[FEATURE][processing] Add custom OPTIONS to contour algorithm (#7834)

python/plugins/processing/algs/gdal/contour.py

@@ -55,6 +55,7 @@ class contour(GdalAlgorithm):
     IGNORE_NODATA = 'IGNORE_NODATA'
     NODATA = 'NODATA'
     OFFSET = 'OFFSET'
+    OPTIONS = 'OPTIONS'
     OUTPUT = 'OUTPUT'
 
     def __init__(self):
@@ -104,6 +105,13 @@ def initAlgorithm(self, config=None):
         nodata_param.setFlags(offset_param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
         self.addParameter(offset_param)
 
+        options_param = QgsProcessingParameterString(self.OPTIONS,
+                                                     self.tr('Additional creation options'),
+                                                     defaultValue='',
+                                                     optional=True)
+        options_param.setFlags(options_param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
+        self.addParameter(options_param)
+
         self.addParameter(QgsProcessingParameterVectorDestination(
             self.OUTPUT, self.tr('Contours'), QgsProcessing.TypeVectorLine))
 
@@ -163,6 +171,10 @@ def getConsoleCommands(self, parameters, context, feedback, executing=True):
         if offset:
             arguments.append('-off {}'.format(offset))
 
+        options = self.parameterAsString(parameters, self.OPTIONS, context)
+        if options:
+            arguments.append(options)
+
         if outFormat:
             arguments.append('-f {}'.format(outFormat))
 

python/plugins/processing/tests/GdalAlgorithmsTest.py

@@ -589,6 +589,18 @@ def testContour(self):
              '-b 1 -a elev -i 5.0 -snodata 0.0 -f "GPKG" ' +
              source + ' ' +
              'd:/temp/check.gpkg'])
+        # fixed level contours
+        self.assertEqual(
+            alg.getConsoleCommands({'INPUT': source,
+                                    'BAND': 1,
+                                    'FIELD_NAME': 'elev',
+                                    'INTERVAL': 0,
+                                    'OPTIONS': '-fl 100 125 150 200',
+                                    'OUTPUT': 'd:/temp/check.shp'}, context, feedback),
+            ['gdal_contour',
+             '-b 1 -a elev -i 0.0 -fl 100 125 150 200 -f "ESRI Shapefile" ' +
+             source + ' ' +
+             'd:/temp/check.shp'])
 
     def testGdal2Tiles(self):
         context = QgsProcessingContext()