Validating User Input - Stripes...and Java Web Development is Fun Again - page 84

Previous validation errors?

yes

when=ValidationState ? no

ALWAYS

call methods
annotated with
@ValidationMethod

NO_ERRORS

errors

ValidationErrorHandler {
Resolution handleValidationErrors(
ValidationErrors errors);

no errors

}

errors no errors

use returned Resolution
or getSourcePage()

Execute
event handler

Figure 4.9: Custom validation methods

For example, we might be adding a record in a database and we won't
know whether there is a duplication error until the operation returns
or throws an exception:

try {
database.add(record);
// all is well

}
catch (DuplicateRecordException) {
// validation error: duplicate record

}