nested_form, has_many :through, updating attribute on join model

Question

I\'m using ryan bates\' plugin nested_form and i have been trying to write my form for a has_many :through relationship.

I have 3 models:

Profile
          


        

Answer 1

As I saw here on StackOverflow with another question, I need to nest the hm => t like so

= f.fields_for :memberships do |mem|
= mem.fields_for :organisation do |org|
  .row
    .span5.org_name
      = org.input :name, :label => "Name of the Organization"
    .span5
      = mem.input :title, :label => "Title in the Organization"
  .row
    .span5
      = mem.input :starting_year, :label => "Starting Year"
    .span5
      = mem.input :ending_year, :label => "Ending Year"
  .row
    .span10
      = org.text_area :description, :label => "Description of Organisation"
= mem.link_to_remove "Remove this oranisation"
= f.link_to_add "Add an organisation", :memberships

BUt with Ryan Bates' plugin, the association to memberships organisations is not built as far as i can tell, so i created a new method like this:

     = f.link_to_add_hmt "Add an organisation", :organisation, :memberships

And then I pretty much just copied Ryan Bates' plugin verbatim adding a new parameter adding 2 lines below

def link_to_add_hmt(*args, &block)
  options = args.extract_options!.symbolize_keys
  association = args.pop
  association_two = args.pop
  options[:class] = [options[:class], "add_nested_fields"].compact.join(" ")
  options["data-association"] = association
  args << (options.delete(:href) || "javascript:void(0)")
  args << options
  @fields ||= {}
  @template.after_nested_form(association) do
    model_object = object.class.reflect_on_association(association).klass.new
    model_object.send(:"build_#{association_two}")
    output = %Q[
].html_safe
    output << fields_for(association, model_object, :child_index => "new_#{association}", &@fields[association])
    output.safe_concat('
')
    output
  end 
  @template.link_to(*args, &block)
end 

Look for the references to "association_two". This works great!