How to create a new nested resource? - ruby-on-rails

Question

A users can have many favorites top_songs,top_movies through songs and movies table.
A user registered user(current_user) want to post his favorites movies and songs.
Perhaps all Model association are right, i am stuck in controller and view (form).
When i submit from, i gets errors-
Can't mass-assign protected attributes: songs
How can i achieve this please?
all codes are below.
User Model
class User < ActiveRecord::Base
attr_accessible :id, :name_special_char, :screenname, :fullname, :username, :prefix, :firstname, :lastname,:middlename, :suffix, :age, :sex, :email,
:top_movies_attributes,:top_songs_attributes
has_many :top_movies
has_many :movies, through: :top_movies
has_many :top_songs
has_many :songs, through: :top_songs
accepts_nested_attributes_for :top_songs, :allow_destroy => true
accepts_nested_attributes_for :top_movies, :allow_destroy => true
end
Movie Model
class Movie < ActiveRecord::Base
attr_accessible :name
has_many :top_movies
has_many :users, through: :top_movies
end
TopMovie Model
class TopMovie < ActiveRecord::Base
belongs_to :user
belongs_to :movie
# attr_accessible :title, :body
end
Song Model
class Song < ActiveRecord::Base
attr_accessible :name
has_many :top_songs
has_many :users, through: :top_songs
end
TopSong Model
class TopSong < ActiveRecord::Base
belongs_to :user
belongs_to :song
# attr_accessible :title, :body
end
Controller
class MyTopFivesController < ApplicationController
def new
#favorites = current_user
#favorites=#favorites.movies.build()
#favorites=#favorites.songs.build()
respond_to do |format|
format.html # new.html.erb
format.json { render json: #useraccounts_my_top_fife }
end
end
def create
#favorites = current_user(params[:user])
#favorites.save!
# Here i have stuck. i am not sure how to save.
end
view form
<%=nested_form_for #favorites ,:url=>favorites_path(#favorites),:method=>'post' do |f| %>
<label >Songs</label>
<%= f.fields_for :songs do |songs| %>
<div id="Topsongs" >
<div class="input-control text span5 place-left ">
<%= songs.text_field :name,:placeholder=>"songs name.." %>
</div>
<div class="span1 place-left">
<%= songs.link_to_remove "", :class=>"icon-minus" %>
</div>
</div>
<% end %>
<span >
<%= f.link_to_add "", :songs, :class=>"icon-plus", :data => { :target => "#Topsongs" } %>
</span>
<label >movies</label>
<%= f.fields_for :movies do |movies| %>
<div id="Topmovies">
<div class="input-control text span5 place-left ">
<%= movies.text_field :name,:placeholder=>"movies name.." %>
</div>
<div class="span1 place-left">
<%= movies.link_to_remove "", :class=>"icon-minus" %>
</div>
</div>
<% end %>
<span>
<%= f.link_to_add "", :movies, :class=>"icon-plus",:style=>"font-size: 14px;", :data => { :target => "#Topmovies" } %>
</span>
<div class="actions">
<%= f.submit %>
</div>
<% end %>

Answer 1

There are two options for setting up the associations here. One you have used by creating two join models for top songs and top movies. And other, to use polymorphic association.
Lets use polymorphic association. We are going to use User, Movie, Song and Favourite models for this stuff. The Favourite model will contain the polymorphic fields.
User.rb
class User < ActiveRecord::Base
attr_accessible :id, :name_special_char, :screenname, :fullname, :username, :prefix, :firstname, :lastname,:middlename, :suffix, :age, :sex, :email
has_many :favourites
has_many :movies, through: :favourites, source: :favouritable, source_type: 'Movie'
has_many :songs, through: :favourites, source: :favouritable, source_type: 'Song'
end
Movie.rb
class Movie < ActiveRecord::Base
attr_accessible :name
has_many :favourites, as: :favouritable
has_many :users, through: :favourites
end
Song.rb
class Song < ActiveRecord::Base
attr_accessible :name
has_many :favourites, as: :favouritable
has_many :users, through: :favourites
end
Favourite.rb
class Favourite < ActiveRecord::Base
belongs_to :users
belongs_to :favouritable, polymorphic: true
end
We also need to create the migration for new model "Favourite". As of now, we just need 3 columns ie. user_id, favouritable_id, favouritable_type. Here favouritable_type and favouritable_id are the polymorphic fields. favouritable_type is a string and favouritable_id is reference type.
Migration File
class CreateFavourites < ActiveRecord::Migration
def change
create_table :favourites do |t|
t.integer :user_id
t.references :favouritable, polymorphic: true
t.timestamps
end
end
end
Now, as we are going to mark some movies and songs to be favourite for a user, then we can place the code for building the data in UsersController instead of creating another controller or we can also create a controller for Favourites. I am going to use UsersController here. I am using update action to update the favourites as we don't need any extra functionality here. You can add a new action if you want.
In UsersController.rb
def edit_favourites #or some generic name
#user = current_user.includes(:movies, :songs)
#movies = Movie.all
#songs = Song.all
end
def update
#user = User.find(params[:id])
if #user.update_attributes(params[:user])
redirect_to users_path #user index page
else
if params[:user][:movie_ids].present? or params[:user][:song_ids].present?
render :edit_favourites
else
render :edit
end
end
end
edit_favourites.html.erb
<%= form_for(#user) do |f| %>
<div class="fields">
<%= f.label :movie_ids, "Favourite Movies: " %>
<%= f.collection_select :movie_ids, #movies, :id, :name, {}, multiple: true %>
</div>
<div class="fields">
<%= f.label :song_ids, "Favourite Songs: " %>
<%= f.collection_select :song_ids, #songs, :id, :name, {}, multiple: true %>
</div>
<% end %>
Also, Add the new action to routes.