Rails - Jul 2011 - ActiveRecord has_many associations

Given the models Country, State, City and Person as follows.

class Country < ActiveRecord::Base
  has_many :states
end

class State < ActiveRecord::Base
  belongs_to :country
  has_many :cities
end

class City < ActiveRecord::Base
  belongs_to :state
  has_many :people
end

class Person < ActiveRecord::Base
  belongs_to :city
end

Is there any way that doesn''t allow to delete a country if it has
states?
(will do the same for states and cities, cities and persons).
Didn''t saw nothing like that in the dependent option.

Thanks in advance.

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Hi!

I''m new to Rails, but I''ll try to help.

Maybe you could use the before_destroy callback:

http://guides.rubyonrails.org/active_record_validations_callbacks.html#destroying-an-object

Best Regards,

Everaldo

On Tue, Jul 26, 2011 at 10:35 AM, Piter Fcbk
<piter.fcbk-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Given the models Country, State, City and Person as follows.
>
> class Country < ActiveRecord::Base
>   has_many :states
> end
>
> class State < ActiveRecord::Base
>   belongs_to :country
>   has_many :cities
> end
>
> class City < ActiveRecord::Base
>   belongs_to :state
>   has_many :people
> end
>
> class Person < ActiveRecord::Base
>   belongs_to :city
> end
>
> Is there any way that doesn''t allow to delete a country if it has
states?
> (will do the same for states and cities, cities and persons).
> Didn''t saw nothing like that in the dependent option.
>
> Thanks in advance.
>
> --
> You received this message because you are subscribed to the Google Groups
> "Ruby on Rails: Talk" group.
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>
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>
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