gistfile1.txt

class Comment < ActiveRecord::Base
  belongs_to :commentable, polymorphic: true
  validates :content,      presence: true
  validates :author_email, presence: true
  validates :author,       presence: true
end

class Project < ActiveRecord::Base
  attr_accessible :name, :technologies_used
  validates :technologies_used, presence: true
  validates :name, length: { in: 4..255 }
  has_many :comments, as: :commentable
end

class Post < ActiveRecord::Base
  belongs_to :author, class_name: "User"
  has_many :comments, as: :commentable
  scope :published, where(published: true)
  def publish!
    published = true
    save!
  end
end