Mongoose returns null array when populate - node.js

Question

I'm trying to create a webapp with mongoose and nodejs. This is the first time i'm using mongoose and nodejs so i'm not quit good at it.
I have a person model:
var PERSON = new mongoose.Schema({
name: {type: String, required: true},
zipcode: {type: String, required: true},
city: {type: String, required: true},
street: {type: String, required: true},
address: {type: Number, required: true},
email: {type: String, required: true},
type: {type: String, enum: ['lid', 'passant'], required: true},
ships: {
type: [{
name: {type: String, required: true},
length: {type: Number, required: true},
type: {type: String, required: true},
picture: {type: Buffer, required: false}
}],
required: false
},
user: {
type: {
userName: {type: String, required: true},
password: {type: String, required: true},
passwordKey: {type: String, required: true},
roles: {type: [{type: mongoose.Schema.Types.ObjectId, ref: 'role'}], required: true}
},
required: false
}
},
{
collection: 'PERSON'
});
And the rol model:
var ROLE = new mongoose.Schema({
name: {type: String, required: true}
},
{
collection: 'ROLE'
});
When i'm trying to run a find query on the person model, I want to populate the user.roles array. But as a result it remains empty.
/ GET a specific person by id or type/
server.get('/api/person/:id', function (req, res, next) {
if (helper.isValidObjectID(req.params.id)) {
person.findById(req.params.id).populate("user.roles").exec(function (err, result) {
if (err) {
res.status(404).json(err);
} else {
res.status(200).json(result);
}
}
);
} else {
next();
}
}, function (req, res, next) {
person.find({type: req.params.id}).populate('user.roles').exec(function (err, result) {
if (err) {
res.status(404).json(err);
} else {
res.status(200).json(result);
}
});
});
and as a result i get:
{
"_id":"553f79d4f1481c0c14b42d59",
"name":"Wilco Boogert",
"zipcode":"4305RH",
"city":"Ouwerkerk",
"street":"baalpapenweg",
"address":2,
"email":"wilcoboogert17#gmail.com",
"type":"lid",
"user":{
"userName":"wboogert",
"password":"sha1$168fd599$1$502b965cb083ebdfcafb17e655455ef63779e1a1",
"passwordkey":"kfjvlksdfm",
"roles":[
]
},
"__v":0,
"ships":[
{
"name":"titanic",
"length":269,
"type":"Olympic-klasse",
"_id":"553f79d4f1481c0c14b42d5a"
}
]
}
The orginal object in the database is:
{
"_id": {
"$oid": "553f79d4f1481c0c14b42d59"
},
"name": "Wilco Boogert",
"zipcode": "4305RH",
"city": "Ouwerkerk",
"street": "baalpapenweg",
"address": 2,
"email": "wilcoboogert17#gmail.com",
"type": "lid",
"user": {
"roles": [
{
"$oid": "5522996f0fff331ed03cae6c"
}
],
"passwordkey": "kfjvlksdfm",
"password": "sha1$168fd599$1$502b965cb083ebdfcafb17e655455ef63779e1a1",
"userName": "wboogert"
},
"ships": [
{
"name": "titanic",
"length": 269,
"type": "Olympic-klasse",
"picture": "<Binary Data>",
"_id": {
"$oid": "553f79d4f1481c0c14b42d5a"
}
}
],
"__v": 0
}
so as you an see the roles is empty. And I search the web but i cannot find what the problem is. Can annyone help me?

Answer 1

You should replace this line :
roles: {type: [{type: mongoose.Schema.Types.ObjectId, ref: 'role'}], required: true}
with this one :
roles: {type: [{type: mongoose.Schema.Types.ObjectId, ref: 'ROLE'}], required: true}
In fact, the reference must be the exact same name as it's defined :
collection: 'ROLE'
It's case sensitive.