Batch write with Firebase Cloud Functions - javascript

I'm using Firebase as backend to my iOS app and can't figure out how to construct a batch write through their Cloud Functions.
I have two collections in my Firestore, drinks and customers. Each new drink and each new customer is assigned a userId property that corresponds to the uid of the currently logged in user. This userId is used with a query to the Firestore to fetch only the drinks and customers connected to the logged in user, like so: Firestore.firestore().collection("customers").whereField("userId", isEqualTo: Auth.auth().currentUser.uid)
Users are able to log in anonymously and also subscribe while anonymous. The problem is if they log out there's no way to log back in to the same anonymous uid. The uid is also stored as an appUserID with the RevenueCat SDK so I can still access it, but since I can't log the user back in to their anonymous account using the uid the only way to help a user access their data in case of a restoring of purchases is to update the userId field of their data from the old uid to the new uid. This is where the need for a batch write comes in.
I'm relatively new to programming in general but I'm super fresh when it comes to Cloud Functions, JavaScript and Node.js. I dove around the web though and thought I found a solution where I make a callable Cloud Function and send both old and new userID with the data object, query the collections for documents with the old userID and update their userId fields to the new. Unfortunately it's not working and I can't figure out why.
Here's what my code looks like:
// Cloud Function
exports.transferData = functions.https.onCall((data, context) => {
const firestore = admin.firestore();
const customerQuery = firestore.collection('customers').where('userId', '==', `${data.oldUser}`);
const drinkQuery = firestore.collection('drinks').where('userId', '==', `${data.oldUser}`);
const customerSnapshot = customerQuery.get();
const drinkSnapshot = drinkQuery.get();
const batch = firestore.batch();
for (const documentSnapshot of customerSnapshot.docs) {
batch.update(documentSnapshot.ref, { 'userId': `${data.newUser}` });
};
for (const documentSnapshot of drinkSnapshot.docs) {
batch.update(documentSnapshot.ref, { 'userId': `${data.newUser}` });
};
return batch.commit();
});
// Call from app
func transferData(from oldUser: String, to newUser: String) {
let functions = Functions.functions()
functions.httpsCallable("transferData").call(["oldUser": oldUser, "newUser": newUser]) { _, error in
if let error = error as NSError? {
if error.domain == FunctionsErrorDomain {
let code = FunctionsErrorCode(rawValue: error.code)
let message = error.localizedDescription
let details = error.userInfo[FunctionsErrorDetailsKey]
print(code)
print(message)
print(details)
}
}
}
}
This is the error message from the Cloud Functions log:
Unhandled error TypeError: customerSnapshot.docs is not iterable
at /workspace/index.js:22:51
at fixedLen (/workspace/node_modules/firebase-functions/lib/providers/https.js:66:41)
at /workspace/node_modules/firebase-functions/lib/common/providers/https.js:385:32
at processTicksAndRejections (internal/process/task_queues.js:95:5)
From what I understand customerSnapshot is something called a Promise which I'm guessing is why I can't iterate over it. By now I'm in way too deep for my sparse knowledge and don't know how to handle these Promises returned by the queries.
I guess I could just force users to create a login before they subscribe but that feels like a cowards way out now that I've come this far. I'd rather have both options available and make a decision instead of going down a forced path. Plus, I'll learn some more JavaScript if I figure this out!
Any and all help is greatly appreciated!
EDIT:
Solution:
// Cloud Function
exports.transferData = functions.https.onCall(async(data, context) => {
const firestore = admin.firestore();
const customerQuery = firestore.collection('customers').where('userId', '==', `${data.oldUser}`);
const drinkQuery = firestore.collection('drinks').where('userId', '==', `${data.oldUser}`);
const customerSnapshot = await customerQuery.get();
const drinkSnapshot = await drinkQuery.get();
const batch = firestore.batch();
for (const documentSnapshot of customerSnapshot.docs.concat(drinkSnapshot.docs)) {
batch.update(documentSnapshot.ref, { 'userId': `${data.newUser}` });
};
return batch.commit();
});

