Develop Reference

Push new Object inside a document array

I have this schema for my user
const userSchema = mongoose.Schema({
firstName: {
type: String,
},
notifications : [{
description: String,
status: {
type: String,
enum : ['read', 'unread'],
default: 'unread'
},
dateAdded:{
type: Date,
default: Date.now
}
}],
})
supposedly I want to find the user _id first then insert a new object inside the new notification array. and it should look like this
{
_id: ObjectId('123')
firstName: 'John Doe'
notifications:[
{
description: 'somedescription'
status: 'unread'
},
{
description: 'somedescription2'
status: 'unread'
}
]
}
How can I achieve this, assuming that the notification property is non existent in the user document first, i need to check if notification property is present else add the notification property and push the new object
User.updateOne(
{ _id: userId },
{ $push: { notifications: {description: 'new notifications'} } }
)
this code is not working for me

Use $addToSet operator to achieve that
User.updateOne(
{ _id: userId },
{ $addToSet: { notifications: {description: 'new notifications'} } }
)
If that doesn't work try to add the default value too, and then that must work
User.updateOne(
{ _id: userId },
{ $addToSet: { notifications: {description: 'new notifications',
'status': 'unread'} } }
)

How to add an object to an array of object, using addToSet, or push operators in mongodb

I have an array of reviews, I want to add a review using addToSet that will check if user is present in the array, then we do not want to add since one user can only review once.
My schema looks like this:
const sellerSchema = new mongoose.Schema({
user: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
unique: true,
},
reviews: [
{
by: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
unique: true,
},
title: {
type: String,
},
message: {
type: String,
},
rating: Number,
imagesUri: [{ String }],
timestamp: {
type: Date,
default: Date.now,
},
},
],
});
I might be doing the query wrong, but can't figure out how to add a review and check if current user has not reviewed before.
Here is the query where I add the review:
router.post("/review/:_id/", async (req, res) => {
try {
const stylist_id = mongoose.Types.ObjectId(req.params._id);
const review = {
by: req.user._id,
title: req.body.title,
message: req.body.message,
rating: parseFloat(req.body.rating),
};
if (req.body.imagesUri) {
//if there is images, we need to set it up
review.imagesUri = req.body.imagesUri;
}
await Seller.updateOne(
{ _id: seller_id },
{ $addToSet: { reviews: review } } //get the review that matches to the user_id
);
return res.status(200).send(true);
}catch(err){
res.status(502).send({
error: "Error creating a review.",
});
}
});
I'm thinking of checking for seller's id and also check that no review is by current user, but it is not working.
const userID = req.user._id;
await Seller.updateOne(
{ _id: seller_id, reviews: { $elemMatch: { by: { $ne: { userID } } } } },
{ $addToSet: { reviews: review } } //get the review that matches to the user_id
);
ANSWER:
I was able to solve the issue, in case other people have same issue. I did this:
await Seller.updateOne(
{
_id: seller_id,
"reviews.by": { $nin: [req.user.id] },
//knowing req.user._id is a mongoose.Types.ObjectId.
//You can also use [id1, id2, ...] to the array to check for other id's
},
{ $addToSet: { reviews: review } } //get the review that matches to the user_id
);
Here is the documentation for $nin operator: https://www.mongodb.com/docs/manual/reference/operator/query/nin/

You are pushing the review object inside an object.
Instead do this:
await Seller.updateOne(
{ _id: seller_id },
{ $addToSet: { reviews: review } }
);

