rails tips

1. rails 2.0

for nested resource, edit url helper is changed from parent_edit_child_path to edit_parent_child_path

http://blog.hasmanythrough.com/2006/4/3/polymorphic-through
has_many :through - The other side of polymorphic :through associations


http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html

Some extensions can only be made to work with knowledge of the association proxy‘s internals. Extensions can access relevant state using accessors on the association proxy:

    * proxy_owner - Returns the object the association is part of.
    * proxy_reflection - Returns the reflection object that describes the association.
    * proxy_target - Returns the associated object for belongs_to and has_one, or the collection of associated objects for has_many and has_and_belongs_to_many.