[processing][GRASS] Correctly handle input vector layers with |layername= param

Fixes #20277

Author: nyalldawson

python/plugins/processing/algs/grass7/Grass7Algorithm.py

@@ -62,7 +62,8 @@
                        QgsProcessingParameterFolderDestination,
                        QgsProcessingOutputHtml,
                        QgsProcessingUtils,
-                       QgsVectorLayer)
+                       QgsVectorLayer,
+                       QgsProviderRegistry)
 from qgis.utils import iface
 from osgeo import ogr
 
@@ -110,12 +111,15 @@ def __init__(self, descriptionfile):
         self.params = []
         self.hardcodedStrings = []
         self.inputLayers = []
+        self.commands = []
+        self.outputCommands = []
+        self.exportedLayers = {}
         self.descriptionFile = descriptionfile
 
         # Default GRASS parameters
         self.region = None
         self.cellSize = None
-        self.snaptTolerance = None
+        self.snapTolerance = None
         self.outputType = None
         self.minArea = None
         self.alignToResolution = None
@@ -801,7 +805,18 @@ def loadVectorLayerFromParameter(self, name, parameters, context, feedback, exte
         :param external: use v.external (v.in.ogr if False).
         """
         layer = self.parameterAsVectorLayer(parameters, name, context)
-        if layer is None or layer.dataProvider().name() != 'ogr':
+
+        is_ogr_disk_based_layer = layer is not None and layer.dataProvider().name() == 'ogr'
+        if is_ogr_disk_based_layer:
+            # we only support direct reading of disk based ogr layers -- not ogr postgres layers, etc
+            source_parts = QgsProviderRegistry.instance().decodeUri('ogr', layer.source())
+            if not source_parts.get('path'):
+                is_ogr_disk_based_layer = False
+            elif source_parts.get('layerId'):
+                # no support for directly reading layers by id in grass
+                is_ogr_disk_based_layer = False
+
+        if not is_ogr_disk_based_layer:
             # parameter is not a vector layer or not an OGR layer - try to convert to a source compatible with
             # grass OGR inputs and extract selection if required
             path = self.parameterAsCompatibleSourceLayerPath(parameters, name, context,
@@ -827,28 +842,36 @@ def loadVectorLayer(self, name, layer, external=False, feedback=None):
             external = ProcessingConfig.getSetting(
                 Grass7Utils.GRASS_USE_VEXTERNAL)
 
+        source_parts = QgsProviderRegistry.instance().decodeUri('ogr', layer.source())
+        file_path = source_parts.get('path')
+        layer_name = source_parts.get('layerName')
+
         # safety check: we can only use external for ogr layers which support random read
         if external:
-            feedback.pushInfo('Attempting to use v.external for direct layer read')
+            if feedback is not None:
+                feedback.pushInfo('Attempting to use v.external for direct layer read')
             ds = ogr.Open(file_path)
             if ds is not None:
                 ogr_layer = ds.GetLayer()
                 if ogr_layer is None or not ogr_layer.TestCapability(ogr.OLCRandomRead):
-                    feedback.reportError('Cannot use v.external: layer does not support random read')
+                    if feedback is not None:
+                        feedback.reportError('Cannot use v.external: layer does not support random read')
                     external = False
             else:
-                feedback.reportError('Cannot use v.external: error reading layer')
+                if feedback is not None:
+                    feedback.reportError('Cannot use v.external: error reading layer')
                 external = False
 
         self.inputLayers.append(layer)
         self.setSessionProjectionFromLayer(layer)
         destFilename = 'vector_{}'.format(os.path.basename(getTempFilename()))
         self.exportedLayers[name] = destFilename
-        command = '{0}{1}{2} input="{3}" output="{4}" --overwrite -o'.format(
+        command = '{0}{1}{2} input="{3}"{4} output="{5}" --overwrite -o'.format(
             'v.external' if external else 'v.in.ogr',
             ' min_area={}'.format(self.minArea) if not external else '',
             ' snap={}'.format(self.snapTolerance) if not external else '',
-            os.path.normpath(layer.source()),
+            os.path.normpath(file_path),
+            ' layer="{}"'.format(layer_name) if layer_name else '',
             destFilename)
         self.commands.append(command)
 

python/plugins/processing/tests/Grass7AlgorithmsVectorTest.py

@@ -31,6 +31,7 @@
 import shutil
 import os
 import tempfile
+import re
 
 from qgis.core import (QgsVectorLayer,
                        QgsApplication,
@@ -48,6 +49,9 @@
 from processing.algs.grass7.Grass7Utils import Grass7Utils
 
