gistfile1.rb

module Bureaucrat
  module Quickfields
    def date(name, options = {})
      field name, DateField.new(options)
    end
  end

  module Fields
    class DateField < RegexField
      DATE_RE = %r{^(19|20)\d\d[- /.](0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])$}

      set_error :invalid, "Enter a valid date (YYYY-MM-DD)"

      def initialize(options = {})
        super(DATE_RE, options)
      end

      def widget_attrs(widget)
        { :class => 'datepicker' }
      end

      def clean(value)
        value = super(value)
        Date.parse(value)
      end
    end
  end
end