jscheffl opened a new issue, #62049: URL: https://github.com/apache/airflow/issues/62049
### Apache Airflow version 3.1.7 ### If "Other Airflow 3 version" selected, which one? _No response_ ### What happened? In Airflow 2.11 we use trigger forms with enum values in order to have users selecting a value with a choice. In Airflow 2.11 it was possible to also add a "null"/`None` value and make the field optional, also adding this to enum. In Airflow 3 this fails rendering the form. This generates on the UI the error: <img width="526" height="273" alt="Image" src="https://github.com/user-attachments/assets/5eaca414-adf0-4765-b716-3d6e9ff5f6a4"; /> ### What you think should happen instead? The empty default should be rendered. And it should be possible to pick a "null" value. Note that workarounds seem to be impossible: If the "null" value is removed from the list of values in enum and the user clicks on the "x" icon in the dropdown the value is cleared, form submission fails though with HTTP 400 as an empty field value is not in the enum list and therefore invalid. ### How to reproduce Start airflow e.g. via `breeze start-airflow --load-example-dags` and modify the `airflow-core/src/airflow/example_dags/example_params_ui_tutorial.py` and make the normal example dropdown being an optional field: ``` "pick_with_label": Param( 3, type=["number", "null"], title="Select one Number", description="With drop down selections you can also have nice display labels for the values.", enum=[*range(1, 10), None], values_display={ 1: "One", 2: "Two", 3: "Three", 4: "Four - is like you take three and get one for free!", 5: "Five", 6: "Six", 7: "Seven", 8: "Eight", 9: "Nine", }, section="Drop-Downs and selection lists", ), ``` Click on the UI to trigger the form and the error above is displayed. ### Operating System any ### Versions of Apache Airflow Providers any ### Deployment Official Apache Airflow Helm Chart ### Deployment details any ### Anything else? Tested on main as well as 3.1.7 but might be existing for a longer time already. ### Are you willing to submit PR? - [ ] Yes I am willing to submit a PR! ### Code of Conduct - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md) -- 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]
