Joining PyQGIS script parts

Question

On my way to find a solution to This Question, I´m trying to merge some automatic generated script with This example.

My thought is that after the last step, I could insert the script that does nothing with the file but only rename the output temporary file, because it´s not a native source.

Running everything in the toolbox.

How can I set the temporary output as an input to the example script?

This is the part of the automatic generated script:

        OUTPUT='OUTPUT'

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterVectorLayer('maininput', 'Main Input', types=[QgsProcessing.TypeVector], defaultValue=None))
        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT,self.tr('My output layer')))

        # Buffer
        alg_params = {
            'DISSOLVE': False,
            'DISTANCE': 10,
            'END_CAP_STYLE': 0,
            'INPUT': parameters['maininput'],
            'JOIN_STYLE': 0,
            'MITER_LIMIT': 2,
            'SEGMENTS': 5,
            'OUTPUT': QgsProcessing.TEMPORARY_OUTPUT
        }
        outputs['Buffer'] = processing.run('native:buffer', alg_params, context=context, feedback=feedback, is_child_algorithm=True)

and after that, I want to insert the other script, having "outputs['Buffer']['OUTPUT']" instead of "INPUT"

        source = self.parameterAsSource(parameters, outputs['Buffer']['OUTPUT'], context)

        (sink, dest_id) = self.parameterAsSink(
            parameters, "OUTPUT", context,
        source.fields(), source.wkbType(), source.sourceCrs())

        total = 100.0 / source.featureCount() if source.featureCount() else 0
        features = source.getFeatures()
        for current, feature in enumerate(features):
            if feedback.isCanceled():
                break
            out_feature = QgsFeature(feature)
            sink.addFeature(out_feature, QgsFeatureSink.FastInsert)
            feedback.setProgress(int(current * total))

        return {"OUTPUT": dest_id}

I got an error

AttributeError: 'NoneType' object has no attribute 'fields'

score 0 · Accepted Answer · answered Sep 27 '19 at 16:16

As a partial solution I saved the template script with the desired output name and put it as the last step of my main script.

So I did not join parts of scripts, but whole scripts. However, the result was as expected, the output file is displayed with the name I assigned.

Joining PyQGIS script parts

1 Answers1