As you already guessed, the call customerQuery.get() returns a promise.
In order to understand what you need, you should first get familiar with the concept of promises here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise
For your use case, you will probably end up with either using the then callback:
customerQuery.get().then((result) => {
// now you can access the result
}
or by making the method call synchronous, by using the await statement:
const result = await customerQuery.get()
// now you can access the result

Related

Issue with scheduled function. Error: Value for argument "value" is not a valid query constraint. Cannot use "undefined" as a Firestore value

I am writing a cloud function that will move expired events from a collection to another. It is not working as expected and I am very novice at Javascript. Please save me.
const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();
const db = admin.firestore();
exports.expireEvents = functions.region("us-west2").pubsub.schedule('* * * * *').onRun(async (context) => {
await db.collection("Events").where('endDate', '<=', admin.firestore.Timestamp.now().millisecondsSinceEpoch).get().then((snapshot) => {
snapshot.forEach(async (doc) => {
// For all expired events, we will perform operations on some of their fields
const event = doc.data();
// Write document to collection of "expired events"
await db.collection("ArchivedEvents").doc(event.eid).set(event);
// For all the guests in that expired event, do stuff; guests should be a list of strings.
event.guests.forEach(async (uid) => {
// Create a new write batch
const batch = db.batch();
// Get user and update some attributes
const guest = await db.collection("Users").doc(uid);
// Add all operations to be performed for given user to this batch
batch.update(guest, {eventsAttended: admin.firestore.FieldValue.arrayUnion(event.eid)});
batch.update(guest, {eventsAttending: admin.firestore.FieldValue.arrayRemove(event.eid)});
// Execute batch of operations
await batch.commit();
});
// Delete doc from "not expired" collection
await db.collection("Events").doc(event.eid).delete();
});
console.log(`Successfully expired events ending on ${admin.firestore.Timestamp.now()}.`);
return true;
})
.catch((err) => {
console.error(`Could not get or update documents. Error ${err}.`);
return false;
});
});
This is the next part of the error. I tried with a collection with no documents and a few documents, but I am starting to think that because none of them have expired yet, that's why I am getting this error?
Rest of error log
If you want to ignore undefined values, enable `ignoreUndefinedProperties`.
at Object.validateUserInput (/workspace/node_modules/#google-cloud/firestore/build/src/serializer.js:277:19)
at validateQueryValue (/workspace/node_modules/#google-cloud/firestore/build/src/reference.js:2230:18)
at CollectionReference.where (/workspace/node_modules/#google-cloud/firestore/build/src/reference.js:1061:9)
at /workspace/index.js:139:33
at cloudFunction (/workspace/node_modules/firebase-functions/lib/cloud-functions.js:131:23)
at /layers/google.nodejs.functions-framework/functions-framework/node_modules/#google-cloud/functions-framework/build/src/function_wrappers.js:144:25
at processTicksAndRejections (node:internal/process/task_queues:96:5)
You've at least two problems:
I think you want a JavaScript Date object (not Firebase Timestamp object) in your query, i.e. where('endDate', '<=', new Date())
Firebase Timestamp doesn't have a millisecondsSinceEpoch property which is -- I think -- causing the "undefined" error that you're encountering.

Firebase Firestore transactions on cloud functions ( getAll method on the callback function first param ) How to use it?

