Question

I have been struggling on this for a couple days. I have this model:

class BusinessEntity < ActiveRecord::Base

  has_many :business_locations
  accepts_nested_attributes_for :business_locations, :allow_destroy => true,
        :reject_if => proc { |attributes| attributes.all? { |key, value| key == '_destroy' || value.blank? } }

 after_initialize :build_child

  ....

  def build_child
    self.business_locations.build if self.business_locations.empty?    
  end

business_entites.rb (factory)

FactoryGirl.define do
  factory :business_entity do
    name "DaveHahnDev"
    association :company, :factory => :company
    association :default_currency, :factory => :currency

    factory :business_entity_with_locations do
      after(:build) do |business_entity|
        business_entity.class.skip_callback(:create, :after, :set_primary_business_info)
        business_entity.business_locations << FactoryGirl.build(:business_location)
      end
    end
  end

  factory :business_location do
    name "Main Office"
    business_entity
    address1 "139 fittons road west"
    address2 "a different address"
    city { Faker::Address.city }
    province "Ontario"
    country "Canada"
    postal_code "L3V3V3"

  end
end

Now when I call FactoryGirl.create(:business_entity) in a spec I get valdation error on business_locations have blank attributes. This is the child initialized by the after_initialize callback. I thought the reject_if would take care of this, as it does if you use the application from a browser. If i add:

  before_validation :remove_blank_children

  def remove_blank_children
    self.business_locations.each do |bl|
        bl.mark_for_destruction if bl.attributes.all? {|k,v| v.blank?}
    end
  end

everything will pass fine, but I feel like I should not need to do this.

Is it possible I am testing this wrong, or is it bad practice to build children in the models.

Any thoughts will be a great help.

Answer 1

is it bad practice to build children in the models

Not necessarily, but I’d avoid after_initialize—it is executed on every instantiation of your model, even a straight find.

I think you’d be better off isolating the cases where you need to add a business_location and doing it explicitly. And as it seems that your business_entity_with_locations factory is doing exactly that, I’m not sure why you need the callback at all.

As for why the accepts_nested_attributes_for is not working, I believe that is because you are not using it. It expects an attribute hash like:

{ :business_locations => { 0 => { :name => “Sample Name } } }

to be passed into a method like new. That’s not what you’re doing—you’re calling build on the association without any parameters. So the attribute-setter logic provided by accepts_nested_attributes_for is never invoked.