post.rb

class Post < ActiveRecord::Base
    belongs_to :post
    has_many :replies, :class_name => "Post"
    validates_length_of :title, :maximum => 32, :allow_nil => false, :allow_blank => false, :too_short => "Please, enter a title.", :too_long => "Title is too long. Enter a shorter title."
    validates_length_of :text, :maximum => 10240, :allow_nil => false, :allow_blank => false, :too_short => "Please, enter a text", :too_long => "Text is too long. Enter a shorter text."
end