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Javascript issue storing user id when updating Strapi

For a research study, I am trying to record user's interactions with a web interface. I setup a back end with Strapi to store that data. Connection and setting up of a new participant ID is not a problem, but when I try to update the data I get an interesting behavior that is unfamiliar to me.
Basically, it seems that I am setting the participants ID but when accessing it, my logs show that I have a duplicate with no data stored. Below the logs I am getting while debugging:
//Initialising study. connectStrapi.js?t=1668867760343:11
//No participant ID existing. Creating.. connectStrapi.js?t=1668867760343:15
//Confirming, Participant ID: 121 interactionLogger.js?t=1668867760343:199
//On Event: participant id is: 121. interactionLogger.js?t=1668867760343:81
//On Event: participant id is: undefined interactionLogger.js:81
The connectStrapi.js sets up the study and participant data. When no id is present at the start, I am creating new data. The interactionLogger.js is responsible to log the data and update Strapi when something happens.
I am not completely new to JavaScript, but I go to admit, that I have no idea what the different identifiers mean. I am only updating once, but I the same line twice - once for interactionLogger.js?t=1668867760343:81 and a second time for interactionLogger.js:81. I am not exactly sure, what the .js?t=1668867760343 means and how I can ensure passing the right value at the right time.
Currently, I when I am updating the data, the undefined value is being passed resulting in no data being updated. I am thinking, I am missing something basic here but can't figure it out.. In case it matters, I have implemented the JavaScript files as type=modules and import functions accordingly.
InitialiseStudy function from connectStrapi.js:
import * as interactionLogger from './interactionLogger.js/'
//...
export const initialiseStudy = async (participantData, id) => {
console.log("Initialising study.")
if(id === undefined) {
await axios.post(apiUrl, participantData)
.then( response =>{
console.log('No participant ID existing. Creating..')
//setupParticipant(response.data.data);
interactionLogger.setParticipantID(response.data.data.id)
})
.catch( error => {
if (error.response){
console.log('error:', error.response)
}
else if (error.request){
console.log('error:', error.request)
}
else if (error.message){
console.log('error:', error.message)
}
else {
console.log('error:', error)
}
})
} else {
axios.put(apiUrl+ id, participantData)
.then(response => {
console.log('response.data:', response.data)
})
.catch( error => {
console.log('error:', error)
})
}
}
My updateData function from connectStrapi.js:
export const updateData = (data, id) => {
if (id === undefined) {
alert("No Participant ID")
} else {
axios.put(apiUrl + '/' + id, data)
.then( response => {
console.log('response.data:', response.data)
} )
.catch( error => {
console.err('error:', error)
})
}
}
The setter from interactionLogger.js is a normal setter:
let participantID
//...
export const setParticipantID = (id) => {
participantID = id
}
The logData function uses updateData, which is imported before it based on events in interactionLogger.js:
import * as connectStrapi from './connectStrapi.js'
//...
const logData = (data) => {
connectStrapi.updateData(data, participantID) //<- This is a local variable initialized as undefined but updated using the setParticipantID in connectStrapi.js
}
Thanks in advance!

Sequelize update via PATCH, how to process each possible result

I'm creating a rest api for CRUD operations using Sequelize and MySql. I'm using a controller to run an update on a PATCH request to update fields of a product. It technically works, but I feel like there is a more elegant way to handle this.
Sequelize's update method will return an array of objects depending on the results. Array[0] is the number of rows affected by the update (should just be one in my case, as I'm updating by id). Array[1] will return an object with details about the update as well as all the old values and new values. Here's how I'm handling that currently:
//products.controller.js
//Update a single product using id (PUT/PATCH)
const patch = (req, res) => {
const id = req.params.id;
Product.update(req.body, { where: { id }, individualHooks: true })
.then((rowsAffected) => {
//Item not found
if (Object.entries(rowsAffected[1]).length === 0) {
res.status(404).send({
success: false,
status: 404, //Not found
message: `Product with id ${id} not found. Update failed.`,
});
return;
}
//if rowsAffected[0] === 1 then success
if (rowsAffected[0] === 1) { //row changed
res.status(200).send({
success: true,
status: 200,
message: `Product updated.`,
id: id,
payload: req.body,
});
} else {
// if rowsAffected[0] !== 1 then it failed.
res.status(200).send({
success: false,
status: 200, //Not Modified
message: `No fields have changed. Product not updated.`,
});
}
})
.catch((err) => {
res.status(500).send({
success: false,
status: 500,
message:
err.message || "Something went wrong while updating the product.",
});
});
}
As you can see, first I'm checking to see if the the update function returns the product details (meaning it successfully found it in the database). If not then sending 404. Then I check the affected rows. If 1 then success, if 0 then nothing changed. Finally I'm catching any server errors.
I feel like there is a better way rather than having to break down the update function's return (like Object.entries(rowsAffected[1]).length === 0)

