JezK
Edit File: translator.rb
require 'time' require 'date' module SQLite3 # The Translator class encapsulates the logic and callbacks necessary for # converting string data to a value of some specified type. Every Database # instance may have a Translator instance, in order to assist in type # translation (Database#type_translation). # # Further, applications may define their own custom type translation logic # by registering translator blocks with the corresponding database's # translator instance (Database#translator). class Translator # Create a new Translator instance. It will be preinitialized with default # translators for most SQL data types. def initialize @translators = Hash.new( proc { |type,value| value } ) @type_name_cache = {} register_default_translators end # Add a new translator block, which will be invoked to process type # translations to the given type. The type should be an SQL datatype, and # may include parentheses (i.e., "VARCHAR(30)"). However, any parenthetical # information is stripped off and discarded, so type translation decisions # are made solely on the "base" type name. # # The translator block itself should accept two parameters, "type" and # "value". In this case, the "type" is the full type name (including # parentheses), so the block itself may include logic for changing how a # type is translated based on the additional data. The "value" parameter # is the (string) data to convert. # # The block should return the translated value. def add_translator( type, &block ) # :yields: type, value warn(<<-eowarn) if $VERBOSE #{caller[0]} is calling `add_translator`. Built in translators are deprecated and will be removed in version 2.0.0 eowarn @translators[ type_name( type ) ] = block end # Translate the given string value to a value of the given type. In the # absense of an installed translator block for the given type, the value # itself is always returned. Further, +nil+ values are never translated, # and are always passed straight through regardless of the type parameter. def translate( type, value ) unless value.nil? # FIXME: this is a hack to support Sequel if type && %w{ datetime timestamp }.include?(type.downcase) @translators[ type_name( type ) ].call( type, value.to_s ) else @translators[ type_name( type ) ].call( type, value ) end end end # A convenience method for working with type names. This returns the "base" # type name, without any parenthetical data. def type_name( type ) @type_name_cache[type] ||= begin type = "" if type.nil? type = $1 if type =~ /^(.*?)\(/ type.upcase end end private :type_name # Register the default translators for the current Translator instance. # This includes translators for most major SQL data types. def register_default_translators [ "time", "timestamp" ].each { |type| add_translator( type ) { |t, v| Time.parse( v ) } } add_translator( "date" ) { |t,v| Date.parse(v) } add_translator( "datetime" ) { |t,v| DateTime.parse(v) } [ "decimal", "float", "numeric", "double", "real", "dec", "fixed" ].each { |type| add_translator( type ) { |t,v| v.to_f } } [ "integer", "smallint", "mediumint", "int", "bigint" ].each { |type| add_translator( type ) { |t,v| v.to_i } } [ "bit", "bool", "boolean" ].each do |type| add_translator( type ) do |t,v| !( v.strip.gsub(/00+/,"0") == "0" || v.downcase == "false" || v.downcase == "f" || v.downcase == "no" || v.downcase == "n" ) end end add_translator( "tinyint" ) do |type, value| if type =~ /\(\s*1\s*\)/ value.to_i == 1 else value.to_i end end end private :register_default_translators end end