Quick way to retrieve doc from other doc's ref in Mongoose (Node.js)

Question

I have a model Product with a ref field Grocer. At some point I have the Product doc but with the Grocer field not populated, just the ObjectId. Is there a quick way to populate a doc using mongoose? or I have to extend it somehow?, so from:

// product 'product1'
{
  _id: 'ksjdflasdf78aslwk3jk8df9',
  name: 'Product 1',
  grocer: 'jasf97342jlihwe79834hkjhdkf'
}

I could do something like:

doc.populate('grocer');

Now doc is:

// product 'product1'
{
  _id: 'ksjdflasdf78aslwk3jk8df9',
  name: 'Product 1',
  grocer: {
    _id: 'jasf97342jlihwe79834hkjhdkf',
    name: 'Johan'
  }
}

Answer 1

I'll answer myself instead deleting the question. Mongoose gives the option to populate a doc since v3.6.

Examples:

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

http://mongoosejs.com/docs/api.html#document_Document-populate