Develop Reference

Firebase firestore Cannot read property 'firebase' of undefined

I'm trying to create a collection called "users" but there seems to be a problem with the firebase reference , I'm using an already existing repo where I added my addUserToDb() function, in the function above called saveMessagingDeviceToken() there seems to be no problem with the firebase.
<code>
// Saves the messaging device token to the datastore.
function saveMessagingDeviceToken() {
firebase.messaging().getToken().then(function(currentToken) {
if (currentToken) {
console.log('Got FCM device token:', currentToken);
// Saving the Device Token to the datastore.
firebase.firestore().collection('fcmTokens').doc(currentToken)
.set({uid: firebase.auth().currentUser.uid});
} else {
// Need to request permissions to show notifications.
requestNotificationsPermissions();
}
}).catch(function(error){
console.error('Unable to get messaging token.', error);
});
}
// Add the user to DB
function addUserToDb(profilePicUrl, userName, userID){
var db = this.firebase.firestore();
db.collection("users").doc(userID).set({
name: userName,
profilePic: profilePicUrl,
uid: userID
})
.then(function() {
console.log("Document successfully written!");
})
.catch(function(error) {
console.error("Error writing document: ", error);
});
}
</code>
The way to add is taken from https://firebase.google.com/docs/firestore/manage-data/add-data which is the documentation.
the full error :
TypeError: Cannot read property 'firebase' of undefined
at addUserToDb (main.js:115)
at Object.authStateObserver [as next] (main.js:199)
at subscribe.ts:104
at subscribe.ts:233

Why am I not able to populate the posts field?

So, as you could see from my previous questions, I've been stuck in populate of mongoose. I have two models, User and Post, and currently, I'm trying to get a single user's posts but not able to do it.
getUserPosts: async (req, res) => {
try {
const user = await User.findById(req.params.id).populate("posts");
if (!user) {
return res.status(400).json({ error: "No user" });
}
return res.status(200).json({ userposts: user.posts });
} catch (err) {
return res.status(500).json({ error: "Server error" });
}
}
The problem is I'm somehow getting an empty array of posts. If I manually push the posts documents post id, then it's working, otherwise it's not.

Accessing Mongo DB from within Node

I’m trying to connect to a database through node. I’ve got it working with smaller databases using a Mongo URL of the form:
mongodb://[username]:[password]#db1-a0.example.net:27017/[DB-Name]
When I switched it out to use a larger DB, using the Mongo URL of the form:
mongodb://[username]:[password]#db1-a1.example.net:27017,db2.example.net:2500/[DB-Name]?replicaSet=test
It throws a ‘ RangeError: Maximum call stack size exceeded’ error and won’t connect. This URL is the onlything that has changed between the databases.
I’ve checked the db details and can access it through RoboMongo / Robo 3T so the database definitely exists.
Trying to connect through Mongoose version ^5.2.10 using the following code:
function connect() {
if (MONGO_URL) {
mongoose.connect(MONGO_URL, err => {
if (err) {
console.log('error connecting')
console.log(err)
}
})
} else {
mongoose.connect(`mongodb://${host}`, {
user,
pass,
dbName,
useNewUrlParser: true //depresiation issue
}, err => {
if (err) {
console.log('error connecting')
console.log(err)
}
})
}
}
mongoose.connection.on('error', (message) => {
console.log('connection error!') //This is logged
console.log(message)
process.exit()
})
mongoose.connection.on('disconnected', connect)
connect()

Looks like you are trying to use a replica set. If so try to connect like following`
var uri = `mongodb://${userName}:${encodeURIComponent(password)}#${clusterName}/${dbName}?ssl=true&replicaSet=${process.env.replicaSetName}&authSource=${authDB}`
var db = mongoose.connect(uri).then().catch() // Whatever inside the then and catch blocks
`

I can`t delete anything from my MongoDB [duplicate]

I'm currently working on my first node.js rest api with express, mongodb (atlas cloud) and mongoose, when i try to make a .remove request i get this error:
{
"error": {
"name": "MongoError",
"message": "Cannot use (or request) retryable writes with limit=0",
"driver": true,
"index": 0,
"code": 72,
"errmsg": "Cannot use (or request) retryable writes with limit=0"
}
This is my request:
router.delete('/:productId', (req, res, next) => {
const id = req.params.productId;
Product.remove({ _id: id })
.exec()
.then(result => {
res.status(200).json(result);
})
.catch(err => {
console.log(err);
res.status(500).json({
error: err
})
}); ;
});

