Right, you'd want to try and use 2.3 Constraint composition from the
spec to keep from reimplementing the existing constraints.
-Donald
On 5/9/10 6:54 PM, Carlos Vara wrote:
> I liked your idea when I first read it, but then I realized it is quite
> similar to the payload solution with the disadvantage that you have to
> duplicate the parameters of the annotation that you are "extending".
>
> On its favour, I would say that IMHO, parameter duplication wouldn't be
> so terrible as hinted by the hibernate guys. At least in my experience,
> validation constraints get aggregated into domain definitions, so if you
> have for example a client code represented in a string, you wouldn't
> annotate it this way:
>
> @NotNull
> @Size(min=2,max=4)
> @Pattern(regexp="[1-4]*")
> String clientCode;
>
> As you would have to keep those annotations and their parameters
> synchronized in all the strings that represent a client code. You would do:
>
> @ClientCode
> String clientCode;
>
> @NotNull
> @Size(min=2,max=4)
> @Pattern(regexp="[1-4]*")
> ...
> public @interface clientCode {
> // very likely parameter less, as you don't want to keep parameters
> synchronized
> }
>
> So you would just need to add:
>
> @ClientCode
> @ListValidation
> public @interface clientCodeIterable {
> // groups, message and payload only, which are mandatory
> }
>
>
> Regards,
> Carlos
>
>
>
> LieGrue,
> strub
>
> --- Carlos Vara <[email protected] <mailto:[email protected]>>
> schrieb am Fr, 7.5.2010:
>
> Von: Carlos Vara <[email protected] <mailto:[email protected]>>
> Betreff: Re: An interesting post about validating collections
> An: [email protected]
> <mailto:[email protected]>
> Datum: Freitag, 7. Mai, 2010 17:54 Uhr
>
> IMHO it isn't business logic, but a pretty valid concern about
> something that the standard cannot currently solve.
>
> To explain myself, take the example given in Hibernate's blog, if
> emails weren't stored in a String but on their own class, we already
> have a solution with @Valid.
>
> public class User {
> @NotEmpty
> private String name;
>
> @NotEmpty
> @Valid
> private List<Email> emailList;
>
> }But if you want to validate a type which you cannot annotate, there
> is no "clean" way of doing it. Solving it by writing a custom
> validator like @ListOfEmailStrings (which is what I have been doing
> atm) is not a good solution as you have to replicate the validation
> logic of all the annotations that the individual email has.
>
>
> To put this in perspective, if a single email was annotated like this:
>
>
> @NotNull
> @Email
>
> String email;
>
>
> The custom validator for the list of emails will have to replicate
> the validation logic of those two constraints (as it should never
> instantiate the validators), and it would also have to be manually
> mantained to always validate your definition of an email.
>
>
> I personally think that implementing the first solution is a clean
> way of doing it and fits the role of the library. Of course, that
> involves waiting, but waiting to be able to do something right is
> never bad in my book :-)
>
>
>
> I hope that Hibernate guys don't rush a suboptimal solution like the
> other ones exposed, as it would be a clear point of incompatibility
> with Apache's version.
>
> Regards,
> Carlos
>
>
> On Fri, May 7, 2010 at 3:19 PM, Gerhard Petracek
> <[email protected] <mailto:[email protected]>> wrote:
>
>
> we are currently discussing it in the eg.maybe we should just wait
> for [1].
> regards,gerhard
> [1] http://openjdk.java.net/projects/type-annotations/
>
>
>
>
>
> http://www.irian.at
>
> Your JSF powerhouse -
> JSF Consulting, Development and
> Courses in English and German
>
> Professional Support for Apache MyFaces
>
>
>
>
> 2010/5/7 Mark Struberg <[email protected] <mailto:[email protected]>>
>
>
>
>
> I honestly think this goes into the wrong direction.
>
> This is business logic, and if we start to provide annotations for
> all those kinds of problems, it will end up getting terribly
> complicated.
>
>
>
> I'd prefer to keep it simple and stupid.
>
>
>
> LieGrue,
>
> strub
>
>
>
>
>
> >
>
> >Von: Carlos Vara <[email protected] <mailto:[email protected]>>
>
> >An: [email protected]
> <mailto:[email protected]>
>
> >Gesendet: Freitag, den 7. Mai 2010, 10:57:11 Uhr
>
> >Betreff: An interesting post about validating collections
>
> >
>
> >http://in.relation.to/Bloggers/AValidationStickler
>
> >
>
> >Currently as an user, I was solving this by writing custom
> validators, which it seems is no more of a hack than the other
> proposed solutions (except the one that implies waiting for JDK7 to
> hopefully implement JSR-308).
>
>
>
>
>
> >
>
> >Any of you guys have an idea of how we could implement it?
>
> >
>
>
>
>
>
>
>
>
>
>
>
>
>
>
