uranusjr commented on code in PR #38674:
URL: https://github.com/apache/airflow/pull/38674#discussion_r1577423825
##########
docs/apache-airflow/authoring-and-scheduling/deferring.rst:
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@@ -141,6 +141,60 @@ The ``self.defer`` call raises the ``TaskDeferred``
exception, so it can work an
``execution_timeout`` on operators is determined from the *total runtime*, not
individual executions between deferrals. This means that if
``execution_timeout`` is set, an operator can fail while it's deferred or while
it's running after a deferral, even if it's only been resumed for a few seconds.
+Triggering Deferral from Start
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you want to defer your task directly to the triggerer without going into
the worker, you can add the class level attributes ``start_trigger`` and
``_next_method`` to your deferrable operator.
+
+* ``start_trigger``: An instance of a trigger you want to defer to. It will be
serialized into the database.
+* ``next_method``: The method name on your operator that you want Airflow to
call when it resumes.
+
+
+This is particularly useful when deferring is the only thing the ``execute``
method does. Here's a basic refinement of the previous example.
+
+.. code-block:: python
+
+ from datetime import timedelta
+ from typing import Any
+
+ from airflow.sensors.base import BaseSensorOperator
+ from airflow.triggers.temporal import TimeDeltaTrigger
+ from airflow.utils.context import Context
+
+
+ class WaitOneHourSensor(BaseSensorOperator):
+ start_trigger = TimeDeltaTrigger(timedelta(hours=1))
+ next_method = "execute_complete"
+
+ def execute_complete(self, context: Context, event: dict[str, Any] |
None = None) -> None:
+ # We have no more work to do here. Mark as complete.
+ return
+
+``start_trigger`` and ``next_method`` can also be set at the instance level
for more flexible configuration.
+
+.. warning::
+ Dynamic task mapping is not supported when ``start_trigger`` and
``next_method`` are assigned in instance level.
Review Comment:
```suggestion
Dynamic task mapping is not supported when ``start_trigger`` and
``next_method`` are assigned at the instance level.
```
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