Rails nested resources and devise - ruby-on-rails

Question

Let's say I have a devise model called "User" which has_many :notes and :notebooks and each :notebook has_many :notes.
So a notes will have two foreign key, :user_id and :notebook_id, so how to build/find a note?
current_user.notebooks.find(param).notes.new(params[:item]) will create the foreign_key only for notebook or also for the user in the note record in the DB?
If the second case (foreign key only for notebook), how should I write?
Using MongoDB with MongoID and referenced relations

Answer 1

Mongoid will manage the document references and queries for you, just make sure to specify the association/relationship for each direction that you need (e.g., User has_many :notes AND Note belongs_to :user). Like ActiveRecord, it appears to be "smart" about the relations. Please do not manipulate the references manually, but instead let your ODM (Mongoid) work for you. As you run your tests (or use the rails console), you can tail -f log/test.log (or log/development.log) to see what MongoDB operations are being done by Mongoid for you and you can see the actual object references as the documents are updated. You can see how a relationship makes use of a particular object reference, and if you pay attention to this, the link optimization should become clearer.
The following models and test work for me. Details on the setup are available on request. Hope that this helps.
Models
class User
include Mongoid::Document
field :name
has_many :notebooks
has_many :notes
end
class Note
include Mongoid::Document
field :text
belongs_to :user
belongs_to :notebook
end
class Notebook
include Mongoid::Document
belongs_to :user
has_many :notes
end
Test
require 'test_helper'
class UserTest < ActiveSupport::TestCase
def setup
User.delete_all
Note.delete_all
Notebook.delete_all
end
test "user" do
user = User.create!(name: 'Charles Dickens')
note = Note.create!(text: 'It was the best of times')
notebook = Notebook.create!(title: 'Revolutionary France')
user.notes << note
assert_equal(1, user.notes.count)
user.notebooks << notebook
assert_equal(1, user.notebooks.count)
notebook.notes << note
assert_equal(1, notebook.notes.count)
puts "user notes: " + user.notes.inspect
puts "user notebooks: " + user.notebooks.inspect
puts "user notebooks notes: " + user.notebooks.collect{|notebook|notebook.notes}.inspect
puts "note user: " + note.user.inspect
puts "note notebook: " + note.notebook.inspect
puts "notebook user: " + notebook.user.inspect
end
end
Result
Run options: --name=test_user
# Running tests:
user notes: [#<Note _id: 4fa430937f11ba65ce000002, _type: nil, text: "It was the best of times", user_id: BSON::ObjectId('4fa430937f11ba65ce000001'), notebook_id: BSON::ObjectId('4fa430937f11ba65ce000003')>]
user notebooks: [#<Notebook _id: 4fa430937f11ba65ce000003, _type: nil, user_id: BSON::ObjectId('4fa430937f11ba65ce000001'), title: "Revolutionary France">]
user notebooks notes: [[#<Note _id: 4fa430937f11ba65ce000002, _type: nil, text: "It was the best of times", user_id: BSON::ObjectId('4fa430937f11ba65ce000001'), notebook_id: BSON::ObjectId('4fa430937f11ba65ce000003')>]]
note user: #<User _id: 4fa430937f11ba65ce000001, _type: nil, name: "Charles Dickens">
note notebook: #<Notebook _id: 4fa430937f11ba65ce000003, _type: nil, user_id: BSON::ObjectId('4fa430937f11ba65ce000001'), title: "Revolutionary France">
notebook user: #<User _id: 4fa430937f11ba65ce000001, _type: nil, name: "Charles Dickens">
.
Finished tests in 0.018622s, 53.6999 tests/s, 161.0998 assertions/s.
1 tests, 3 assertions, 0 failures, 0 errors, 0 skips

Answer 2

I would use
class User
has_many :notebooks
has_many :notes, :through => :notebooks
end
http://guides.rubyonrails.org/association_basics.html#the-has_many-through-association
Update
You could always set the user_id manually, like this (I assume param is the ID for your notebook?):
Notebook.find(param).notes.new(params[:item].merge(:user_id => current_user.id))