Port Create Constant Raster to new API and add test

python/plugins/processing/algs/qgis/CreateConstantRaster.py

@@ -27,12 +27,10 @@ __revision__ = '$Format:%H$'
 
 from osgeo import gdal
 
-from qgis.core import (QgsApplication,
-                       QgsProcessingUtils)
+from qgis.core import (QgsProcessingParameterRasterLayer,
+                       QgsProcessingParameterNumber,
+                       QgsProcessingParameterRasterDestination)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.core.parameters import ParameterRaster
-from processing.core.parameters import ParameterNumber
-from processing.core.outputs import OutputRaster
 from processing.tools.raster import RasterWriter
 
 
@@ -49,14 +47,12 @@ class CreateConstantRaster(QgisAlgorithm):
         super().__init__()
 
     def initAlgorithm(self, config=None):
-        self.addParameter(ParameterRaster(self.INPUT,
-                                          self.tr('Reference layer')))
-        self.addParameter(ParameterNumber(self.NUMBER,
-                                          self.tr('Constant value'),
-                                          default=1.0))
-
-        self.addOutput(OutputRaster(self.OUTPUT,
-                                    self.tr('Constant')))
+        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT,
+                                                            self.tr('Reference layer')))
+        self.addParameter(QgsProcessingParameterNumber(self.NUMBER,
+                                                       self.tr('Constant value'), QgsProcessingParameterNumber.Double,
+                                                       defaultValue=1))
+        self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT, self.tr('Constant')))
 
     def name(self):
         return 'createconstantrasterlayer'
@@ -65,10 +61,10 @@ class CreateConstantRaster(QgisAlgorithm):
         return self.tr('Create constant raster layer')
 
     def processAlgorithm(self, parameters, context, feedback):
-        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
-        value = self.getParameterValue(self.NUMBER)
+        layer = self.parameterAsRasterLayer(parameters, self.INPUT, context)
+        value = self.parameterAsDouble(parameters, self.NUMBER, context)
 
-        output = self.getOutputFromName(self.OUTPUT)
+        outputFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
 
         raster = gdal.Open(layer.source(), gdal.GA_ReadOnly)
         geoTransform = raster.GetGeoTransform()
@@ -76,7 +72,7 @@ class CreateConstantRaster(QgisAlgorithm):
         cellsize = (layer.extent().xMaximum() - layer.extent().xMinimum()) \
             / layer.width()
 
-        w = RasterWriter(output.getCompatibleFileName(self),
+        w = RasterWriter(outputFile,
                          layer.extent().xMinimum(),
                          layer.extent().yMinimum(),
                          layer.extent().xMaximum(),
@@ -88,3 +84,5 @@ class CreateConstantRaster(QgisAlgorithm):
                          )
         w.matrix.fill(value)
         w.close()
+
+        return {self.OUTPUT: outputFile}

python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py

@@ -49,6 +49,7 @@ from .BoundingBox import BoundingBox
 from .CheckValidity import CheckValidity
 from .ConcaveHull import ConcaveHull
 from .CreateAttributeIndex import CreateAttributeIndex
+from .CreateConstantRaster import CreateConstantRaster
 from .Delaunay import Delaunay
 from .DeleteColumn import DeleteColumn
 from .DeleteHoles import DeleteHoles
@@ -146,7 +147,6 @@ from .ZonalStatistics import ZonalStatistics
 # from .FieldsCalculator import FieldsCalculator
 # from .FieldPyculator import FieldsPyculator
 # from .JoinAttributes import JoinAttributes
-# from .CreateConstantRaster import CreateConstantRaster
 # from .PointsDisplacement import PointsDisplacement
 # from .PointsFromPolygons import PointsFromPolygons
 # from .PointsFromLines import PointsFromLines
@@ -205,7 +205,7 @@ class QGISAlgorithmProvider(QgsProcessingProvider):
         #         PointsFromLines(), PointsToPaths(),
         #         SetVectorStyle(), SetRasterStyle(),
         #          HypsometricCurves(),
-        #         CreateConstantRaster(),
+        #
         #         FieldsMapper(), SelectByAttributeSum(), Datasources2Vrt(),
         #         OrientedMinimumBoundingBox(),
         #         DefineProjection(),
@@ -228,6 +228,7 @@ class QGISAlgorithmProvider(QgsProcessingProvider):
                 CheckValidity(),
                 ConcaveHull(),
                 CreateAttributeIndex(),
+                CreateConstantRaster(),
                 Delaunay(),
                 DeleteColumn(),
                 DeleteHoles(),

python/plugins/processing/tests/testdata/expected/constant_raster.tif.aux.xml

@@ -0,0 +1,10 @@
+<PAMDataset>
+  <PAMRasterBand band="1">
+    <Metadata>
+      <MDI key="STATISTICS_MAXIMUM">3</MDI>
+      <MDI key="STATISTICS_MEAN">3</MDI>
+      <MDI key="STATISTICS_MINIMUM">3</MDI>
+      <MDI key="STATISTICS_STDDEV">0</MDI>
+    </Metadata>
+  </PAMRasterBand>
+</PAMDataset>

python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml

@@ -1215,6 +1215,19 @@ tests:
 #        hash: 7fe0e0174185fd743e23760f33615adf10f771b4275f320db6f7f4f8
 #        type: rasterhash
 
+  - algorithm: qgis:createconstantrasterlayer
+    name: Create constant raster
+    params:
+      INPUT:
+        name: raster.tif
+        type: raster
+      NUMBER: 3.0
+    results:
+      OUTPUT:
+        hash: 4cb3e82e8512cdbb75d9c39a10adc818dd6842c5dc6361fbc43dd9aa
+        type: rasterhash
+
+
   # Case 1: Keep all fields
   - algorithm: qgis:lineintersections
     name: Line Intersection Keep All Fields from Both