Added Base.abstract_class? that marks which classes are not part of the Active Record hierarchy. closes #3704

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3882 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,26 @@
 *SVN*
 
+* Added Base.abstract_class? that marks which classes are not part of the Active Record hierarchy #3704 [Rick Olson]
+
+    class CachedModel < ActiveRecord::Base
+      self.abstract_class = true
+    end
+    
+    class Post < CachedModel
+    end
+    
+    CachedModel.abstract_class?
+    => true
+    
+    Post.abstract_class?
+    => false
+
+    Post.base_class
+    => Post
+    
+    Post.table_name
+    => 'posts'
+
 * Allow :dependent options to be used with polymorphic joins. #3820 [Rick Olson]
 
     class Foo < ActiveRecord::Base

activerecord/lib/active_record/associations/association_proxy.rb

@@ -77,7 +77,7 @@ def extract_options_from_args!(args)
         def set_belongs_to_association_for(record)
           if @reflection.options[:as]
             record["#{@reflection.options[:as]}_id"]   = @owner.id unless @owner.new_record?
-            record["#{@reflection.options[:as]}_type"] = ActiveRecord::Base.send(:class_name_of_active_record_descendant, @owner.class).to_s
+            record["#{@reflection.options[:as]}_type"] = @owner.class.base_class.name.to_s
           else
             record[@reflection.primary_key_name] = @owner.id unless @owner.new_record?
           end

activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb

@@ -9,7 +9,7 @@ def replace(record)
 
           unless record.new_record?
             @owner[@reflection.primary_key_name] = record.id
-            @owner[@reflection.options[:foreign_type]] = ActiveRecord::Base.send(:class_name_of_active_record_descendant, record.class).to_s
+            @owner[@reflection.options[:foreign_type]] = record.class.base_class.name.to_s
           end
 
           @updated = true

activerecord/lib/active_record/associations/has_many_association.rb

@@ -168,7 +168,7 @@ def construct_sql
             when @reflection.options[:as]
               @finder_sql = 
                 "#{@reflection.klass.table_name}.#{@reflection.options[:as]}_id = #{@owner.quoted_id} AND " + 
-                "#{@reflection.klass.table_name}.#{@reflection.options[:as]}_type = '#{ActiveRecord::Base.send(:class_name_of_active_record_descendant, @owner.class).to_s}'"
+                "#{@reflection.klass.table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote @owner.class.base_class.name.to_s}"
               @finder_sql << " AND (#{interpolate_sql(@conditions)})" if @conditions
             
             else

activerecord/lib/active_record/associations/has_many_through_association.rb

@@ -67,7 +67,7 @@ def construct_conditions
             conditions = 
               "#{@reflection.table_name}.#{@reflection.klass.primary_key} = #{through_reflection.table_name}.#{@reflection.klass.to_s.foreign_key} " +
               "AND #{through_reflection.table_name}.#{through_reflection.options[:as]}_id = #{@owner.quoted_id} " + 
-              "AND #{through_reflection.table_name}.#{through_reflection.options[:as]}_type = '#{ActiveRecord::Base.send(:class_name_of_active_record_descendant, @owner.class).to_s}'"
+              "AND #{through_reflection.table_name}.#{through_reflection.options[:as]}_type = #{@owner.class.quote @owner.class.base_class.name.to_s}"
           else
             conditions = 
               "#{@reflection.klass.table_name}.#{@reflection.klass.primary_key} = #{through_reflection.table_name}.#{@reflection.klass.to_s.foreign_key} " +

activerecord/lib/active_record/associations/has_one_association.rb

@@ -69,7 +69,7 @@ def construct_sql
             when @reflection.options[:as]
               @finder_sql = 
                 "#{@reflection.klass.table_name}.#{@reflection.options[:as]}_id = #{@owner.quoted_id} AND " + 
-                "#{@reflection.klass.table_name}.#{@reflection.options[:as]}_type = '#{ActiveRecord::Base.send(:class_name_of_active_record_descendant, @owner.class).to_s}'"          
+                "#{@reflection.klass.table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote @owner.class.base_class.name.to_s}"          
             else
               @finder_sql = "#{@reflection.table_name}.#{@reflection.primary_key_name} = #{@owner.quoted_id}"
           end

activerecord/lib/active_record/base.rb

@@ -599,7 +599,7 @@ def table_name
       end
 
       def reset_table_name
-        name = "#{table_name_prefix}#{undecorated_table_name(class_name_of_active_record_descendant(self))}#{table_name_suffix}"
+        name = "#{table_name_prefix}#{undecorated_table_name(base_class.name)}#{table_name_suffix}"
         set_table_name(name)
         name
       end
@@ -614,9 +614,9 @@ def reset_primary_key
         key = 'id'
         case primary_key_prefix_type
           when :table_name
-            key = Inflector.foreign_key(class_name_of_active_record_descendant(self), false)
+            key = Inflector.foreign_key(base_class.name, false)
           when :table_name_with_underscore
-            key = Inflector.foreign_key(class_name_of_active_record_descendant(self))
+            key = Inflector.foreign_key(base_class.name)
         end
         set_primary_key(key)
         key
@@ -936,7 +936,15 @@ def base_class
         class_of_active_record_descendant(self)
       end
 
