Package io.permazen.annotation

Annotation Interface OnValidate

@Documented @Inherited @Retention(RUNTIME) @Target({ANNOTATION_TYPE,METHOD}) public @interface OnValidate
Annotates a Permazen model class method that should be invoked any time the associated model object is validated.

This annotation does not change when an object will be enqueued for validation. It only affects the behavior once validation of an instance is actually performed.

An optional list of validation groups() may be specified; if so, the annotated method will only be invoked when one or more of specified validation groups (or a superclass thereof) is being validated. In particular, if groups() is non-empty and does not contain a class that extends Default, then the method will not be invoked by automatic validation.

The annotated method must be an instance method (i.e., not static), return void, and take zero parameters. If validation fails, the method should throw a ValidationException.

"Fixup" Validations

Annotated methods are not restricted from performing additional mutating operations in the transaction. Therefore, in some cases, it may be possible for an annotated method to actually fix a validation problem, by modifying a field or even deleting the object.

However, by default Permazen invokes @OnValidate methods after the other validation checks (i.e., JSR 303 and uniqueness constraints). This makes it easier to write @OnValidate methods because one can assume those checks have already passed, but it also means it is too late fix any violations of those checks.

To have an @OnValidate method inovked prior to the other validation checks instead of after them, set early() = true. When doing this, be careful not to trigger infinite loops, as @OnChange notifications and @OnDelete notifications will still occur.

Meta-Annotations

This annotation may be configured indirectly as a Spring meta-annotation when spring-core is on the classpath.

See Also:

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    boolean
    early
    Specify when to invoke the annotated method relative to JSR 303 and uniqueness constraint validation.
    Class<?>[]
    groups
    Specify the validation group(s) for which the annotated method should be invoked.

  • Element Details

    • groups

      Class<?>[] groups
      Specify the validation group(s) for which the annotated method should be invoked.
      Returns:
      validation group(s) to use for validation; if empty, Default is assumed
      Default:
      {}

    • early

      boolean early
      Specify when to invoke the annotated method relative to JSR 303 and uniqueness constraint validation.

      If true, the annotated method will be invoked prior to JSR 303 and uniqueness constraint validation; if false, afterward.

      Returns:
      true to invoke the annotated method prior other validation checks
      Default:
      false