How to populate array of objects with Mongoose - node.js

Question

I have the following schemas in mongoose:
var documentsSchema = new Schema({
"document" : {
"_project" : {
type : Schema.ObjectId,
ref : 'Projects'
},
"_addedBy" : {
type : Schema.ObjectId,
ref : 'Users'
},
"_associateUsers" : [{
type : Schema.ObjectId,
ref : 'Users'
}],
"_codes" : [{
type : Schema.ObjectId,
ref : 'Codes'
}],
"paragraphTitle" : String,
"paragraphText" : String,
"memos" : [
{
"_addedBy" : {
type: Schema.Types.ObjectId,
ref: 'Users'
},
"memoData" : String
}
]}});
and the Codes:
var codesSchema = new Schema({
"code" : {
"_addedBy" : {
type : Schema.ObjectId,
ref : 'Users'
},
"codeText" : String,
"codeWeight" : Number
}});
I need to populate _codes.codeText (or codes fields) of the all elements of the array, but looks like I am not doing it properly.
Documents.find({
"document._project": element._id
}).
populate('document._codes.code','codeText').
exec(function (err, result) { .... }
this and various tries with populate arguments are either not populating the fields or not returning any data.
What am I doing wrong?

Answer 1

You have defined the schema, but not the model. The _codes has a ref to the model Codes but it doesn't exists. When you call .populate with the first two params it assumes that the model is Codes (taked from reference)
To fix this, toy need to add:
mongoose.model('Codes', codesSchema);
mongoose.model('Documents', documentsSchema);
Maybe you need to do the same with Users
See the complete documentation for populate here
P.S. A recommendation: If you are defining an schema for codes or whatever you don't need to define again the name of the object as part of the same schema, look:
From this
//your style
var catsSchema = new Schema({
"cat" : {
"attr1" : {type: ...},
"attr2" : {type: ...}
}
});
to this
//obviously attr1 and attr2 are part of cat object/document
var catsSchema = new Schema({
"attr1" : {type: ...},
"attr2" : {type: ...}
});