Problems with object reflection in nested form with has_many association - ruby-on-rails

Question

I'm trying to implement the has_many pattern shown in "Ruby on Rails Nested Attributes". I'm combining it with some of my own methods and know exactly where it's raising an exception and why. I just don't know how to fix it. I'm using accepts_nested_attributes. I have a class called ProfilePhones.
In profile_email.rb:
def self.attrs
column_names.map(&:to_sym) - [:created_at, :updated_at]
end
The use the above for nested attributes so if the model changes it doesn't break the other controller. In the profiles_controller.rb I have:
def profile_params
params.require(:profile).permit(.... profile_phones_attributes: ProfilePhone.attrs)
In the Profile views folder, I have _profile_email_fields.html.erb with the fields for the ProfilePhone records:
<%= f.text_field :kind, placeholder: "Type" %>
<%= f.text_field :email_address, placeholder: "Email" %>
There's a bit more in this partial, but I'm simplifying it because the partial functions fine. In the main _form partial I have the following:
<%= f.fields_for :profile_emails do |f| %>
<%= render 'profile_email_fields', f: f %>
<%= link_to_add_fields('Add Another Email', f, :profile_emails) %>
<% end %>
In application_helper.rb:
def link_to_add_fields(name = nil, f = nil, association = nil, options = nil, html_options = nil, &block)
f, association, options, html_options = name, f, association, options if block_given?
options = {} if options.nil?
html_options = {} if html_options.nil?
if options.include? :locals
locals = options[:locals]
else
locals = { }
end
if options.include? :partial
partial = options[:partial]
else
partial = association.to_s.singularize + '_fields'
end
new_object = f.object.class.reflect_on_association(association).klass.new
fields = f.fields_for(association, new_object, child_index: 'new_record') do |builder|
render(partial, locals.merge!( f: builder))
end
html_options['data-form-prepend'] = raw CGI::escapeHTML( fields )
html_options['href'] = '#'
content_tag(:a, name, html_options, &block)
end
Finally, in the profiles.coffee:
$('[data-form-prepend]').click (e) ->
obj = $($(this).attr('data-form-prepend'))
obj.find('input, select, textarea').each ->
$(this).attr 'name', ->
$(this).attr('name').replace 'new_record', (new Date).getTime()
return
obj.insertBefore this
false
The problem is in the application_helper method above on the following line:
new_object = f.object.class.reflect_on_association(association).klass.new
f.object.class returns:
ProfileEmail(id: integer, kind: string, email_address: string, profile_id: integer, created_at: datetime, updated_at: datetime)
association is set as :profile_emails. The problem is that this produces Nil. Also, I need to reflect on the model it belongs to Profile. When I switch out with:
Profile.reflect_on_association(association).klass.new
It returns:
-> #<ProfileEmail id: nil, kind: nil, email_address: nil, profile_id: nil, created_at: nil, updated_at: nil>
Which is what I want. However, when I go to the view and click on 'Add another email' link nothing happens. This probably an issue either with my coffeescript or a consequence of calling Profile explicitly. I'm not sure.
My two problems are:
In my reflection method I should be reflecting on Profile and not Profile email, but I'm not sure how to fix it. I can get a string of the profile name, but that doesn't help.
When I explicitly call Profile in the helper method, nothing happens.

Answer 1

one problem seems to be that you have shadowing variable names for the form_builder parameter here:
<%= f.fields_for :profile_emails do |f| %>
<%= render 'profile_email_fields', f: f %>
<%= link_to_add_fields('Add Another Email', f, :profile_emails) %>
<% end %>
try changing to
<%= f.fields_for :profile_emails do |ff| %>
<%= render 'profile_email_fields', f: ff %>
<%= link_to_add_fields('Add Another Email', f, :profile_emails) %>
<% end %>