 
+testDataPath = os.path.join(os.path.dirname(__file__), 'testdata')
+
+
 class TestGrass7AlgorithmsVectorTest(unittest.TestCase, AlgorithmsTestBase.AlgorithmsTest):
 
     @classmethod
@@ -241,6 +245,65 @@ def testOutputToGeopackage(self):
 
         QgsProject.instance().removeMapLayer(layer)
 
+    def testVectorLayerInput(self):
+        alg = QgsApplication.processingRegistry().createAlgorithmById('grass7:v.buffer')
+        self.assertIsNotNone(alg)
+        self.assertFalse(alg.commands)
+
+        def get_command(alg):
+            command = alg.commands[-1]
+            command = re.sub(r'output=".*?"', 'output="###"', command)
+            command = command.replace(testDataPath, 'testdata')
+            return command
+
+        # GML source
+        source = os.path.join(testDataPath, 'points.gml')
+        vl = QgsVectorLayer(source)
+        self.assertTrue(vl.isValid())
+        alg.loadVectorLayer('test_layer', vl, external=False)
+        self.assertEqual(get_command(alg), 'v.in.ogr min_area=None snap=None input="testdata/points.gml" output="###" --overwrite -o')
+        # try with external -- not support for GML, so should fall back to v.in.ogr
+        alg.loadVectorLayer('test_layer', vl, external=True)
+        self.assertEqual(get_command(alg), 'v.in.ogr min_area=None snap=None input="testdata/points.gml" output="###" --overwrite -o')
+
+        # SHP source
+        source = os.path.join(testDataPath, 'lines_z.shp')
+        vl = QgsVectorLayer(source)
+        self.assertTrue(vl.isValid())
+        alg.loadVectorLayer('test_layer', vl, external=False)
+        self.assertEqual(get_command(alg), 'v.in.ogr min_area=None snap=None input="testdata/lines_z.shp" output="###" --overwrite -o')
+        # try with external -- should work for shapefile
+        alg.loadVectorLayer('test_layer', vl, external=True)
+        self.assertEqual(get_command(alg), 'v.external input="testdata/lines_z.shp" output="###" --overwrite -o')
+
+        # GPKG source
+        source = os.path.join(testDataPath, 'custom/pol.gpkg')
+        vl = QgsVectorLayer(source + '|layername=pol2')
+        self.assertTrue(vl.isValid())
+        alg.loadVectorLayer('test_layer', vl, external=False)
+        self.assertEqual(get_command(alg), 'v.in.ogr min_area=None snap=None input="testdata/custom/pol.gpkg" layer="pol2" output="###" --overwrite -o')
+        # try with external -- should work for Geopackage (although grass itself tends to crash here!)
+        alg.loadVectorLayer('test_layer', vl, external=True)
+        self.assertEqual(get_command(alg), 'v.external input="testdata/custom/pol.gpkg" layer="pol2" output="###" --overwrite -o')
+
+        # different layer
+        source = os.path.join(testDataPath, 'custom/pol.gpkg')
+        vl = QgsVectorLayer(source + '|layername=pol3')
+        self.assertTrue(vl.isValid())
+        alg.loadVectorLayer('test_layer', vl, external=False)
+        self.assertEqual(get_command(alg), 'v.in.ogr min_area=None snap=None input="testdata/custom/pol.gpkg" layer="pol3" output="###" --overwrite -o')
+        alg.loadVectorLayer('test_layer', vl, external=True)
+        self.assertEqual(get_command(alg), 'v.external input="testdata/custom/pol.gpkg" layer="pol3" output="###" --overwrite -o')
+
+        # GPKG no layer: you get what you get and you don't get upset
+        source = os.path.join(testDataPath, 'custom/pol.gpkg')
+        vl = QgsVectorLayer(source)
+        self.assertTrue(vl.isValid())
+        alg.loadVectorLayer('test_layer', vl, external=False)
+        self.assertEqual(get_command(alg), 'v.in.ogr min_area=None snap=None input="testdata/custom/pol.gpkg" output="###" --overwrite -o')
+        alg.loadVectorLayer('test_layer', vl, external=True)
+        self.assertEqual(get_command(alg), 'v.external input="testdata/custom/pol.gpkg" output="###" --overwrite -o')
+
 
