Rails - Jul 2006 - Forms: handle foreign keys (AssociationTypeMismatch)

Hi all

I tried and tried and tried, but I still fail in creating a form with 
proper validation and stuff for foreign keys... So I''d really like to 
get some help here.

I''m creating a booking site for DJ''s, and for every booking
one can
choose one of different countries:

class Booking < ActiveRecord::Base
  validates_presence_of :country_id
  validates_numericality_of :country_id # Necessary? Correct???

  belongs_to  :country,
              :dependent => true
end

class Country < ActiveRecord::Base
  has_many  :countries
end

Now I have created a scaffold of the bookings, but sadly this does not 
include the wanted select box for country selection. So I added it 
myself:

<%= error_messages_for ''booking'' %>
<%= start_form_tag :action => ''new'' %>

Country: <%= collection_select(:booking, :country, @countries, :id, 
:name, :include_blank => true) %>

<%= end_form_tag %>

So far, so good, the countries are well displayed in a select box. But 
when I submit the form, I get the following error:

 ActiveRecord::AssociationTypeMismatch in BookingsController#new

Country expected, got String

RAILS_ROOT: /Users/Josh/Webwork/psyguideorg/public/../config/..
Application Trace | Framework Trace | Full Trace

/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/associations/association_proxy.rb:134:in
`raise_on_type_mismatch''
/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/associations/belongs_to_association.rb:22:in
`replace''
/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/associations.rb:850:in
`country=''
/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1510:in
`attributes=''
/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1509:in
`attributes=''
/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1354:in
`initialize_without_callbacks''
/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/callbacks.rb:236:in
`initialize''
#{RAILS_ROOT}/app/controllers/bookings_controller.rb:27:in `new''

Can anybody tell me what to do? Do I have to add some sort of 
before_validation method that creates the Country object instead of the 
String (which is the ID of the selected country)?

Thanks very much for help.
Joshua

-- 
Posted via http://www.ruby-forum.com/.

No one...? Please, I really need this to continue with my work, and I 
just CAN''T be the only one with this type of problem...?

-- 
Posted via http://www.ruby-forum.com/.

Joshua Muheim wrote:
>Hi all
>
>I tried and tried and tried, but I still fail in creating a form with 
>proper validation and stuff for foreign keys... So I''d really like
to
>get some help here.
>
>I''m creating a booking site for DJ''s, and for every
booking one can
>choose one of different countries:
>
>class Booking < ActiveRecord::Base
>  validates_presence_of :country_id
>  validates_numericality_of :country_id # Necessary? Correct???
>  
>
I would say use validates_presence_of :country instead of the above two 
lines.
>  belongs_to  :country,
>              :dependent => true
>end
>
>class Country < ActiveRecord::Base
>  has_many  :countries
>end
>
>Now I have created a scaffold of the bookings, but sadly this does not 
>include the wanted select box for country selection. So I added it 
>myself:
>
><%= error_messages_for ''booking'' %>
><%= start_form_tag :action => ''new'' %>
>
>Country: <%= collection_select(:booking, :country, @countries, :id, 
>:name, :include_blank => true) %>
>  
>
This should be country_id not just country. Otherwise it is assigning 
the id that comes from the form into the booking.country association 
rather than the booking.country_id where it should be.
><%= end_form_tag %>
>
>So far, so good, the countries are well displayed in a select box. But 
>when I submit the form, I get the following error:
>
> ActiveRecord::AssociationTypeMismatch in BookingsController#new
>
>Country expected, got String
>
>RAILS_ROOT: /Users/Josh/Webwork/psyguideorg/public/../config/..
>Application Trace | Framework Trace | Full Trace
>
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/associations/association_proxy.rb:134:in
>`raise_on_type_mismatch''
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/associations/belongs_to_association.rb:22:in
>`replace''
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/associations.rb:850:in
>`country=''
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1510:in
>`attributes=''
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1509:in
>`attributes=''
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:1354:in
>`initialize_without_callbacks''
>/Applications/Locomotive2/Bundles/rails112.locobundle/powerpc/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/callbacks.rb:236:in
>`initialize''
>#{RAILS_ROOT}/app/controllers/bookings_controller.rb:27:in `new''
>
>Can anybody tell me what to do? Do I have to add some sort of 
>before_validation method that creates the Country object instead of the 
>String (which is the ID of the selected country)?
>
>Thanks very much for help.
>Joshua
>
>  
>

-- 
Jack Christensen
jackc@hylesanderson.edu

Thanks a lot, man! Funny, how much time sometimes is needed to find an 
error that''s caused by a few wrong characters in the code... ;-)

-- 
Posted via http://www.ruby-forum.com/.