[processing][FEATURE] Return multi geometries from split alg

accept multi geometries as input
qgis · Dec 2, 2016 · b02c6a3 · b02c6a3
1 parent 3a789e5
commit b02c6a3
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Showing 8 changed files with 108 additions and 133 deletions.
diff --git a/python/plugins/processing/algs/help/qgis.yaml b/python/plugins/processing/algs/help/qgis.yaml
@@ -504,6 +504,8 @@ qgis:snappointstogrid: >
 
 qgis:splitwithlines: >
   This algorithm splits the lines or polygons in one layer using the lines in another layer to define the breaking points. Intersection between geometries in both layers are considered as split points.
+
+  Output will contain multi geometries for split features.
 
 qgis:splitvectorlayer: >
   This algorithm takes a vector layer and an attribute and generates a set of vector layers in an output folder. Each of the layers created in that folder contains all features from the input layer with the same value for the specified attribute.

diff --git a/python/plugins/processing/algs/qgis/SplitWithLines.py b/python/plugins/processing/algs/qgis/SplitWithLines.py
@@ -26,7 +26,7 @@
 
 __revision__ = '$Format:%H$'
 
-from qgis.core import QgsFeatureRequest, QgsFeature, QgsGeometry, QgsSpatialIndex, QgsWkbTypes, QgsMessageLog
+from qgis.core import QgsFeatureRequest, QgsFeature, QgsGeometry, QgsSpatialIndex, QgsWkbTypes, QgsPoint
 from processing.core.GeoAlgorithm import GeoAlgorithm
 from processing.core.parameters import ParameterVector
 from processing.core.outputs import OutputVector
@@ -61,7 +61,7 @@ def processAlgorithm(self, progress):
         fieldList = layerA.fields()
 
         writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fieldList,
-                                                                     layerA.wkbType(), layerA.crs())
+                        QgsWkbTypes.multiType(layerA.wkbType()), layerA.crs())
 
         spatialIndex = QgsSpatialIndex()
         splitGeoms = {}
@@ -81,107 +81,107 @@ def processAlgorithm(self, progress):
         else:
             total = 100.0 / float(len(features))
 
-        multiGeoms = 0 # how many multi geometries were encountered
-
         for current, inFeatA in enumerate(features):
             inGeom = inFeatA.geometry()
+            attrsA = inFeatA.attributes()
+            outFeat.setAttributes(attrsA)
 
             if inGeom.isMultipart():
-                multiGeoms += 1
-                # MultiGeometries are not allowed because the result of a splitted part cannot be clearly defined:
-                # 1) add both new parts as new features
-                # 2) store one part as a new feature and the other one as part of the multi geometry
-                # 2a) which part should be which, seems arbitrary
+                inGeoms = []
+
+                for g in inGeom.asGeometryCollection():
+                    inGeoms.append(g)
             else:
-                attrsA = inFeatA.attributes()
-                outFeat.setAttributes(attrsA)
                 inGeoms = [inGeom]
-                lines = spatialIndex.intersects(inGeom.boundingBox())
 
-                if len(lines) > 0:  # has intersection of bounding boxes
-                    splittingLines = []
+            lines = spatialIndex.intersects(inGeom.boundingBox())
+
+            if len(lines) > 0:  # has intersection of bounding boxes
+                splittingLines = []
+
+                engine = QgsGeometry.createGeometryEngine(inGeom.geometry())
+                engine.prepareGeometry()
 
-                    engine = QgsGeometry.createGeometryEngine(inGeom.geometry())
-                    engine.prepareGeometry()
+                for i in lines:
+                    try:
+                        splitGeom = splitGeoms[i]
+                    except:
+                        continue
 
-                    for i in lines:
-                        try:
-                            splitGeom = splitGeoms[i]
-                        except:
+                    # check if trying to self-intersect
+                    if sameLayer:
+                        if inFeatA.id() == i:
                             continue
 
-                        # check if trying to self-intersect
-                        if sameLayer:
-                            if inFeatA.id() == i:
+                    if engine.intersects(splitGeom.geometry()):
+                        splittingLines.append(splitGeom)
+
+                if len(splittingLines) > 0:
+                    for splitGeom in splittingLines:
+                        splitterPList = None
+                        outGeoms = []
+
+                        split_geom_engine = QgsGeometry.createGeometryEngine(splitGeom.geometry())
+                        split_geom_engine.prepareGeometry()
+
+                        while len(inGeoms) > 0:
+                            inGeom = inGeoms.pop()
+
+                            if inGeom.isEmpty(): # this has been encountered and created a run-time error
                                 continue
 
