Relationship for a user to store “favorites” in ruby on rails?

Question

I have a Rails application where a User can create many Articles:

class User < ActiveRecord::Base
  has_many :articles
end

class Article < ActiveRecord::Base
  belongs_to :user
end

Now I want to save user favorites. But I can't figure out a structure for how to manage user favorites within the existing sturcture. Should I make a new many to many relation?

Or will I have to change the entire structure?

Answer 1

Your current setup is Article - Author (user) relation and you should not change it.

What you need to add, to support favorites, is a new table (model):

class UserAtricles
  belongs_to user
  belongs_to article
end

which will create many-to-many relationship between User s and Article s.

class User
  has_many :articles
  has_many :user_articles
  has_many :favorites, through: :user_acticles, class_name: 'Article'

  # Add favorite article to the instance of User.
  def add_favorite(article)
    if self.favorites.where(id: article.id).empty?
      UserArticle.create(user: self, article: article)
    end
  end
end

Answer 2

You'd better to add new model favorite.rb where it belongs to User and Article . This table will save article and user id

First, you can add migration

rails generate model Favorite user_id:integer article_id:integer

Then, you can add association here

class Favorite < ActiveRecord::Base
  belongs_to :user
  belongs_to :article
  validates_uniqueness_of :user_id, scope: :article_id
end

class User < ActiveRecord::Base
  has_many :articles
  has_many :favorites
  has_many :favorite_articles, through: :favorites, source: :article
end

class Article < ActiveRecord::Base
  belongs_to :user
  has_many :favorites
end

In User model, there is favorite_articles to get your user favorite articles. Then, you can add validate uniqueness of user_id with scope article_id to ovoid double entry.

To add favorite article user controller

def add_favorite
  @favorite = current_user.favorites.build(article_id: params[:article_id])
  if @favorite.save
    flash[:notice] = "Added a new favorite article."
    redirect_to root_url
  else
   flash[:error] = "Unable to add favorite article."
   redirect_to root_url
 end
end

To get user favorite articles

current_user.favorite_articles

UPDATE I change class_name into source: :article . Then, I create new def method to add favorite in users_controller.rb

This is what I want to describe. I hope this help you.