Develop Reference

how to create a user with firebase without signing in [duplicate]

So I have this issue where every time I add a new user account, it kicks out the current user that is already signed in. I read the firebase api and it said that "If the new account was created, the user is signed in automatically" But they never said anything else about avoiding that.
//ADD EMPLOYEES
addEmployees: function(formData){
firebase.auth().createUserWithEmailAndPassword(formData.email, formData.password).then(function(data){
console.log(data);
});
},
I'm the admin and I'm adding accounts into my site. I would like it if I can add an account without being signed out and signed into the new account. Any way i can avoid this?

Update 20161110 - original answer below
Also, check out this answer for a different approach.
Original answer
This is actually possible.
But not directly, the way to do it is to create a second auth reference and use that to create users:
var config = {apiKey: "apiKey",
authDomain: "projectId.firebaseapp.com",
databaseURL: "https://databaseName.firebaseio.com"};
var secondaryApp = firebase.initializeApp(config, "Secondary");
secondaryApp.auth().createUserWithEmailAndPassword(em, pwd).then(function(firebaseUser) {
console.log("User " + firebaseUser.uid + " created successfully!");
//I don't know if the next statement is necessary
secondaryApp.auth().signOut();
});
If you don't specify which firebase connection you use for an operation it will use the first one by default.
Source for multiple app references.
EDIT
For the actual creation of a new user, it doesn't matter that there is nobody or someone else than the admin, authenticated on the second auth reference because for creating an account all you need is the auth reference itself.
The following hasn't been tested but it is something to think about
The thing you do have to think about is writing data to firebase. Common practice is that users can edit/update their own user info so when you use the second auth reference for writing this should work. But if you have something like roles or permissions for that user make sure you write that with the auth reference that has the right permissions. In this case, the main auth is the admin and the second auth is the newly created user.

Update 20161108 - original answer below
Firebase just released its firebase-admin SDK, which allows server-side code for this and other common administrative use-cases. Read the installation instructions and then dive into the documentation on creating users.
original answer
This is currently not possible. Creating an Email+Password user automatically signs that new user in.

I just created a Firebase Function that triggers when a Firestore document is Created (with rules write-only to admin user). Then use admin.auth().createUser() to create the new user properly.
export const createUser = functions.firestore
.document('newUsers/{userId}')
.onCreate(async (snap, context) => {
const userId = context.params.userId;
const newUser = await admin.auth().createUser({
disabled: false,
displayName: snap.get('displayName'),
email: snap.get('email'),
password: snap.get('password'),
phoneNumber: snap.get('phoneNumber')
});
// You can also store the new user in another collection with extra fields
await admin.firestore().collection('users').doc(newUser.uid).set({
uid: newUser.uid,
email: newUser.email,
name: newUser.displayName,
phoneNumber: newUser.phoneNumber,
otherfield: snap.get('otherfield'),
anotherfield: snap.get('anotherfield')
});
// Delete the temp document
return admin.firestore().collection('newUsers').doc(userId).delete();
});
You can Algo use functions.https.onCall()
exports.createUser= functions.https.onCall((data, context) => {
const uid = context.auth.uid; // Authorize as you want
// ... do the same logic as above
});
calling it.
const createUser = firebase.functions().httpsCallable('createUser');
createUser({userData: data}).then(result => {
// success or error handling
});

Swift 5: Simple Solution
First store the current user in a variable called originalUser
let originalUser = Auth.auth().currentUser
Then, in the completion handler of creating a new user, use the updateCurrentUser method to restore the original user
Auth.auth().updateCurrentUser(originalUser, completion: nil)

