I am using Firebase authentication to store users. I have two types of users: Manager and Employee. I am storing the manager's UID in Firestore employee along with the employee's UID. The structure is shown below.
Firestore structure
Company
|
> Document's ID
|
> mng_uid: Manager's UID
> emp_uid: Employee's UID
Now I want to perform a query like "Retrieve employees' info which is under the specific manager." To do that I tried to run the below code.
module.exports = {
get_users: async (mng_uid, emp_uid) => {
return await db.collection("Company").where("manager_uid", "==", mng_uid).get().then(snaps => {
if (!snaps.empty) {
let resp = {};
let i = 0;
snaps.forEach(async (snap) => {
resp[i] = await admin.auth().getUser(emp_uid).then(userRecord => {
return userRecord;
}).catch(err => {
return err;
});
i++;
});
return resp;
}
else return "Oops! Not found.";
}).catch(() => {
return "Error in retrieving employees.";
});
}
}
Above code returns {}. I tried to debug by returning data from specific lines. I got to know that the issue is in retrieving the user's info using firebase auth function which I used in forEach loop. But it is not returning any error.
Thank you.
There are several points to be corrected in your code:
You use async/await with then() which is not recommended. Only use one of these approaches.
If I understand correctly your goal ("Retrieve employees' info which is under the specific manager"), you do not need to pass a emp_uid parameter to your function, but for each snap you need to read the value of the emp_uid field with snap.data().emp_uid
Finally, you need to use Promise.all() to execute all the asynchronous getUser() method calls in parallel.
So the following should do the trick:
module.exports = {
get_users: async (mng_uid) => {
try {
const snaps = await db
.collection('Company')
.where('manager_uid', '==', mng_uid)
.get();
if (!snaps.empty) {
const promises = [];
snaps.forEach(snap => {
promises.push(admin.auth().getUser(snap.data().emp_uid));
});
return Promise.all(promises); //This will return an Array of UserRecords
} else return 'Oops! Not found.';
} catch (error) {
//...
}
},
};
Related
I'm a beginner in Next.js and Firebase. I was trying to make a log in system that has roles. I used Firebase Authentication and stored the account's roles on firestore. I connected the authentication account and firestore data by using the UID (from authentication) as the Firestore Document ID.
Ps. I'm not sure if this is the best way to do this but I am able to fetch data from a field by looking for the Document ID fetched using the UID.
What I need to happen is to get the role of the Account from the Firestore and use that for a function to push the correct page for that account type. The problem is, my pushToPage() fires first before my getData() gets the information it asks for from the firestore.
This is the LogIn function. I used auth.onAuthStateChanged to get the UID of the user.
var firebaseDocument = ' ';
var accountType = '';
var databaseRef = '';
function LogIn() {
signInWithEmailAndPassword(auth, email, password)
.then((response) => {
sessionStorage.setItem('Token', response.user.accessToken);
auth.onAuthStateChanged((user) => {
if (user) {
firebaseDocument = user.uid;
databaseRef = doc(database, 'users', firebaseDocument);
} else {
console.log('user logged out');
}
});
})
.catch((err) => {
console.log(err.code);
});
accountType = getData();
pushToPage(accountType);
}
This is the getData function where it fetches the account role
const getData = async () => {
try {
const docSnap = await getDoc(databaseRef);
if (docSnap.exists()) {
return docSnap.data().account_type;
} else {
console.log('Document does not exist');
}
} catch (e) {
console.log(e);
}
};
this is the pushToPage function that reads the var accountType value to decide on what page to go.
const pushToPage = (accountType) => {
if (accountType == 'management') {
router.push('/accounts/management');
} else if (accountType == 'dean') {
router.push('/accounts/deans');
} else {
router.push('/accounts/faculty');
}
};
Running this code does not only make my Program wait for the firebase response but also displays this error
Unhandled Runtime Error
FirebaseError: Expected first argument to collection() to be a CollectionReference, a DocumentReference or FirebaseFirestore
I didn't use collection() though.
Also, I searched for similar problems and I think I need to place a .then() function somewhere or somekind of Asynchronous Programming technique. Unfortunately, I struggle in understanding these.
I hope I can find help here. Thanks guys.
