Added ActiveRecord::Base.store for declaring simple single-column key/value stores [DHH]

3 files changed, 51 insertions, 1 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 132dc12680..3572c640eb 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -69,6 +69,7 @@ module ActiveRecord
     autoload :Schema
     autoload :SchemaDumper
     autoload :Serialization
+    autoload :Store
     autoload :SessionStore
     autoload :Timestamp
     autoload :Transactions
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 78159d13d4..6dae90266e 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -2145,7 +2145,7 @@ MSG
     # AutosaveAssociation needs to be included before Transactions, because we want
     # #save_with_autosave_associations to be wrapped inside a transaction.
     include AutosaveAssociation, NestedAttributes
-    include Aggregations, Transactions, Reflection, Serialization
+    include Aggregations, Transactions, Reflection, Serialization, Store
 
     NilClass.add_whiner(self) if NilClass.respond_to?(:add_whiner)
 
diff --git a/activerecord/lib/active_record/store.rb b/activerecord/lib/active_record/store.rb
new file mode 100644
index 0000000000..d5910df891
--- /dev/null
+++ b/activerecord/lib/active_record/store.rb
@@ -0,0 +1,49 @@
+module ActiveRecord
+  # Store gives you a thin wrapper around serialize for the purpose of storing hashes in a single column.
+  # It's like a simple key/value store backed into your record when you don't care about being able to
+  # query that store outside the context of a single record.
+  #
+  # You can then declare accessors to this store that are then accessible just like any other attribute
+  # of the model. This is very helpful for easily exposing store keys to a form or elsewhere that's
+  # already built around just accessing attributes on the model.
+  #
+  # Make sure that you declare the database column used for the serialized store as a text, so there's
+  # plenty of room.
+  #
+  # Examples:
+  #
+  #   class User < ActiveRecord::Base
+  #     store :settings, accessors: [ :color, :homepage ]
+  #   end
+  #   
+  #   u = User.new(color: 'black', homepage: '37signals.com')
+  #   u.color                          # Accessor stored attribute
+  #   u.settings[:country] = 'Denmark' # Any attribute, even if not specified with an accessor
+  #
+  #   # Add additional accessors to an existing store through store_accessor
+  #   class SuperUser < User
+  #     store_accessor :settings, :privileges, :servants
+  #   end
+  module Store
+    extend ActiveSupport::Concern
+  
+    module ClassMethods
+      def store(store_attribute, options = {})
+        serialize store_attribute, Hash
+        store_accessor(store_attribute, options[:accessors]) if options.has_key? :accessors
+      end
+
+      def store_accessor(store_attribute, *keys)
+        Array(keys).flatten.each do |key|
+          define_method("#{key}=") do |value|
+            send(store_attribute)[key] = value
+          end
+    
+          define_method(key) do
+            send(store_attribute)[key]
+          end
+        end
+      end
+    end
+  end
+end
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