Added a require_association hook on const_missing that makes it possible to use any model class without requiring it first. Added that Active Record associations are now reloaded instead of cleared to work with the new const_missing hook in Active Record.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@233 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 43 insertions, 3 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index b8e3e0f4ba..c642369bec 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,18 @@
 *SVN*
 
+* Added a require_association hook on const_missing that makes it possible to use any model class without requiring it first. This makes STI look like:
+
+    before:
+      require_association 'person'
+      class Employee < Person
+      end
+    
+    after:
+      class Employee < Person
+      end
+
+  This also reduces the usefulness of Controller.model in Action Pack to currently only being for documentation purposes.      
+
 * Added that Base.update_all and Base.delete_all return an integer of the number of affected rows #341
 
 * Changed the interface on AbstractAdapter to require that adapters return the number of affected rows on delete and update operations.
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index ba7f34d729..a66a6c9a5c 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -3,8 +3,28 @@ require 'active_record/associations/has_many_association'
 require 'active_record/associations/has_and_belongs_to_many_association'
 require 'active_record/deprecated_associations'
 
-unless Object.respond_to?(:require_association)
-  Object.send(:define_method, :require_association) { |file_name| ActiveRecord::Base.require_association(file_name) }
+
+class << Object #:nodoc:
+  # Make require_association available as a bare method.
+  unless respond_to?(:require_association)
+    def require_association(file_name)
+      ActiveRecord::Base.require_association(file_name)
+    end
+  end
+
+  # Use const_missing to autoload associations so we don't have to
+  # require_association when using single-table inheritance.
+  unless respond_to?(:pre_association_const_missing)
+    alias_method :pre_association_const_missing, :const_missing
+
+    def const_missing(class_id)
+      begin
+        require_association(Inflect.underscore(Inflector.demodulize(class_id.to_s)))
+      rescue LoadError
+        pre_association_const_missing(class_id)
+      end
+    end
+  end
 end
 
 module ActiveRecord
@@ -464,6 +484,11 @@ module ActiveRecord
       def reset_associations_loaded
         self.associations_loaded = []
       end
+      
+      # Reload all the associations that have already been loaded once.
+      def reload_associations_loaded
+        associations_loaded.each { |file_name| silence_warnings { load("#{file_name}.rb") } }
+      end
 
       private
         # Raises an exception if an invalid option has been specified to prevent misspellings from slipping through 
diff --git a/railties/CHANGELOG b/railties/CHANGELOG
index 003ac065ac..a0e402e5e1 100644
--- a/railties/CHANGELOG
+++ b/railties/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added that Active Record associations are now reloaded instead of cleared to work with the new const_missing hook in Active Record.
+
 * Added graceful handling of an inaccessible log file by redirecting output to STDERR with a warning #330 [rainmkr]
 
 * Added support for a -h/--help parameter in the generator #331 [Ulysses]
diff --git a/railties/lib/dispatcher.rb b/railties/lib/dispatcher.rb
index e3fd36d89a..0fcd295094 100644
--- a/railties/lib/dispatcher.rb
+++ b/railties/lib/dispatcher.rb
@@ -43,7 +43,7 @@ class Dispatcher
       if ActionController::Base.reload_dependencies
         Object.send(:remove_const, "ApplicationController") if Object.const_defined?(:ApplicationController)
         Object.send(:remove_const, controller_class_name(controller_name)) if Object.const_defined?(controller_class_name(controller_name))
-        ActiveRecord::Base.reset_associations_loaded
+        ActiveRecord::Base.reload_associations_loaded
         ActiveRecord::Base.reset_column_information_and_inheritable_attributes_for_all_subclasses
       end