Created
September 20, 2022 16:17
-
-
Save mturoci/f4511e0cf6b9a70e5c5a5e9d0f14884d to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import concurrent.futures | |
| from threading import Event | |
| import time | |
| from h2o_wave import main, app, Q, ui | |
| # This takes a lot of time (compute heavy). | |
| async def blocking_function(q: Q): | |
| count = 0 | |
| total = 10 | |
| while count < total: | |
| # Check if cancelled. | |
| if q.client.event.is_set(): | |
| await show_cancel(q) | |
| return | |
| # This blocks the main thread and prevents any other execution. | |
| # This would be a heavy compute job in the real world. | |
| time.sleep(1) | |
| count += 1 | |
| # Assume you are able to emit some kind of progress. | |
| await update_ui(q, count / total) | |
| # Show a notification at the end. | |
| await show_notification(q) | |
| async def show_cancel(q: Q): | |
| q.page['meta'].dialog.items[0].progress.caption = 'Cancelled' | |
| q.page['meta'].dialog.closable = True | |
| await q.page.save() | |
| async def show_notification(q: Q): | |
| q.page['meta'].dialog = None | |
| q.page['meta'].notification_bar = ui.notification_bar( | |
| name='success_notification', | |
| text='Job done!', | |
| type='success', | |
| events=['dismissed'] | |
| ) | |
| await q.page.save() | |
| async def update_ui(q: Q, value: int): | |
| q.page['meta'].dialog.items[0].progress.value = value | |
| await q.page.save() | |
| @app('/') | |
| async def serve(q: Q): | |
| # Unimportant, draw initial UI. | |
| if not q.client.initialized: | |
| q.page['meta'] = ui.meta_card(box='') | |
| q.page['form'] = ui.form_card(box='1 1 1 1', items=[ | |
| ui.button(name='start_job', label='Start job') | |
| ]) | |
| q.client.initialized = True | |
| # Handle start job button click. | |
| if q.args.start_job: | |
| q.page['meta'].dialog = ui.dialog(title='Blocking job', blocking=True, items=[ | |
| ui.progress(label='Progress', value=0), | |
| ui.button(name='cancel', label='Cancel'), | |
| ]) | |
| # Do not run like this - will block the whole thread - freeze the app. | |
| # blocking_function(q, loop) | |
| q.client.event = Event() | |
| with concurrent.futures.ProcessPoolExecutor() as pool: | |
| await q.exec(pool, blocking_function, q) | |
| if q.args.cancel: | |
| q.client.event.set() | |
| # Unimportant, just handle notification dismissal. | |
| if q.events.success_notification and q.events.success_notification.dismissed: | |
| q.page['meta'].notification_bar = None | |
| await q.page.save() |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment