Eu acabei de entrarhas_many :through Associação. Estou tentando implementar a capacidade de salvar dados para todas as 3 tabelas (Physician, Patient e tabela de associação) através de um único formulário.

Minhas migrações:

class CreatePhysicians < ActiveRecord::Migration
  def self.up
    create_table :physicians do |t|
      t.string :name
      t.timestamps
    end
  end
end

class CreatePatients < ActiveRecord::Migration
  def self.up
    create_table :patients do |t|
      t.string :name
      t.timestamps
    end
  end
end

class CreateAppointments < ActiveRecord::Migration
  def self.up
    create_table :appointments do |t|
      t.integer :physician_id
      t.integer :patient_id
      t.date :appointment_date
      t.timestamps
    end
  end
end

Meus modelos:

class Patient < ActiveRecord::Base
  has_many :appointments
  has_many :physicians, :through => :appointments
  accepts_nested_attributes_for :appointments
  accepts_nested_attributes_for :physicians
end
class Physician < ActiveRecord::Base
  has_many :appointments
  has_many :patients, :through => :appointments
  accepts_nested_attributes_for :patients
  accepts_nested_attributes_for :appointments
end
class Appointment < ActiveRecord::Base
  belongs_to :physician
  belongs_to :patient
end

Meu controlador:

def new
    @patient = Patient.new
    @patient.physicians.build
    @patient.appointments.build
end

Minha visão (new.html.rb):

<% form_for(@patient) do |patient_form| %>
  <%= patient_form.error_messages %>
  <p>
    <%= patient_form.label :name, "Patient Name" %>
    <%= patient_form.text_field :name %>
  </p>
  <%  patient_form.fields_for :physicians do |physician_form| %>
    <p>
      <%= physician_form.label :name, "Physician Name" %>
      <%= physician_form.text_field :name %>
    </p>
 <% end %>

  <p>
    <%= patient_form.submit 'Create' %>
  </p>
<% end %>

<%= link_to 'Back', patients_path %>

Eu sou capaz de criar um novoPatient, Physician e registro associado para umAppointment, mas agora eu quero ter campo paraappointment_date também na forma. Onde devo colocar campos paraAppointments e quais alterações são necessárias no meu controlador? Eu tentei googling e tenteiisto, mas ficou preso em algum erro ou outro tipo de implementação.