Fix connection form meta when fab provider is missing

[pierrejeambrun]

#47588 introduces a dependency on fab provider from core. (or its transitive dependencies wtforms flask_babel flask_appbuilder). This makes sure that the monkey patching only occurs when modules are installed. Also this passed the CI, I assume it means there's no API test suite without fab provider installed ?

We are trying to patch modules that aren't there in the first place. This can happen if fab provider is not installed.

To reproduce, just go into airflow-core, uv sync --no-dev (fab provider should not be there), then start airflow api-server and go to the connection page in the UI.

To be honest this might be enough to cancel rc3 in my opinion as connection page in the UI will be broken for anybody that does not have the fab-provider installed. @kaxil I’ll wait for a discussion before casting my vote.

Before

After

[pierrejeambrun]

cc: @ephraimbuddy @dstandish @jscheffl @kaxil

[jscheffl]

Args, with the mocking I added the target was actually to be independent of FAB. But at time of implementation FAB still was mandatory... so maybe this had not been tested sufficiently... sorry.

I am still on the move, will be home by tomorrow evening. Earliest Sunday I'm able to really review and understand. WHat is the outcome if the exception is catched because dependencies are missing? Will just be no element displayed?

[dstandish]

Here's an alternative that just rips out the mocking. Seems to work with my local testing.

#49448

[pierrejeambrun]

What is the outcome if the exception is catched because dependencies are missing? Will just be no element displayed?

As I understand if the element is missing (module not installed) it means that no provider depends on fab provider, which means that no get_connection_from_widgets depends on it (for instance wtform widgets). Therefore yes the widged will not be there, but no connection form acatually use it, so it shouldn't cause trouble, to my understanding.

[ashb]

Will do for 3.0

[jscheffl]

Thanks for the fix! I am very Sorry this caused RC4 :-(