diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/class')
-rw-r--r-- | activesupport/lib/active_support/core_ext/class/delegating_attributes.rb | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/class/delegating_attributes.rb b/activesupport/lib/active_support/core_ext/class/delegating_attributes.rb new file mode 100644 index 0000000000..f5f0ef8779 --- /dev/null +++ b/activesupport/lib/active_support/core_ext/class/delegating_attributes.rb @@ -0,0 +1,40 @@ +# These class attributes behave something like the class +# inheritable accessors. But instead of copying the hash over at +# the time the subclass is first defined, the accessors simply +# delegate to their superclass unless they have been given a +# specific value. This stops the strange situation where values +# set after class definition don't get applied to subclasses. +class Class + def superclass_delegating_reader(*names) + class_name_to_stop_searching_on = self.superclass.name.blank? ? "Object" : self.superclass.name + names.each do |name| + class_eval <<-EOS + def self.#{name} + if defined?(@#{name}) + @#{name} + elsif superclass < #{class_name_to_stop_searching_on} && superclass.respond_to?(:#{name}) + superclass.#{name} + end + end + def #{name} + self.class.#{name} + end + EOS + end + end + + def superclass_delegating_writer(*names) + names.each do |name| + class_eval <<-EOS + def self.#{name}=(value) + @#{name} = value + end + EOS + end + end + + def superclass_delegating_accessor(*names) + superclass_delegating_reader(*names) + superclass_delegating_writer(*names) + end +end
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