This is ok if this is the only way you can check the effects of the update. What I can suggest is putting an abstraction above it.
First thing that checking (rowsAffected[0] === 1) does not make much sense, since the update is idempotent and you end up with the same resource state no matter what the actual values are. If you insist, then I would not pair success: false with a 200 ok status, because failure is failure and it requires an error message and 4xx or 5xx status. So either delete it or convert it into a proper error. Hard to find such a status code, but maybe using 409 conflict is ok in these cases https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/409 though I would just remove this part of the code. I keep it for the sake of the example.
As of the success and status properties in the body, they don't make much sense either, because they travel in the header, and it is evident from the HTTP standard that 2xx means success, 4xx and 5xx means error. So I would remove those too.
If you don't want to support detailed error codes and exception types and parameters, then just send the error messages and the body can be even a string instead of an object.
Sending the err.message to the consumers is a bad idea by unexpected errors. You don't know what you send out. You need to log them and send something general instead. Communicating errors is always a higher abstraction level stuff, many times. As of the Product with id ${id} not found. Update failed. here adding the id is not necessary, because the request contains it.
So atm. the code looks like this:
const patch = (req, res) => {
const id = req.params.id;
Product.update(req.body, { where: { id }, individualHooks: true })
.then((rowsAffected) => {
if (Object.entries(rowsAffected[1]).length === 0) {
res.status(404).send({message: `Product not found. Update failed.`});
return;
}
//if rowsAffected[0] === 1 then success
if (rowsAffected[0] === 1) { //row changed
res.status(200).send({
message: `Product updated.`,
id: id,
payload: req.body,
});
} else {
res.status(409).send({message: "No fields have changed. Product not updated."});
}
})
.catch((err) => {
res.status(500).send({message: "Something went wrong while updating the product."});
});
}
We can go further by mapping status codes to status messages and extracting the possibly repeating parts of the story into separate functions.
const patch = (req, res) => {
const id = req.params.id;
const statusMessages = {
200: "Product updated."
404: "Product not found. Update failed."
409: "No fields have changed. Product not updated.",
500: "Something went wrong while updating the product."
};
Product.update(req.body, { where: { id }, individualHooks: true })
.then(updateStatusVerification)
.then(successHandler(res, statusMessages, () => {
return {
id: id,
payload: req.body,
};
}))
.catch(apiErrorHandler(res, statusMessages));
}
function successHandler(res, statusMessages, callback){
return function (){
let body = callback();
body.message = statusMessages[200];
res.status(200).send(body);
};
}
function apiErrorHandler(res, statusMessages){
return function (err){
let statusCode = 500;
if (err instanceof NotFoundError)
statusCode = 404;
else if (err instanceof NotUpdatedError)
statusCode = 409;
res.status(statusCode).send({
message: statusMessages[statusCode]
});
};
}
function updateStatusVerification(rowsAffected){
return new Promise((resolve, reject) => {
if (Object.entries(rowsAffected[1]).length === 0)
reject(new NotFoundError);
else if (rowsAffected[0] !== 1)
reject(new NotUpdatedError);
else
resolve();
});
}
class ApiError extends Error {}
class NotFoundError extends ApiError {}
class NotUpdatedError extends ApiError {}
We can move the status messages to the documentation. So you will end up with something like this and some utility functions:
const patch = (req, res) => {
const id = req.params.id;
statusMessages = docs.product.update.statusMessages;
Product.update(req.body, { where: { id }, individualHooks: true })
.then(updateStatusVerification)
.then(successHandler(res, statusMessages, () => {
return {
id: id,
payload: req.body,
};
}))
.catch(apiErrorHandler(res, statusMessages));
}
We can go even further if this is a frequent pattern:
const patch = (req, res) => {
const id = req.params.id;
handleUpdate(
Product.update(req.body, { where: { id }, individualHooks: true }),
() => {id: id, payload: req.body},
docs.product.update.statusMessages
);
}
function handleUpdate(dbUpdatePromise, successCallback, statusMessages){
dbUpdatePromise.then(updateStatusVerification)
.then(successHandler(res, statusMessages, successCallback))
.catch(apiErrorHandler(res, statusMessages));
}
So it can be as abstract as you like, it really depends on your needs and what the current usage allows. You can decide how many and what kind of layers you need based on actual use cases and repetitions.

