Implement mattr_acessor :default option

1 files changed, 19 insertions, 24 deletions

diff --git a/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb b/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb
index 2c24081eb9..9244cfa157 100644
--- a/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb
+++ b/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb
@@ -38,13 +38,10 @@ class Module
   #
   #   Person.new.hair_colors # => NoMethodError
   #
-  #
-  # Also, you can pass a block to set up the attribute with a default value.
+  # You can set a default value for the attribute.
   #
   #   module HairColors
-  #     mattr_reader :hair_colors do
-  #       [:brown, :black, :blonde, :red]
-  #     end
+  #     mattr_reader :hair_colors, default: [:brown, :black, :blonde, :red]
   #   end
   #
   #   class Person
@@ -52,8 +49,7 @@ class Module
   #   end
   #
   #   Person.new.hair_colors # => [:brown, :black, :blonde, :red]
-  def mattr_reader(*syms)
-    options = syms.extract_options!
+  def mattr_reader(*syms, instance_reader: true, instance_accessor: true, default: nil)
     syms.each do |sym|
       raise NameError.new("invalid attribute name: #{sym}") unless /\A[_A-Za-z]\w*\z/.match?(sym)
       class_eval(<<-EOS, __FILE__, __LINE__ + 1)
@@ -64,14 +60,16 @@ class Module
         end
       EOS
 
-      unless options[:instance_reader] == false || options[:instance_accessor] == false
+      if instance_reader && instance_accessor
         class_eval(<<-EOS, __FILE__, __LINE__ + 1)
           def #{sym}
             @@#{sym}
           end
         EOS
       end
-      class_variable_set("@@#{sym}", yield) if block_given?
+
+      sym_default_value = (block_given? && default.nil?) ? yield : default
+      class_variable_set("@@#{sym}", sym_default_value) unless sym_default_value.nil?
     end
   end
   alias :cattr_reader :mattr_reader
@@ -107,12 +105,10 @@ class Module
   #
   #   Person.new.hair_colors = [:blonde, :red] # => NoMethodError
   #
-  # Also, you can pass a block to set up the attribute with a default value.
+  # You can set a default value for the attribute.
   #
   #   module HairColors
-  #     mattr_writer :hair_colors do
-  #       [:brown, :black, :blonde, :red]
-  #     end
+  #     mattr_writer :hair_colors, default: [:brown, :black, :blonde, :red]
   #   end
   #
   #   class Person
@@ -120,8 +116,7 @@ class Module
   #   end
   #
   #   Person.class_variable_get("@@hair_colors") # => [:brown, :black, :blonde, :red]
-  def mattr_writer(*syms)
-    options = syms.extract_options!
+  def mattr_writer(*syms, instance_writer: true, instance_accessor: true, default: nil)
     syms.each do |sym|
       raise NameError.new("invalid attribute name: #{sym}") unless /\A[_A-Za-z]\w*\z/.match?(sym)
       class_eval(<<-EOS, __FILE__, __LINE__ + 1)
@@ -132,14 +127,16 @@ class Module
         end
       EOS
 
-      unless options[:instance_writer] == false || options[:instance_accessor] == false
+      if instance_writer && instance_accessor
         class_eval(<<-EOS, __FILE__, __LINE__ + 1)
           def #{sym}=(obj)
             @@#{sym} = obj
           end
         EOS
       end
-      send("#{sym}=", yield) if block_given?
+
+      sym_default_value = (block_given? && default.nil?) ? yield : default
+      send("#{sym}=", sym_default_value) unless sym_default_value.nil?
     end
   end
   alias :cattr_writer :mattr_writer
@@ -197,12 +194,10 @@ class Module
   #   Person.new.hair_colors = [:brown]  # => NoMethodError
   #   Person.new.hair_colors             # => NoMethodError
   #
-  # Also you can pass a block to set up the attribute with a default value.
+  # You can set a default value for the attribute.
   #
   #   module HairColors
-  #     mattr_accessor :hair_colors do
-  #       [:brown, :black, :blonde, :red]
-  #     end
+  #     mattr_accessor :hair_colors, default: [:brown, :black, :blonde, :red]
   #   end
   #
   #   class Person
@@ -210,9 +205,9 @@ class Module
   #   end
   #
   #   Person.class_variable_get("@@hair_colors") # => [:brown, :black, :blonde, :red]
-  def mattr_accessor(*syms, &blk)
-    mattr_reader(*syms, &blk)
-    mattr_writer(*syms)
+  def mattr_accessor(*syms, instance_reader: true, instance_writer: true, instance_accessor: true, default: nil, &blk)
+    mattr_reader(*syms, instance_reader: instance_reader, instance_accessor: instance_accessor, default: default, &blk)
+    mattr_writer(*syms, instance_writer: instance_writer, instance_accessor: instance_accessor, default: default)
   end
   alias :cattr_accessor :mattr_accessor
 end