[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=43148#comment-43148 ] 

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

Well unfortunately I have to work with JSF1.2 and JBoss5.1 since my customer doesn't want to work with a community edition of JBoss. However CDI could solve the issue although it would not be a real call context. May be even with JSF or JPA some of the call's context could be worth forwarding to the ConstraintValidator (e.g. Principal, Session, PersistenceUnit) but this should be the developer's decision. Note that this contextual information could not be necessary for the validation itself but for the message interpolation. Especially when validating object graphs it is important to tell the user what exactly went wrong. Recently I had to customize the message interpolation to point out which of hundreds records in a object hierarchy was invalid (the object could only be identified by its position in the hierarchy). I think we should focus on the message interpolation and it's extensibility. WDYT?

> 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
>
> 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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