nested form in simple_form

ruby

# app/models/building.rb
class Building < ActiveRecord::Base
  has_many :people, :dependent => :destroy

  accepts_nested_attributes_for :people, :allow_destroy => true
end

# app/views/buildings/_form.html.erb

<%= simple_form_for(@building) do |f| %>
  <%= f.input :name %>

  <%= f.simple_fields_for :people do |builder| %>
    <%= render 'person_fields', :f => builder %>
  <% end %>

  <%= f.submit %>
<% end %>

# app/views/buildings/_person_fields.html.erb

<%= f.input :firstname, :label => t("simple_form.labels.person.firstname") %>
<%= f.input :surname, :label => t("simple_form.labels.person.surname") %>