Mongoose populate returns an empty array | multiple levels of embedded documents

I am trying to populate my ChatRoom model with the User reference. However, it returns a ChatRoom object with only _ids where I expected usernames, as if I never applied populate on it.
Here is an extract of my ChatRoom model :
const ChatRoom = mongoose.model("ChatRoom", {
sender: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
},
roomname: { type: String, default: "new room" },
messages: [
{
messages: {
type: mongoose.Schema.Types.ObjectId,
ref: "Message",
},
meta: [
{
user: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
},
delivered: Boolean,
read: Boolean,
},
],
},
],
participants: [
{
user: { type: mongoose.Schema.Types.ObjectId, ref: "User" },
},
],
isPrivate: { type: Boolean, default: "false" },
});
My User model :
const User = mongoose.model("User", {
username: { required: true, unique: true, type: String },
avatar: Object,
token: String,
hash: String,
salt: String,
chatroom: {
type: mongoose.Schema.Types.ObjectId,
ref: "ChatRoom",
},
});
As this seems to be a recurrent issue, I tested several StackOverflow answers for my populate code :
Using populate('participants.user') and 'model: user' or just populate('participants.user'), same solution here:
const chatroom = await ChatRoom.findById(req.params.id)
.populate([
{
path: "participants.user",
model: "User",
},
])
.exec((err, user) => {
if (err) {
console.log("error", err);
} else {
console.log("Populated User " + user);
}
});
The console.log returns :
Populated User { _id: new ObjectId("62262b342e28298eb438d9eb"),
sender: new ObjectId("6225d86c9340237fe2a3f067"), roomname:
'Hosmeade', participants: [ { _id: new
ObjectId("6225d86c9340237fe2a3f067") } ], isPrivate: false,
messages: [], __v: 0 }
As if no populate method was ever applied. On the client side, I get an empty string.
Checking my documents aren't empty, this link mentions that Mongoose get problems with detecting referring model across multiple files but the solution doesn't work for me :
_id:6225d86c9340237fe2a3f067 username:"Berlioz" token:"rTCLAiU7jq3Smi3B"
hash:"wvJdqq25jYSaJjfiHAV4YRn/Yub+s1KHXzGrkDpaPus="
salt:"hZdiqIQQXGM1ryYK" avatar:Object
__v:0
If I remove the .exec(...) part, I get the info on the client side, but participants is still filled with only id :
chatroom response : Object { _id: "62262bb14e66d86fb8a041e8",
sender: "6225d86c9340237fe2a3f067", roomname: "Very secret room",
participants: (1) […], isPrivate: false, messages: [], __v: 0 }
I also tried with select: 'username' and get the same result as above :
const chatroom = await ChatRoom.findById(req.params.id).populate({
path: "participants.user",
select: "username",
});
Populating it "as an array"
Changing type of participants.user in my ChatRoom model into an Object (nothing changes)
If needed hereafter are my repos:
Client side and Backend
I run out of ideas on how to debbug my code. Any help would be great !

Save array of ObjectId's using Mongoose's Schema

I have a Mongoose Schema like:
const Role = new Schema({
guildID: {
type: Schema.Types.ObjectId,
ref: 'guilds',
required: true
},
roles: {
owner: {
id: {
type: Number,
required: false
},
commands: [[Schema.Types.ObjectId]]
}
}
})
And a small function to test whether it saves the data as desired which contains:
const roleTest = new Role({
guildID: "61a679e18d84bff40c2f88fd",
roles: {
owner: {
id: 123456789
},
commands: [
"61af57d828b9fd5a07dbdcba",
"61af5a6728b9fd5a07dbdcbb",
"61af5ab728b9fd5a07dbdcbc"
]
}
})
roleTest.save((err, doc) => {
if (err) return res.sendStatus(500)
console.log('Done')
})
It saves everything correctly except the array ObjectIds (commands). What is going wrong here?

