1 files changed, 78 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/type/value.rb b/activerecord/lib/active_record/type/value.rb
new file mode 100644
index 0000000000..875fb98c4b
--- /dev/null
+++ b/activerecord/lib/active_record/type/value.rb
@@ -0,0 +1,78 @@
+module ActiveRecord
+  module Type
+    class Value # :nodoc:
+      attr_reader :precision, :scale, :limit
+
+      # Valid options are +precision+, +scale+, and +limit+.
+      # They are only used when dumping schema.
+      def initialize(options = {})
+        options.assert_valid_keys(:precision, :scale, :limit)
+        @precision = options[:precision]
+        @scale = options[:scale]
+        @limit = options[:limit]
+      end
+
+      # The simplified type that this object represents. Subclasses
+      # must override this method.
+      def type; end
+
+      def type_cast_from_database(value)
+        type_cast(value)
+      end
+
+      def type_cast_from_user(value)
+        type_cast(value)
+      end
+
+      def type_cast_for_database(value)
+        value
+      end
+
+      def type_cast_for_schema(value)
+        value.inspect
+      end
+
+      def text?
+        false
+      end
+
+      def number?
+        false
+      end
+
+      def binary?
+        false
+      end
+
+      def klass # :nodoc:
+      end
+
+      # +old_value+ will always be type-cast.
+      # +new_value+ will come straight from the database
+      # or from assignment, so it could be anything. Types
+      # which cannot typecast arbitrary values should override
+      # this method.
+      def changed?(old_value, new_value, _new_value_before_type_cast) # :nodoc:
+        old_value != new_value
+      end
+
+      def changed_in_place?(*) # :nodoc:
+        false
+      end
+
+      private
+      # Takes an input from the database, or from attribute setters,
+      # and casts it to a type appropriate for this object. This method
+      # should not be overriden by subclasses. Instead, override `cast_value`.
+      def type_cast(value) # :api: public
+        cast_value(value) unless value.nil?
+      end
+
+      # Responsible for casting values from external sources to the appropriate
+      # type. Called by `type_cast` for all values except `nil`.
+      def cast_value(value) # :api: public
+        value
+      end
+    end
+  end
+end