Is there a better way to get the browser timezone without triggering the serve function?

[Nayananga]

attaches to this discussion #2072

one of our core apps uses a custom JS script to emit an event to collect browser timezone. This has come with a trade-off as we hit three events from WAVE SDK when we hit the browser refresh button

1. Disconnect from previous load.
2. Initial serve.
3. JS callback to get the timezone.

Is there a better way to get the browser timezone without triggering the serve function?

from h2o_wave import main, app, Q, ui, on, handle_on


@on()
async def button_click(q: Q):
    q.page["meta"].notification_bar = ui.notification_bar(
        text=f'you timezone is {q.client.timezone}',
        type='success',
        position=ui.NotificationBarPosition.TOP_CENTER,
    )


@on("global_events.set_timezone")
async def window_loaded(q: Q) -> None:
    q.client.timezone = q.events.global_events.set_timezone


def resolve_timezone() -> str:
    return """
                wave.emit(
                    "global_events",
                    "set_timezone",
                    Intl.DateTimeFormat().resolvedOptions().timeZone
                );
            """


@app('/')
async def serve(q: Q):
    if not q.client.initialized:
        q.client.initialized = True
        q.page['meta'] = ui.meta_card(
            box='',
            layouts=[
                ui.layout(
                    breakpoint="xs",
                    zones=[
                        ui.zone(
                            name="body",
                            direction=ui.ZoneDirection.ROW,
                        ),
                    ],
                )
            ],
            script=ui.inline_script(resolve_timezone(), requires=[])
        )

    q.page['body'] = ui.form_card(box='body', items=[
        ui.button(name='button_click', label='Button Click'),
    ])

    await handle_on(q)

    await q.page.save()

[mturoci]

Is there a better way to get the browser timezone without triggering the serve function?

No, that's how the web works.