how to check and store data in mongo

i am trying to store data in MongoDB.Here I am checking whether data is present or not. if data already exists then throwing an error or else storing data. please check the below code
in the below data having duplicate data(name and ICC). after saving the first record it should throw an error but here it's not throwing any error.
let Records = [{
name: 'test',
icc: 'testId'
},
{
name: 'test',
icc: 'testId'
}]
await Promise.all(Records.map(async (item) => {
try {
item['id'] = id
let ItemObj = table_name.build();
item.name = item.name;
item.icc = item.icc;
let found = await table_name.findOne({ where: { name: item.name, id: id } })
console.log("11111111111111111");
if (found) {
console.log("22222222222222222222");
throw new Error(item.name + " is already exist!");
} else {
console.log("333333333333333333333333333333");
Object.assign(ItemObj.dataValues, item);
console.log("4444444444444444444")
await ItemObj.save()
console.log("5555555555555555555")
}
} catch (err) {
throw new Error(err);
}
})
).then((data) => {
console.log("final");
}).catch((err) => {
console.log("error logged");
})
here flow goes like
on console
11111111111111111
33333333333333333
44444444444444444
11111111111111111
33333333333333333
44444444444444444
55555555555555555
55555555555555555

Array of promise inside Promise.all get executed immediately, i mean it does not wait for first one to complete then move on to other. Imagine this as parallel execution (not actual working).
So keeping above analogy in mind, your try block for both item is getting executed simultaneously. When the finOne is executed for both items, none of them is saved so response is null

Retrieve an array from a Firestore document and store it to Node.Js then use it as tokens to send notifications

I've been trying to figure this out for hours and I just can't. I'm still a beginner with Node.js and Firebase. I need your help to be able to retrieve the tokens array in my "userdata" collection to Node.js and be able to use it to send notifications in the Cloud Function. So far this is what I've been working on. Here is what my database looks like:
The receiverId is gathered from when I have an onCreate function whenever a user sends a new message. Then I used it to access the userdata of a specific user which uses the receiverId as their uid.
In the cloud function, I was able to start the function and retrieve the receiverId and print the userToken[key]. However, when I try to push the token it doesnt go through and it results in an error that says that the token is empty. See the image:
Your help would mean a lot. Thank you!
newData = snapshot.data();
console.log("Retrieving Receiver Id");
console.log(newData.receiverId); //uid of the user
const tokens = [];
const docRef = db.collection('userdata').doc(newData.receiverId);
docRef.get().then((doc) => {
if (doc.exists) {
console.log("DocRef exist");
const userToken = doc.data().tokens;
for(var key in userToken){
console.log(userToken[key]);
tokens.push(userToken[key]);
}
} else {
// doc.data() will be undefined in this case
console.log("No such document!");
}
}).catch((error) => {
console.log("Error getting document:", error);
});
//Notification Payload
var payload = {
notification: {
title: newData.sendBy,
body: 'Sent you a message',
sound: 'default',
},
data: {
click_action : 'FLUTTER_NOTIFICATION_CLICK',
route: '/telconsultinbox',
}
};
console.log("Sending Notification now.");
console.log(tokens);
try{
//send to device
const response = await admin.messaging().sendToDevice(tokens, payload);
console.log('Notification sent successfully');
console.log(newData.sendBy);
}catch(err){
console.log(err);
}

I think you should avoid using for..in to iterate through an array (you can read more about it in this answer). Try one of these 2 options:
You could use forEach(), which is more elegant:
userToken.forEach((token) => {
console.log(token);
tokens.push(token);
});
for-of statement:
for(const token of userToken){
console.log(token);
tokens.push(token);
}
Also, I would consider renaming userToken to userTokens, since it should contain multiple values. Makes the code a bit more readable.