I've been struggling for a while to find out how exactly to use the getAll function on the first param of the callback function on runTransation function.
The doc firebase doc only shows how to use the get function to retrieve a single doc, but I want to retrieve multiple docs based on multiple where statements from a collection.
the question is how to use getAll function bellow?
export const match = functions.firestore
.document('waitingList/{userId}').onCreate(async (snapshot, context) => {
app.firestore().runTransaction(async transaction => {
transaction.getAll( //?); // ???
});
});
UPDATE 1 | 23/4/2022
I figured out a way (but I'm not fully satisfied with it because of duplication in reading from firestore).
The solution is as follows
app.firestore().runTransaction(async transaction => {
const docRefs: FirebaseFirestore.DocumentReference<any>[] = [];
(await firestore
.collection('collectionName')
.limit(100)
.get())
.forEach((doc) => {
docRefs.push(doc.ref);
}); //This is reading the Database for 100 docs
const users = await transaction.getAll(...docRefs); // This also is reading the database for the same 100 docs (But in a transaction context)
});
if someone knows how to read the docs only once in the transaction please do provide the solution.
Something like that:
transaction.getAll(...docRefs).then((docs) => {
docs.forEach((doc) => {/*...*/}
}
As #Abobker already stated, I agree that for now this will be the best way to retrieve multiple docs based on multiple where statements from a collection:
app.firestore().runTransaction(async transaction => {
const docRefs: FirebaseFirestore.DocumentReference<any>[] = [];
(await firestore
.collection('collectionName')
.limit(100)
.get())
.forEach((doc) => {
docRefs.push(doc.ref);
}); //This is reading the Database for 100 docs
const users = await transaction.getAll(...docRefs); // This also is reading the database for the same 100 docs (But in a transaction context)
});
Although is not the most efficient solution, It does address the problem.

retrieving data from database according to query conditions

"_id":{"$id":"61b5eb36029b48135465e766"},
"name":"push-ups","link":"https://google.com",
"image":"https://google.com",
"gender":["0","1","2"],
"goal":["lw","gw","sf"],
"age":60,
"excersietype":"chest",
"__v":0
this is how my data is stored in database
and I want to fetch data according to 3 condition
I got 3 queries from front gender goal and age and according to that I have to retrieve data
const gender = req.query.gender;
const age = req.query.age;
const goal = req.query.goal
const level = req.query.level
if (level==='fb'){
const getdata = new Forbeg.find({gender:{$in:gender}},{age:{$lte:age}},{goal:{$in:goal}});
console.log(getdata)
}
Is this a good way to find the data because I am getting error
UnhandledPromiseRejectionWarning: MongooseError: `Model.find()` cannot run without a model as `this`. Make sure you are not calling `new Model.find()`
I am getting above error while fetching
The error is explicit : Make sure you are not calling 'new Model.find()'. Use const getdata = Forbeg.find(...).
However, you will immediately run into the next problem, as Mongoose models return thenables (Promise-like). console.log(getdata) will log Promise<pending>. You need to resolve your database call, either by doing
Forbeg.find(...).then( getdata => console.log(getData));
or (much more better!):
const getdata = await Forbeg.find(...);
console.log(getdata)
Even better, add .lean() to get simple JSON data instead of an array of Mongoose objects (faster), and .exec() to get a true Promise instead of a thenable :
const getdata = await Forbeg.find(...).lean().exec();
console.log(getdata)
Remove new operator
const getData = Forbeg.find({gender:{$in:gender}},{age:{$lte:age}},{goal:{$in:goal}});

How do I Collect User IDs + Retrieve Corresponding Tokens + Send a Push Notification Via Firebase Cloud Function (JS)

