validation problems

[gnulp]

I have created a page with two forms. Both form buttons are calling two actionMethods in the same statefull session bean on the server. The stateful session bean injects two entities with the @In and @Valid statement for childbeanvalidation.

Here I try to reduce my case for simplicity ...

@Stateful
@Name("myController")
@Interceptors(SeamInterceptor.class)
public class MyController {

 // this entity will be set from form-1
 @In(value="user",create=true)
 @Valid
 protected User user;

 // this entity will be set from form-2
 @In(value="address",create=true)
 @Valid
 protected Address address;

 // this should handle form one
 public String pressButtonOneHandlingUsers() {
 ... do something ...
 }

 // this should handle form two
 public String pressButtonTwoHandlingAddress() {
 ... do something ...
 }
}

Now to the problem: If I press button-1 both entities are injected ! The user-entity-properties which are filled from form-1 are set correctly with no errors, but the address-entity-properties beeing set from form-2 complains about validation errors - what is of course true, because form-2 is empty and not used, yet.
Is there a way to do the validation for a specific entity when a method is called ?

Thx for help ...

[gnulp]

sorry - simplified too much - I lost the @IfInvalid-annotations ;-)
here is the code again ...

@Stateful
@Name("myController")
@Interceptors(SeamInterceptor.class)
public class MyController {

 // this entity will be set from form-1
 @In(value="user",create=true)
 @Valid
 protected User user;

 // this entity will be set from form-2
 @In(value="address",create=true)
 @Valid
 protected Address address;

 // this should handle form one
 @IfInvalid(outcome=Outcome.REDISPLAY)
 public String pressButtonOneHandlingUsers() {
 ... do something ...
 }

 // this should handle form two
 @IfInvalid(outcome=Outcome.REDISPLAY)
 public String pressButtonTwoHandlingAddress() {
 ... do something ...
 }
}

[patrick_ibg]

You're example won't work, because validation is applied to all the fields marked @Valid.

You might be able to trick it out by setting the field value to null if you don't want it validated. However, you have to do this *before* the pressButtonXXX methods are invoked by SEAM, which is tricky.

It's much easier (and better design) to have two controller classes, one for each "button".

[gnulp]

you are right - sometimes its better and easier to have a controller for each button, but sometimes not !
What if you want the actions to interact on shared variables ? So you would have to introduce a number of interfaces and classes for a simple interaction of two business-actions ...

I believe, that for generosity, a framework should offer all possible variations and not force an architect/developer into a specific direction.

thx for your "tricky" advice - maybe I can find another solution - I will let you know ...

[sunfire]

Not a solution to your problem but a feature request:
wouldn't it be nice to add more granularity to the @Valid and @IfInvalid annotations so that you would be able to exactly specify what @Valid annotation should be validated with a call to a specific @IfInvalid annotation.

Example:

@Stateful
@Name("myController")
@Interceptors(SeamInterceptor.class)
public class MyController {

 // this entity will be set from form-1
 @In(value="user",create=true)
 @Valid(targets={"Objects, "moreObjects"})
 protected User user;

 // this entity will be set from form-2
 @In(value="address",create=true)
 @Valid(targets={"moreObjects"})
 protected Address address;

 // this should validate user
 @IfInvalid(validate="Objects",outcome=Outcome.REDISPLAY)
 public String pressButtonOneHandlingUsers() {
 ... do something ...
 }

 // this should validate user and address
 @IfInvalid(validate="moreObjects",outcome=Outcome.REDISPLAY)
 public String pressButtonTwoHandlingAddress() {
 ... do something ...
 }
}

I at least would love to see this feature since it opens up a quite flexible way for validation in multiple-step-wizzard like applications. :)

Cheers, Thorsten

[gnulp]

cheers - great idea - i would also love to have this flexibility ...

what you suggest is to setup validation-groups that can individually be triggerd with the @IfInvalid annotation.

I had a look at the sources, and what I saw is, that this change would not only be part of seam but also reflect into the ClassValidator-Implementation of hibernate-annotations ... (at least I think so, but I am not an expert in this area !!!)

Any ideas/help ???