Here is a simple solution using web SDKs.
Create a cloud function (https://firebase.google.com/docs/functions)
import admin from 'firebase-admin';
import * as functions from 'firebase-functions';
const createUser = functions.https.onCall((data) => {
return admin.auth().createUser(data)
.catch((error) => {
throw new functions.https.HttpsError('internal', error.message)
});
});
export default createUser;
Call this function from your app
import firebase from 'firebase/app';
const createUser = firebase.functions().httpsCallable('createUser');
createUser({ email, password })
.then(console.log)
.catch(console.error);
Optionally, you can set user document information using the returned uid.
createUser({ email, password })
.then(({ data: user }) => {
return database
.collection('users')
.doc(user.uid)
.set({
firstname,
lastname,
created: new Date(),
});
})
.then(console.log)
.catch(console.error);

I got André's very clever workaround working in Objective-C using the Firebase iOS SDK:
NSString *plistPath = [[NSBundle mainBundle] pathForResource:#"GoogleService-Info" ofType:#"plist"];
FIROptions *secondaryAppOptions = [[FIROptions alloc] initWithContentsOfFile:plistPath];
[FIRApp configureWithName:#"Secondary" options:secondaryAppOptions];
FIRApp *secondaryApp = [FIRApp appNamed:#"Secondary"];
FIRAuth *secondaryAppAuth = [FIRAuth authWithApp:secondaryApp];
[secondaryAppAuth createUserWithEmail:user.email
password:user.password
completion:^(FIRUser * _Nullable user, NSError * _Nullable error) {
[secondaryAppAuth signOut:nil];
}];

Update for Swift 4
I have tried a few different options to create multiple users from a single account, but this is by far the best and easiest solution.
Original answer by Nico
First Configure firebase in your AppDelegate.swift file
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
FirebaseApp.configure()
FirebaseApp.configure(name: "CreatingUsersApp", options: FirebaseApp.app()!.options)
return true
}
Add the following code to action where you are creating the accounts.
if let secondaryApp = FirebaseApp.app(name: "CreatingUsersApp") {
let secondaryAppAuth = Auth.auth(app: secondaryApp)
// Create user in secondary app.
secondaryAppAuth.createUser(withEmail: email, password: password) { (user, error) in
if error != nil {
print(error!)
} else {
//Print created users email.
print(user!.email!)
//Print current logged in users email.
print(Auth.auth().currentUser?.email ?? "default")
try! secondaryAppAuth.signOut()
}
}
}
}

You can use firebase function for add users.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
const cors = require('cors')({
origin: true,
});
exports.AddUser = functions.https.onRequest(( req, res ) => {
// Grab the text parameter.
cors( req, res, () => {
let email = req.body.email;
let passwd = req.body.passwd;
let role = req.body.role;
const token = req.get('Authorization').split('Bearer ')[1];
admin.auth().verifyIdToken(token)
.then(
(decoded) => {
// return res.status(200).send( decoded )
return creatUser(decoded);
})
.catch((err) => {
return res.status(401).send(err)
});
function creatUser(user){
admin.auth().createUser({
email: email,
emailVerified: false,
password: passwd,
disabled: false
})
.then((result) => {
console.log('result',result);
return res.status(200).send(result);
}).catch((error) => {
console.log(error.message);
return res.status(400).send(error.message);
})
}
});
});
CreateUser(){
//console.log('Create User')
this.submitted = true;
if (this.myGroup.invalid) {
return;
}
let Email = this.myGroup.value.Email;
let Passwd = this.myGroup.value.Passwd;
let Role = 'myrole';
let TechNum = this.myGroup.value.TechNum;
let user = JSON.parse(localStorage.getItem('user'));
let role = user.role;
let AdminUid = user.uid;
let authToken = user.stsTokenManager.accessToken;
let httpHeaders = new HttpHeaders().set('Authorization', 'Bearer ' + authToken);
let options = { headers: httpHeaders };
let params = { email:Email,passwd:Passwd,role:Role };
this.httpClient.post('https://us-central1-myproject.cloudfunctions.net/AddUser', params, options)
.subscribe( val => {
//console.log('Response from cloud function', val );
let createdUser:any = val;
//console.log(createdUser.uid);
const userRef: AngularFirestoreDocument<any> = this.afs.doc(`users/${createdUser.uid}`);
const userUpdate = {
uid: createdUser.uid,
email: createdUser.email,
displayName: null,
photoURL: null,
emailVerified: createdUser.emailVerified,
role: Role,
TechNum:TechNum,
AccountAccess:this.AccountAccess,
UserStatus:'open',
OwnerUid:AdminUid,
OwnerUidRole:role,
RootAccountAccess:this.RootAccountAccess
}
userRef.set(userUpdate, {
merge: false
});
this.toastr.success('Success, user add','Success');
this.myGroup.reset();
this.submitted = false;
},
err => {
console.log('HTTP Error', err.error)
this.toastr.error(err.error,'Error')
},
() => console.log('HTTP request completed.')
);
}

