BUG: psm_df connection from example dataset import vanishes if run is loaded

[hendraet]

What is the issue?

If a run is loaded that includes the importing of the psm_df in the "example dataset import" step, the psm_df output icon vanishes from this step and with it all drawn connections. However, internally everything seems to work as expected. In the screenshot below, you can see an example where I successfully executed the "Filter PSM step" again, even if the psm_df has no connection.

As soon as the "example dataset import" step is revisited and the checkbox is rechecked, the connection is drawn, which unfortunately also invalidates all following steps.

I suspected the following lines to be the culprit:

PROTzilla/backend/protzilla/methods/importing.py

Lines 405 to 413 in 6c80346

	self.output_keys = self.output_keys = (
	[
	DataKey.METADATA_DF,
	DataKey.PEPTIDE_DF,
	DataKey.PROTEIN_DF,
	]
	if import_peptide_data_field.value
	else [DataKey.METADATA_DF, DataKey.PROTEIN_DF]
	)

Probably import_peptide_data_field.value is not properly set when reloading a run and thus defaults to false again.

How to reproduce the issue?

Just create a run based on the example dataset workflow, have some step that needs a psm_df (like the Filter PSM step), execute the steps and then reload the run from the home screen. (Sorry couldn't upload my run, failed for some reason)
Sometimes a reload of the PROTzilla containers seems to be needed for reproduction. When I loaded the run, fixed the psm_df issue, went back to the home screen, and then loaded the run again, I couldn't reproduce this bug.

What is the expected behavior?

The psm_df connection is always drawn when loading a run.