class RegexSettingValidator LOREM = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam eget sem non elit tincidunt rhoncus.'.freeze def initialize(opts={}) @opts = opts end def valid_value?(val) !val.present? || valid_regex?(val) end # Check that string is a valid regex, and that it doesn't match most of the lorem string. def valid_regex?(val) r = Regexp.new(val) matches = r.match(LOREM) matches.nil? || matches[0].length < (LOREM.length - 10) rescue false end def error_message I18n.t('site_settings.errors.invalid_regex') end end