Start separating primary key concerns

4 files changed, 76 insertions, 65 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index b2c1c9c024..5e9ce0600a 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -73,6 +73,7 @@ module ActiveRecord
   module AttributeMethods
     autoload :BeforeTypeCast, 'active_record/attribute_methods/before_type_cast'
     autoload :Dirty, 'active_record/attribute_methods/dirty'
+    autoload :PrimaryKey, 'active_record/attribute_methods/primary_key'
     autoload :Query, 'active_record/attribute_methods/query'
     autoload :Read, 'active_record/attribute_methods/read'
     autoload :TimeZoneConversion, 'active_record/attribute_methods/time_zone_conversion'
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 0d444f0239..5cb536af1f 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -39,6 +39,36 @@ module ActiveRecord
         undefine_attribute_methods
       end
 
+      # Defines an "attribute" method (like +inheritance_column+ or
+      # +table_name+). A new (class) method will be created with the
+      # given name. If a value is specified, the new method will
+      # return that value (as a string). Otherwise, the given block
+      # will be used to compute the value of the method.
+      #
+      # The original method will be aliased, with the new name being
+      # prefixed with "original_". This allows the new method to
+      # access the original value.
+      #
+      # Example:
+      #
+      #   class A < ActiveRecord::Base
+      #     define_attr_method :primary_key, "sysid"
+      #     define_attr_method( :inheritance_column ) do
+      #       original_inheritance_column + "_id"
+      #     end
+      #   end
+      def define_attr_method(name, value=nil, &block)
+        sing = metaclass
+        sing.send :alias_method, "original_#{name}", name
+        if block_given?
+          sing.send :define_method, name, &block
+        else
+          # use eval instead of a block to work around a memory leak in dev
+          # mode in fcgi
+          sing.class_eval "def #{name}; #{value.to_s.inspect}; end"
+        end
+      end
+
       # Returns MatchData if method_name is an attribute method.
       def match_attribute_method?(method_name)
         rebuild_attribute_method_regexp unless defined?(@@attribute_method_regexp) && @@attribute_method_regexp
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
new file mode 100644
index 0000000000..365fdeb55a
--- /dev/null
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -0,0 +1,44 @@
+module ActiveRecord
+  module AttributeMethods
+    module PrimaryKey
+      extend ActiveSupport::Concern
+
+      module ClassMethods
+        # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
+        # primary_key_prefix_type setting, though.
+        def primary_key
+          reset_primary_key
+        end
+
+        def reset_primary_key #:nodoc:
+          key = get_primary_key(base_class.name)
+          set_primary_key(key)
+          key
+        end
+
+        def get_primary_key(base_name) #:nodoc:
+          key = 'id'
+          case primary_key_prefix_type
+            when :table_name
+              key = base_name.to_s.foreign_key(false)
+            when :table_name_with_underscore
+              key = base_name.to_s.foreign_key
+          end
+          key
+        end
+
+        # Sets the name of the primary key column to use to the given value,
+        # or (if the value is nil or false) to the value returned by the given
+        # block.
+        #
+        #   class Project < ActiveRecord::Base
+        #     set_primary_key "sysid"
+        #   end
+        def set_primary_key(value = nil, &block)
+          define_attr_method :primary_key, value, &block
+        end
+        alias :primary_key= :set_primary_key
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 7fabb5bfc6..ce93ea8eee 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1225,29 +1225,6 @@ module ActiveRecord #:nodoc:
         name
       end
 
-      # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
-      # primary_key_prefix_type setting, though.
-      def primary_key
-        reset_primary_key
-      end
-
-      def reset_primary_key #:nodoc:
-        key = get_primary_key(base_class.name)
-        set_primary_key(key)
-        key
-      end
-
-      def get_primary_key(base_name) #:nodoc:
-        key = 'id'
-        case primary_key_prefix_type
-          when :table_name
-            key = base_name.to_s.foreign_key(false)
-          when :table_name_with_underscore
-            key = base_name.to_s.foreign_key
-        end
-        key
-      end
-
       # Defines the column name for use with single table inheritance
       # -- can be set in subclasses like so: self.inheritance_column = "type_id"
       def inheritance_column
@@ -1277,18 +1254,6 @@ module ActiveRecord #:nodoc:
       end
       alias :table_name= :set_table_name
 
-      # Sets the name of the primary key column to use to the given value,
-      # or (if the value is nil or false) to the value returned by the given
-      # block.
-      #
-      #   class Project < ActiveRecord::Base
-      #     set_primary_key "sysid"
-      #   end
-      def set_primary_key(value = nil, &block)
-        define_attr_method :primary_key, value, &block
-      end
-      alias :primary_key= :set_primary_key
-
       # Sets the name of the inheritance column to use to the given value,
       # or (if the value # is nil or false) to the value returned by the
       # given block.
@@ -2077,36 +2042,6 @@ module ActiveRecord #:nodoc:
           end
         end
 
-        # Defines an "attribute" method (like +inheritance_column+ or
-        # +table_name+). A new (class) method will be created with the
-        # given name. If a value is specified, the new method will
-        # return that value (as a string). Otherwise, the given block
-        # will be used to compute the value of the method.
-        #
-        # The original method will be aliased, with the new name being
-        # prefixed with "original_". This allows the new method to
-        # access the original value.
-        #
-        # Example:
-        #
-        #   class A < ActiveRecord::Base
-        #     define_attr_method :primary_key, "sysid"
-        #     define_attr_method( :inheritance_column ) do
-        #       original_inheritance_column + "_id"
-        #     end
-        #   end
-        def define_attr_method(name, value=nil, &block)
-          sing = metaclass
-          sing.send :alias_method, "original_#{name}", name
-          if block_given?
-            sing.send :define_method, name, &block
-          else
-            # use eval instead of a block to work around a memory leak in dev
-            # mode in fcgi
-            sing.class_eval "def #{name}; #{value.to_s.inspect}; end"
-          end
-        end
-
       protected
         # Scope parameters to method calls within the block.  Takes a hash of method_name => parameters hash.
         # method_name may be <tt>:find</tt> or <tt>:create</tt>. <tt>:find</tt> parameters may include the <tt>:conditions</tt>, <tt>:joins</tt>,
@@ -3184,6 +3119,7 @@ module ActiveRecord #:nodoc:
     include Locking::Optimistic, Locking::Pessimistic
     include AttributeMethods
     include AttributeMethods::Read, AttributeMethods::Write, AttributeMethods::BeforeTypeCast, AttributeMethods::Query
+    include AttributeMethods::PrimaryKey
     include AttributeMethods::TimeZoneConversion
     include AttributeMethods::Dirty
     include Callbacks, ActiveModel::Observing, Timestamp