From b5e4b02d9c1be39ccc34fc218adcabfbfa040ab0 Mon Sep 17 00:00:00 2001 From: Masen Furer Date: Thu, 21 Nov 2024 16:32:38 -0800 Subject: [PATCH] New Event Action: temporal (#4404) When an event/event spec is marked as "temporal", it will not be queued unless the backend is up. This can be used to prevent periodic events (like from `rx.moment`) from queueing up while the backend is down, and then stampeding when the backend comes up and the queue is drained. It can be used to avoid processing many periodic events at once when the app is only expecting to process such an event every so often. --- reflex/.templates/web/utils/state.js | 5 +++++ reflex/event.py | 12 ++++++++++++ 2 files changed, 17 insertions(+) diff --git a/reflex/.templates/web/utils/state.js b/reflex/.templates/web/utils/state.js index 72733777e..e14c669f5 100644 --- a/reflex/.templates/web/utils/state.js +++ b/reflex/.templates/web/utils/state.js @@ -705,6 +705,11 @@ export const useEventLoop = ( _e.stopPropagation(); } const combined_name = events.map((e) => e.name).join("+++"); + if (event_actions?.temporal) { + if (!socket.current || !socket.current.connected) { + return; // don't queue when the backend is not connected + } + } if (event_actions?.throttle) { // If throttle returns false, the events are not added to the queue. if (!throttle(combined_name, event_actions.throttle)) { diff --git a/reflex/event.py b/reflex/event.py index a9e92b635..624bc1728 100644 --- a/reflex/event.py +++ b/reflex/event.py @@ -181,6 +181,18 @@ class EventActionsMixin: event_actions={"debounce": delay_ms, **self.event_actions}, ) + @property + def temporal(self): + """Do not queue the event if the backend is down. + + Returns: + New EventHandler-like with temporal set to True. + """ + return dataclasses.replace( + self, + event_actions={"temporal": True, **self.event_actions}, + ) + @dataclasses.dataclass( init=True,