blatann.waitables.event_waitable module

class blatann.waitables.event_waitable.EventWaitable(event)

Bases: Waitable[Tuple[TSender, TEvent]]

Waitable implementation which waits on an Event.

wait(timeout=None, exception_on_timeout=True)

Waits for the asynchronous operation to complete

Warning

If this call times out, it cannot be (successfully) called again as it will clean up all event handlers for the waitable. This is done to remove lingering references to the waitable object through event subscriptions

Parameters:

  • timeout – How long to wait, or None to wait indefinitely

  • exception_on_timeout – Flag to either throw an exception on timeout, or instead return None object(s)

Return type:

Tuple[TypeVar(TSender), TypeVar(TEvent)]

Returns:

The result of the asynchronous operation

Raises:

TimeoutError

async as_async(timeout=None, exception_on_timeout=True, loop=None)

Waits for the asynchronous operation to complete that can be ``await``ed in async methods.

Warning

This method is experimental!

Parameters:

  • timeout (Optional[float]) – How long to wait, or None to wait indefinitely

  • exception_on_timeout – Flag to either throw an exception on timeout, or instead return None object(s)

  • loop (Optional[AbstractEventLoop]) – Optional asyncio event loop to use instead of the default one returned by asyncio.get_event_loop()

Return type:

Tuple[TypeVar(TSender), TypeVar(TEvent)]

Returns:

The result of the asynchronous operation

Raises:

TimeoutError

then(callback)

Registers a function callback that will be called when the asynchronous operation completes

Note

Only a single callback is supported– subsequent calls to this method will overwrite previous callbacks

Parameters:

callback (Callable[[TypeVar(TSender), TypeVar(TEvent)], None]) – The function to call when the async operation completes

Returns:

This waitable object

class blatann.waitables.event_waitable.IdBasedEventWaitable(event, event_id)

Bases: EventWaitable

Extension of EventWaitable for high-churn events which require IDs to ensure the correct operation is waited upon, such as characteristic read, write and notify operations