diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/class/attribute.rb')
-rw-r--r-- | activesupport/lib/active_support/core_ext/class/attribute.rb | 65 |
1 files changed, 36 insertions, 29 deletions
diff --git a/activesupport/lib/active_support/core_ext/class/attribute.rb b/activesupport/lib/active_support/core_ext/class/attribute.rb index 1504e18839..f2a221c396 100644 --- a/activesupport/lib/active_support/core_ext/class/attribute.rb +++ b/activesupport/lib/active_support/core_ext/class/attribute.rb @@ -44,7 +44,8 @@ class Class # Base.setting # => [] # Subclass.setting # => [:foo] # - # For convenience, a query method is defined as well: + # For convenience, an instance predicate method is defined as well. + # To skip it, pass <tt>instance_predicate: false</tt>. # # Subclass.setting? # => false # @@ -71,50 +72,56 @@ class Class options = attrs.extract_options! instance_reader = options.fetch(:instance_accessor, true) && options.fetch(:instance_reader, true) instance_writer = options.fetch(:instance_accessor, true) && options.fetch(:instance_writer, true) + instance_predicate = options.fetch(:instance_predicate, true) - # We use class_eval here rather than define_method because class_attribute - # may be used in a performance sensitive context therefore the overhead that - # define_method introduces may become significant. attrs.each do |name| - class_eval <<-RUBY, __FILE__, __LINE__ + 1 - def self.#{name}() nil end - def self.#{name}?() !!#{name} end + define_singleton_method(name) { nil } + define_singleton_method("#{name}?") { !!public_send(name) } if instance_predicate - def self.#{name}=(val) - singleton_class.class_eval do - remove_possible_method(:#{name}) - define_method(:#{name}) { val } - end + ivar = "@#{name}" + + define_singleton_method("#{name}=") do |val| + singleton_class.class_eval do + remove_possible_method(name) + define_method(name) { val } + end - if singleton_class? - class_eval do - remove_possible_method(:#{name}) - def #{name} - defined?(@#{name}) ? @#{name} : singleton_class.#{name} + if singleton_class? + class_eval do + remove_possible_method(name) + define_method(name) do + if instance_variable_defined? ivar + instance_variable_get ivar + else + singleton_class.send name end end end - val end + val + end - if instance_reader - remove_possible_method :#{name} - def #{name} - defined?(@#{name}) ? @#{name} : self.class.#{name} - end - - def #{name}? - !!#{name} + if instance_reader + remove_possible_method name + define_method(name) do + if instance_variable_defined?(ivar) + instance_variable_get ivar + else + self.class.public_send name end end - RUBY + define_method("#{name}?") { !!public_send(name) } if instance_predicate + end attr_writer name if instance_writer end end private - def singleton_class? - ancestors.first != self + + unless respond_to?(:singleton_class?) + def singleton_class? + ancestors.first != self + end end end |