Polymorphism, acts_as_relation gem and nested attributes

I have the following polymorphic association set up with acts_as_relation (https://github.com/hzamani/acts_as_relation)

Model code:

    class Email < ActiveRecord::Base       belongs_to :detail       validates_presence_of :address     end

    class Detail < ActiveRecord::Base       acts_as_superclass       has_many :emails       accepts_nested_attributes_for :emails, allow_destroy: true     end

    class User < ActiveRecord::Base       acts_as :detail       validates_presence_of :username, :password     end

Migration code:

    class CreateInfo < ActiveRecord::Migration       def change         create_table :details, :as_relation_superclass => true do |t|           t.timestamps         end       end     end

    class CreateEmails < ActiveRecord::Migration       def change         create_table :emails do |t|           t.string :address           t.string :address_type           t.string :detail_id

          t.timestamps         end       end     end

    class CreateUsers < ActiveRecord::Migration       def change         create_table :users do |t|           t.string :name           t.string :username           t.string :password

          t.timestamps         end       end     end

I'm want to be able to have a form (eventually) that will allow multiple email addresses, addresses and so on. But I'm struggling to get it to work. I use HAML for whoever may reply with the view code, which is a lot more readable.

I have the form currently something like this:

    views/users/_form.html.haml

    = form_for(@user) do |f|       - if @user.errors.any?         #error_explanation           %h2             = pluralize(@user.errors.count, "error")             prohibited this user from being saved:           %ul             - @user.errors.full_messages.each do |msg|               %li= msg       .field         = f.label :name         = f.text_field :name       .field         = f.label :username         = f.text_field :username       .field         = f.label :password         = f.text_field :password       = f.fields_for :emails do |ff|         .field           = ff.label :address, 'Email address'           = ff.text_field :address         .field           = ff.label :address_type, 'Type'           = ff.text_field :address_type       .actions         = f.submit

Attachments: http://www.ruby-forum.com/attachment/7227/polymorphic-asso.jpg