Question

I have form partial that allows the user to enter the subject and message that will be included in the outbound email. I want to allow the users to select the recipients of the email from the contacts that are associated with the invoice that the email belongs to. The email recipients that are selected through the nested form are to be stored in a separate table.

class EmailRecipient < ActiveRecord::Base
  attr_accessible :contact_id, :email_id

  belongs_to :email

end

class Email < ActiveRecord::Base
  attr_accessible :subject, :message, :invoice_id, :email_recipients_attributes

  belongs_to :invoice
  has_many :email_recipients

  accepts_nested_attributes_for :email_recipients

end

<%= simple_form_for [:invoice, @email], html: {class: "form-horizontal"} do |f| %>
  <%= f.error_notification %>

  <% @invoice.contacts do |c|%>
    <%= f.fields_for :email_recipients do |builder| %>
      <%= builder.input :contact_id, :as => :check_boxes %>
      <%= c.name %><br/>    
    <% end %>
  <% end %>

  <%= f.input :subject, :as => "string" %>
  <%= f.input :message, :input_html => { :class => 'span7', :rows => 10 } %>

  <div class="form-actions">
    <%= f.button :submit, "Send Invoice", :class => 'btn-warning' %>
    <%= link_to 'Cancel', invoice_path(@invoice), :class => 'btn' %>
  </div>
<% end %>

Answer 1

This isn’t the prettiest answer, so I would love to see a better solution, but it gets the job done until my skills improve.

In the controller for the parent form I added:

@invoice.contacts.each { |c| @email.email_recipients.build(contact_id: c.id) }

This builds the records for all contacts whether they are needed or not. Then in the form partial I modified the nested form:

<%= simple_form_for [:invoice, @email], html: {class: "form-horizontal"} do |f| %>
  <%= f.error_notification %>
  <% count = 0 %>
  <%= f.simple_fields_for :email_recipients do |email_recipients_form| %>
    <%= email_recipients_form.input :_destroy, as: :boolean, :label => false do %>
      <%= email_recipients_form.check_box :_destroy, {}, "false", "true" %>
      <% contact = @invoice.contacts.find(@email.email_recipients[count].contact_id) %>
      <%= contact.name + " (" + contact.email + ")" %>
    <% end %>
  <%= email_recipients_form.input :contact_id, as: :hidden %>
  <% count += 1 %>
<% end %>