Saving a modified document (with a modified subdocument array) in Mongoose model

Question

The code I currently have is:

User.findOne(
    {
        "subUsers.email" : userEmail
    },
    {
        subUsers : {
            $elemMatch: {
                email : userEmail                            }
        }
    },
    function(err, user){
        if(user){
            var information = user.subUsers[0].information.id(id);

            information.arrayA.push({someId : "something"});

            user.save(callback(err)); // Also tried information.save()
                                      // without luck
        }

        callback(err);
    }
);

This doesn't return any kind of error, but when I check the DB, the new array element hasn't been pushed (the whole document is intact).

Any help would be much appreciated. Thanks!

Answer 1

You should probably check out the first faq, here: http://mongoosejs.com/docs/faq.html

Mongoose doesn't create getters/setters for array indexes; without them mongoose never gets 
notified of the change and so doesn't know to persist the new value. The work-around is to 
use [MongooseArray set][1] available in Mongoose >= 3.2.0.

So in your case, you want to add this third line

var information = user.subUsers[0].information.id(id);
information.arrayA.push({someId : "something"});
user.subUsers.set(0, information);

Or something like that.

Answer 2

As of today, Mongoose is currently not prepared for multilevel nesting in an atomic way.

Therefore, even if it's going back to a kind-of relational database, in this case it's better to split the nesting into at least 2 collections, and reference using the automatically generated ObjectId.