I don't think I need the .then() function anymore. I just called the pushToPage() inside the getData.
const getData = async () => {
try {
const docSnap = await getDoc(databaseRef);
if (docSnap.exists()) {
accountType = docSnap.data().account_type;
pushToPage(accountType);
} else {
console.log('Document does not exist');
}
} catch (e) {
console.log(e);
}
};
I am developping an app to order food online. As backend service I am using firestore to store the data and files. The user can order dishes and there are limited stocks. So every time a user order a dish and create a basket I update the stock of the corresponding ordered dishes. I am using a firebase function in order to perform this action. To be honest it is the first I am creating firebase function.
Into the Basket object, there is a list of ordered Dishes with the corresponding database DishID. When the basket is created, I go through the DishID list and I update the Quantity in the firestore database. On my local emulator it works perfectly and very fast. But online it takes minutes to perform the first update. I can deal with some seconds. Even if it takes a few seconds (like for cold restart) it's okay. But sometimes it can take 3 minutes and someone else can order a dish during this time.
Here is my code:
//Update the dishes quantities when a basket is created
exports.updateDishesQuantity = functions.firestore.document('/Baskets/{documentId}').onCreate(async (snap, context) => {
try{
//Get the created basket
const originalBasket = snap.data();
originalBasket.OrderedDishes.forEach(async dish => {
const doc = await db.collection('Dishes').doc(dish.DishID);
console.log('Doc created');
return docRef = doc.get()
.then((result) =>{
console.log('DocRef created');
if(result.exists){
console.log('Result exists');
const dishAvailableOnDataBase = result.data().Available;
console.log('Data created');
const newQuantity = { Available: Math.max(dishAvailableOnDataBase - dish.Quantity, 0)};
console.log('Online doc updated');
return result.ref.set(newQuantity, { merge: true });
}else{
console.log("doc doesnt exist");
}
})
.catch(error =>{
console.log(error);
return null;
});
});
}catch(error){
console.log(error);
}
});
I have a couple of logs output to debug the outputs on the server. It's the doc.get() function that takes 2 minutes to execute as you can see on the logger below:
Firebase logger
Thanks for your help,
Thansk for your help. I just edited a little bit your code to make it work. I post my edited code. Thanks a lot, now it takes just 4 seconds to update the quantities.
Kid regards
//Update the dishes quantities when a basket is created
exports.updateDishesQuantity = functions.firestore.document('/Baskets/{documentId}').onCreate(async (snap, context) => {
try {
//Get the created basket
const originalBasket = snap.data();
const promises = [];
const quantities = [];
originalBasket.OrderedDishes.forEach(dish => {
promises.push(db.collection('Dishes').doc(dish.DishID).get());
quantities.push(dish.Quantity);
});
const docSnapshotsArray = await Promise.all(promises);
console.log("Promises", promises);
const promises1 = [];
var i = 0;
docSnapshotsArray.forEach(result => {
if (result.exists) {
const dishAvailableOnDataBase = result.data().Available;
const newQuantity = { Available: Math.max(dishAvailableOnDataBase - quantities[i], 0) };
promises1.push(result.ref.set(newQuantity, { merge: true }));
}
i++;
})
return Promise.all(promises1)
} catch (error) {
console.log(error);
return null;
}
});
You should not use async/await within a forEach() loop, see "JavaScript: async/await with forEach()" and "Using async/await with a forEach loop".
And since your code executes, in parallel, a variable number of calls to the asynchronous Firebase get() and set() methods, you should use Promise.all().
You should refactor your Cloud Function along the following lines:
//Update the dishes quantities when a basket is created
exports.updateDishesQuantity = functions.firestore.document('/Baskets/{documentId}').onCreate(async (snap, context) => {
try {
//Get the created basket
const originalBasket = snap.data();
const promises = [];
originalBasket.OrderedDishes.forEach(dish => {
promises.push(db.collection('Dishes').doc(dish.DishID).get());
});
const docSnapshotsArray = await Promise.all(promises);
const promises1 = [];
docSnapshotsArray.forEach(snap => {
if (result.exists) {
const dishAvailableOnDataBase = result.data().Available;
const newQuantity = { Available: Math.max(dishAvailableOnDataBase - dish.Quantity, 0) };
promises1.push(result.ref.set(newQuantity, { merge: true }));
}
})
return Promise.all(promises1)
} catch (error) {
console.log(error);
return null;
}
});
Note that instead of looping and calling push() you could use the map() method for a much concise code. However, for SO answers, I like the clarity brought by creating an empty array, populating it with a forEach() loop and passing it to Promise.all()...
