Validator class for validating the absence of value in a field if other conditions are met.

absence_validator.rb

class AbsenceValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    return unless value

    if options.empty? # don't know why you would want this
      record.errors[attribute] << "must be blank"
    elsif options[:all] && options[:all].all? {|sym| record.read_attribute(sym)}
      record.errors[attribute] << "must be blank if the following attributes are defined: #{options[:all].join(', ')}"
    elsif options[:any] && options[:any].any? {|sym| record.read_attribute(sym)}
      record.errors[attribute] << "must be blank if any of the following attributes are defined: #{options[:any].join(", ")}"
    else
    end
  end
end