-      
+      # Set this to true if this is an abstract class (see #abstract_class?).
+      attr_accessor :abstract_class
+
+      # Returns whether this class is a base AR class.  If A is a base class and
+      # B descends from A, then B.base_class will return B.
+      def abstract_class?
+        abstract_class == true
+      end
+
       private
         # Finder methods must instantiate through this method to work with the single-table inheritance model
         # that makes it possible to create objects of different types from the same table.
@@ -1016,7 +1024,7 @@ def type_condition
         end
 
         # Guesses the table name, but does not decorate it with prefix and suffix information.
-        def undecorated_table_name(class_name = class_name_of_active_record_descendant(self))
+        def undecorated_table_name(class_name = base_class.name)
           table_name = Inflector.underscore(Inflector.demodulize(class_name))
           table_name = Inflector.pluralize(table_name) if pluralize_table_names
           table_name
@@ -1172,7 +1180,7 @@ def compute_type(type_name)
 
         # Returns the class descending directly from ActiveRecord in the inheritance hierarchy.
         def class_of_active_record_descendant(klass)
-          if klass.superclass == Base
+          if klass.superclass == Base || klass.superclass.abstract_class?
             klass
           elsif klass.superclass.nil?
             raise ActiveRecordError, "#{name} doesn't belong in a hierarchy descending from ActiveRecord"
@@ -1183,7 +1191,7 @@ def class_of_active_record_descendant(klass)
 
         # Returns the name of the class descending directly from ActiveRecord in the inheritance hierarchy.
         def class_name_of_active_record_descendant(klass)
-          class_of_active_record_descendant(klass).name
+          klass.base_class.name
         end
 
         # Accepts an array or string.  The string is returned untouched, but the array has each value

activerecord/lib/active_record/calculations.rb

@@ -172,7 +172,7 @@ def execute_grouped_calculation(operation, column_name, column, aggregate, aggre
 
         if association
           key_ids     = calculated_data.collect { |row| row[group_alias] }
-          key_records = ActiveRecord::Base.send(:class_of_active_record_descendant, association.klass).find(key_ids)
+          key_records = association.klass.base_class.find(key_ids)
           key_records = key_records.inject({}) { |hsh, r| hsh.merge(r.id => r) }
         end
 

activerecord/test/associations_join_model_test.rb

@@ -38,7 +38,15 @@ def test_polymorphic_belongs_to
   def test_polymorphic_has_many_going_through_join_model
     assert_equal tags(:general), posts(:welcome).tags.first
   end
-  
+
+  def test_polymorphic_has_many_create_model_with_inheritance_and_custom_base_class
+    post = SubStiPost.create :title => 'SubStiPost', :body => 'SubStiPost body'
+    assert_instance_of SubStiPost, post
+    
+    tagging = tags(:misc).taggings.create(:taggable => post)
+    assert_equal "SubStiPost", tagging.taggable_type
+  end
+
   def test_polymorphic_has_many_going_through_join_model_with_inheritance
     assert_equal tags(:general), posts(:thinking).tags.first
   end

activerecord/test/base_test.rb

@@ -21,6 +21,7 @@ class TestOracleDefault < ActiveRecord::Base; end
 
 class LoosePerson < ActiveRecord::Base
   attr_protected :credit_rating, :administrator
+  self.abstract_class = true
 end
 
 class LooseDescendant < LoosePerson
@@ -1148,8 +1149,12 @@ def test_scoped_find_limit_offset
   end
 
   def test_base_class
-    assert_equal LoosePerson, LoosePerson.base_class
-    assert_equal LoosePerson, LooseDescendant.base_class
+    assert LoosePerson.abstract_class?
+    assert !LooseDescendant.abstract_class?
+    assert_equal LoosePerson,     LoosePerson.base_class
+    assert_equal LooseDescendant, LooseDescendant.base_class
+    assert_equal TightPerson,     TightPerson.base_class
+    assert_equal TightPerson,     TightDescendant.base_class
   end
 
   def test_assert_queries

activerecord/test/fixtures/post.rb

@@ -39,5 +39,9 @@ def self.what_are_you
 class SpecialPost < Post; end;
 
 class StiPost < Post
+  self.abstract_class = true
   has_one :special_comment, :class_name => "SpecialComment"
 end
+
+class SubStiPost < StiPost
+end