Port clip algorithm to new API

qgis · Jun 6, 2017 · f1511a2 · f1511a2
1 parent 9038872
commit f1511a2
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Showing 3 changed files with 116 additions and 106 deletions.
diff --git a/python/plugins/processing/algs/qgis/Clip.py b/python/plugins/processing/algs/qgis/Clip.py
@@ -34,11 +34,14 @@
                        QgsFeatureRequest,
                        QgsWkbTypes,
                        QgsMessageLog,
-                       QgsProcessingUtils)
+                       QgsProcessingUtils,
+                       QgsProcessingParameterFeatureSource,
+                       QgsProcessingParameterFeatureSink,
+                       QgsProcessingOutputVectorLayer,
+                       QgsProcessingParameterDefinition
+                       )
 
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
-from processing.core.parameters import ParameterVector
-from processing.core.outputs import OutputVector
 from processing.tools import dataobjects
 
 pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
@@ -58,11 +61,12 @@ def group(self):
 
     def __init__(self):
         super().__init__()
-        self.addParameter(ParameterVector(Clip.INPUT,
-                                          self.tr('Input layer')))
-        self.addParameter(ParameterVector(Clip.OVERLAY,
-                                          self.tr('Clip layer'), [dataobjects.TYPE_VECTOR_POLYGON]))
-        self.addOutput(OutputVector(Clip.OUTPUT, self.tr('Clipped')))
+
+        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT, self.tr('Input layer')))
+        self.addParameter(QgsProcessingParameterFeatureSource(self.OVERLAY, self.tr('Clip layer'), [QgsProcessingParameterDefinition.TypeVectorPolygon]))
+
+        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Clipped')))
+        self.addOutput(QgsProcessingOutputVectorLayer(self.OUTPUT, self.tr("Clipped")))
 
     def name(self):
         return 'clip'
@@ -71,17 +75,17 @@ def displayName(self):
         return self.tr('Clip')
 
     def processAlgorithm(self, parameters, context, feedback):
-        source_layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(Clip.INPUT), context)
-        mask_layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(Clip.OVERLAY), context)
 
-        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(source_layer.fields(),
-                                                                     QgsWkbTypes.multiType(source_layer.wkbType()),
-                                                                     source_layer.crs(), context)
+        feature_source = self.parameterAsSource(parameters, self.INPUT, context)
+        mask_source = self.parameterAsSource(parameters, self.OVERLAY, context)
+
+        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
+                                               feature_source.fields(), QgsWkbTypes.multiType(feature_source.wkbType()), feature_source.sourceCrs())
 
         # first build up a list of clip geometries
         clip_geoms = []
-        for maskFeat in QgsProcessingUtils.getFeatures(mask_layer, context, QgsFeatureRequest().setSubsetOfAttributes([])):
-            clip_geoms.append(maskFeat.geometry())
+        for mask_feature in mask_source.getFeatures(QgsFeatureRequest().setSubsetOfAttributes([])):
+            clip_geoms.append(mask_feature.geometry())
 
         # are we clipping against a single feature? if so, we can show finer progress reports
         if len(clip_geoms) > 1:
@@ -98,8 +102,10 @@ def processAlgorithm(self, parameters, context, feedback):
         tested_feature_ids = set()
 
         for i, clip_geom in enumerate(clip_geoms):
-            input_features = [f for f in QgsProcessingUtils.getFeatures(source_layer, context,
-                                                                        QgsFeatureRequest().setFilterRect(clip_geom.boundingBox()))]
+            if feedback.isCanceled():
+                break
+
+            input_features = [f for f in feature_source.getFeatures(QgsFeatureRequest().setFilterRect(clip_geom.boundingBox()))]
 
             if not input_features:
                 continue
@@ -110,6 +116,9 @@ def processAlgorithm(self, parameters, context, feedback):
                 total = 0
 
             for current, in_feat in enumerate(input_features):
+                if feedback.isCanceled():
+                    break
+
                 if not in_feat.geometry():
                     continue
 
@@ -137,7 +146,7 @@ def processAlgorithm(self, parameters, context, feedback):
                     out_feat = QgsFeature()
                     out_feat.setGeometry(new_geom)
                     out_feat.setAttributes(in_feat.attributes())
-                    writer.addFeature(out_feat)
+                    sink.addFeature(out_feat)
                 except:
                     QgsMessageLog.logMessage(self.tr('Feature geometry error: One or more '
                                                      'output features ignored due to '
@@ -151,4 +160,4 @@ def processAlgorithm(self, parameters, context, feedback):
                 # coarse progress report for multiple clip geometries
                 feedback.setProgress(100.0 * i / len(clip_geoms))
 