On the web, this is due to unexpected behavior when you call createUserWithEmailAndPassword out of the registration context; e.g. inviting a new user to your app by creating a new user account.
Seems like, createUserWithEmailAndPassword method triggers a new refresh token and user cookies are updated too. (This side-effect is not documented)
Here is a workaround for Web SDK:
After creating the new user;
firebase.auth().updateCurrentUser (loggedInUser.current)
provided that you initiate loggedInUser with the original user beforehand.

Hey i had similar problem ,trying to create users through admin , as it is not possible to signUp user without signIn ,I created a work around ,adding it below with steps
Instead of signup create a node in firebase realtime db with email as key (firebase do not allow email as key so I have created a function to generate key from email and vice versa, I will attach the functions below)
Save a initial password field while saving user (can even hash it with bcrypt or something, if you prefer though it will be used one time only)
Now Once user try to login check if any node with that email (generate key from email) exist in the db and if so then match the password provided.
If the password matched delete the node and do authSignUpWithEmailandPassword with provided credentials.
User is registered successfully
//Sign In
firebaseDB.child("users").once("value", (snapshot) => {
const users = snapshot.val();
const userKey = emailToKey(data.email);
if (Object.keys(users).find((key) => key === userKey)) {
setError("user already exist");
setTimeout(() => {
setError(false);
}, 2000);
setLoading(false);
} else {
firebaseDB
.child(`users`)
.child(userKey)
.set({ email: data.email, initPassword: data.password })
.then(() => setLoading(false))
.catch(() => {
setLoading(false);
setError("Error in creating user please try again");
setTimeout(() => {
setError(false);
}, 2000);
});
}
});
//Sign Up
signUp = (data, setLoading, setError) => {
auth
.createUserWithEmailAndPassword(data.email, data.password)
.then((res) => {
const userDetails = {
email: res.user.email,
id: res.user.uid,
};
const key = emailToKey(data.email);
app
.database()
.ref(`users/${key}`)
.remove()
.then(() => {
firebaseDB.child("users").child(res.user.uid).set(userDetails);
setLoading(false);
})
.catch(() => {
setLoading(false);
setError("error while registering try again");
setTimeout(() => setError(false), 4000);
});
})
.catch((err) => {
setLoading(false);
setError(err.message);
setTimeout(() => setError(false), 4000);
});
};
//Function to create a valid firebase key from email and vice versa
const emailToKey = (email) => {
//firebase do not allow ".", "#", "$", "[", or "]"
let key = email;
key = key.replace(".", ",0,");
key = key.replace("#", ",1,");
key = key.replace("$", ",2,");
key = key.replace("[", ",3,");
key = key.replace("]", ",4,");
return key;
};
const keyToEmail = (key) => {
let email = key;
email = email.replace(",0,", ".");
email = email.replace(",1,", "#");
email = email.replace(",2,", "$");
email = email.replace(",3,", "[");
email = email.replace(",4,", "]");
return email;
};

If you want to do it in your front end create a second auth reference use it to create other users and sign out and delete that reference. If you do it this way you won't be signed out when creating a new user and you won't get the error that the default firebase app already exists.
const createOtherUser =()=>{
var config = {
//your firebase config
};
let secondaryApp = firebase.initializeApp(config, "secondary");
secondaryApp.auth().createUserWithEmailAndPassword(email, password).then((userCredential) => {
console.log(userCredential.user.uid);
}).then(secondaryApp.auth().signOut()
)
.then(secondaryApp.delete()
)
}

