module Padrino::Helpers::FormHelpers

def error_messages_for(*params)
  options = params.extract_options!.symbolize_keys
  objects = params.collect {|object_name| object_name.is_a?(Symbol) ? instance_variable_get("@#{object_name}") : object_name }.compact
  count   = objects.inject(0) {|sum, object| sum + object.errors.count }
  unless count.zero?
    html = {}
    [:id, :class].each do |key|
      if options.include?(key)
        value = options[key]
        html[key] = value unless value.blank?
      else
        html[key] = 'field-errors'
      end
    end
    options[:object_name] ||= params.first.class
    I18n.with_options :locale => options[:locale], :scope => [:models, :errors, :template] do |locale|
      header_message = if options.include?(:header_message)
        options[:header_message]
      else
        object_name = options[:object_name].to_s.gsub('_', ' ')
        object_name = I18n.t(object_name, :default => object_name, :scope => :models, :count => 1)
        locale.t :header, :count => count, :model => object_name
      end
      message = options.include?(:message) ? options[:message] : locale.t(:body)
      error_messages = objects.map {|object| object.errors.full_messages.map {|msg| content_tag(:li, msg) } }.join
      contents = ''
      contents << content_tag(options[:header_tag] || :h2, header_message) unless header_message.blank?
      contents << content_tag(:p, message) unless message.blank?
      contents << content_tag(:ul, error_messages)
      content_tag(:div, contents, html)
    end
  else
    ''
  end
end