The Problem:
I have been unable to use Firebase (Google) Cloud Functions to collect and utilize device tokens for the cloud messaging feature.
Context:
I am a self-taught android-Java developer and have no JavaScript experience. Despite that, I believe I have code that should work and am not sure what the problem is. To my understanding, it could be one of three things:
Somehow my Firebase Realtime Database references are being called incorrectly and I am not retrieving data as expected.
I may need to use Promises to wait for all calls to be made before proceeding, however I don't really understand how I would incorporate that into the code I have.
I may be using multiple return statements incorrectly (which I am also fuzzy on).
My error message on the Firebase Realtime Database console is as follows:
#firebase/database: FIREBASE WARNING: Exception was thrown by user callback. Error: Registration token(s) provided to sendToDevice() must be a non-empty string or a non-empty array.
at FirebaseMessagingError.FirebaseError [as constructor] (/srv/node_modules/firebase-admin/lib/utils/error.js:42:28)
at FirebaseMessagingError.PrefixedFirebaseError [as constructor] (/srv/node_modules/firebase-admin/lib/utils/error.js:88:28)
at new FirebaseMessagingError (/srv/node_modules/firebase-admin/lib/utils/error.js:254:16)
at Messaging.validateRegistrationTokensType (/srv/node_modules/firebase-admin/lib/messaging/messaging.js:729:19)
at Messaging.sendToDevice (/srv/node_modules/firebase-admin/lib/messaging/messaging.js:328:14)
at admin.database.ref.once.snapshot (/srv/index.js:84:12)
at onceCallback (/srv/node_modules/#firebase/database/dist/index.node.cjs.js:4933:51)
at /srv/node_modules/#firebase/database/dist/index.node.cjs.js:4549:22
at exceptionGuard (/srv/node_modules/#firebase/database/dist/index.node.cjs.js:698:9)
at EventList.raise (/srv/node_modules/#firebase/database/dist/index.node.cjs.js:9684:17)
The above indicates I am not retrieving data either at all or by the time the return is called. My JavaScript function code is:
'use strict';
const admin = require('firebase-admin');
admin.initializeApp();
exports.pushNotification = functions.database.ref('/Chat Messages/{chatId}/{pushID}').onCreate((snapshot, context) => {
const valueObject = snapshot.after.val();
return admin.database().ref(`/Chat Basics/${valueObject.chatKey}/Chat Users`).once('value', statusSnapshot => {
var index = 0;
var totalkeys = statusSnapshot.numChildren();
var msgIDs = [];
statusSnapshot.forEach(msg=>{
msgIDs.push(msg.key.toString());
if(index === totalkeys - 1){
const payload = {
notification : {
title: valueObject.userName,
body: valueObject.message,
sound: "default"
}
}
sendNotificationPayload(valueObject.uid, payload);
}
index++;
});
});
});
function sendNotificationPayload(uid, payload){
admin.database()
.ref(`/User Token Data/${uid}`)
.once('value', snapshot=> {
var tokens = [];
//if(!snapshot.exists())return;
snapshot.forEach(item =>{
tokens.push(item.val())
});
admin.messaging()
.sendToDevice(tokens, payload)
.then(res => {
return console.log('Notification sent')
})
.catch(err => {
return console.log('Error in sending notification = '+err)
});
});
}
This code is mostly inspired by what was said to be a working example here from another Stack Overflow question here. I have successfully tested sending a notification to a single device by manually copying a device token into my function, so the function does run to completion. My Java code seems to be irrelevant to the problem, so I have not added it (please ask in the comments if you would like it added for further context).
What I Have Tried:
I have tried implementing promises into my code, but I don't think I was doing it properly. My main reference for this was here. I have also looked at the documentation for literally everything related to this topic, however my knowledge of JS is not sufficient to really apply barebones examples to my code.
My Firebase Realtime Database Nodes:
#1: Loop through chat members to collect user IDs:
"Chat Basics" : {
"1607801501690_TQY41wIfArhHDxEisyupZxwyHya2" : {
"Chat Users" : {
"JXrclZuu1aOwEpCe6KW8vSDea9h2" : true,
"TQY41wIfArhHDxEisyupZxwyHya2" : true
},
#2: Collect user tokens from collected IDs (ignore that tokens are matching):
"User Token Data" : {
"JXrclZuu1aOwEpCe6KW8vSDea9h2" : "duDR3KH3i3I:APA91bH_LCeslZlqL8akYw-LrM9Dv__nx4nU1TquCS0j6bGF1tlIARcheREuNdX1FheC92eelatBC8LO4t6gt8liRdFHV-NDuNLa13oHYxKgl3JBPPlrMo5rB5XhH7viTo4vfYOMftRi",
"TQY41wIfArhHDxEisyupZxwyHya2" : "duDR3KH3i3I:APA91bH_LCeslZlqL8akYw-LrM9Dv__nx4nU1TquCS0j6bGF1tlIARcheREuNdX1FheC92eelatBC8LO4t6gt8liRdFHV-NDuNLa13oHYxKgl3JBPPlrMo5rB5XhH7viTo4vfYOMftRi"
}
Conclusion:
Concrete examples would be much appreciated, especially since I am crunching right now. Thanks for your time and help!
Update:
After some more testing, it looks like the problem is definitely due to my lack of understanding of promises in two areas. Firstly, only one user is collected before the final return is called. Secondly, the final return is called before the 2nd forEach() loop can store snapshot data to an array.
For this code then, how may I modify (or rebuild) it so that it collects all keys before proceeding to retrieve token data from all keys - ultimately before returning the notification?
Just as with every question I post, I managed to figure out how to do it (tentatively) a few hours later. Below is a full example of how to send a notification to chat users based on a message sent (although it does not yet exclude the sender) to a given chat. The order of operations are as such:
User message is saved and triggers event. Relevant data the message contains are:
username, chat key, message
These are retrieved, with (username + message) as the (title + body) of the
notification respectively, and the chat key is used for user id reference.
Loop through chat user keys + collect.
Loop through array of chat user keys to collect array of device tokens.
Send notification when complete.
The code:
//Use firebase functions:log to see log
exports.pushNotification = functions.database.ref('/Chat Messages/{chatId}/{pushId}').onWrite((change, context) => {
const valueObject = change.after.val();
return admin.database().ref(`/Chat Basics/${valueObject.chatKey}/Chat Users`).once('value', statusSnapshot => {
var index = 0;
var totalkeys = statusSnapshot.numChildren();
var msgIDs = [];
statusSnapshot.forEach(msg=>{
msgIDs.push(msg.key.toString());
if(index === totalkeys - 1){
const payload = {
notification : {
title: valueObject.userName,
body: valueObject.message,
sound: "default"
}
}
let promises = [];
var tokens = [];
for(let i=0; i < msgIDs.length; i++){
let userId = msgIDs[i];
let promise = admin.database().ref(`/User Token Data/${userId}`).once('value', snapshot=> {
tokens.push(snapshot.val());
})
promises.push(promise);
}
return Promise.all(promises).then(() => {
return admin.messaging().sendToDevice(tokens, payload);
});
}
index++;
return false;
});
});
});