Update 19.05.2022 - using #angular/fire (latest available = v.7.3.0)
If you are not using firebase directly in your app, but use e.g. #angular/fire for auth purposes only, you can use the same approach as suggested earlier as follows with the #angular/fire library:
import { Auth, getAuth, createUserWithEmailAndPassword } from '#angular/fire/auth';
import { deleteApp, initializeApp } from '#angular/fire/app';
import { firebaseConfiguration } from '../config/app.config'; // <-- Your project's configuration here.
const tempApp = initializeApp(firebaseConfiguration, "tempApp");
const tempAppAuth = getAuth(tempApp);
await createUserWithEmailAndPassword(tempAppAuth, email, password)
.then(async (newUser) => {
resolve( () ==> {
// Do something, e.g. add user info to database
});
})
.catch(error => reject(error))
.finally( () => {
tempAppAuth.signOut()
.then( () => deleteApp(tempApp));
});

The Swift version:
FIRApp.configure()
// Creating a second app to create user without logging in
FIRApp.configure(withName: "CreatingUsersApp", options: FIRApp.defaultApp()!.options)
if let secondaryApp = FIRApp(named: "CreatingUsersApp") {
let secondaryAppAuth = FIRAuth(app: secondaryApp)
secondaryAppAuth?.createUser(...)
}

Here is a Swift 3 adaptaion of Jcabrera's answer :
let bundle = Bundle.main
let path = bundle.path(forResource: "GoogleService-Info", ofType: "plist")!
let options = FIROptions.init(contentsOfFile: path)
FIRApp.configure(withName: "Secondary", options: options!)
let secondary_app = FIRApp.init(named: "Secondary")
let second_auth = FIRAuth(app : secondary_app!)
second_auth?.createUser(withEmail: self.username.text!, password: self.password.text!)
{
(user,error) in
print(user!.email!)
print(FIRAuth.auth()?.currentUser?.email ?? "default")
}

If you are using Polymer and Firebase (polymerfire) see this answer: https://stackoverflow.com/a/46698801/1821603
Essentially you create a secondary <firebase-app> to handle the new user registration without affecting the current user.

Android solution (Kotlin):
1.You need FirebaseOptions BUILDER(!) for setting api key, db url, etc., and don't forget to call build() at the end
2.Make a secondary auth variable by calling FirebaseApp.initializeApp()
3.Get instance of FirebaseAuth by passing your newly created secondary auth, and do whatever you want (e.g. createUser)
// 1. you can find these in your project settings under general tab
val firebaseOptionsBuilder = FirebaseOptions.Builder()
firebaseOptionsBuilder.setApiKey("YOUR_API_KEY")
firebaseOptionsBuilder.setDatabaseUrl("YOUR_DATABASE_URL")
firebaseOptionsBuilder.setProjectId("YOUR_PROJECT_ID")
firebaseOptionsBuilder.setApplicationId("YOUR_APPLICATION_ID") //not sure if this one is needed
val firebaseOptions = firebaseOptionsBuilder.build()
// indeterminate progress dialog *ANKO*
val progressDialog = indeterminateProgressDialog(resources.getString(R.string.progressDialog_message_registering))
progressDialog.show()
// 2. second auth created by passing the context, firebase options and a string for secondary db name
val newAuth = FirebaseApp.initializeApp(this#ListActivity, firebaseOptions, Constants.secondary_db_auth)
// 3. calling the create method on our newly created auth, passed in getInstance
FirebaseAuth.getInstance(newAuth).createUserWithEmailAndPassword(email!!, password!!)
.addOnCompleteListener { it ->
if (it.isSuccessful) {
// 'it' is a Task<AuthResult>, so we can get our newly created user from result
val newUser = it.result.user
// store wanted values on your user model, e.g. email, name, phonenumber, etc.
val user = User()
user.email = email
user.name = name
user.created = Date().time
user.active = true
user.phone = phone
// set user model on /db_root/users/uid_of_created_user/, or wherever you want depending on your structure
FirebaseDatabase.getInstance().reference.child(Constants.db_users).child(newUser.uid).setValue(user)
// send newly created user email verification link
newUser.sendEmailVerification()
progressDialog.dismiss()
// sign him out
FirebaseAuth.getInstance(newAuth).signOut()
// DELETE SECONDARY AUTH! thanks, Jimmy :D
newAuth.delete()
} else {
progressDialog.dismiss()
try {
throw it.exception!!
// catch exception for already existing user (e-mail)
} catch (e: FirebaseAuthUserCollisionException) {
alert(resources.getString(R.string.exception_FirebaseAuthUserCollision), resources.getString(R.string.alertDialog_title_error)) {
okButton {
isCancelable = false
}
}.show()
}
}
}

