Added a require_association hook on const_missing that makes it possible to...

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

activerecord/CHANGELOG

 *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.

activerecord/lib/active_record/associations.rb

@@ -3,8 +3,28 @@
 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 @@ def require_association(file_name)
       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 

railties/CHANGELOG

 *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]

railties/lib/dispatcher.rb

@@ -43,7 +43,7 @@ def self.dispatch(cgi = CGI.new, session_options = ActionController::CgiRequest:
       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