Also note that since you are updating quantities in a basket you may need to use a Transaction.
I am developing the backend of an application using Node JS, Sequelize and Postgres database.
When the course is registered, the user must inform which organizations, companies and teachers will be linked to it.
The organization IDs are passed through an array to the backend, I am trying to do a check to make sure that the passed IDs exist.
What I've done so far is this:
const { organizations } = req.body;
const organizationsArray = organizations.map(async (organization) => {
const organizationExists = await Organization.findByPk(organization);
if (!organizationExists) {
return res
.status(400)
.json({ error: `Organization ${organization} does not exists!` });
}
return {
course_id: id,
organization_id: organization,
};
});
await CoursesOrganizations.bulkCreate(organizationsArray);
This link has the complete controller code, I believe it will facilitate understanding.
When !OrganizationExists is true, I am getting the return that the organization does not exist. The problem is when the organization exists, I am getting the following message error.
The Array.map() is returning an array of promises that you can resolve to an array using Promise.all(). Inside the map you should use throw new Error() to break out of the map - this error will be raised by Promise.all() and you can then catch it and return an error to the client (or swallow it, etc).
This is a corrected version of your pattern, resolving the Promise results.
const { organizations } = req.body;
try {
// use Promise.all to resolve the promises returned by the async callback function
const organizationsArray = await Promise.all(
// this will return an array of promises
organizations.map(async (organization) => {
const organizationExists = await Organization.findByPk(organization, {
attributes: ['id'], // we only need the ID
raw: true, // don't need Instances
});
if (!organizationExists) {
// don't send response inside the map, throw an Error to break out
throw new Error(`Organization ${organization} does not exists!`);
}
// it does exist so return/resolve the value for the promise
return {
course_id: id,
organization_id: organization,
};
})
);
// if we get here there were no errors, create the records
await CoursesOrganizations.bulkCreate(organizationsArray);
// return a success to the client
return res.json({ success: true });
} catch (err) {
// there was an error, return it to the client
return res.status(400).json({ error: err.message });
}
This is a refactored version that will be a bit faster by fetching all the Organizations in one query and then doing the checks/creating the Course inserts.
const { Op } = Sequelize;
const { organizations } = req.body;
try {
// get all Organization matches for the IDs
const organizationsArray = await Organization.findAll({
attributes: ['id'], // we only need the ID
where: {
id: {
[Op.in]: organizations, // WHERE id IN (organizations)
}
},
raw: true, // no need to create Instances
});
// create an array of the IDs we found
const foundIds = organizationsArray.map((org) => org.id);
// check to see if any of the IDs are missing from the results
if (foundIds.length !== organizations.length) {
// Use Array.reduce() to figure out which IDs are missing from the results
const missingIds = organizations.reduce((missingIds, orgId) => {
if (!foundIds.includes(orgId)){
missingIds.push(orgId);
}
return missingIds;
}, []); // initialized to empty array
throw new Error(`Unable to find Organization for: ${missingIds.join(', ')}`);
}
// now create an array of courses to create using the foundIds
const courses = foundIds.map((orgId) => {
return {
course_id: id,
organization_id: orgId,
};
});
// if we get here there were no errors, create the records
await CoursesOrganizations.bulkCreate(courses);
// return a success to the client
return res.json({ success: true });
} catch (err) {
// there was an error, return it to the client
return res.status(400).json({ error: err.message });
}
If you have an array of Ids and you want to check if they exist you should you use the (in) operator, this makes it so that you are hitting the DB only once and getting all the records in one hit (instead of getting them one by one in a loop), after you get these records you can check their lengths to determine if they all exist or not.
const { Op } = require("sequelize");
let foundOrgs = await Organization.findAll({
where: {
id: {
[Op.in]: organizationsArray,
}
}
});
I am trying to create a simple back end blog api with user authentication and authorization. It is built with mongoose and express. In my userSchema, I have a property that is an array called "subscribedTo". Here, users can subscribe to different users to get their blogs. The subscribedTo array stores objectIDs of the users that wished to be subscribed too.
