentsDocs = await admin.firestore().collection(`users/${context.params.uid}/posts/${context.params.postId}/comments`).get()
const userIds = commentsDocs.docs.map(comment => comment.userId)
const usersReq = userIds.map(u => admin.auth().getUser(u.uid))
const emails = (await Promise.all(usersReq))).map((user) => user.email)

Use for loop instead.
for (let i = 0; i < commentsArrUids.length; i++) {
let user = await new Promise((resolve, reject) => {
admin.auth().getUser(commentsArrUids[i]).then((user) => {
resolve(user);
});
};
emailAddresses.push(user);
}

I will replace forEach with for of and the promises is in series. Also, I rewrite some of your codes as they are redundant.
export const sendCommentNotification = functions.firestore
.document("users/{uid}/posts/{postId}/comments/{commentId}")
.onCreate(async (snapshot, context) => {
try {
const comments = await admin
.firestore()
.collection(
`users/${context.params.uid}/posts/${context.params.postId}/comments`
)
.get();
const uids = new Set();
for (const comment of comments) {
uids.add(comment.data().uid);
}
const emailAddresses = [];
for (const uid of uids) {
const res = await admin.auth().getUser(uid);
emailAddresses.push(res);
}
} catch (err) {
console.log(err);
}
});

How do I use a document's field from one collection to retrieve another document field from a different collection?

Here is how my database is structured:
challenges table &
users table
Here is the error I'm getting: error image
I want to use the "created_by" field which is also a document id for the users table, where I want to retrieve both the display name and the photo URL.
I'm not all the way sure how promises work and I have a feeling that is why I'm struggling, but the code I have thus far is below:
Data Retrieval:
UsersDao.getUserData(ChallengesDao.getChallenges().then(result => {return result['author'][0]})).then(result => {console.log(result)})
Challenges DAO:
export default class ChallengesDao {
static async getChallenges() {
const db = require('firebase').firestore();
// const challenges = db.collection('challenges').limit(number_of_challenges)
// challenges.get().then(())
const snapshot = await db.collection('challenges').get()
const names = snapshot.docs.map(doc => doc.data().name)
const createdBy = snapshot.docs.map(doc => doc.data().created_by)
const highScores = snapshot.docs.map(doc => doc.data().high_score.score)
return {challengeName: names, author: createdBy, score: highScores}
}
Users DAO:
const db = require('firebase').firestore();
export default class UsersDao {
static async getUserData(uid: string) {
let userData = {};
try {
const doc = await db
.collection('users')
.doc(uid)
.get();
if (doc.exists) {
userData = doc.data();
} else {
console.log('User document not found!');
}
} catch (err) {}
return userData;
}
}

You're getting close. All that's left to do is to call getUserData for each UID you get back from getChallenges.
Combining these two would look something like this:
let challenges = await getChallenges();
let users = await Promise.all(challenges.author.map((uid) => getUserData(uid));
console.log(challenges.challengeName, users);
The new thing here is Promise.all(), which combines a number of asynchronous calls and returns a promise that completes when all of them complete.
Your code looks a bit odd to me at first, because of the way you return the data from getChallenges. Instead of returning three arrays with simple values, I'd recommend returning a single array where each object has three values:
static async getChallenges() {
const db = require('firebase').firestore();
const snapshot = await db.collection('challenges').get();
const challenges = snapshot.docs.map(doc => { name: doc.data().name, author: doc.data().created_by, score: doc.data().high_score.score });
return challenges;
}
If you then want to add the user name to each object in this array, in addition to the UID that's already there, you could do:
let challenges = await getChallenges();
await Promise.all(challenges.forEach(async(challenge) => {
challenge.user = await getUserData(challenge.author);
});
console.log(challenges);

How to access date in next .then() - fetch api

I wonder if there is a way to access data from then on the next one? Code looks like this:
fetch(`http://localhost:3003/users/${userObject.id}`)
.then(res => res.json())
.then(user => {
...
})
.then(???)
and in second then I have all the needed info about the user. When I put everything in second then it works, but code is very messy and repetitive and I would like to put some things into function. Unfortunately, in that case, I don't have access to some data...
Any ideas? Thanks!

You can pass an argument to the next promise by returning it from the previous one.
fetch(`http://localhost:3003/users/${userObject.id}`)
.then(res => res.json())
.then(user => {
return user.id;
})
.then(userId => {
console.log('user id is:', userId);
});
Also, you can accomplish same result by using async programming like bellow:
async function fetchSomeData() {
var res = await fetch(`http://localhost:3003/users/${userObject.id}`);
var user = await res.json();
return user;
}
fetchSomeData().then(user => {
console.log('user id is:', user.id)
});

but code is very messy and repetitive and I would like to put some
things into function
Just use async/await syntax, it's much more understandable.
(async() => {
const request = await fetch(`http://localhost:3003/users/${userObject.id}`);
const result = await request.json();
// proceed to do whatever you want with the object....
})();
This is a self-executing function, but you can also declare this in the following way:
const myFunc = async() => {
const request = await fetch(`http://localhost:3003/users/${userObject.id}`);
const result = await request.json();
// your logic here or you can return the result object instead;
};
or even without arrow functions:
const myFunc = async function() {
const request = await fetch(`http://localhost:3003/users/${userObject.id}`);
const result = await request.json();
console.log(result.id);
};