couchrest_model/lib/couchrest/mixins/properties.rb
2009-07-16 19:52:53 -07:00

158 lines
5.7 KiB
Ruby

require 'time'
require File.join(File.dirname(__FILE__), '..', 'more', 'property')
class Time
# returns a local time value much faster than Time.parse
def self.mktime_with_offset(string)
string =~ /(\d{4})\/(\d{2})\/(\d{2}) (\d{2}):(\d{2}):(\d{2}) ([\+\-])(\d{2})/
# $1 = year
# $2 = month
# $3 = day
# $4 = hours
# $5 = minutes
# $6 = seconds
# $7 = time zone direction
# $8 = tz difference
# utc time with wrong TZ info:
time = mktime($1, RFC2822_MONTH_NAME[$2.to_i - 1], $3, $4, $5, $6, $7)
tz_difference = ("#{$7 == '-' ? '+' : '-'}#{$8}".to_i * 3600)
time + tz_difference + zone_offset(time.zone)
end
end
module CouchRest
module Mixins
module Properties
class IncludeError < StandardError; end
def self.included(base)
base.class_eval <<-EOS, __FILE__, __LINE__
extlib_inheritable_accessor(:properties) unless self.respond_to?(:properties)
self.properties ||= []
EOS
base.extend(ClassMethods)
raise CouchRest::Mixins::Properties::IncludeError, "You can only mixin Properties in a class responding to [] and []=, if you tried to mixin CastedModel, make sure your class inherits from Hash or responds to the proper methods" unless (base.new.respond_to?(:[]) && base.new.respond_to?(:[]=))
end
def apply_defaults
return if self.respond_to?(:new_document?) && (new_document? == false)
return unless self.class.respond_to?(:properties)
return if self.class.properties.empty?
# TODO: cache the default object
self.class.properties.each do |property|
key = property.name.to_s
# let's make sure we have a default
unless property.default.nil?
if property.default.class == Proc
self[key] = property.default.call
else
self[key] = Marshal.load(Marshal.dump(property.default))
end
end
end
end
def cast_keys
return unless self.class.properties
self.class.properties.each do |property|
next unless property.casted
key = self.has_key?(property.name) ? property.name : property.name.to_sym
# Don't cast the property unless it has a value
next unless self[key]
target = property.type
if target.is_a?(Array)
klass = ::CouchRest.constantize(target[0])
self[property.name] = self[key].collect do |value|
# Auto parse Time objects
obj = ( (property.init_method == 'new') && klass == Time) ? Time.parse(value) : klass.send(property.init_method, value)
obj.casted_by = self if obj.respond_to?(:casted_by)
obj
end
else
# Auto parse Time objects
self[property.name] = if ((property.init_method == 'new') && target == 'Time')
# Using custom time parsing method because Ruby's default method is toooo slow
self[key].is_a?(String) ? Time.mktime_with_offset(self[key].dup) : self[key]
# Float instances don't get initialized with #new
elsif ((property.init_method == 'new') && target == 'Float')
cast_float(self[key])
else
# Let people use :send as a Time parse arg
klass = ::CouchRest.constantize(target)
klass.send(property.init_method, self[key].dup)
end
self[property.name].casted_by = self if self[property.name].respond_to?(:casted_by)
end
end
def cast_float(value)
begin
Float(value)
rescue
value
end
end
end
module ClassMethods
def property(name, options={})
existing_property = self.properties.find{|p| p.name == name.to_s}
if existing_property.nil? || (existing_property.default != options[:default])
define_property(name, options)
end
end
protected
# This is not a thread safe operation, if you have to set new properties at runtime
# make sure to use a mutex.
def define_property(name, options={})
# check if this property is going to casted
options[:casted] = options[:cast_as] ? options[:cast_as] : false
property = CouchRest::Property.new(name, (options.delete(:cast_as) || options.delete(:type)), options)
create_property_getter(property)
create_property_setter(property) unless property.read_only == true
properties << property
end
# defines the getter for the property (and optional aliases)
def create_property_getter(property)
# meth = property.name
class_eval <<-EOS, __FILE__, __LINE__
def #{property.name}
self['#{property.name}']
end
EOS
if property.alias
class_eval <<-EOS, __FILE__, __LINE__
alias #{property.alias.to_sym} #{property.name.to_sym}
EOS
end
end
# defines the setter for the property (and optional aliases)
def create_property_setter(property)
meth = property.name
class_eval <<-EOS
def #{meth}=(value)
self['#{meth}'] = value
end
EOS
if property.alias
class_eval <<-EOS
alias #{property.alias.to_sym}= #{meth.to_sym}=
EOS
end
end
end # module ClassMethods
end
end
end