Vaadin Validate date, not empty - vaadin

Question

Im trying to write validation in Vaadin but I don't understand how to check if date field is empty
I wrote something like this
#Override
public void setConfiguration(EditorConfiguration editorConfiguration) {
boolean required = ((DateFieldConfiguration) editorConfiguration).isRequired();
if (required == true) {
setRequiredIndicatorVisible(true);
addValueChangeListener(event -> validate(event.getSource().getDefaultValidator(), event.getValue()));
}
}
private void validate(Validator<LocalDate> defaultValidator, LocalDate localDate) {
binder.forField(this).withValidator(validator).asRequired("Mandatory").bind(s -> getValue(),
(b, v) -> setValue(v));
}
I have achived a validation with a text field:
String Validator code
public class VaadinStringEditor extends TextField implements HasValueComponent<String> {
/**
*
*/
private static final long serialVersionUID = 6271513226609012483L;
private Binder<String> binder;
#PostConstruct
public void init() {
setWidth("100%");
binder = new Binder<>();
}
#Override
public void initDefaults() {
setValue("");
binder.validate();
}
#Override
public void setConfiguration(EditorConfiguration editorConfiguration) {
Validator<String> validator = ((TextFieldConfiguration) editorConfiguration).getValidator();
if (validator != null) {
binder.forField(this).withValidator(validator).asRequired("Mandatory").bind(s -> getValue(),
(b, v) -> setValue(v));
}
and I valid it here:
question.setEditorConfiguration(new TextFieldConfiguration(textRequiredValidator()));
Validator:
private Validator<String> textRequiredValidator() {
return Validator.from(v -> v != null && StringUtils.trimAllWhitespace((String) v).length() != 0,
, "Not empty");
}

Answer 1

You should use com.vaadin.ui.DateField for LocalDate values. Have a look at the following example.
Example bean:
public class MyBean {
private LocalDate created;
public LocalDate getCreated() {
return created;
}
public void setCreated(LocalDate created) {
this.created = created;
}
}
Editor
DateField dateField = new DateField("Date selector");
binder.forField(dateField)
.bind(MyBean::getCreated, MyBean::setCreated);
If for some reason you would like to have com.vaadin.ui.TextField for editing date, then you need to set converter like this:
Binder<MyBean> binder = new Binder<>();
TextField textDateField = new TextField("Date here:");
binder.forField(textDateField)
.withNullRepresentation("")
.withConverter(new StringToLocalDateConverter())
.bind(MyBean::getCreated, MyBean::setCreated);
Converter implementation:
public class StringToLocalDateConverter implements Converter<String, LocalDate> {
#Override
public Result<LocalDate> convertToModel(String userInput, ValueContext valueContext) {
try {
return Result.ok(LocalDate.parse(userInput));
} catch (RuntimeException e) {
return Result.error("Invalid value");
}
}
#Override
public String convertToPresentation(LocalDate value, ValueContext valueContext) {
return Objects.toString(value, "");
}
}
Note that this converter does not utilise ValueContext object that contains information that should be taken into account in more complex cases. For example, user locale should be handled.