Firestore Document Typescript doc.data() undefined?

Currently cleaning up a bit of code and rewritting a lot in typescript. What I found what made me curious is the following code:
const userRef = firestore.collection('users').doc(userId);
const userDoc = await userRef.get();
if (userDoc.exists) {
const userData = userDoc.data();
const currentUserBalance = userData.balance ? userData.balance : 0;
}
Now Typescript will complain that userData is possibily undefined, but the Documents .data() cannot be undefined when I check for the document existing above in my if block. Just curious on why that happens and if I have a logic issue here or not.
TypeScript doesn't have any knowledge of the relationship between exists and data(). It just knows the signature of data() says that the return value can be DocumentSnapshot or undefined. So, you must satisfy the compiler by either:
First checking for "truthiness", then use the results if so:
const data = userDoc.data()
if (data) {
// In this block, data is now typed as just DocumentData,
// undefined is no longer an option.
}
Telling TypeScript that you know for sure that the results will be "truthy" by using the ! operator:
const data = userDoc.data()! // data is now typed as just DocumentData
Unfortunately, even though Firestore adapters both for Node.js and the web are written mainly in TypeScript, they aren't designed for the language.
To solve the problem, I wrote Typesaurus, TypeScript-first ORM (or ODM if you wish) that solves this problem:
import { get, collection } from './src'
type User = { name: string }
const users = collection<User>('users')
async function main() {
const user = await get(users, 'qwe') // get will return document or undefined
if (user) {
console.log(user.data.name) // user is Doc<User>
} else {
// user is undefined
}
}
main()

Categories