Add required mark to methods in a form.

form_builder.rb

#config/initializers/form_builder.rb

class ActionView::Helpers::FormBuilder
  alias :orig_label :label

  def label(method, content_or_options = nil, options = nil, &block)
    if content_or_options && content_or_options.class == Hash
      options = content_or_options
    else
      content = content_or_options
    end

    #This looks to see if allow blank is turned onn/of for the
    #attribute. Default it's set to true.
    allow_blank = true
    object.class.validators_on(method).map(&:options).each { |field_option|
      unless field_option.empty?
        if field_option.has_key?(:allow_blank)
          allow_blank = field_option[:allow_blank]
        end
      end
    }

    #puts "method:#{method}"
    #puts "allow_blank:#{allow_blank}"

    required_mark = ''
    required_mark = '<div class="required-field-icon"><i class="icon-exclamation-sign"></i></div>' if object.class.validators_on(method).map(&:class).include? ActiveModel::Validations::PresenceValidator
    required_mark = '<div class="required-field-icon"><i class="icon-exclamation-sign"></i></div>' if object.class.validators_on(method).map(&:class).include?(ActiveModel::Validations::InclusionValidator) && !allow_blank

    content ||= method.to_s.humanize
    content = (content + required_mark).html_safe

    self.orig_label(method, content, options || {}, &block)
  end
end