Why is my user_id nil?

Question

def destroy
  @dignity.destroy
end

Sorry, that's not code, that's just how I feel right now. I know there are a ton of beginner questions on Devise, I think I looked at almost every single one.

I have a very simple Devise setup in Rails 3. I did:

rails generate devise User

I'm also running the rails 3 GeoKit plugin,(not sure if that's relevant, just know that I have this other model) so I have another model called Location, and it acts_as_mappable.

Before I post the code, the basic problem is that I cannot seem to get user_id to auto-increment. It was my understanding that a bit of Rails magic should take care of this for me, if I add a column called user_id to Location class. (which I did through a migration.) and then simply set has_many and belongs_to accordingly. (see below)

I can't figure out why user_id is always nil. Does it have something to do with the way the Devise engine works? I am pretty sure I've made this type of association work in the past in the same way when I wasn't using Devise.

user.rb:

class User < ActiveRecord::Base

  has_many :locations

  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable, :lockable and :timeoutable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me
end

location.rb:

class Location < ActiveRecord::Base
  belongs_to :user


  attr_accessible :street_adress, :city, :state, :zip, :item, :user_id
  acts_as_mappable :auto_geocode => true

  def address
    return "#{self.street_adress}, #{self.city}, #{self.state}, #{self.zip}, #{self.item}"
  end

end

here is the migration that added the column:

class AddUseridToLocation < ActiveRecord::Migration
  def self.up
    add_column :locations, :user_id, :integer
  end

  def self.down
    remove_column :locations, :user_id
  end
end

And finally, here is the schema.rb:

ActiveRecord::Schema.define(:version => 20110213035432) do

  create_table "locations", :force => true do |t|
    t.string   "street_adress"
    t.string   "city"
    t.string   "state"
    t.string   "zip"
    t.float    "lat"
    t.float    "lng"
    t.datetime "created_at"
    t.datetime "updated_at"
    t.string   "item"
    t.integer  "user_id"
  end

  create_table "users", :force => true do |t|
    t.string   "email",                               :default => "", :null => false
    t.string   "encrypted_password",   :limit => 128, :default => "", :null => false
    t.string   "password_salt",                       :default => "", :null => false
    t.string   "reset_password_token"
    t.string   "remember_token"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",                       :default => 0
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.string   "current_sign_in_ip"
    t.string   "last_sign_in_ip"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  add_index "users", ["email"], :name => "index_users_on_email", :unique => true
  add_index "users", ["reset_password_token"], :name => "index_users_on_reset_password_token", :unique => true

end

EDIT: I'm okay with a RTFM response, as long as I can get a little push in the right direction. I have a suspicion that I need to tell rails something in the create action of my locations_controller.rb ? Someone just give me a little hint here!

Answer 1

def destroy
  @dignity.destroy
end

Clearly the first thing to be done is:

raise self.esteem

You say you can't get user_id to "autoincrement". I think what you meant is that user_id is not being assigned (i.e. it is always nil). Can you show the part of the code that assigns a location to a user? Either of these should work:

@user.locations.build
@user.locations << Location.new

EDIT

To expand on this a bit, say you have a request that looks like this:

POST /users/37/locations

And the submitted form contains input name=user[location][name] value="Paris". A typical Rails controller create action might look like this:

def create
  @user = User.find(params[:user_id])
  @user.locations.build(params[:user][:location])
  if @user.save
    flash[:notice] = "Location created successfully"
    redirect_to user_locations_path(@user)
  else
    render :new
  end
end

The 'magic' is basically Rails inferring from the has_many statement that it needs to set the value of the foreign key column ('user_id') in the related row in the locations table. When you call @user.save it adds a new row in locations and sets user_id to the value of @user.id.