You've written the commands in schema with nested array. Try with single array:
{
commands: [Schema.Types.ObjectId],
}

Try this:
commands: [
{ type: mongoose.Schema.Types.ObjectId }
]

Can't get populate() to fill out array in Mongoose

Let me begin by saying I know that this seems to be a frequently asked question and I've spent a couple of days trying to figure it out but no answer seems to work so I'm trying on here.
I have two models, User and Chapter: a Chapter can have have many members (Users). When I do router.get('/chapters') I want to see an array of all the Users associated with a Chapter as a property along with the other Chapter properties, like so:
[
{
"leads": [],
"members": [
{"_id":"someString1","firstName":"...", "lastName":"..."},
{"_id":"someString2","firstName":"...", "lastName":"..."},
],
"date": "2018-12-12T15:24:45.877Z",
"_id": "5c11283d7d13687e60c186b3",
"country": "5c11283d7d13687e60c185d6",
"city": "Buckridgestad",
"twitterURL": "qui",
"bannerPic": "http://lorempixel.com/640/480/people",
"__v": 0
}
]
But what I'm getting is this:
[
{
"leads": [],
"members": [],
"date": "2018-12-12T15:24:45.877Z",
"_id": "5c11283d7d13687e60c186b3",
"country": "5c11283d7d13687e60c185d6",
"city": "Buckridgestad",
"twitterURL": "qui",
"bannerPic": "http://lorempixel.com/640/480/people",
"__v": 0
}
]
These are my Schemas:
Chapter
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
// Create Schema
const ChapterSchema = new Schema({
country: {
type: Schema.Types.ObjectId,
ref: "countries"
},
city: {
type: String,
required: true
},
leads: [
{
type: Schema.Types.ObjectId,
ref: "users"
}
],
members: [
{
type: Schema.Types.ObjectId,
ref: "users"
}
],
twitterURL: {
type: String,
required: true
},
bannerPic: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now()
}
});
module.exports = Chapter = mongoose.model("chapters", ChapterSchema);
User
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
// Create Schema
const UserSchema = new Schema({
username: {
type: String,
required: true
},
firstName: {
type: String,
required: true
},
lastName: {
type: String,
required: true
},
organisation: {
type: String,
required: true
},
chapter: {
type: Schema.Types.ObjectId,
ref: "chapters"
},
email: {
type: String,
required: true
},
admin: {
type: Boolean,
default: false
},
lead: {
type: Boolean,
default: false
},
password: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now()
}
});
module.exports = User = mongoose.model("users", UserSchema);
Like I said, when I call the endpoint, I want it to return me all the Chapters with all the Users as a populated property.
I've tried a lot of variations of .populate() but to know luck. The closest I got was going through the early levels of callback hell which I know isn't necessary with today's tech, but nothing is working!
My routes/api/chapters.js
// #route GET api/chapters
// #desc Get all Chapters
// #access Public
router.get("/", (req, res) => {
Chapter.find()
.populate("members")
.then(chapters => {
return res.json(chapters);
})
.catch(err =>
res.status(404).json({ nochaptersfound: "No Chapters found" })
);
});
I can get it to work the other way around:
My routes/api/users.js
// #route GET api/users
// #desc Return all users
// #access Public
router.get("/", (req, res) => {
User.find()
.populate("chapter")
.exec()
.then(users => res.status(200).json(users))
.catch(err => console.log(err));
Returns a user with the populated Chapter, but I can't populate the chapter.members array
Any help would be greatly appreciated!
Thanks!!

From your comment, I believe you are not actually storing users in your chapters. What you are doing is this:
User.create({..., chapter: id})...
And assuming chapter now has a user. Its not the way it works with mongoose, so if you want to actually save in both place, you will need to do it yourself. You are thinking about this as if it were a relational database
You will need to do something like:
const user = await User.create({..., chapter: id})
const chapter = await Chapter.findOne({ _id: id })
chapter.members.push(user)
chapter.save()
If your populate wasn't working, you'd not get an empty array, you'd get an array with ids. Your current populate query is fine, you just don't have any data to populate
With promises, it would look like this:
var userPromise = User.create({..., chapter: id}).exec()
var chapterPromise = Chapter.findOne({ _id: id }).exec()
Promise.all([userPromise, chapterPromise]).then((user, chapter) => {
chapter.members.push(user)
return chapter.save()
}).then(chapter => {
// send response
})
If you need 10 chapters with 10 to 50 users, I'd create 50 users, then push all of them into the chapters and save the chapter.