For Android, i suggest a simpler way to do it, without having to provide api key, application id...etc by hand by just using the FirebaseOptions of the default instance.
val firebaseDefaultApp = Firebase.auth.app
val signUpAppName = firebaseDefaultApp.name + "_signUp"
val signUpApp = try {
FirebaseApp.initializeApp(
context,
firebaseDefaultApp.options,
signUpAppName
)
} catch (e: IllegalStateException) {
// IllegalStateException is throw if an app with the same name has already been initialized.
FirebaseApp.getInstance(signUpAppName)
}
// Here is the instance you can use to sign up without triggering auth state on the default Firebase.auth
val signUpFirebaseAuth = Firebase.auth(signUpApp)
How to use ?
signUpFirebaseAuth
.createUserWithEmailAndPassword(email, password)
.addOnSuccessListener {
// Optional, you can send verification email here if you need
// As soon as the sign up with sign in is over, we can sign out the current user
firebaseAuthSignUp.signOut()
}
.addOnFailureListener {
// Log
}

My solution to this question is to store the User Name/Email and password in a static class and then add a new user log out the new user and immediately log in as the admin user(id pass you saved). Works like a charm for me :D

This is a version for Kotlin:
fun createUser(mail: String, password: String) {
val opts = FirebaseOptions.fromResource(requireContext())
if (opts == null) return
val app = Firebase.initialize(requireContext(), opts, "Secondary")
FirebaseAuth.getInstance(app)
.createUserWithEmailAndPassword(mail, password)
.addOnSuccessListener {
app.delete()
doWhateverWithAccount(it)
}.addOnFailureListener {
app.delete()
showException(it)
}
}
It uses the configuration from your default Firebase application instance, just under a different name.
It also deletes the newly created instance afterwards, so you can call this multiple times without any exception about already existing Secondary application.

