nil object in view when building objects on two different associations
- by Shako
Hello all. I'm relatively new to Ruby on Rails so please don't mind my newbie level!
I have following models:
class Paintingdescription < ActiveRecord::Base
belongs_to :paintings
belongs_to :languages
end
class Paintingtitle < ActiveRecord::Base
belongs_to :paintings
belongs_to :languages
end
class Painting < ActiveRecord::Base
has_many :paintingtitles, :dependent => :destroy
has_many :paintingdescriptions, :dependent => :destroy
has_many :languages, :through => :paintingdescriptions
has_many :languages, :through => :paintingtitles
end
class Language < ActiveRecord::Base
has_many :paintingtitles, :dependent => :nullify
has_many :paintingdescriptions, :dependent => :nullify
has_many :paintings, :through => :paintingtitles
has_many :paintings, :through => :paintingdescriptions
end
In my painting new/edit view, I would like to show the painting details, together with its title and description in each of the languages, so I can store the translation of those field.
In order to build the languagetitle and languagedescription records for my painting and each of the languages, I wrote following code in the new method of my Paintings_controller.rb:
@temp_languages = @languages
@languages.size.times{@painting.paintingtitles.build}
@painting.paintingtitles.each do |paintingtitle|
paintingtitle.language_id = @temp_languages[0].id
@temp_languages.slice!(0)
end
@temp_languages = @languages
@languages.size.times{@painting.paintingdescriptions.build}
@painting.paintingdescriptions.each do |paintingdescription|
paintingdescription.language_id = @temp_languages[0].id
@temp_languages.slice!(0)
end
In form partial which I call in the new/edit view, I have
<% form_for @painting, :html => { :multipart => true} do |f| %>
...
<% languages.each do |language| %>
<p>
<%= label language, language.name %>
<% paintingtitle = @painting.paintingtitles[counter] %>
<% new_or_existing = paintingtitle.new_record? ? 'new' : 'new' %>
<% prefix = "painting[#{new_or_existing}_title_attributes][]" %>
<% fields_for prefix, paintingtitle do |paintingtitle_form| %>
<%= paintingtitle_form.hidden_field :language_id%>
<%= f.label :title %><br />
<%= paintingtitle_form.text_field :title%>
<% end %>
<% paintingdescription = @painting.paintingdescriptions[counter] %>
<% new_or_existing = paintingdescription.new_record? ? 'new' : 'new' %>
<% prefix = "painting[#{new_or_existing}_title_attributes][]" %>
<% fields_for prefix, paintingdescription do |paintingdescription_form| %>
<%= paintingdescription_form.hidden_field :language_id%>
<%= f.label :description %><br />
<%= paintingdescription_form.text_field :description %>
<% end %>
</p>
<% counter += 1 %>
<% end %>
...
<% end %>
But, when running the code, ruby encounters a nil object when evaluating paintingdescription.new_record?:
You have a nil object when you didn't expect it!
You might have expected an instance of ActiveRecord::Base.
The error occurred while evaluating nil.new_record?
However, if I change the order in which I
a) build the paintingtitles and painting descriptions in the paintings_controller new method and
b) show the paintingtitles and painting descriptions in the form partial
then I get the nil on the paintingtitles.new_record? call.
I always get the nil for the objects I build in second place. The ones I build first aren't nil in my view.
Is it possible that I cannot build objects for 2 different associations at the same time? Or am I missing something else?
Thanks in advance!