The findOneAndRemove() function would work more accordingly since its specific to the filtering method passed in the function .findOneAndRemove(filter, options) to remove the filtered object. Still, if the remove process is interrupted by the connection the retryRewrites=true will attempt the execution of the function when connected.
More information here
When using retryRewrites set to true tells the MongoDB to retry the same process again which in fact can help prevent failed connections to the database and operate correctly, so having it turn on is recommended.
More info here
If you are using Mongoose 5^ and MongoDB 3.6 your code is better written like:
mongoose.connect('mongodb.....mongodb.net/test?retryWrites=true', (err) => {
if(err){
console.log("Could not connect to MongoDB (DATA CENTER) ");
}else{
console.log("DATA CENTER - Connected")
}
});// CONNECTING TO MONGODB v. 3.6
router.delete('/:productId', (req, res, next) => {
const id = req.params.productId;
Product.findOneAndRemove({ _id: id })//updated function from .remove()
.exec()
.then(result => {
res.status(200).json({
message: "Product Removed Successfuly"
});
})
.catch(err => {
console.log(err);
res.status(500).json({
error: err
})
}); ;
});

I just changed the true to false in retryWrites=true and it worked. Is that a good approach? Or there is a better way to solve this problem?

retryWrites=true is a good thing, a workaround for this incompatibility is to use findOneAndRemove instead of remove (looks like you're using mongoose)

ReactJS + Redux: Why isn't MongoDB saving data to the database even with correct API requests?

I have a MongoDB/Webpack/NodeJS Express set up in my ReactJS + Redux project.
I am making API calls from action creators in redux, and reach the API server and get a successful status back, yet the data never gets saved and the database never gets created even checking with in terminal mongo -> dbs and it doesn't show practicedb database which I named it as.
What could be the issue? Am I missing something?
Any guidance or insight would be greatly appreciated. Thank you
This is my set up for API:
import axios from 'axios';
import { browserHistory } from 'react-router';
import cookie from 'react-cookie';
import { AUTH_USER, AUTH_ERROR } from './types';
const API_URL = 'http://localhost:3000/api';
export function errorHandler(dispatch, error, type) {
let errorMessage = (error.data.error) ? error.data.error : error.data;
// NOT AUTHENTICATED ERROR
if(error.status === 401) {
errorMessage = 'You are not authorized to do this.';
}
dispatch({
type: type,
payload: errorMessage
});
}
export function registerUser({ email }) {
return function(dispatch) {
axios.post(`${API_URL}/auth/register`, { email })
.then(response => {
console.log('THIS IS TESTING PURPOSE')
console.log(response)
dispatch({ type: AUTH_USER });
})
.catch((error) => {
errorHandler(dispatch, error.response, AUTH_ERROR)
});
}
}
And my API controller is set up as such:
"use strict";
const User = require('../models/user')
exports.register = function(req, res, next) {
const email = req.body.email;
console.log('ERROR 1')
if(!email) {
return res.status(422).send({ error: 'You must enter an email address.'})
console.log('ERROR 1')
}
User.findOne({ email: email }, function(err, existingUser) {
if(err) { return next(err); }
console.log('ERROR 2')
if(existingUser) {
return res.status(422).send({ error: 'That email address is already in use.'})
}
console.log('ERROR 3')
let user = new User({
email: email,
})
console.log('ERROR 4')
user.save(function(err, user) {
if(err) { return next(err); }
console.log('ERROR 5')
res.status(201).json({
user: user,
})
})
})
console.log('ERROR 6')
}
Configuration for the API:
module.exports = {
'database': 'mongodb://localhost/practicedb',
'port': process.env.PORT || 3000,
'secret': 'dogcat',
}
The project so far just has an input text field, where it accepts an email address. If the email has already been registered, the API should return the error That email address is already in use. and it does.
So I tried console logging to see what the problem is, and the first time I submit the POST request, it logs the following (the terminal showing API console logs):
And if I try to submit the same email again, it throws me the API error that the email is already in use with 422 error, yet the data do not get saved and database (practicedb) never get created:
Also, what is the OPTIONS request that shows up in terminal? I only made an attempt to POST. Lastly, is OPTIONS why the ERROR log in API server is not logging in chronological order?
EDIT

You're using the wrong Mongo shell command: db will only show you the current database (test), but if you want to see a list of all databases, you should use show dbs.
If you want to switch databases:
use practicedb
And, if you want to see the collections in the current database:
show collections