Firebase Function onDelete from database and storage

I want to be able to delete a folder in firebase storage while onDelete in functions is triggered.
here is my firebase node code, once deleted, it will trigger functions to delete the corresponding folder in firebase storage. I am allowing user to delete their message conversion that includes images. I was able to delete the folder without using the {friendId} but {friendId} is needed in case the user have conversions with two different users.
My Firebase storage is as follow
messages_image_from_friends/
iLJ6nGJodeat2HRi5Q2xdTUmZnw2/
MXGCZv96aVUkSHZeU8kNTZqTQ0n2/
image.png
and Firebase Functions
const functions = require("firebase-functions");
const admin = require("firebase-admin");
const firebase = admin.initializeApp();
exports.deletePhotos = functions.database.ref('/messagesFriends/{userId}/{friendId}')
.onDelete((snap, context) => {
const { userId } = context.params;
<---- const { friendId } = context.params.friendId; ????? ---- >
const bucket = firebase.storage().bucket();
return bucket.deleteFiles({
prefix: `messages_image_from_friends/${userId}/{friendId}`
}, function(err) {
if (err) {
console.log(err);
} else {
console.log(`All the Firebase Storage files in
messages_image_from_friends/${userId}/{friendId} have been deleted`);
}
});
});
Log states that {friendId} is undefined. How do i get {friendId} from exports into prefix.
I have tried "snapshot" and "then()" but do not really know how to implement it as I am new to functions. Please help.
Update!!! 9/12/2020
I was able to get this working by changing onDelete to functions.https.onCall to use hashmap instead.. hope this help others
const functions = require("firebase-functions");
const admin = require("firebase-admin");
const firebase = admin.initializeApp();
exports.deletePhotos = functions.https.onCall((data, context) => {
const userId = data.userId;
const friendId = data.friendId;
console.log(userId, friendId);
const bucket = firebase.storage().bucket();
return bucket.deleteFiles({
prefix: `messages_image_from_friends/`+userId+`/`+friendId+`/`
}, function(err) {
if (err) {
console.log(err);
} else {
console.log(`messages_image_from_friends/`+userId+`/`+friendId);
}
});
// return {response:"This means success"};
});
and the code to call the function from your android app
private FirebaseFunctions mFunctions;
protected void onCreate(Bundle savedInstanceState) {
mFunctions = FirebaseFunctions.getInstance();
////String userId is current firebase user id
////String friendId is from getIntent(), etc
deletePhotos(userId, friendId);
}
private Task<String> deletePhotos(String userId, String friendId) {
// Create the arguments to the callable function.
Map<String, Object> data = new HashMap<>();
data.put("userId", userId);
data.put("friendId", friendId);
return mFunctions
.getHttpsCallable("deletePhotos")
.call(data)
.continueWith(new Continuation<HttpsCallableResult,
String>() {
#Override
public String then(#NonNull Task<HttpsCallableResult>
task) throws Exception {
// This continuation runs on either success or
failure, but if the task
// has failed then getResult() will throw an
Exception which will be
// propagated down.
String result = (String)
task.getResult().getData();
return result;
}
});
}
MAKE SURE YOU MAKE A NEW FIREBASE INIT FOLDER..
I MADE THE MISTAKE OF REDEPLOYING THIS DIRECTLY IN CLOUD FUNCTION CONSOLE WHILE IT WAS CONNECTED AS onDelete and IT WAS UPDATING THE index.js ONLY INSTEAD OF THE WHOLE FUNCTION FOLDER. SO DON'T DO WHAT I DID BECAUSE YOU WILL GET A TypeError: Cannot read property 'origin' of undefined at /srv/node_modules/cors/lib/
HOPE THIS HELPS OTHERS!!!
Update 9/18/20
I was able to make it work with onDelete with this
'use-strict'
const functions = require("firebase-functions");
const admin = require("firebase-admin");
const firebase = admin.initializeApp();
exports.deletePhotos =
functions.database.ref('/messagesFriends/{userId}/{friendId}')
.onDelete((snap, context) => {
const userId = context.params.userId;
const friendId = context.params.friendId;
const bucket = firebase.storage().bucket();
console.log(userId + ' ' + friendId + " found");
return bucket.deleteFiles({
prefix: `messages_image_from_friends/`+userId+`/`+friendId
}, function(err) {
if (err) {
console.log(`messages_image_from_friends/`+userId+`/`+friendId + `
remove error`);
} else {
console.log(`messages_image_from_friends/`+userId+`/`+friendId + `
removed`);
}
});
});

context.params is an object whose properties are populated with each of the wildcards from the trigger path. You're not using it correctly.
const userId = context.params.userId;
const friendId = context.params.friendId;
I suggest reviewing the documentation for database triggers, especially the part on specifying the path:
You can specify a path component as a wildcard by surrounding it with curly brackets; ref('foo/{bar}') matches any child of /foo. The values of these wildcard path components are available within the EventContext.params object of your function. In this example, the value is available as event.params.bar.

