refactor store_accessor

activerecord/CHANGELOG.md

 ## Rails 4.0.0 (unreleased) ##
 
+*   You can now override the generated accessor methods for stored attributes
+    and reuse the original behavior with `read_store_attribute` and `write_store_attribute`,
+    which are counterparts to `read_attribute` and `write_attribute`.
+
+    *Matt Jones*
+
 *   Accept belongs_to (including polymorphic) association keys in queries
 
     The following queries are now equivalent:
@@ -38,7 +44,7 @@
 
     *Jan Bernacki*
 
-*   Fix bug when call `store_accessor` multiple times.
+*   Fix bug when calling `store_accessor` multiple times.
     Fixes #7532.
 
     *Matt Jones*

activerecord/lib/active_record/store.rb

@@ -37,6 +37,28 @@ module ActiveRecord
   # The stored attribute names can be retrieved using +stored_attributes+.
   #
   #   User.stored_attributes[:settings] # [:color, :homepage]
+  #
+  # == Overwriting default accessors
+  #
+  # All stored values are automatically available through accessors on the Active Record
+  # object, but sometimes you want to specialize this behavior. This can be done by overwriting
+  # the default accessors (using the same name as the attribute) and calling
+  # <tt>read_store_attribute(store_attribute_name, attr_name)</tt> and
+  # <tt>write_store_attribute(store_attribute_name, attr_name, value)</tt> to actually
+  # change things.
+  #
+  #   class Song < ActiveRecord::Base
+  #     # Uses a stored integer to hold the volume adjustment of the song
+  #     store :settings, accessors: [:volume_adjustment]
+  #
+  #     def volume_adjustment=(decibels)
+  #       write_store_attribute(:settings, :volume_adjustment, decibels.to_i)
+  #     end
+  #
+  #     def volume_adjustment
+  #       read_store_attribute(:settings, :volume_adjustment).to_i
+  #     end
+  #   end
   module Store
     extend ActiveSupport::Concern
 
@@ -55,15 +77,11 @@ def store_accessor(store_attribute, *keys)
         keys = keys.flatten
         keys.each do |key|
           define_method("#{key}=") do |value|
-            attribute = initialize_store_attribute(store_attribute)
-            if value != attribute[key]
-              send :"#{store_attribute}_will_change!"
-              attribute[key] = value
-            end
+            write_store_attribute(store_attribute, key, value)
           end
 
           define_method(key) do
-            initialize_store_attribute(store_attribute)[key]
+            read_store_attribute(store_attribute, key)
           end
         end
 
@@ -72,6 +90,20 @@ def store_accessor(store_attribute, *keys)
       end
     end
 
+    protected
+      def read_store_attribute(store_attribute, key)
+        attribute = initialize_store_attribute(store_attribute)
+        attribute[key]
+      end
+
+      def write_store_attribute(store_attribute, key, value)
+        attribute = initialize_store_attribute(store_attribute)
+        if value != attribute[key]
+          send :"#{store_attribute}_will_change!"
+          attribute[key] = value
+        end
+      end
+
     private
       def initialize_store_attribute(store_attribute)
         attribute = send(store_attribute)

activerecord/test/cases/store_test.rb

@@ -29,6 +29,12 @@ class StoreTest < ActiveRecord::TestCase
     assert_equal 'graeters', @john.reload.settings[:icecream]
   end
 
+  test "overriding a read accessor" do
+    @john.settings[:phone_number] = '1234567890'
+
+    assert_equal '(123) 456-7890', @john.phone_number
+  end
+
   test "updating the store will mark it as changed" do
     @john.color = 'red'
     assert @john.settings_changed?
@@ -54,6 +60,12 @@ class StoreTest < ActiveRecord::TestCase
     assert_equal false, @john.remember_login
   end
 
+  test "overriding a write accessor" do
+    @john.phone_number = '(123) 456-7890'
+
+    assert_equal '1234567890', @john.settings[:phone_number]
+  end
+
   test "preserve store attributes data in HashWithIndifferentAccess format without any conversion" do
     @john.json_data = HashWithIndifferentAccess.new(:height => 'tall', 'weight' => 'heavy')
     @john.height = 'low'
@@ -124,7 +136,7 @@ class StoreTest < ActiveRecord::TestCase
   end
 
   test "all stored attributes are returned" do
-    assert_equal [:color, :homepage, :favorite_food], Admin::User.stored_attributes[:settings]
+    assert_equal [:color, :homepage, :favorite_food, :phone_number], Admin::User.stored_attributes[:settings]
   end
 
   test "stores_attributes are class level settings" do

activerecord/test/models/admin/user.rb

 class Admin::User < ActiveRecord::Base
   belongs_to :account
   store :settings, :accessors => [ :color, :homepage ]
-  store_accessor :settings, :favorite_food
+  store_accessor :settings, :favorite_food, :phone_number
   store :preferences, :accessors => [ :remember_login ]
   store :json_data, :accessors => [ :height, :weight ], :coder => JSON
   store :json_data_empty, :accessors => [ :is_a_good_guy ], :coder => JSON
+
+  def phone_number
+    read_store_attribute(:settings, :phone_number).gsub(/(\d{3})(\d{3})(\d{4})/,'(\1) \2-\3')
+  end
+
+  def phone_number=(value)
+    write_store_attribute(:settings, :phone_number, value && value.gsub(/[^\d]/,''))
+  end
 end