Mongoose populate after save

In case that anyone is still looking for this.

Mongoose 3.6 has introduced a lot of cool features to populate:

book.populate('_creator', function(err) {
 console.log(book._creator);
});

or:

Book.populate(book, '_creator', function(err) {
 console.log(book._creator);
});

see more at: https://github.com/LearnBoost/mongoose/wiki/3.6-Release-Notes#population

But this way you would still query for the user again.

A little trick to accomplish it without extra queries would be:

book = book.toObject();
book._creator = user;

The solution which returns a promise (no callbacks):

Use Document#populate

book.populate('creator').execPopulate();

// summary
doc.populate(options);               // not executed
doc.populate(options).execPopulate() // executed, returns promise

Possible Implementation

var populatedDoc = doc.populate(options).execPopulate();
populatedDoc.then(doc => {
   ... 
});

Read about document population here.

You should be able to use the Model's populate function to do this: http://mongoosejs.com/docs/api.html#model_Model.populate In the save handler for book, instead of:

book._creator = user;

you'd do something like:

Book.populate(book, {path:"_creator"}, function(err, book) { ... });

Probably too late an answer to help you, but I was stuck on this recently, and it might be useful for others.

The solution for me was to use execPopulate, like so

const t = new MyModel(value)
return t.save().then(t => t.populate('my-path').execPopulate())