First, very early, AbstractController code. More to come

1 files changed, 79 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb b/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb
index 70fdde3a58..c121933050 100644
--- a/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb
+++ b/activesupport/lib/active_support/core_ext/class/inheritable_attributes.rb
@@ -138,3 +138,82 @@ class Class # :nodoc:
     alias inherited_without_inheritable_attributes inherited
     alias inherited inherited_with_inheritable_attributes
 end
+
+class Class
+  # Defines class-level inheritable attribute reader. Attributes are available to subclasses,
+  # each subclass has a copy of parent's attribute.
+  #
+  # @param *syms<Array[#to_s]> Array of attributes to define inheritable reader for.
+  # @return <Array[#to_s]> Array of attributes converted into inheritable_readers.
+  #
+  # @api public
+  #
+  # @todo Do we want to block instance_reader via :instance_reader => false
+  # @todo It would be preferable that we do something with a Hash passed in
+  #   (error out or do the same as other methods above) instead of silently
+  #   moving on). In particular, this makes the return value of this function
+  #   less useful.
+  def extlib_inheritable_reader(*ivars)
+    instance_reader = ivars.pop[:reader] if ivars.last.is_a?(Hash)
+
+    ivars.each do |ivar|
+      self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+        def self.#{ivar}
+          return @#{ivar} if self.object_id == #{self.object_id} || defined?(@#{ivar})
+          ivar = superclass.#{ivar}
+          return nil if ivar.nil? && !#{self}.instance_variable_defined?("@#{ivar}")
+          @#{ivar} = ivar && !ivar.is_a?(Module) && !ivar.is_a?(Numeric) && !ivar.is_a?(TrueClass) && !ivar.is_a?(FalseClass) ? ivar.dup : ivar
+        end
+      RUBY
+      unless instance_reader == false
+        self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+          def #{ivar}
+            self.class.#{ivar}
+          end
+        RUBY
+      end
+    end
+  end
+
+  # Defines class-level inheritable attribute writer. Attributes are available to subclasses,
+  # each subclass has a copy of parent's attribute.
+  #
+  # @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to
+  #   define inheritable writer for.
+  # @option syms :instance_writer<Boolean> if true, instance-level inheritable attribute writer is defined.
+  # @return <Array[#to_s]> An Array of the attributes that were made into inheritable writers.
+  #
+  # @api public
+  #
+  # @todo We need a style for class_eval <<-HEREDOC. I'd like to make it
+  #   class_eval(<<-RUBY, __FILE__, __LINE__), but we should codify it somewhere.
+  def extlib_inheritable_writer(*ivars)
+    instance_writer = ivars.pop[:instance_writer] if ivars.last.is_a?(Hash)
+    ivars.each do |ivar|
+      self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+        def self.#{ivar}=(obj)
+          @#{ivar} = obj
+        end
+      RUBY
+      unless instance_writer == false
+        self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+          def #{ivar}=(obj) self.class.#{ivar} = obj end
+        RUBY
+      end
+    end
+  end
+
+  # Defines class-level inheritable attribute accessor. Attributes are available to subclasses,
+  # each subclass has a copy of parent's attribute.
+  #
+  # @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to
+  #   define inheritable accessor for.
+  # @option syms :instance_writer<Boolean> if true, instance-level inheritable attribute writer is defined.
+  # @return <Array[#to_s]> An Array of attributes turned into inheritable accessors.
+  #
+  # @api public
+  def extlib_inheritable_accessor(*syms)
+    class_inheritable_reader(*syms)
+    class_inheritable_writer(*syms)
+  end
+end
\ No newline at end of file