stuartbain

class SubdomainValidator < ActiveModel::EachValidator
  # http://matthewhutchinson.net/2010/10/27/rails-3-subdomain-validation-activemodeleachvalidator

  def validate_each(object, attribute, value)
    return unless value.present?
    reserved_names = %w(www ftp mail pop smtp admin ssl sftp)
    reserved_names = options[:reserved] if options[:reserved]
    if reserved_names.include?(value)
      object.errors[attribute] << 'cannot be a reserved name'
    end