Am I doing it wrong?

post_comment.rb

# Controllers

class PostController
  before_filter :set_entry
  
  def create
    @entry.comments.create!(params.merge(author: @current_user))
  end

  protected

    def set_entry
      @entry = current_user.entries.find(params[:id])
    end
end

class ApplicationController
  rescue_from ThisIsSpam, :with => :reject_spam

  protected

    def reject_spam
      head :bad_request
    end
end

# Models

class Entry
  has_many :comments
end

class Comment
  before_create :spam_check
  after_create :to_twitter
  after_create :to_facebook

  def spam_check
    raise ThisIsSpam if spam?
  end

  def spam?
    SpamChecker.spam?(self.body)
  end
  
  def to_twitter 
    self.entry.user.to_twitter(self);
  end

  def to_facebook
    self.entry.user.to_facebook(self);
  end

  def to_s
    self.body
  end
end

class User
  def to_twitter(object)
    Twitter.post(self, object.to_s) if object.share.twitter?
  end

  def to_facebook(object) 
    Facebook.comment(self, object.to_s) if object.share.facebook?
  end
end