Deprecated `define_attr_method` in `ActiveModel::AttributeMethods`

This only existed to support methods like `set_table_name` in Active
Record, which are themselves being deprecated.

1 files changed, 20 insertions, 37 deletions

diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index e69cb5c459..dba059eacd 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -66,46 +66,29 @@ module ActiveModel
     end
 
     module ClassMethods
-      # 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 Person
-      #
-      #     include ActiveModel::AttributeMethods
-      #
-      #     cattr_accessor :primary_key
-      #     cattr_accessor :inheritance_column
-      #
-      #     define_attr_method :primary_key, "sysid"
-      #     define_attr_method( :inheritance_column ) do
-      #       original_inheritance_column + "_id"
-      #     end
-      #
-      #   end
-      #
-      # Provides you with:
-      #
-      #   Person.primary_key
-      #   # => "sysid"
-      #   Person.inheritance_column = 'address'
-      #   Person.inheritance_column
-      #   # => 'address_id'
-      def define_attr_method(name, value=nil, &block)
+      def define_attr_method(name, value=nil, deprecation_warning = true, &block) #:nodoc:
+        # This deprecation_warning param is for internal use so that we can silence
+        # the warning from Active Record, because we are implementing more specific
+        # messages there instead.
+        #
+        # It doesn't apply to the original_#{name} method as we want to warn if
+        # people are calling that regardless.
+        if deprecation_warning
+          ActiveSupport::Deprecation.warn("define_attr_method is deprecated and will be removed without replacement.")
+        end
+
         sing = singleton_class
         sing.class_eval <<-eorb, __FILE__, __LINE__ + 1
-          if method_defined?('original_#{name}')
-            undef :'original_#{name}'
+          remove_possible_method :'original_#{name}'
+          remove_possible_method :'_original_#{name}'
+          alias_method :'_original_#{name}', :'#{name}'
+          define_method :'original_#{name}' do
+            ActiveSupport::Deprecation.warn(
+              "This method is generated by ActiveModel::AttributeMethods::ClassMethods#define_attr_method, " \
+              "which is deprecated and will be removed."
+            )
+            send(:'_original_#{name}')
           end
-          alias_method :'original_#{name}', :'#{name}'
         eorb
         if block_given?
           sing.send :define_method, name, &block