isaiahiruoha opened a new pull request, #54756: URL: https://github.com/apache/airflow/pull/54756
__closes: #54753__ ## Problem Description The Airflow UI Graph View fails to display DAGs containing dynamically mapped operators (created with `.expand()`). When users try to view such DAGs in the Graph View, the page fails to load and shows a 500 Internal Server Error due to cascading errors in the UI rendering pipeline. ## Errors Observed __First Error:__ ```javascript AttributeError: 'MappedOperator' object has no attribute 'topological_sort' INFO: GET /ui/structure/structure_data?dag_id=integration_test HTTP/1.1" 500 Internal Server Error ``` __Subsequent Error (after fixing the first):__ ```javascript AttributeError: 'MappedOperator' object has no attribute 'downstream_group_ids'. Did you mean: 'downstream_task_ids'? ``` Both errors occur because `MappedOperator` instances are incorrectly treated as `TaskGroup` objects throughout the UI rendering pipeline, causing the system to call TaskGroup-specific methods that don't exist on `MappedOperator`. ## Proposed Solution Updated both functions to properly recognize `MappedOperator` as a task-like object rather than a TaskGroup. These changes ensure `MappedOperator` instances are handled consistently as tasks throughout the entire UI rendering pipeline, preventing both the initial error and subsequent cascading failures. ## Testing <img width="729" height="271" alt="Screenshot 2025-08-20 at 4 51 45 PM" src="https://github.com/user-attachments/assets/44e3f92d-113c-4ed7-9d3a-cef8f5a4bd40"; /> - Verified Graph View now displays correctly for DAGs with mapped operators - Tested with example DAGs containing `task.expand()` operations <!-- 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. --> <!-- Thank you for contributing! Please make sure that your code changes are covered with tests. And in case of new features or big changes remember to adjust the documentation. Feel free to ping committers for the review! In case of an existing issue, reference it using one of the following: closes: #ISSUE related: #ISSUE How to write a good git commit message: http://chris.beams.io/posts/git-commit/ --> <!-- Please keep an empty line above the dashes. --> --- **^ Add meaningful description above** Read the **[Pull Request Guidelines](https://github.com/apache/airflow/blob/main/contributing-docs/05_pull_requests.rst#pull-request-guidelines)** for more information. In case of fundamental code changes, an Airflow Improvement Proposal ([AIP](https://cwiki.apache.org/confluence/display/AIRFLOW/Airflow+Improvement+Proposals)) is needed. In case of a new dependency, check compliance with the [ASF 3rd Party License Policy](https://www.apache.org/legal/resolved.html#category-x). In case of backwards incompatible changes please leave a note in a newsfragment file, named `{pr_number}.significant.rst` or `{issue_number}.significant.rst`, in [airflow-core/newsfragments](https://github.com/apache/airflow/tree/main/airflow-core/newsfragments). -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
