Rails - Jul 2010 - Validating user’s ability using CanCan with model associations

I have a TakeAction model that looks like this:

class TakeAction < ActiveRecord::Base
  belongs_to :user
  has_many :take_action_notes
  attr_protected :user_id
end
and a TakeActionNote model that looks like this:

class TakeActionNote < ActiveRecord::Base
  belongs_to :take_action
  validates_presence_of :note
end
Using CanCan, I''m trying to allow the user that owns the take_action
to create and destroy (manage) notes.

I''ve tried defining abilities with a block like this.

 can :manage, TakeActionNote do |action, note|
    note.take_action.user.id == user.id
 end
I can add notes to the take_action without any problem but when I try
to destroy it I get:

NoMethodError in Take action notesController#33 undefined method
`take_action'' for nil:NilClass

Is there anything I''m missing or doing wrong? Any help is appreciated.
Thanks!

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On Thu, Jul 22, 2010 at 19:51, Carlos A. Cabrera
<carlos-x6sHsmbquPczbzzl3JCKVQ@public.gmane.org> wrote:
>  can :manage, TakeActionNote do |action, note|
>    note.take_action.user.id == user.id
>  end
> I can add notes to the take_action without any problem but when I try
> to destroy it I get:
>
> NoMethodError in Take action notesController#33 undefined method
> `take_action'' for nil:NilClass
Undefined methods on nil:NilClass mean that you''re expecting something
to be an object, but it''s really nil.  With something this short,
it''s
probably not so much *this* code, as whatever call it (or causes it to
be called, whatever).  If you don''t know what calls it, perhaps you
can insert something that would look for a nil value and dump the call
stack in that case.  (Sorry I can''t be more specific, as I
don''t know
CanCan myself; this is just a general code troubleshooting technique.)

-Dave

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