A model inside another model creation

Rails
1

I got a model relationships
Country <- (hm) city <- (hm) Address

The table city has two fields (both required)
integer :country_id
string :name

When creating a city the user can type a country in a country field
<%form_for @city do |f| %>
<%= f.label :country %>
<%= f.text_field :country %>
<%= f.label :country %>
<%= f.text_field :country %>
<%end%>

Before creating i would like to find a country by its name, if the
name wouldn’t exist then a new country would be created and it’s id
(the new created ones) would be placed in country_id (so
self.country_id = id) field of the new city.
Then if it validated a new city would be saved to database.

I was trying to do this in the model but couldn’t succeed.
My general idea was to do it with a callback like before_create, but
it failed.

Any ideas on this one?

2

On Thu, Jul 24, 2008 at 8:09 AM, Adam [email protected] wrote:

<%= f.label :country %>

I was trying to do this in the model but couldn’t succeed.
My general idea was to do it with a callback like before_create, but
it failed.

Any ideas on this one?

Did you try before_validation_on_create?

3

I’ve tried that one and i didn’t work.

i get a ‘undefined method `new_record?’ for “Palestinian Territory,
Occupied”:String’

the app trace

vendor/rails/activerecord/lib/active_record/associations.rb:903:in
belongs_to_before_save_for_country' vendor/rails/activesupport/lib/active_support/callbacks.rb:173:insend’
vendor/rails/activesupport/lib/active_support/callbacks.rb:173:in
evaluate_method' vendor/rails/activesupport/lib/active_support/callbacks.rb:161:incall’
vendor/rails/activesupport/lib/active_support/callbacks.rb:93:in run' vendor/rails/activesupport/lib/active_support/callbacks.rb:92:ineach’
vendor/rails/activesupport/lib/active_support/callbacks.rb:92:in
send' vendor/rails/activesupport/lib/active_support/callbacks.rb:92:inrun’
vendor/rails/activesupport/lib/active_support/callbacks.rb:272:in
run_callbacks' vendor/rails/activerecord/lib/active_record/callbacks.rb:298:incallback’
vendor/rails/activerecord/lib/active_record/callbacks.rb:206:in
create_or_update' vendor/rails/activerecord/lib/active_record/base.rb:2200:insave_without_validation’
vendor/rails/activerecord/lib/active_record/validations.rb:901:in
save_without_dirty' vendor/rails/activerecord/lib/active_record/dirty.rb:75:insave_without_transactions’
vendor/rails/activerecord/lib/active_record/transactions.rb:106:in
save' vendor/rails/activerecord/lib/active_record/connection_adapters/ abstract/database_statements.rb:66:intransaction’
vendor/rails/activerecord/lib/active_record/transactions.rb:79:in
transaction' vendor/rails/activerecord/lib/active_record/transactions.rb:98:intransaction’
vendor/rails/activerecord/lib/active_record/transactions.rb:106:in
save' vendor/rails/activerecord/lib/active_record/transactions.rb:118:inrollback_active_record_state!’
vendor/rails/activerecord/lib/active_record/transactions.rb:106:in
save' app/controllers/cities_controller.rb:39:increate’
app/controllers/cities_controller.rb:38:in `create’
script\server:3

the City model

class City < ActiveRecord::Base
belongs_to :country

validates_presence_of :name,:country
validates_uniqueness_of :name

attr_accessor :country

#here sould be all the automation happening
def before_validation_on_create
self.country_id = 0
end
end

4

Ok so I’ve figured out some thing
There is a problem between the belongs_to :country
and the attr_accessor :country

The names should be different
I hope from now on it’ll be a piece of cacke :wink: