Putting TextField to LAZY value change mode causes and obsolete server round-trip, even if the textfield is not used

[mstahv]

Description of the bug

Putting TextField to LAZY value change mode causes and obsolete server round-trip, even if the textfield is not used

Expected behavior

No extra request should be caused.

Minimal reproducible example

Use this UI with web inspector open and check the network tab. Ideally there should be only 1 (or 0) XHRs, but there is three. This bug causes one, #17428 causes another. Don't go focusing-blurring the textfield because you will get confused becase of #17429.

@Route
public class MainView extends VerticalLayout {

    public MainView() {
        TextField textField = new TextField();
        textField.setValueChangeMode(ValueChangeMode.LAZY);
        add(textField);
    }
}

Versions

Vaadin: 24.1.4
Flow: 24.1.5
Java: Eclipse Adoptium 17.0.2
OS: aarch64 Mac OS X 13.5
Browser: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36
Live reload: Java active (Spring Boot Devtools): Front end active

[TatuLund]

I think this related to vaadin/flow-components#4986

[mstahv]

Maybe, but my example has not validators at all 🤷‍♂️

[caalador]

Setting the valueChangeMode to LAZY adds a debounce timeout of TRAILING which seems to be the one that sends the extra XHR value change even if nothing has changed.

Mode TIMEOUT also sets a throttle debounce of LEADING so that also sends an value-changed event, but earlier than LAZY

[mstahv]

We might want to double check if this issue is still there after: #17410 . I think I tried to verify it is, but with way too long days last week, I may have missed some "mvn vaadin:dance" 🤷‍♂️ And if it is still there, my guess is that this technically belongs to the components team.