ensl.org/app/models/forum.rb

# == Schema Information
#
# Table name: forums
#
#  id          :integer          not null, primary key
#  title       :string(255)
#  description :string(255)
#  category_id :integer
#  created_at  :datetime
#  updated_at  :datetime
#  position    :integer
#

class Forum < ActiveRecord::Base
  include Extra
  
  BANS = 8
  TRASH = 12

  attr_protected :id, :updated_at, :created_at

  scope :public,
    :select => "forums.*",
    :joins => "LEFT JOIN forumers ON forumers.forum_id = forums.id AND forumers.access = #{Forumer::ACCESS_READ}",
    :conditions => "forumers.id IS NULL"
  scope :of_forum,
    lambda { |forum| {:conditions => {"forums.id" => forum.id}} }
  scope :ordered, :order => "position"

  has_many :topics
  has_many :posts, :through => :topics
  has_many :forumers
  has_many :groups, :through => :forumers
  has_one :forumer
  belongs_to :category

  after_create :update_position

  acts_as_readable

  def to_s
    self.title
  end

  def update_position
    update_attribute :position, self.id
  end

  def can_show? cuser
    if cuser
      Forum.available_to(cuser, Forumer::ACCESS_READ).of_forum(self).first
    else
      Forum.public.of_forum(self).first
    end
  end

  def can_create? cuser
    cuser and cuser.admin?
  end

  def can_update? cuser
    cuser and cuser.admin?
  end

  def can_destroy? cuser
    cuser and cuser.admin?
  end

  def self.available_to cuser, level
  user_has_access =
    Forum .joins("JOIN forumers ON forumers.forum_id = forums.id
                           AND forumers.access =  #{level}")
    .joins("JOIN groups ON forumers.group_id = groups.id")
    .joins("JOIN groupers ON groupers.group_id = groups.id
                        AND groupers.user_id = #{cuser.id}")

  is_admin = Grouper.where(user_id: cuser, group_id: Group::ADMINS)
  Forum.where("EXISTS (#{is_admin.to_sql}) OR
               id IN (SELECT q.id from (#{user_has_access.to_sql}) q ) OR
               id IN (SELECT q.id from (#{Forum.public.to_sql}) q )")
  end

end