gistfile1.rb

module ActsAsTaggable

  module Taggable
    def self.included(base)
      base.field :tags, :type => Array, :default => []
    end
  end
  
  module Tagger
    def tag(object, tags)
      return if tags.empty?
      deleted_tags =  object.tags.to_a - tags
      new_tags = tags - object.tags.to_a
      p new_tags
      p deleted_tags
      new_tags.each do |t|
        add_tag(object, t)
      end
      deleted_tags.each do |t|
        remove_tag(object, t)
      end
      object.tags = tags
      object.save
    end
    
    def add_tag(object, tag)
      a = ActsAsTaggable::Tag.find_or_initialize_by(:name => tag, :tagger_id => self.id, :tagger_type => self.class.to_s)
      a.tagged = (a.tagged << {"object_class" => object.class.to_s, "object_id" => object.id}).uniq
      a.save
    end
    
    def remove_tag(object, tag)
      a = ActsAsTaggable::Tag.where(:name => tag, :tagger_id => self.id, :tagger_type => self.class.to_s).first
      a.tagged = (a.tagged - [{"object_class" => object.class.to_s, "object_id" => object.id}]).uniq
      if a.tagged.count == 0
        a.destroy
      else
        a.save
      end
    end
    
    
    def tags
      ActsAsTaggable::Tag.where(:tagger_id => self.id, :tagger_type => self.class.to_s)
    end
    
    def tags_on(klasses)
      ActsAsTaggable::Tag.where(:tagger_id => self.id, :tagger_type => self.class.to_s).any_in("tagged.object_class" => klasses)
    end
  end
  
  class Tag
    include Mongoid::Document
    field :name, :type => String
    field :tagged, :type => Array, :default => []
    field :tagger_id, :type => String
    field :tagger_type, :type => String
    
    
  end

end