Retrieve multiple users info from firebase auth using Node js

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) {
//...
}
},
};

How to make a subquery synchronously in Firebase realtime with Cloud Funtions

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

Calling a Firebase Cloud Function 'ForEach' child of a Snapshot

I'm trying to deploy a Firebase Cloud Function that sends a text message to its associated recipient for x number of text messages. The function is triggered in my iOS app when an update is made to the 'send' Realtime Database reference, indicating that the user has pressed the 'send' button.
My Firebase structure is
{
"user1uid": {
"send": false
"messagesToSend": {
"messageuid1": {
"messageText": "What's for dinner?",
"recipientNumber": "+18017378888",
}
"messageuid2:
"messageText": "Who won the Cowboys game?",
"recipientNumber": "+18017377787",
}
}
"user2uid": {
"send": false
"messagesToSend": {
"messageuid1": {
"messageText": "What's for dinner?",
"recipientNumber": "+18017378888",
}
"messageuid2:
"messageText": "Who won the Cowboys game?",
"recipientNumber": "+18017377787",
}
}
}
My code currently only sends one message, and I'm not sure how I can properly iterate through the messagesToSend node for each user and send all the messages in it.
I've been trying to follow the tutorial located here. I have looked at the following Stack Overflow responses but am unable to decipher or derive a solution from them:
Firebase cloud function promises
Am I using ForEach correctly?
My index.js code that sends one message is as follows:
const functions = require('firebase-functions');
// The Firebase Admin SDK to access the Firebase Realtime Database.
const admin = require('firebase-admin');
admin.initializeApp();
const twilio = require('twilio')
const accountSid = functions.config().twilio.sid;
const authToken = functions.config().twilio.token;
const client = new twilio(accountSid, authToken);
const twilioNumber = functions.config().twilio.number;
// Start cloud function
exports.sendSecrets = functions.database
.ref('/{uid}/send')
.onUpdate((change,context) => {
const uid = context.params.uid;
return admin.database().ref(uid+'/messagesToSend').once('value').then(snapshot => {
snapshot.forEach(function(childSnapshot) {
var key = childSnapshot.key;
var messageData = childSnapshot.val();
**if (messageData.sanitized) return true;**
var message = messageData.messageText;
var phoneNumber = messageData.recipientNumber;
const textMessage = {
body: `From My App - ${message}`,
from: twilioNumber, // From Twilio number
to: phoneNumber // Text to this number
}
return client.messages.create(textMessage)
})
**return snapshot.ref.toString();**
});
});
Please note that the lines marked with ** at either end indicate that I know I need to return something based on error messages I received indicating that 'Each then() should return a value or throw'.

I make the assumption that you are using the twilio-node library that use promises: https://www.npmjs.com/package/twilio.
Since you want to send several messages in parallel, you have to use Promise.all(), as follows:
const functions = require('firebase-functions');
// The Firebase Admin SDK to access the Firebase Realtime Database.
const admin = require('firebase-admin');
admin.initializeApp();
const twilio = require('twilio')
const accountSid = functions.config().twilio.sid;
const authToken = functions.config().twilio.token;
const client = new twilio(accountSid, authToken);
const twilioNumber = functions.config().twilio.number;
// Start cloud function
exports.sendSecrets = functions.database
.ref('/{uid}/send')
.onUpdate((change,context) => {
const uid = context.params.uid;
return admin.database().ref(uid+'/messagesToSend').once('value')
.then(snapshot => {
const promises = [];
snapshot.forEach(function(childSnapshot) {
var key = childSnapshot.key;
var messageData = childSnapshot.val();
//**if (messageData.sanitized) return true;**
var message = messageData.messageText;
var phoneNumber = messageData.recipientNumber;
const textMessage = {
body: `From My App - ${message}`,
from: twilioNumber, // From Twilio number
to: phoneNumber // Text to this number
}
promises.push(client.messages.create(textMessage));
})
return Promise.all(promises);
})
// Edits made below to parentheses/brackets
.then(results => {
//Do whatever you want !!
// e.g. print the results which will be an array of messages
// (see https://www.twilio.com/docs/libraries/node#testing-your-installation)
})
});
You can also simply return Promise.all() as follows:
....
return Promise.all(promises);
})
});