[patrick_ibg]

The way I understand it, this can be handled completely within SEAM. The @Valid annotation is specific to the Hibernate validator. However, the @IfInvalid is all SEAM. My variation on the idea is to change @IfInvalid as follows

@Stateful
@Name("myController")
@Interceptors(SeamInterceptor.class)
public class MyController {

 // this entity will be set from form-1
 @In (value="user",create=true)
 protected User user;

 // this entity will be set from form-2
 @In (value="address",create=true)
 protected Address address;

 // this should validate user
 @IfInvalid (name="user", outcome=Outcome.REDISPLAY)
 public String pressButtonOneHandlingUsers() {
 ... do something ...
 }

 // this should validate user and address
 @IfInvalid (name="address", outcome=Outcome.REDISPLAY)
 public String pressButtonTwoHandlingAddress() {
 ... do something ...
 }
}

IfInvalid could also take a "names" parameter:
@IfInvalid (names={"address","user"}, outcome= ...)

[js8523]

but obviously default to all @Valid annotated fields, when nothing is defined.

James

[gnulp]

yes, looks nice but regarding sources - seam is just using the @IfInvalid annotation to trigger the hibernate-validation. Unfortunatelly all the loops take place in the hibernate-code where all @Valid flags are processed - there our new nice @IfInvalid-syntax is not known ;-)

Gavin - you are the king of validations/annotations as I saw you wrote both classes - do you see a simple solution without touching both sources (seam and hibernate-annotation) ?

thx for help ...

[gavin.king]

Emmanuel is now king of validations ;-)

I must say I don't love the proposed solution (kinda complex).


Is there a better way?

[gnulp]

any idea is welcome - currently i don't see a simpler solution, but I think functionality like that is needed as the example shows ...

consider we have 100 buttons in the frontend - do we really need 100 Controllers in the serverside - just for validation ?

As I said - any better idea than this is welcome, because I need a solution. The only thing I don't like is that this influences both libraries ...

Maybe I can write a patch deriving from the original ClassValidator - I will have a look - any help is appriciated ...

thx

[gnulp]

well it's done - I made a patch now using jira-135 patch from Marvin van Schalkwyk who implemented a plugabble factory for custom validations ...

I tried to derive from hibernates ClassValidator but without success - too many private variables and procedures ...

Thus created a SeamClassValidator of my own (nearly a copy of hibernate ClassValidator with small changes ...) and plugged it into Marvins patch (nice work ;-) ...

the syntax now is as follows ...

@Stateful
@Name("myController")
@Interceptors(SeamInterceptor.class)
public class MyController {

 // this entity will be set from form-1
 @In (value="user",create=true)
 @Valid
 protected User user;

 // this entity will be set from form-2
 @In (value="address",create=true)
 @Valid
 protected Address address;

 /**
 * this only validates user in contrast to the original implementation
 * where user and address was validated
 **/
 @IfInvalid (validate={"user"}, outcome=Outcome.REDISPLAY)
 public String pressButtonOneHandlingUsers() {
 ... do something ...
 }

 // this should validate user and address
 @IfInvalid (validate={"address","user"}, outcome=Outcome.REDISPLAY)
 public String pressButtonTwoHandlingAddressAndUser() {
 ... do something ...
 }

 /**
 * this should also validate user and address, because the default
 * is the same as it was without the patch ...
 */
 @IfInvalid (outcome=Outcome.REDISPLAY)
 public String pressButtonThreeHandlingAddressAndUser() {
 ... do something ...
 }
}

If anybody is interested in the patch I can deliver it - I would suggest to add the patch to jira-135, beause I had to make minor changes to the this patch, too

give me a short notice please ...

thx

[sunfire]

I'd be very interested to take a look at it. Is there a download link?

Thanks, Thorsten

[gnulp]

ahh - forgot to update the forum - i added the patch to jira-135, give me feedback if the patch itself works ... you need the latest cvs and can then use the @IfInvalid-patch, that also includes the validate-patch ... at least it worked for me ;-)

[epbernard]

I don't want to put that in Hibernate Validator because it mixes invariant constraints and GUI "partial" validation concerns.

Plus these static definitions does not allow you to do:
Valid a if button 1 is pressed
Valid b if button 2 is pressed
Valid a and b is button 3 is pressed
If you have 1 controller for both that's because they are correlated and my use case will arise at some point.