Each then() should return a value or throw

I am trying to send push notifications using cloud functions for a group chat system, but i keep getting this error in my terminal: Each then() should return a value or throw
Why is this happening?
Here's my code:
let functions = require('firebase-functions');
let admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.sendNotification = functions.database.ref('/chatrooms/{chatroomId}/chatroom_messages/{chatmessageId}')
.onWrite((snap, context) => {
console.log("System: starting");
console.log("snapshot: ", snap);
console.log("snapshot.after: ", snap.after);
console.log("snapshot.after.val(): ", snap.after.val());
//get the message that was written
let message = snap.after.val().message;
let messageUserId = snap.after.val().user_id;
console.log("message: ", message);
console.log("user_id: ", messageUserId);
//get the chatroom id
let chatroomId = context.params.chatroomId;
console.log("chatroom_id: ", chatroomId);
return snap.after.ref.parent.parent.once('value').then(snap => {
let data = snap.child('users').val();
console.log("data: ", data);
//get the number of users in the chatroom
let length = 0;
for(value in data){
length++;
}
console.log("data length: ", length);
//loop through each user currently in the chatroom
let tokens = [];
let i = 0;
for(var user_id in data){
console.log("user_id: ", user_id);
//get the token and add it to the array
let reference = admin.database().ref("/users/" + user_id);
return reference.once('value').then(snap => {
//get the token
let token = snap.child('messaging_token').val();
console.log('token: ', token);
tokens.push(token);
i++;
//also check to see if the user_id we're viewing is the user who posted the message
//if it is, then save that name so we can pre-pend it to the message
let messageUserName = "";
if(snap.child('user_id').val() === messageUserId){
messageUserName = snap.child('name').val();
console.log("message user name: " , messageUserName);
message = messageUserName + ": " + message;
}
//Once the last user in the list has been added we can continue
if(i === length){
console.log("Construction the notification message.");
let payload = {
data: {
data_type: "data_type_chat_message",
title: "Tabian Consulting",
message: message,
chatroom_id: chatroomId
}
};
return admin.messaging().sendToDevice(tokens, payload)
.then(function(response) {
// See the MessagingDevicesResponse reference documentation for
// the contents of response.
console.log("Successfully sent message:", response);
return response;
})
.catch(function(error) {
console.log("Error sending message:", error);
});
}
});
}
});
});

