Dialog is not updated when doing hotswap

[Artur-]

Description of the bug

Given

@Route(value = "overlay", layout = MainLayout.class)
@AnonymousAllowed
public class OverlayView extends VerticalLayout {

    @Override
    protected void onAttach(AttachEvent attachEvent) {
        super.onAttach(attachEvent);

        Dialog dialog = new Dialog("The Dialog");
        dialog.setCloseOnOutsideClick(true);
        dialog.setCloseOnEsc(true);

        dialog.add(new Div("Text nr 1"));

        dialog.open();
    }

}

if you are running using HotswapAgent and edit the div text to "Text nr 2", then a dialog with "Text nr 1" remains on screen and a dialog with "Text nr 2" is not added at all. If you manually refresh the page, the dialog with "Text nr 2" is shown

Expected behavior

The old dialog is closed and the new one opened

Minimal reproducible example

as above

Versions

• Vaadin / Flow version: 24.5.3

[mcollovati]

Refresh seems to work if the dialog is added to the route component.

add(dialog);
dialog.open();

If not added explicitly to another component, the dialog has UI as a parent, so it is not detached during refresh.
On refresh, we could probably remove modal components, but this might not be correct in all situations.
For example, if the dialog is added by a layout, and we request a refresh for the route component only, the dialog would not be re-opened, since the layout is not detached and attached.

[mcollovati]

In the case of route chain refresh, if dialogs attached to the UI are forcibly removed, they are not re-added.
Dialog class registers an afterNavigationListener that for programmatic navigation removes the beforeClientResponse callback that should do the attach.

https://github.com/vaadin/flow-components/blob/985c10c20d40bb706326d401bed7be50a45de4eb/vaadin-dialog-flow-parent/vaadin-dialog-flow/src/main/java/com/vaadin/flow/component/dialog/Dialog.java#L899-L925

[sveinnetnordic]

I am working with a big dialog an tough that form field was updated on the "new" hotswap way, but that did not happen.
What about having a way to set the way hotswap should work in Copilot in the browser (set at cookie etc). Mode: Full refresh/"new refresh". A -Dvaadin.hotswapmode=... would also be nice. I assume the "new hotswap" will be default.

EDIT: At the moment of saving this text a fix was created :-)