message method
Returns the validation error message.
Implementation
@override
String message(ValidationContext context) {
final value = context.value;
if (value is List<UploadedFile> && value.isEmpty) {
return 'file_required_validation';
}
// Check for specific filename errors if we could pass context info,
// but generic 'file_validation' is okay, or we can add specific errors.
return 'file_validation';
}