Why does AR use base_class for polymorphic relationship "type"

rubyonrails-talk
1

I have a couple models that inherit from a base class that then inherits from AR.

When they are used in a polymorphic relationship the "type" is always the base class.

Just curious if anyone has a reason why it doesn't use the *actual* class rather then the base_class. I have patched AR to use the actual class if !base_class.table_exists? but it adds another query each time (which in turn fails some of the rails tests).

My only guess was for use with STI, but even then I am not sure if there is a better solution then using the base_class

-Eric

2

By default, Rails stores the class name that corresponds to the *table* name that the record is from (to avoid storing duplicate data for STI subclasses). If you're actually storing the subclasses in different tables, you'll probably want to do 'self.abstract_class = true' in the base class to make this clearer.

--Matt Jones