Viewshed algorithm does not return path to file if temporary output is used

[kannes]

When I specify "OUTPUT": QgsProcessing.TEMPORARY_OUTPUT for the visibility:viewshed algorithm, the returned dictionary of results does not include a path to a temporary file (like QGIS' native raster algorithms would).

You can see this too if you execute the algorithm graphically in QGIS' processing toolbox and do not specify a file path to save to:

Eingabeparameter:
{
    "ANALYSIS_TYPE": 0,
    "DEM": "[stripped]",
    "OBSERVER_POINTS": "[stripped]",
    "OPERATOR": 0,
    "OUTPUT": "TEMPORARY_OUTPUT",
    "REFRACTION": 0.13,
    "USE_CURVATURE": False,
}

Execution completed in 0.10 Sekunden
Ergebnisse:
{'OUTPUT': <QgsProcessingOutputLayerDefinition {'sink':TEMPORARY_OUTPUT, 'createOptions': {'fileEncoding': 'System'}}>}

vs a working tool like native:createconstantrasterlayer:

Eingabeparameter:
{
    "EXTENT": "[stripped]",
    "NUMBER": 1,
    "OUTPUT": "TEMPORARY_OUTPUT",
    "OUTPUT_TYPE": 5,
    "PIXEL_SIZE": 111,
    "TARGET_CRS": QgsCoordinateReferenceSystem("EPSG:25832"),
}

Execution completed in 0.08 Sekunden
Ergebnisse:
{'OUTPUT': '/tmp/processing_vUgXtq/bd28c750529d4a8089dee19cce3967e5/OUTPUT.tif'}

This behaviour makes it impossible to use the viewshed analysis in a chain of processing.run() calls to other algorithms and potentially also the modeller?

[kannes]

This can be used as a workaround currently:

        for output in self.outputDefinitions():
            outputName = output.name()

            if outputName in parameters :
                results[outputName] = parameters[outputName]
                results["OUTPUT"] = output_path

[zoran-cuckovic]

Thanks for this input ! I'll consider this for the next version.

[zoran-cuckovic]

Fixed in 1.9 version (pending approval)