The message is caused by eslint detecting that you have a then() handler that can finish without returning a value or throwing an error.
It is caused by your for loop on the following line because you do not return a value or throw if data is empty:
for (var user_id in data) {
As others have commented, your for-loop won't execute correctly because you are returning a promise and finishing the handler on only the first iteration.
for (var user_id in data) {
// ...
return reference.once('value').then(snap => {
// ...
}
Arrays in Firebase RTDB
Based on your code, you encountered some of the issues with working with arrays in the RTDB as detailed in this blog post.
Instead of using an array to keep track of a chat room's members (below), it would be best to use a key-value pair approach instead. The value stored in the key-value pair can be a simple true value; or it can be given meaning (true for admins, false for others).
// Array-based list
"chatrooms/chatroomId1": {
"chatroom_messages": { ... },
"users": [
"userId1",
"userId2",
"userId3"
]
}
// RTDB stores above data as:
"chatrooms/chatroomId1": {
"chatroom_messages": { ... },
"users": {
"0": "userId1",
"1": "userId2",
"2": "userId3"
}
}
// Recommeneded: key-value pairs
"chatrooms/chatroomId1": {
"chatroom_messages": { ... },
"users": {
"userId1": true,
"userId2": false,
"userId3": false
}
}
The main benefit of such an approach is that delete a user from a room is simpler which will help with cleaning spam users/messages. To delete a user, you just call
firebase.database().ref("chatrooms/chatroomId1/users/userId1").delete();
rather than
firebase.database().ref("chatrooms/chatroomId1/users").orderByValue().equalTo("userId1").once('value')
.then((snap) => snap.delete());
Furthermore, sending a notification/message that a user was added or removed could be easily implemented using Cloud Functions defined using:
functions.database.ref('/chatrooms/{chatroomId}/users/{userId}').onCreate(...)
functions.database.ref('/chatrooms/{chatroomId}/users/{userId}').onDelete(...)
Chaining promises
When working with asynchronous tasks, avoid using for loops entirely because they are prone to causing undetectable mistakes and modern Javascript provides better alternatives. One such method is using the Promise.all(someArray.map(value => {...})) idiom covered in this answer.
It was also suggested in the question comments to flatten your promise chain, due to the number of changes needed to do the task efficiently, I decided to just make them and note each change in the code itself. The code below relies on the restructure of the chatroom members list discussed above.
let functions = require('firebase-functions');
let admin = require('firebase-admin');
admin.initializeApp(); // CHANGED: Cloud Functions provides the needed environment variables to initialize this for you when called without arguments.
exports.sendNotification = functions.database.ref('/chatrooms/{chatroomId}/chatroom_messages/{chatMessageId}') // CHANGED: renamed 'chatmessageId' to 'chatMessageId' (consistent camelCaseStyling)
.onWrite((change, context) => { // CHANGED: renamed 'snap' to 'change' (matches actual type & less ambiguous below)
if (!change.after.exists()) { // CHANGED: Handle when message was deleted
// message deleted. abort
console.log(`Message #${context.params.chatMessageId} in Room #${context.params.chatroomId} deleted. Aborting.`);
return;
}
let messageData = change.after.val(); // CHANGED: avoid calling change.after.val() multiple times
// console.log("New data written: ", messageData); // CHANGED: Removed verbose log commands.
let message = messageData.message;
let messageAuthorId = messageData.user_id; // CHANGED: renamed 'messageUserId' to 'messageAuthorId' (less ambiguous)
let chatroomId = context.params.chatroomId;
console.log("New message:", { // CHANGED: merged log commands (less StackDriver API overhead when deployed)
user_id: messageAuthorId,
chatroom_id: chatroomId,
message: message
});
let chatroomMembersRef = change.after.ref.parent.parent.child('users'); // CHANGED: only got needed data
return chatroomMembersRef.once('value')
.then(snap => {
// DATABASE STRUCTURE CHANGE: "/chatrooms/{chatroomId}/users" - change array (["userId1", "userId2", "userId3"]) to a userId keyed OBJECT (e.g. {"userId1": true, "userId2": true, "userId3": true})
let chatroomMemberList = Object.keys(snap.val()); // CHANGED: renamed 'data' to 'chatroomMemberList' (less ambiguous)
// console.log("Chatroom Members: ", {
// count: chatroomMemberList.length,
// members: chatroomMemberList
// });
// Asyncronously, in parallel, retrieve each member's messaging token
let chatroomMemberTokenPromises = chatroomMemberList.map((memberId) => { // CHANGED: renamed 'user_id' to 'memberId' (less ambiguous, consistent camelCaseStyling)
let memberDataRef = admin.database().ref("/users/" + memberId); // CHANGED: renamed 'reference' to 'memberDataRef' (less ambiguous)
// CHANGED: For each member, get only their registration token (rather than all of their user data)
let getMessagingTokenPromise = memberDataRef.child('messaging_token').once('value').then((memberTokenSnap) => {
console.log("Got messaging token for member #", memberId);
return memberTokenSnap.val();
});
// If this member is the message author, also get their name to prepend to the notification message.
if (memberId === messageAuthorId) {
let prependUserNamePromise = memberDataRef.child('name').once('value')
.then((memberNameSnap) => {
let messageAuthorName = memberNameSnap.val();
console.log("Message author's name: " , messageAuthorName);
message = messageAuthorName + ": " + message;
});
return Promise.all([getMessagingTokenPromise, prependUserNamePromise])
.then(results => results[0]); // only return result of getMessagingTokenPromise
} else {
return getMessagingTokenPromise;
}
});
// Wait for all of the messaging tokens
return Promise.all(chatroomMemberTokenPromises);
})
.then((chatroomMemberTokensArray) => {
console.log("Constructing the notification message...");
let payload = {
data: {
data_type: "data_type_chat_message",
title: "Tabian Consulting",
message: message,
chatroom_id: chatroomId
}
};
return admin.messaging().sendToDevice(chatroomMemberTokensArray, payload)
.then(function(response) {
// See the MessagingDevicesResponse reference documentation for
// the contents of response.
console.log("Successfully sent message:", response);
return response;
})
.catch(function(error) {
console.log("Error sending message:", error);
});
})
.catch((error) {
console.log("Unexpected error:", error)
});
});