active_record_defaults.rb

module ActiveRecordExtensions
  def self.included(base)
    base.extend(ClassMethods)
  end
  
  module ClassMethods
    def ids(field = nil)
      attribute(field ||= "id").map{|id| id.to_i}
    end
    
    def attribute(field = nil)
      connection.select_values(send(:construct_finder_sql, field ? {:select => field} : {}))
    end

    def attributes(fields)
      connection.send(:select_all, send(:construct_finder_sql, :select => fields))
    end
    
    def cache_id(prefix = nil)
      ActionController::RecordIdentifier.dom_class(self, prefix)
    end
  end
  
end

ActiveRecord::Base.class_eval do
  include ActiveRecordExtensions
  
  def cache_id(prefix = nil)
    ActionController::RecordIdentifier.dom_id(self, prefix)
  end
  
  named_scope :limit, lambda {|limit| {:limit => limit}}
  named_scope :order, lambda {|order| {:order => order}}
  
  named_scope :except, lambda {|object|
    klass = Array(object).first && Array(object).first.class.table_name
    objects = Array(object).compact.map {|object| object.id}
    objects.blank? ? {} : {:conditions => ["#{klass}.id NOT IN (?)", objects]}
  }
end