I am using QGIS 3.0.

Following up on Calling a QgsProcessingAlgorithm from a Processing python script in QGIS 3.0?, I am writing a Processing python script based on the template provided here.

It takes a few additional parameters in addition to the 'INPUT' and 'OUTPUT' from the template. I am using these parameters to create some lines and everything works out fine.

Now I need to call a Processing Algorithm, namely qgis:clip to clip the lines I just created according to the Polygon entered as 'INPUT'.

Is there a way to pipe my output into qgis:clip ? Or do I need to create a temporary layer that I will then feed into qgis:clip and let it's 'OUTPUT' become mine ?

Either way, I'm not sure where to start.

I've tried defining a QgsFeatureSink or a QgsProcessingFeatureSink but the first is an abstract thingy and the second just won't be recognized (I can't even import it from qgis.core)

I've seen Using processing using other output (result from another algorithm) as input and Import error for qgis.core when running OSGeo4w shell script but I couldn't figure out a working solution to my problem so far.

1 Answer 1


Although this is not what I wanted to do, the easiest way to do this is to use the Model.
This way it is easy to plug the output from one Algorithm to the input of another one.

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