Here is my code:
router.get('/blogs', auth, async (req, res) => {
//auth middleware attaches user to the request obj
try {
let blogs = []
req.user.subscribedTo.forEach(async (id) => {
let ownersBlogs = await Blog.find({owner:id})
blogs = [...blogs, ...ownersBlogs]
console.log(blogs)//consoles desired output of users blogs
})
console.log(blogs)//runs first and returns []
res.send(blogs)
}catch(e){
res.status(500).send(e)
}
})
When I use postman for this route it returns [] which is understandable. I can't seem to res.send(blogs) even though the blogs variable returns correctly in the forEach function.
Is there a better way to do this?
You can use without loop like as bellow
Blog.find({ owner: { $in: req.user.subscribedTo } }, function (err, blogResult) {
if (err) {
response.send(err);
} else {
response.send(blogResult);
}
});
OR
send response after loop completed like as bellow
router.get('/blogs', auth, async (req, res) => {
//auth middleware attaches user to the request obj
try {
let blogs = []
let len = req.user.subscribedTo.length;
let i = 0;
if (len > 0) {
req.user.subscribedTo.forEach(async (id) => {
let ownersBlogs = await Blog.find({ owner: id })
blogs = [...blogs, ...ownersBlogs]
console.log(blogs)//consoles desired output of users blogs
i++;
if (i === len) {
//send response when loop reached at the end
res.send(blogs)
}
})
} else {
res.send(blogs);
}
} catch (e) {
res.status(500).send(e)
}
});
You can find all the documents without a foreach loop, use $in
Blog.find({owner:{$in:[array of ids]}});
I'm using firebase functions with JavaScript to make a query about Firebase realtime, which will be used in an Android application. The main query obtains a collection of values that I then go through, and for each of them I launch another query. The results obtained from the second query stores in an array that is the one that I return as a result.
The problem is that the array that I return as an answer is empty, since the response is returned before the subqueries that add the data to the array end, that is, the problem I think is due to the asynchronous nature of the calls.
I have tried to reorganize the code in several ways and use promises to try that the result is not sent until all the queries have been made but the same problem is still happening.
The structure of the JSON database that I consult is the following:
"users" : {
"uidUser" : {
"friends" : {
"uidUserFriend" : "mail"
},
"name" : "nameUser",
...
},
"uidUser2" : {
"friends" : {
"uidUserFriend" : "mail"
},
"name" : "nameUser",
...
}
}
The functions are:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
exports.searchFriends = functions.https.onCall((data,context) => {
const db = admin.database();
const uidUser = data.uidUser;
var arrayOfResults = new Array();
const refFriends = db.ref('/users/'+uidUser+'/friends');
let user;
return refFriends.once('value').then((snapshot) => {
snapshot.forEach(function(userSnapshot){
user = findUser(userSnapshot.key);
arrayOfResults.push(user);
});
return {
users: arrayOfResults
};
}).catch((error) => {
throw new functions.https.HttpsError('unknown', error.message, error);
});
});
function findUser(uid){
const db = admin.database();
const ref = db.ref('/users/'+uid);
return ref.once('value').then((snapshot) => {
console.log(snapshot.key,snapshot.val());
return snapshot.val();
}).catch((error) => {
console.log("Error in the query - "+error);
});
}
I do not know if the problem is because I do not manage the promises well or because I have to orient the code in another way.
Thank you.
Indeed, as you mentioned, you should "manage the promises" differently. Since you are triggering several asynchronous operations in parallel (with the once() method, which returns a promise) you have to use Promise.all().
The following code should do the trick:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
exports.searchFriends = functions.https.onCall((data,context) => {
const db = admin.database();
const uidUser = data.uidUser;
var arrayOfPromises = new Array();
const refFriends = db.ref('/users/' + uidUser + '/friends');
let user;
return refFriends.once('value').then(snapshot => {
snapshot.forEach(userSnapshot => {
user = findUser(userSnapshot.key);
arrayOfPromises.push(user);
});
return Promise.all(arrayOfPromises);
})
.then(arrayOfResults => {
return {
users: arrayOfResults
};
})
.catch((error) => {
throw new functions.https.HttpsError('unknown', error.message, error);
});
});
function findUser(uid){
const db = admin.database();
const ref = db.ref('/users/' + uid);
return ref.once('value').then(snapshot => {
console.log(snapshot.key,snapshot.val());
return snapshot.val();
});
}
Note that I have modified the name of the first array to arrayOfPromises, which makes more sense IMHO.
Note also that you receive the results of Promise.all() in an array corresponding to the fulfillment values in the same order than the queries array, see: Promise.all: Order of resolved values