Micronaut + Thymeleaf Form Validation and Error Handling - groovy

Question

Question: This doesn't seem to work.
#Post("/register")
#Consumes(MediaType.APPLICATION_FORM_URLENCODED)
#View("register")
#Error(exception = ConstraintViolationException.class)
def register(HttpRequest<?> request, ConstraintViolationException constraintViolationException) {
Optional<RegisterFormData> registerFormDataOptional = request.getBody(RegisterFormData.class)
Map<String, Object> map = new HashMap<>()
if(registerFormDataOptional.isPresent()){
RegisterRequest registerRequest = new RegisterRequest(registerFormDataOptional.get().properties)
registerRequest.returnSecureToken = true
try {
def registerResponse = firebaseClient.register(registerRequest, this.firebaseApiKey).blockingSingle()
SendEmailVerificationRequest sendEmailVerificationRequest = new SendEmailVerificationRequest()
sendEmailVerificationRequest.requestType = 'VERIFY_EMAIL'
sendEmailVerificationRequest.idToken = registerResponse.idToken
firebaseClient.sendEmailVerification(sendEmailVerificationRequest, this.firebaseApiKey)
HttpResponse.redirect(URI.create('/register-success'))
}catch(HttpClientResponseException ex){
map.put('errors', [ex.message])
return map
}
}else{
map.put('errors', violationMessageSource.violationsMessages(constraintViolationException.constraintViolations))
return map
}
}
gives me a
{"message":"Required argument [ConstraintViolationException constraintViolationException] not specified","path":"/constraintViolationException","_links":{"self":{"href":"/auth/register","templated":false}}}
Currently using Micronaut and Thymeleaf. Anyone know what else am I missing? I was following the examples from https://guides.micronaut.io/micronaut-error-handling/guide/index.html
The whole point here is to pass some error messages from the controller back to the UI when constraint violations happen. The default one that uses annotations #Body and #Valid don't work since it returns json errors without any views.

Answer 1

#Inject
Validator validator
#Inject
ViolationMessageSource violationMessageSource
#Post("/register")
#Consumes(MediaType.APPLICATION_FORM_URLENCODED)
def register(HttpRequest<?> request, #Body RegisterFormData registerFormData) {
//validate registerformdata object
Map<String, Object> map = new HashMap<>()
Set<ConstraintViolation<RegisterFormData>> violations = validator.validate(registerFormData)
if (violations.size() > 0) {
map.put('registerFormData', registerFormData)
map.put('errors', violationMessageSource.violationsMessages(violations))
HttpResponse.redirect(URI.create('/register')).body(map)
} else {
RegisterRequest registerRequest = new RegisterRequest(registerFormData.properties)
registerRequest.returnSecureToken = true
try {
def registerResponse = firebaseClient.register(registerRequest, this.firebaseApiKey).blockingSingle()
SendEmailVerificationRequest sendEmailVerificationRequest = new SendEmailVerificationRequest()
sendEmailVerificationRequest.requestType = 'VERIFY_EMAIL'
sendEmailVerificationRequest.idToken = registerResponse.idToken
firebaseClient.sendEmailVerification(sendEmailVerificationRequest, this.firebaseApiKey)
HttpResponse.redirect(URI.create('/register-success'))
} catch (HttpClientResponseException ex) {
map.put('errors', [ex.message])
HttpResponse.redirect(URI.create('/register')).body(map)
}
}
}
where I have injected a validator bean in Micronaut like so
#Factory
class ValidatorConfig {
Validator validator
#PostConstruct
void initialize(){
ValidatorFactory factory = Validation.buildDefaultValidatorFactory()
validator = factory.getValidator()
}
#Bean
Validator getValidator(){
return validator
}
}
and my message source like so
#Singleton
public class ViolationMessageSource {
public List<String> violationsMessages(Set<ConstraintViolation<?>> violations) {
return violations.stream()
.map(ViolationMessageSource::violationMessage)
.collect(Collectors.toList());
}
private static String violationMessage(ConstraintViolation violation) {
StringBuilder sb = new StringBuilder();
Path.Node lastNode = lastNode(violation.getPropertyPath());
if (lastNode != null) {
sb.append(lastNode.getName());
sb.append(" ");
}
sb.append(violation.getMessage());
return sb.toString();
}
private static Path.Node lastNode(Path path) {
Path.Node lastNode = null;
for (final Path.Node node : path) {
lastNode = node;
}
return lastNode;
}
}
The answers are based on the fundamentals on javax validation https://www.baeldung.com/javax-validation and error handling in micronaut https://guides.micronaut.io/micronaut-error-handling/guide/index.html