Create new own custome Listener

Support
#1

Hello

How can we Override addTypedValueChangeListener with custom Listener. Currently we are using the Jmix inbuild listener with valueChangeMode=“EAGER” while changing the value from textField every time new request is created in that request the value is visible in plain text how can we fixed this or creating new custom listener we can handal this.

#3

Hello,

In Jmix you don’t typically “override” the built‑in addTypedValueChangeListener directly, but you can replace or supplement it in several ways:

1. Switch from EAGER to LAZY or ON_BLUR mode

This immediately stops a network request on every keystroke (and the plain‑text value in each request):

// in your screen controller or init()
textField.setValueChangeMode(ValueChangeMode.LAZY);
textField.setValueChangeTimeout(300);  // wait 300 ms after typing stops
// —or—
textField.setValueChangeMode(ValueChangeMode.ON_BLUR);

2. Unbind the default and bind manually with your own listener

If you need full control over when and how the value is reported to your backing data:

// 1) Remove the Jmix binder’s auto‑binding aka `com.vaadin.flow.data.binder.Binder`
binder.removeBinding(textField);

// 2) Re‑bind and attach your own ValueChangeListener
binder.forField(textField)
      .withValidator( /* … */ )
      .bind(OrderItem::getName, OrderItem::setName);

// 3) Add your custom listener
textField.addValueChangeListener(event -> {
    // your logic here
});

3. Extend the component and wrap the listener registration

Create your own subclass of TextField to intercept any listener that gets added:

public class CustomTextField extends TextField {

    @Override
    public Registration addValueChangeListener(ValueChangeListener<? super ComponentValueChangeEvent<TextField, String>> listener) {
        ValueChangeListener<ComponentValueChangeEvent<TextField, String>> wrapped
                = e -> {
            // pre‑processing
            listener.valueChanged(e);
            // post‑processing or suppression
        };

        return super.addValueChangeListener(wrapped);
    }
}

Then register it in Spring so views pick up CustomTextField instead of the stock one (using a ComponentProvider bean or a Jmix UI component alias).

4. (Advanced) Client‑side JS listener

If you really want to catch browser events before Vaadin’s wiring:

// in the screen controller
textField.getElement().executeJs(
  "this.addEventListener('input', e -> $0.$server.onInput(e.target.value));",
  getElement()
);

@ClientCallable
public void onInput(String value) {
    // only your code runs—no Jmix binder involvement
}

In most cases switching to LAZY or ON_BLUR mode will solve the “plain‑text on every request” problem. If you still need custom handling, unbind/bind yourself or extend the component as shown above.

If you have more questions, reply this thread.

Best regards,
Dmitry