mongoose js populate embedded objects in array - node.js

Question

I am trying to display a list of subject names associated with a training event, however the object id is the only property that is populated after the query has executed. I have tried the solution in this QUESTION which seems to be similar to what I am trying to achieve, but it is not working.
My load method is at the very bottom of this code snippet.
Any help is appreciated, thanks.
var UserSchema = new Schema({
firstName: {
type: String,
trim: true,
default: '',
validate: [validateLocalStrategyProperty, 'Please fill in your first name']
},
lastName: {
type: String,
trim: true,
default: '',
validate: [validateLocalStrategyProperty, 'Please fill in your last name']
},
displayName: {
type: String,
trim: true
}
});
var SubjectSchema = new Schema({
name: {
type: String,
default: '',
required: 'Please fill subject name',
trim: true
},
description: {
type: String,
default: '',
required: 'Please fill subject description',
trim: true
}
});
var TrainingSubjectSchema = new Schema({
subject: {
type: Schema.ObjectId,
ref: 'Subject'
},
attendanceRate:[{
type: Number
}]
});
var TrainingEventSchema = new Schema({
name: {
type: String,
default: '',
required: 'Please fill training event name',
trim: true
},
created: {
type: Date,
default: Date.now
},
user: {
type: Schema.ObjectId,
ref: 'User'
},
attendees:[{
type: Schema.ObjectId,
ref: 'User'
}],
subjects:[TrainingSubjectSchema]
});
// retrieve method
Training.findById(id).populate('user', 'displayName').populate('subjects.subject','name').exec(function(err, trainingevent)

Answer 1

Not sure why it is not working in your side but I have tried
in my code and it is working as expected.
Here it is how I am creating the Schemas:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost:27017/mongoose_benn');
var UserSchema = new Schema({
firstName: {type: String, trim: true, default: ''},
lastName: {type: String, trim: true, default: ''},
displayName: {type: String, trim: true}
});
var SubjectSchema = new Schema({
name: {
type: String,
default: '',
required: 'Please fill the subject name.',
trim: true
},
description: {
type: String,
default: '',
required: 'Please fill subject description',
trim: true
}
});
var TrainingSubjectSchema = new Schema({
subject: {type: Schema.ObjectId, ref: 'Subject'},
attendanceRate: [{type: Number}]
});
var TrainingEventSchema = new Schema({
name: {
type: String,
default: '',
required: 'Please fill the training event name.',
trim: true
},
created: {type: Date, default: Date.now},
user: {type: Schema.ObjectId, ref: 'User'},
attendes: [{
type: Schema.ObjectId,
ref: 'User'
}],
subjects: [TrainingSubjectSchema]
});
module.exports = {
User: mongoose.model('User', UserSchema),
Subject: mongoose.model('Subject', SubjectSchema),
TrainingSubject: mongoose.model('TrainingSubject', TrainingSubjectSchema),
TrainingEvent: mongoose.model('TrainingEvent', TrainingEventSchema)
};
And here I am processing data with the models:
var async = require('async');
var models = require('./models.js');
var User = models.User;
var Subject = models.Subject;
var TrainingSubject = models.TrainingSubject;
var TrainingEvent = models.TrainingEvent;
async.waterfall(
[
clearDB.bind(null, {collections: [User, Subject, TrainingSubject, TrainingEvent], async: async}),
createUsers.bind(null, {User: User, async: async}),
createSubjects.bind(null, {async: async, Subject: Subject}),
createTrainingEvents.bind(null, {async: async, TrainingEvent: TrainingEvent}),
showTrainingEvents.bind(null, {TrainingEvent: TrainingEvent})
]
);
function createTrainingEvents(data, db, next) {
var firstSubject = db.subjects[0];
var secondSubject = db.subjects[1];
var trainingSubjects = [
{
subject: firstSubject._id,
attendanceRate: [5, 5]
},
{
subject: secondSubject._id,
attendanceRate: [4, 4, 5]
}
];
var trainingEvents = [
{
name: 'October Fest',
user: db.users[0]._id,
subjects: [trainingSubjects[0]],
attendes: [db.users[0]._id, db.users[1]._id]
},
{
name: 'August Fest',
user: db.users[1]._id,
subjects: [trainingSubjects[1]],
attendes: [db.users[0]._id, db.users[1]._id]
}
];
data.async.map(
trainingEvents,
function(trainingEvent, done) {
data.TrainingEvent.create(trainingEvent, done);
},
function(err, result) {
next(err);
}
);
}
function clearDB(data, next) {
async.map(
data.collections,
function(collection, done) {
collection.remove({}, done);
},
function(err) {
next(err);
}
);
}
function createUsers(data, next) {
var users = [
{firstName: 'Wilson', lastName: 'Balderrama', displayName: 'Wily'},
{firstName: 'Santiago', lastName: 'Balderrama', displayName: 'Santi'},
{firstName: 'Keila', lastName: 'Balderrama', displayName: 'Kei'}
];
data.async.map(
users,
function(user, done) {
data.User.create(user, done);
},
function(err, results) {
next(err, {users: results});
}
);
}
function showUsers(data, next) {
data.User.find({}, function(err, users) {
next();
});
}
function createSubjects(data, db, next) {
var subjects = [
{
name: 'JavaScript for Beginners',
description: 'JS fundamentals'
},
{
name: 'Node.JS for Beginners',
description: 'Node.JS streams'
}
];
data.async.map(
subjects,
function(subject, done) {
data.Subject.create(subject, done);
},
function(err, result) {
db.subjects = result;
next(err, db);
}
);
}
function createTrainingSubjects(data, db, next) {
var firstSubject = db.subjects[0];
var secondSubject = db.subjects[1];
var trainingSubjects = [
{
subject: firstSubject._id,
attendanceRate: [5, 5]
},
{
subject: secondSubject._id,
attendanceRate: [4, 4, 5]
}
];
data.async.map(
trainingSubjects,
function(trainingSubject, done) {
data.TrainingSubject.create(trainingSubject, done);
},
function(err, result) {
db.trainingSubjects = result;
next(err, db);
}
);
}
function showTrainingSubjects(data, next) {
data.TrainingSubject
.find({})
.populate('subject')
.exec(function(err, data) {
next();
});
}
function showSubjects(data, next) {
data.Subject.find({}, function(err, data) {
next();
});
}
function showTrainingEvents(data, next) {
data.TrainingEvent
.find({name: 'August Fest'})
.populate('user', 'displayName')
.populate('subjects.subject', 'name')
.exec(function(err, data) {
console.log(JSON.stringify(data));
next();
});
}
And the output is;
[
{
"_id":"55981d58cfd48c905c3a5fde",
"user":{
"_id":"55981d58cfd48c905c3a5fd8",
"displayName":"Santi"
},
"__v":0,
"subjects":[
{
"subject":{
"_id":"55981d58cfd48c905c3a5fdb",
"name":"Node.JS for Beginners"
},
"_id":"55981d58cfd48c905c3a5fdf",
"attendanceRate":[
4,
4,
5
]
}
],
"attendes":[
"55981d58cfd48c905c3a5fd7",
"55981d58cfd48c905c3a5fd8"
],
"created":"2015-0704T17:52:24.181Z",
"name":"August Fest"
}
]