-        del writer
+        return {self.OUTPUT: dest_id}
diff --git a/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
@@ -75,7 +75,7 @@
 # from .ConvexHull import ConvexHull
 # from .FixedDistanceBuffer import FixedDistanceBuffer
 # from .VariableDistanceBuffer import VariableDistanceBuffer
-# from .Clip import Clip
+from .Clip import Clip
 # from .Difference import Difference
 # from .Dissolve import Dissolve
 # from .Intersection import Intersection
@@ -210,7 +210,7 @@ def getAlgs(self):
         #         PolygonsToLines(), LinesToPolygons(), ExtractNodes(),
         #         ConvexHull(), FixedDistanceBuffer(),
         #         VariableDistanceBuffer(), Dissolve(), Difference(),
-        #         Intersection(), Union(), Clip(), ExtentFromLayer(),
+        #         Intersection(), Union(), ExtentFromLayer(),
         #         RandomSelection(), RandomSelectionWithinSubsets(),
         #         SelectByLocation(), RandomExtract(), DeleteHoles(),
         #         RandomExtractWithinSubsets(), ExtractByLocation(),
@@ -263,7 +263,8 @@ def getAlgs(self):
                 Aspect(),
                 AutoincrementalField(),
                 Boundary(),
-                BoundingBox()]
+                BoundingBox(),
+                Clip()]
 
         if hasPlotly:
             #     from .VectorLayerHistogram import VectorLayerHistogram

diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -25,90 +25,90 @@ tests:
 #        name: expected/polys_deleteholes.gml
 #        type: vector
 #
-#  - algorithm: qgis:clip
-#    name: Clip lines by polygons
-#    params:
-#      INPUT:
-#        name: custom/lines2.gml
-#        type: vector
-#      OVERLAY:
-#        name: polys.gml
-#        type: vector
-#    results:
-#      OUTPUT:
-#        name: expected/clip_lines_by_polygon.gml
-#        type: vector
-#
-#  - algorithm: qgis:clip
-#    name: Clip lines by multipolygon
-#    params:
-#      INPUT:
-#        name: lines.gml
-#        type: vector
-#      OVERLAY:
-#        name: multipolys.gml
-#        type: vector
-#    results:
-#      OUTPUT:
-#        name: expected/clip_lines_by_multipolygon.gml
-#        type: vector
-#
-#  - algorithm: qgis:clip
-#    name: Clip polygons by multipolygons
-#    params:
-#      INPUT:
-#        name: polys.gml
-#        type: vector
-#      OVERLAY:
-#        name: multipolys.gml
-#        type: vector
-#    results:
-#      OUTPUT:
-#        name: expected/clip_polys_by_multipolygon.gml
-#        type: vector
-#
-#  - algorithm: qgis:clip
-#    name: Clip multipolygons by polygons
-#    params:
-#      INPUT:
-#        name: multipolys.gml
-#        type: vector
-#      OVERLAY:
-#        name: polys.gml
-#        type: vector
-#    results:
-#      OUTPUT:
-#        name: expected/clip_multipolygons_by_polygons.gml
-#        type: vector
-#
-#  - algorithm: qgis:clip
-#    name: Clip points by polygons
-#    params:
-#      INPUT:
-#        name: points.gml
-#        type: vector
-#      OVERLAY:
-#        name: polys.gml
-#        type: vector
-#    results:
-#      OUTPUT:
-#        name: expected/clip_points_by_polygons.gml
-#        type: vector
-#
-#  - algorithm: qgis:clip
-#    name: Clip points by multipolygons
-#    params:
-#      INPUT:
-#        name: points.gml
-#        type: vector
-#      OVERLAY:
-#        name: multipolys.gml
-#        type: vector
-#    results:
-#      OUTPUT:
-#        name: expected/clip_points_by_multipolygons.gml
-#        type: vector
-#
+  - algorithm: qgis:clip
+    name: Clip lines by polygons
+    params:
+      INPUT:
+        name: custom/lines2.gml
+        type: vector
+      OVERLAY:
+        name: polys.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/clip_lines_by_polygon.gml
+        type: vector
+
+  - algorithm: qgis:clip
+    name: Clip lines by multipolygon
+    params:
+      INPUT:
+        name: lines.gml
+        type: vector
+      OVERLAY:
+        name: multipolys.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/clip_lines_by_multipolygon.gml
+        type: vector
+
+  - algorithm: qgis:clip
+    name: Clip polygons by multipolygons
+    params:
+      INPUT:
+        name: polys.gml
+        type: vector
+      OVERLAY:
+        name: multipolys.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/clip_polys_by_multipolygon.gml
+        type: vector
+
+  - algorithm: qgis:clip
+    name: Clip multipolygons by polygons
+    params:
+      INPUT:
+        name: multipolys.gml
+        type: vector
+      OVERLAY:
+        name: polys.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/clip_multipolygons_by_polygons.gml
+        type: vector
+
+  - algorithm: qgis:clip
+    name: Clip points by polygons
+    params:
+      INPUT:
+        name: points.gml
+        type: vector
+      OVERLAY:
+        name: polys.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/clip_points_by_polygons.gml
+        type: vector
+
+  - algorithm: qgis:clip
+    name: Clip points by multipolygons
+    params:
+      INPUT:
+        name: points.gml
+        type: vector
+      OVERLAY:
+        name: multipolys.gml
+        type: vector
+    results:
+      OUTPUT:
+        name: expected/clip_points_by_multipolygons.gml
+        type: vector
+
 #  # These datasets should produce a geometry collection and not a polygon only
 #  # dataset. If the algorithm is fixed, a new test should be introduced to
 #  # check this behavior.