Ignoring empty output in QGIS Graphical Modeler

Question

In QGIS 3.22.11 I have a model with around 15 output, and a majority of them are empty most of the time. Is there a way to prevent layers with no entities to show up in QGIS after the model?

I tried with conditional branches, but i can't find anything to count entities in an output of an algorithm in the modeler.

I see how I could do this with Python, but I'd rather keep it as a graphical model.

• Taras: Empty output, like null geometries or like a feature with no records in the attribute table ?
• f.hin: No record at all. It's an extract by expression, where the condition is never met.
• Taras: Does it work in a normal mode ?
• f.hin: It is the way it is supposed to work. That is a check on the data. If the condition is met ( = the data is not valid), the data comes up in the table, shows up on Qgis and can be handled by the user. If all data is valid, the table is empty, and no further investigation is needed. But the model still makes an output, the empty table, that I have to delete evrytime. I want only the non empty table to show up.

Answer 1

Yes, there is a solution for this. You need to use Modeler tools > Conditional branch.

In the condition write this statement:

layer_property(@[SPECIFIC_LAYER], 'feature_count')>0

and then you have to mark the dependency on the FOLLOWING PROCESS, so if after the process the feature count will be zero modeler will not PROCESS THE FOLLOWING algorithm and of course there will be no output. But you need to create separate condition for each tool, otherwise it wont work. Good luck!

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Answer 2

My easier solution was "Split Layer by". And the output will write just layers who has at least one feature. TIP: FME Safe Software could help you a lot!

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