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

1 files changed, 49 insertions, 0 deletions

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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