Reminder

ReminderFlow sends a reminder every interval until the recipient opts out. ReminderStep waits for either the interval Timer or the OptOut Channel. When the timer fires, it sends a reminder and moves to itself. When OptOut arrives first, the Step completes the Flow.

Definition graph

ReminderFlow

Valid

python · examples/python/dex_examples/patterns/reminders/reminder_flow.py

ReminderFlow

OptOut

opt_out_reminders

ReminderStepSTART

WaitFor anyOf

⏱️ REMINDER_INTERVAL timer📨 OptOut.for 1

?

gracefulComplete

goTo

🧩 ReminderStep

Press enter or space to select a node. You can then use the arrow keys to move the node around. Press delete to remove it and escape to cancel.

Press enter or space to select an edge. You can then press delete to remove it or escape to cancel.

Core Step

class ReminderStep(Step[None]):
    def __init__(self, service: ServiceDependency, opt_out: Channel[None]) -> None:
        self.service = service
        self.opt_out = opt_out

    def wait_for(self, context: Context, input: None) -> Wait:
        del context, input
        return Wait.any_of(Timer.by_duration(REMINDER_INTERVAL), self.opt_out.for_one())

    def execute(self, context: Context, input: None) -> StepDecision:
        del input
        if not context.has_timer_fired():
            return graceful_complete()
        self.service.send_email("Reminder: please respond", "Hello, ...")
        return go_to(ReminderStep, None)

Example: examples/python/dex_examples/patterns/reminders/reminder_flow.py

Related

• Timer
• Channel