################################################################################
#
# Copyright (C) 2006-2007 pmade inc. (Peter Jones pjones@pmade.com)
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
################################################################################
# The Tagging class connects a tag to some other model object.
class Tagging < ActiveRecord::Base

  ################################################################################
  # Setup associations
  belongs_to(:tag)
  belongs_to(:taggable, :polymorphic => true)

  ################################################################################
  # Callback to keep tags up to date
  before_destroy(:delete_tags)

  ################################################################################
  private

  ################################################################################
  # Remove tags when their reference_count drops below 1
  def delete_tags
    self.tag.reference_count -= 1
    self.tag.reference_count.zero? ? self.tag.destroy : self.tag.save!
  end

end
################################################################################