Mongoose query reference - node.js

Question

I have the below schema structure for my application:
var User = new Schema({
name: {type: String, required: true},
screen_name: {type: String, required: true, index:{unique:true}},
email: {type: String, required: true, unique:true},
created_at: {type: Date, required: true, default: Date}
});
var Line = new Schema({
user: {type: Schema.ObjectId, ref: 'User'},
text: String,
entered_at: {type: Date, required: true, default: Date}
});
var Story = new Schema ({
sid: {type: String, unique: true, required: true},
maxlines: {type: Number, default: 10}, // Max number of lines per user
title: {type: String, default: 'Select here to set a title'},
lines: [Line],
created_at: {type: Date, required: true, default: Date}
});
var Story = db.model('Story', Story);
var User = db.model('User', User);
When i query a Story using the sid i want it to output the lines in that story but also the users screen_name.
Currently i'm using the below to query the story:
app.get('/api/1/story/view/:id', function(req, res){
Story.findOne({ sid: req.params.id }, function(err, story){
if (err) {
res.json(err);
}
else if(story == null) {
res.json(err);
}
else{
res.send(story);
}
});
});
Which just brings back the result like this:
{
"__v": 1,
"_id": "5117878e381d7fd004000002",
"sid": "DIY0Ls5NwR",
"created_at": "2013-02-10T11:42:06.000Z",
"lines": [
{
"user": "511782cab249ff5819000002",
"text": "TESTING",
"_id": "51178795381d7fd004000003",
"entered_at": "2013-02-10T11:42:13.000Z"
}
],
"title": "Select here to set a title",
"maxlines": 10
}
There is a user set-up with that _id but i'm not entirely sure how to output the story and for it to include the users screen_name or even the entire user information along with the output
{
"__v": 0,
"screen_name": "Tam",
"email": "test#test.com",
"name": "Tam",
"_id": "511782cab249ff5819000002",
"created_at": "2013-02-10T11:21:46.000Z"
}

Answer 1

I haven't tested it, but you should be able to use populate to get the full user doc for each lines element like this:
Story.findOne({sid: req.params.id})
.populate('lines.user')
.exec(function(err, story){ ...