<%= mark_required(@user, :email) %>

# module ApplicationHelper
#   def mark_required(object, attribute)
#     "*" if object.class.validators_on(attribute).map(&:class).include? ActiveModel::Validations::PresenceValidator
#   end
# end

   1. <%= form_for(@user) do |f| %>
   2.   <%= render "shared/error_messages", :target => @user %>
   3.   <div class="field">
   4.     <%= f.label :name %><%= mark_required(@user, :name) %><br />
   5.     <%= f.text_field :name %>
   6.   </div>
   7.   <div class="field">
   8.     <%= f.label :email %><%= mark_required(@user, :email) %><br />
   9.     <%= f.text_field :email %>
  10.   </div>
  11.   <div class="actions">
  12.     <%= f.submit %>
  13.   </div>
  14. <% end %>