error_messages_for

gistfile1.rb

def error_messages_for(resource)
  return "" if resource.errors.empty?

  messages = resource.errors.full_messages.map { |msg| content_tag(:li, msg) }.join
  sentence = "Please fix the following errors:"

  html = <<-HTML
  <div class="error_explanation">
    <div class="title">#{sentence}</div>
    <ul>#{messages}</ul>
  </div>
  HTML

  html.html_safe
end