[hibernate-issues] [Hibernate-JIRA] Commented: (BVAL-233) Provide additional including custom variables for message interpolation

[Rene Grob (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/BVAL-233?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=43742#comment-43742 ] 

Rene Grob commented on BVAL-233:
--------------------------------

Well a ClassLoaderService is specific and clear but only solve one particular problem while a call context is more flexible but less explicit.What kind of object should be passed with the call. A generic Map or something more explicit while still extensible? May be internally a Map or Object array could be used but externally a certain Interface or Key has to be used to access it.
However resolving resources is probably a thing that does not need to be decided per call and therefore can be configured in the validation factory.

Note about the call context: The same problem exists for JPA entity listeners: You cannot pass the current user or other call specific context to the entity listener. There are a lot of workarounds in the web using a ThreadLocal variable to emulate this missing parameter. That's not what JEE should be teaching us...

> Provide additional including custom variables for message interpolation
> -----------------------------------------------------------------------
>
>                 Key: BVAL-233
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/BVAL-233
>             Project: Bean Validation
>          Issue Type: New Feature
>          Components: spec-general
>         Environment: See https://forum.hibernate.org/viewtopic.php?f=26&t=1011431
>            Reporter: Emmanuel Bernard
>         Attachments: BeanValidator.java, ExtendedMessageInterpolatorContext.java, ExtendedResourceBundleMessageInterpolator.java, IExtendedMessageInterpolatorContext.java
>
>
> I'm using the Hibernate Validators since the day it got released. I wrote some extensions which also might be useful to other users:
> I extended the MessageInterpolator so that I can use the rootBean, leafBean and the invalidValue in the message templates. Further I added support for nested properties. Here are some samples for (extended) message templates: - "The age of {leafBean.firstname} {leafBean.lastname} must be between {min} and {max} but is {invalidValue}." => "The age of John Doe must be between 18 and 65 but is 17." - "Error on {rootBean}: The the transaction's ({leafBean.transactionId}) amount ({invalidValue}) is too low." - "{invalidValue} is not a valid account number." While this information is unnecessary while you are typing the data and see the whole record, it might be essential if the input is a file and the message is written to a log.
> It would also useful to provide some custom properties in the MessageInterpolator context:
> beanValidator.validateValue(Person.class, "firstName", person.getFirstName); ... ctx.put("fieldName", "first name"); msgInterpolator.interpolate(constraintViolation.getMessageTemplate(), ctx); - "The field '{context.fieldName}' must not be empty."
> While the leafBean is available as "validatedValue" in the MessageInterpolator.Context, I had to extend the context to provide the other values.
> The validator has only access to the validated object and the annotation. It is not always possible and reasonable to set the context information on the validated object. It would be good to have some context available in the validator. Now I pass the context information through a threadlocal variable which is very ugly and error prone. E.g. a validator could check if a value is equal to an entry of a dynamic list which depends on the context.
> Sometimes it would be useful to pass some context to the validator:
> {code}
> validateBean(Object validationContext, T object, Class<?>... groups)
> validateProperty(Object validationContext, T object, String propertyName, Class<?>... groups);
> ...
> public class MyValidator implements javax.validation.ConstraintValidator<MyConstraint, MyObject> {
>    public boolean isValid(MyObject myObject, ConstraintValidatorContext context) {
>             ((MyService) context.getValidatorContext()).doSomeComplexValidation(myObject);
>         }
> {code}
> Of course time consuming validation should not be triggered too often. A constaint causing such a validation would typically not define the Default.class group.
> See also:
> http://relation.to/Bloggers/JSRBeanVali ... mment19490
> Regards René

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