[hibernate-dev] [Validator] method level validation

Hi, forwarding this email to hibernate-dev to get some more feedback. Here are some of my thoughts. The method level validation is suggested in Appendix C of the Bean Validation specification. The method signatures there all return a set of ConstraintViolations. The question is how binding these signatures are. Root bean and property path are indeed questionable for method level validation. By extending ConstraintViolation you still have to deal with these values. Maybe instead of extending we should have a new interface MethodConstraintViolation. Emmanuel, do you have some more feedback on what was discussed regarding appendix C? --Hardy ------- Forwarded message ------- From: "Gunnar Morling" <gunnar.morling(a)googlemail.com&gt; To: "Hardy Ferentschik" <hibernate(a)ferentschik.de&gt; while working on method-level validation I wondered how to represent the failing validation of method parameters. I think javax.validation.ConstraintViolation in its current form is only partly suitable for the needs of parameter/return value validation: * The concept of property path seems not to fit right. How would the property path look for a failing parameter constraint? One could come up with something like "MyBean.MyMethod(String,Int).Parameters[1]" but I can't say I'd like that * The concept of a root bean does only fit partly. I think one would need a safe reference to the "root method" and the parameter index. A direct reference to the class hosting the validated method seems only partly useful (and could anytimes be retrieved from a Method reference). I therefore prototyped this into this direction: * Created a MethodConstraintViolation that extends ConstraintViolation by adding fields the causing method and the parameter index (one surely would add a flag or something in case of return value validation) * In case a constraint directly at one of a method's parameters fail, ConstraintViolation#rootBean and propertyPath are null (but method and parameterIndex are set) * In case a "cascading" constraint fails (meaning in this context, a parameter is annotated with @Valid and the referenced bean has constraints itself which in turn fail), method and parameterIndex are set, rootBean and propertyPath refer to parameter bean itself, *not* the class hosting the validated method WDYT, is this the right way to go? Maybe we should brainstorm a bit on IRC?