class Event < ActiveRecord::Base
  validates_presence_of :article_id, :site_id
  validate :content_and_user_added
 
  # article being updated
  belongs_to :article, :foreign_key => 'article_id'
 
  # updater of the article at the time of the event
  belongs_to :user, :with_deleted => true
  
  belongs_to :comment
  belongs_to :site
 
  protected
    def content_and_user_added
      errors.add_to_base "Title or Body must be changed" unless %w(publish comment).include?(mode) || article.changed?(:title) || article.changed?(:body)
      errors.add_to_base "User must be provided for Article events"   unless (mode == 'comment' && author) || user_id
    end
end