Custom Restrictions

Custom Restrictions are restrictions that allow you to provide a validator class.

<simpleValueType name="Iban">
  <restrictions>
    <restriction name="IbanValidation" type="elements::CustomRestriction">
      <validators>
        <customRestrictionValidator>
          <technology name="JDK"/>
          <implementation>net.democritus.types.IbanValidator</implementation>
        </customRestrictionValidator>
      </validators>
    </restriction>
  </restrictions>
</simpleValueType>

Each CustomRestriction adds one or more validators, each of which are linked to the underlying technology.

Currently, JDK and EJB3 are supported.

• JDK: The validator will be added to the SharedValidator class and can only access java standard libraries.
• EJB3: The validator will be added to the ValidatorBean and has access to ejb-related classes.

Validator Class

The validator has to implement net.democritus.common.validation.Validator. This is an interface that requires 2 methods:

• setTopic(ValidationTopic) is used to pass down information surrounding the field.
• validate(T,ValidationReport) is called to validate the value of the field.

The validate method can add messages to the ValidationReport to describe issues.

  public void validate(String iban, ValidationReport report) {
    if (iban == null || iban.isEmpty()) return;
    try {
      IbanUtil.validate(iban.replace(" ", ""), IbanFormat.None);
    } catch (IbanFormatException | InvalidCheckDigitException | UnsupportedCountryException e) {
      ValidationMessage message = topic.message(e.getMessage());
      report.addValidationError(message);
    }
  }

The messages created with the ValidationTopic already contain a translation key and standard message. You can attach additional information by defining properties. If the message contains a placeholder (e.g. ${foo}), this will be replaced with the provided value.

ValidationMessage message = topic.message(e.getMessage())
    .property("foo", "bar");

TOPIC

Topics are defined in the Validator classes. They contain a translation key for the control layer, a reference to the field and readable error message for tracing.

  private final ValidationTopic nameStringLength = new ValidationTopic("space::Starship::name", "space.starship.name.stringLength", "This string should have a length shorter than ${maximum}.");

Custom Translation

Custom translations are expanded with a generic error message. But it is possible to provide your own translations by adding options <restriction.translation.{LANG}>:

<restriction name="IbanValidation" type="elements::CustomRestriction">
  <validators/>
  <options>
    <restriction.translation.nl>
      De ingevoerde IBAN waarde is niet correct. Gelieve de waarde na te kijken.
    </restriction.translation.nl>
    <restriction.translation.en>
      The entered IBAN number is invalid. Please check the number and try again.
    </restriction.translation.en>
  </options>
</restriction>