Question

For example:

class Post < ActiveRecord::Base
  belongs_to :article
end 

class Article < ActiveRecord::Base
  has_many :posts
end

I need change status in article, when I delete last post or change article to nil in last post, I have two actions with common logic:

  def destroy
    post = Post.find(params[:id])
    article = post.article
    post.destroy
    if article && !article.posts.present?
      if article.status == 2 
        article.status = 1
        article.save
        notice = " and it was last post for article #{article.title} and article status change to empty!"
      end
    end
    redirect_to(posts_path(:by_status=>:all), :notice => "Post was successfully deleted #{notice}")
  end

  def remove_from_article
    post = Post.find(params[:id])
    article = post.article
    post.article = nil
    post.save
    if article && !article.posts.present?
      if article.status == 2 
        article.status = 1
        article.save
        notice = " and it was last post for article #{article.title} and article status change to empty!"
      end
    end
    redirect_to(posts_path(:by_status=>:all), :notice => "Post was successfully updated #{notice}")
  end

How can I refactoring this code, should I use after or around filter, if yes how can I pass article to it?

Answer 1

You can use the before_destroy callback, so something like:

class Post < AR::Base
  belongs_to :article

  before_destroy :change_article_status

  private
  def change_article_status
    article = self.article
    # Status update logic here
  end
end

You can use self to get your model and traverse any relationships you want. In this case it’s getting the article.