couchrest_model/lib/couchrest/mixins/properties.rb
2010-06-16 21:04:53 +02:00

130 lines
4.4 KiB
Ruby

require 'time'
require File.join(File.dirname(__FILE__), '..', 'property')
require File.join(File.dirname(__FILE__), '..', 'casted_array')
module CouchRest
module Mixins
module Properties
class IncludeError < StandardError; end
def self.included(base)
base.class_eval <<-EOS, __FILE__, __LINE__ + 1
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
# Returns the Class properties
#
# ==== Returns
# Array:: the list of properties for model's class
def properties
self.class.properties
end
def read_attribute(property)
self[property.to_s]
end
def write_attribute(property, value)
prop = property.is_a?(::CouchRest::Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
raise "Missing property definition for #{property.to_s}" unless prop
self[prop.to_s] = prop.cast(self, value)
end
def apply_all_property_defaults
return if self.respond_to?(:new?) && (new? == false)
# TODO: cache the default object
self.class.properties.each do |property|
write_attribute(property, property.default_value)
end
end
module ClassMethods
def property(name, *options, &block)
opts = { }
type = options.shift
if type.class != Hash
opts[:type] = type
opts.merge!(options.shift || {})
else
opts.update(type)
end
existing_property = self.properties.find{|p| p.name == name.to_s}
if existing_property.nil? || (existing_property.default != opts[:default])
define_property(name, opts, &block)
end
end
protected
# This is not a thread safe operation, if you have to set new properties at runtime
# make sure a mutex is used.
def define_property(name, options={}, &block)
# check if this property is going to casted
type = options.delete(:type) || options.delete(:cast_as)
if block_given?
type = Class.new(Hash) do
include CastedModel
end
type.class_eval { yield type }
type = [type] # inject as an array
end
property = CouchRest::Property.new(name, type, options)
create_property_getter(property)
create_property_setter(property) unless property.read_only == true
properties << property
property
end
# defines the getter for the property (and optional aliases)
def create_property_getter(property)
# meth = property.name
class_eval <<-EOS, __FILE__, __LINE__ + 1
def #{property.name}
read_attribute('#{property.name}')
end
EOS
if ['boolean', TrueClass.to_s.downcase].include?(property.type.to_s.downcase)
class_eval <<-EOS, __FILE__, __LINE__
def #{property.name}?
value = read_attribute('#{property.name}')
!(value.nil? || value == false)
end
EOS
end
if property.alias
class_eval <<-EOS, __FILE__, __LINE__ + 1
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)
property_name = property.name
class_eval <<-EOS
def #{property_name}=(value)
write_attribute('#{property_name}', value)
end
EOS
if property.alias
class_eval <<-EOS
alias #{property.alias.to_sym}= #{property_name.to_sym}=
EOS
end
end
end # module ClassMethods
end
end
end