136 lines
5.2 KiB
Ruby
136 lines
5.2 KiB
Ruby
#--
|
|
# =============================================================================
|
|
# Copyright (c) 2004, Jamis Buck (jgb3@email.byu.edu)
|
|
# All rights reserved.
|
|
#
|
|
# Redistribution and use in source and binary forms, with or without
|
|
# modification, are permitted provided that the following conditions are met:
|
|
#
|
|
# * Redistributions of source code must retain the above copyright notice,
|
|
# this list of conditions and the following disclaimer.
|
|
#
|
|
# * Redistributions in binary form must reproduce the above copyright
|
|
# notice, this list of conditions and the following disclaimer in the
|
|
# documentation and/or other materials provided with the distribution.
|
|
#
|
|
# * The names of its contributors may not be used to endorse or promote
|
|
# products derived from this software without specific prior written
|
|
# permission.
|
|
#
|
|
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
|
|
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
# =============================================================================
|
|
#++
|
|
|
|
require 'time'
|
|
|
|
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 } )
|
|
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
|
|
@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?
|
|
@translators[ type_name( type ) ].call( type, value )
|
|
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 = $1 if type =~ /^(.*?)\(/
|
|
type.upcase
|
|
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
|
|
[ "date",
|
|
"datetime",
|
|
"time" ].each { |type| add_translator( type ) { |t,v| Time.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( "timestamp" ) { |type, value| Time.at( value.to_i ) }
|
|
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
|