Custom Restrictions

Custom Restrictions are restrictions that allow you to implement the business rules yourself in 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 is 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>

Validator Class​

Custom Translation​

Validator Class

Custom Translation