Source code for airflow.example_dags.example_latest_only_with_trigger

#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
"""
Example LatestOnlyOperator and TriggerRule interactions
"""

from __future__ import annotations

# [START example]
import datetime

import pendulum

from airflow.models.dag import DAG
from airflow.operators.empty import EmptyOperator
from airflow.operators.latest_only import LatestOnlyOperator
from airflow.utils.trigger_rule import TriggerRule

with DAG(
    dag_id="latest_only_with_trigger",
    schedule=datetime.timedelta(hours=4),
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    catchup=False,
    tags=["example3"],
) as dag:
[docs]    latest_only = LatestOnlyOperator(task_id="latest_only")
    task1 = EmptyOperator(task_id="task1")
    task2 = EmptyOperator(task_id="task2")
    task3 = EmptyOperator(task_id="task3")
    task4 = EmptyOperator(task_id="task4", trigger_rule=TriggerRule.ALL_DONE)

    latest_only >> task1 >> [task3, task4]
    task2 >> [task3, task4]
# [END example]