0

If I execute the following example PyQGIS script, the temporary output layer is called "Remaining fields" in the layers panel which is the standard output layer name of the last executed processing algorithm "native:deletecolumn". But I want the output layer of my script to be named "Example output" as defined in the initAlgorithm. How can I change the name of the output layer? Or is there a better way to pass the output of the algorithm to the script's output "ExampleOutput"?

from qgis.core import QgsProcessing
from qgis.core import QgsProcessingAlgorithm
from qgis.core import QgsProcessingMultiStepFeedback
from qgis.core import QgsProcessingParameterVectorLayer
from qgis.core import QgsProcessingParameterFeatureSink
import processing


class Mymodel(QgsProcessingAlgorithm):

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterVectorLayer('example_input', 'Example input', types=[QgsProcessing.TypeVectorPoint], defaultValue=None))
        self.addParameter(QgsProcessingParameterFeatureSink('ExampleOutput', 'Example output', type=QgsProcessing.TypeVectorAnyGeometry, createByDefault=True, supportsAppend=True, defaultValue=None))

    def processAlgorithm(self, parameters, context, model_feedback):
        # Use a multi-step feedback, so that individual child algorithm progress reports are adjusted for the
        # overall progress through the model
        feedback = QgsProcessingMultiStepFeedback(2, model_feedback)
        results = {}
        outputs = {}

        # Add X/Y fields to layer
        alg_params = {
            'CRS': parameters['example_input'],
            'INPUT': parameters['example_input'],
            'PREFIX': '',
            'OUTPUT': QgsProcessing.TEMPORARY_OUTPUT
        }
        outputs['AddXyFieldsToLayer'] = processing.run('native:addxyfields', alg_params, context=context, feedback=feedback, is_child_algorithm=True)

        feedback.setCurrentStep(1)
        if feedback.isCanceled():
            return {}

        # Drop field(s)
        alg_params = {
            'COLUMN': ['x'],
            'INPUT': outputs['AddXyFieldsToLayer']['OUTPUT'],
            'OUTPUT': parameters['ExampleOutput']
        }
        outputs['DropFields'] = processing.run('native:deletecolumn', alg_params, context=context, feedback=feedback, is_child_algorithm=True)
        results['ExampleOutput'] = outputs['DropFields']['OUTPUT']
        return results

    def name(self):
        return 'mymodel'

    def displayName(self):
        return 'mymodel'

    def group(self):
        return 'mygroup'

    def groupId(self):
        return 'mygroup'

    def createInstance(self):
        return Mymodel()
2
  • see this answer gis.stackexchange.com/a/385009/4449
    – Llaves
    Commented Sep 2, 2023 at 16:58
  • @Llaves Thank you for the suggestion, however, I just want to know how to use the standard output name under self.addParameter(QgsProcessingParameterFeatureSink()). I don't know why, but the layer is exported with the output name of the last used algorithm "native:deletecolumn".
    – zfn
    Commented Sep 3, 2023 at 16:14

1 Answer 1

0

I finally found a solution in this issue in the official QGIS repository. Just end the processAlgorithm block with

results['ExampleOutput'] = outputs['DropFields']['OUTPUT']
context.layerToLoadOnCompletionDetails(results['ExampleOutput']).name = "Example output" # Insert your custom layer name here!
return results

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.