 if __name__ == '__main__':
     nose2.main()

python/plugins/processing/tests/testdata/expected/grass7/buffer_polys_layer2.dbf

@@ -0,0 +1 @@
+PROJCS["Hotine_Oblique_Mercator_Azimuth_Center",GEOGCS["GCS_bessel",DATUM["D_unknown",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",2600000],PARAMETER["false_northing",1200000],UNIT["Meter",1]]

python/plugins/processing/tests/testdata/expected/grass7/buffer_polys_layer2.prj

@@ -0,0 +1 @@
+PROJCS["Hotine_Oblique_Mercator_Azimuth_Center",GEOGCS["GCS_bessel",DATUM["D_unknown",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["latitude_of_center",46.95240555555556],PARAMETER["longitude_of_center",7.439583333333333],PARAMETER["azimuth",90],PARAMETER["scale_factor",1],PARAMETER["false_easting",2600000],PARAMETER["false_northing",1200000],UNIT["Meter",1]]

python/plugins/processing/tests/testdata/expected/grass7/buffer_polys_layer2.shp

@@ -32,6 +32,7 @@ tests:
         compare:
           geometry:
             precision: 7
+          ignore_crs_check: true
 
   - algorithm: grass7:v.rast.stats
     name: V.rast.stats
@@ -271,3 +272,62 @@ tests:
       raster_output:
         hash: 7aa8e68b697e1558e6621fa23b5f1f01a5826649ffc31fd255e709a1
         type: rasterhash
+
+  - algorithm: grass7:v.buffer
+    name: Buffer with layername
+    params:
+      -c: false
+      -s: false
+      -t: false
+      GRASS_MIN_AREA_PARAMETER: 0.0001
+      GRASS_OUTPUT_TYPE_PARAMETER: 0
+      GRASS_SNAP_TOLERANCE_PARAMETER: -1.0
+      GRASS_VECTOR_DSCO: ''
+      GRASS_VECTOR_LCO: ''
+      angle: 0.0
+      cats: ''
+      distance: 10.0
+      input:
+        name: custom/pol.gpkg|layername=pol3
+        type: vector
+      scale: 1.0
+      tolerance: 0.01
+      type:
+      - 0
+      - 1
+      - 4
+      where: ''
+    results:
+      output:
+        name: expected/grass7/buffer_polys_layer3.shp
+        type: vector
+
+  - algorithm: grass7:v.buffer
+    name: Buffer with layername 2
+    params:
+      -c: false
+      -s: false
+      -t: false
+      GRASS_MIN_AREA_PARAMETER: 0.0001
+      GRASS_OUTPUT_TYPE_PARAMETER: 0
+      GRASS_SNAP_TOLERANCE_PARAMETER: -1.0
+      GRASS_VECTOR_DSCO: ''
+      GRASS_VECTOR_LCO: ''
+      angle: 0.0
+      cats: ''
+      distance: 10.0
+      input:
+        name: custom/pol.gpkg|layername=pol2
+        type: vector
+      scale: 1.0
+      tolerance: 0.01
+      type:
+      - 0
+      - 1
+      - 4
+      where: ''
+    results:
+      output:
+        name: expected/grass7/buffer_polys_layer2.shp
+        type: vector
+