-                        if engine.intersects(splitGeom.geometry()):
-                            splittingLines.append(splitGeom)
-
-                    if len(splittingLines) > 0:
-                        for splitGeom in splittingLines:
-                            splitterPList = None
-                            outGeoms = []
-
-                            split_geom_engine = QgsGeometry.createGeometryEngine(splitGeom.geometry())
-                            split_geom_engine.prepareGeometry()
-
-                            while len(inGeoms) > 0:
-                                inGeom = inGeoms.pop()
-
-                                if split_geom_engine.intersects(inGeom.geometry()):
-                                    inPoints = vector.extractPoints(inGeom)
-                                    if splitterPList == None:
-                                        splitterPList = vector.extractPoints(splitGeom)
-
-                                    try:
-                                        result, newGeometries, topoTestPoints = inGeom.splitGeometry(splitterPList, False)
-                                    except:
-                                        ProcessingLog.addToLog(ProcessingLog.LOG_WARNING,
-                                                               self.tr('Geometry exception while splitting'))
-                                        result = 1
-
-                                    # splitGeometry: If there are several intersections
-                                    # between geometry and splitLine, only the first one is considered.
-                                    if result == 0:  # split occurred
-                                        if inPoints == vector.extractPoints(inGeom):
-                                            # bug in splitGeometry: sometimes it returns 0 but
-                                            # the geometry is unchanged
-                                            QgsMessageLog.logMessage("appending")
-                                            outGeoms.append(inGeom)
-                                        else:
-                                            inGeoms.append(inGeom)
-
-                                            for aNewGeom in newGeometries:
-                                                inGeoms.append(aNewGeom)
-                                    else:
-                                        QgsMessageLog.logMessage("appending else")
+                            if split_geom_engine.intersects(inGeom.geometry()):
+                                inPoints = vector.extractPoints(inGeom)
+                                if splitterPList == None:
+                                    splitterPList = vector.extractPoints(splitGeom)
+
+                                try:
+                                    result, newGeometries, topoTestPoints = inGeom.splitGeometry(splitterPList, False)
+                                except:
+                                    ProcessingLog.addToLog(ProcessingLog.LOG_WARNING,
+                                                           self.tr('Geometry exception while splitting'))
+                                    result = 1
+
+                                # splitGeometry: If there are several intersections
+                                # between geometry and splitLine, only the first one is considered.
+                                if result == 0:  # split occurred
+                                    if inPoints == vector.extractPoints(inGeom):
+                                        # bug in splitGeometry: sometimes it returns 0 but
+                                        # the geometry is unchanged
                                         outGeoms.append(inGeom)
+                                    else:
+                                        inGeoms.append(inGeom)
+
+                                        for aNewGeom in newGeometries:
+                                            inGeoms.append(aNewGeom)
                                 else:
                                     outGeoms.append(inGeom)
+                            else:
+                                outGeoms.append(inGeom)
 
-                            inGeoms = outGeoms
+                        inGeoms = outGeoms
 
-                for aGeom in inGeoms:
-                    passed = True
+            parts = []
 
-                    if QgsWkbTypes.geometryType( aGeom.wkbType() )  == QgsWkbTypes.LineGeometry \
-                            and not QgsWkbTypes.isMultiType(aGeom.wkbType()):
-                        passed = len(aGeom.asPolyline()) > 2
+            for aGeom in inGeoms:
+                passed = True
 
-                        if not passed:
-                            passed = (len(aGeom.asPolyline()) == 2 and
-                                      aGeom.asPolyline()[0] != aGeom.asPolyline()[1])
-                            # sometimes splitting results in lines of zero length
+                if QgsWkbTypes.geometryType( aGeom.wkbType() )  == QgsWkbTypes.LineGeometry:
+                    numPoints = aGeom.geometry().numPoints()
 
-                    if passed:
-                        outFeat.setGeometry(aGeom)
-                        writer.addFeature(outFeat)
+                    if numPoints <= 2:
+                        if numPoints == 2:
+                            passed = not aGeom.geometry().isClosed() # tests if vertex 0 = vertex 1
+                        else:
+                            passed = False
+                            # sometimes splitting results in lines of zero length
 
-            progress.setPercentage(int(current * total))
+                if passed:
+                    parts.append(aGeom)
 
-        if multiGeoms > 0:
-            ProcessingLog.addToLog(ProcessingLog.LOG_INFO,
-                                   self.tr('Feature geometry error: %s input features ignored due to multi-geometry.') % str(multiGeoms))
+            if len(parts) > 0:
+                outFeat.setGeometry(QgsGeometry.collectGeometry(parts))
+                writer.addFeature(outFeat)
 
+            progress.setPercentage(int(current * total))
         del writer
diff --git a/python/plugins/processing/tests/testdata/expected/split_lines_with_lines.gfs b/python/plugins/processing/tests/testdata/expected/split_lines_with_lines.gfs
@@ -2,11 +2,11 @@
   <GMLFeatureClass>
     <Name>split_lines_with_lines</Name>
     <ElementPath>split_lines_with_lines</ElementPath>
-    <!--LINESTRING-->
-    <GeometryType>2</GeometryType>
+    <!--MULTILINESTRING-->
+    <GeometryType>5</GeometryType>
     <SRSName>EPSG:4326</SRSName>
     <DatasetSpecificInfo>
-      <FeatureCount>11</FeatureCount>
+      <FeatureCount>7</FeatureCount>
       <ExtentXMin>-1.00000</ExtentXMin>
       <ExtentXMax>11.00000</ExtentXMax>
       <ExtentYMin>-3.00000</ExtentYMin>

diff --git a/python/plugins/processing/tests/testdata/expected/split_lines_with_lines.gml b/python/plugins/processing/tests/testdata/expected/split_lines_with_lines.gml
@@ -13,52 +13,32 @@
 
