has_bulk_actions.rb

module HasBulkActions
  extend ActiveSupport::Concern
  
  module ClassMethods
    def bulk_update(ids, attributes, params = {})
      where("#{table_name}.id" => ids).update_all(attributes)
      extract_bulk_events(params[:events], attributes).each do |event|
        notify(event.to_sym)
      end
    end
    
    def bulk_update_associations(ids, attributes, associations = [])
      tables = associations.map do |association|
        extract_associated_table(association)
      end
      bulk_update_tables(ids, attributes, tables)
    end
    
    private
      def bulk_update_tables(ids, attributes, tables)
        # "UPDATE #{tables.split(',')} WHERE ..."
      end
    
      def extract_bulk_events(events, attributes)
        events ? events : attributes.keys.map {|key| "bulk_update_#{key}" }
      end
    
      def extract_associated_table(association)
        reflection = reflect_on_all_associations.detect do |reflection|
          reflection.name.to_s == association.to_s
        end
        reflection ? reflection.options[:active_record].table_name : nil
      end
  end
end