# File lib/tapkit/access/attribute.rb, line 13
                def initialize( list = {}, entity = nil )
                        @entity            = entity
                        @allow_null        = list['allow_null'] 
                        @name              = list['name']
                        @class_name        = list['class_name']
                        @column_name       = list['column_name']
                        @external_type     = list['external_type']
                        @width             = list['width']
                        @precision         = list['precision']
                        @read_only         = list['read_only'] || false
                        @factory_method    = list['factory_method']
                        @conversion_method = list['conversion_method']
                        @read_format       = nil
                        @write_format      = nil

                        if @allow_null.nil? then
                                @allow_null = false 
                        end
                end