   <gml:featureMember>
     <ogr:split_lines_with_lines fid="lines.0">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6,2 9,2 9,3 11,5</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>6,2 9,2 9,3 11,5</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines fid="lines.1">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>-1,-1 1,-1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>-1,-1 1,-1</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines fid="lines.2">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2.0,1.86331771490359 2,2 3,2 3,3</gml:coordinates></gml:LineString></ogr:geometryProperty>
-    </ogr:split_lines_with_lines>
-  </gml:featureMember>
-  <gml:featureMember>
-    <ogr:split_lines_with_lines fid="lines.2">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2,0 2.0,1.86331771490359</gml:coordinates></gml:LineString></ogr:geometryProperty>
-    </ogr:split_lines_with_lines>
-  </gml:featureMember>
-  <gml:featureMember>
-    <ogr:split_lines_with_lines fid="lines.3">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>4.21601489757914,1.0 5,1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>2.0,1.86331771490359 2,2 3,2 3,3</gml:coordinates></gml:LineString></gml:lineStringMember><gml:lineStringMember><gml:LineString><gml:coordinates>2,0 2.0,1.86331771490359</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines fid="lines.3">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>3,1 4.21601489757914,1.0</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>4.21601489757914,1.0 5,1</gml:coordinates></gml:LineString></gml:lineStringMember><gml:lineStringMember><gml:LineString><gml:coordinates>3,1 4.21601489757914,1.0</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines fid="lines.4">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>8.5655671605538,-3.0 10,-3</gml:coordinates></gml:LineString></ogr:geometryProperty>
-    </ogr:split_lines_with_lines>
-  </gml:featureMember>
-  <gml:featureMember>
-    <ogr:split_lines_with_lines fid="lines.4">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>7,-3 8.5655671605538,-3.0</gml:coordinates></gml:LineString></ogr:geometryProperty>
-    </ogr:split_lines_with_lines>
-  </gml:featureMember>
-  <gml:featureMember>
-    <ogr:split_lines_with_lines fid="lines.5">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6.91202704418487,-2.08797295581513 10,1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>8.5655671605538,-3.0 10,-3</gml:coordinates></gml:LineString></gml:lineStringMember><gml:lineStringMember><gml:LineString><gml:coordinates>7,-3 8.5655671605538,-3.0</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines fid="lines.5">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6,-3 6.91202704418487,-2.08797295581513</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>6.91202704418487,-2.08797295581513 10,1</gml:coordinates></gml:LineString></gml:lineStringMember><gml:lineStringMember><gml:LineString><gml:coordinates>6,-3 6.91202704418487,-2.08797295581513</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines>
   </gml:featureMember>
   <gml:featureMember>

diff --git a/python/plugins/processing/tests/testdata/expected/split_lines_with_lines_same.gfs b/python/plugins/processing/tests/testdata/expected/split_lines_with_lines_same.gfs
@@ -2,8 +2,8 @@
   <GMLFeatureClass>
     <Name>split_lines_with_lines_same</Name>
     <ElementPath>split_lines_with_lines_same</ElementPath>
-    <!--LINESTRING-->
-    <GeometryType>2</GeometryType>
+    <!--MULTILINESTRING-->
+    <GeometryType>5</GeometryType>
     <SRSName>EPSG:4326</SRSName>
     <DatasetSpecificInfo>
       <FeatureCount>7</FeatureCount>

diff --git a/python/plugins/processing/tests/testdata/expected/split_lines_with_lines_same.gml b/python/plugins/processing/tests/testdata/expected/split_lines_with_lines_same.gml
@@ -13,32 +13,32 @@
 
   <gml:featureMember>
     <ogr:split_lines_with_lines_same fid="lines.0">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6,2 9,2 9,3 11,5</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>6,2 9,2 9,3 11,5</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines_same>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines_same fid="lines.1">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>-1,-1 1,-1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>-1,-1 1,-1</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines_same>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines_same fid="lines.2">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>2,0 2,2 3,2 3,3</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>2,0 2,2 3,2 3,3</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines_same>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines_same fid="lines.3">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>3,1 5,1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>3,1 5,1</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines_same>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines_same fid="lines.4">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>7,-3 10,-3</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>7,-3 10,-3</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines_same>
   </gml:featureMember>
   <gml:featureMember>
     <ogr:split_lines_with_lines_same fid="lines.5">
-      <ogr:geometryProperty><gml:LineString srsName="EPSG:4326"><gml:coordinates>6,-3 10,1</gml:coordinates></gml:LineString></ogr:geometryProperty>
+      <ogr:geometryProperty><gml:MultiLineString srsName="EPSG:4326"><gml:lineStringMember><gml:LineString><gml:coordinates>6,-3 10,1</gml:coordinates></gml:LineString></gml:lineStringMember></gml:MultiLineString></ogr:geometryProperty>
     </ogr:split_lines_with_lines_same>
   </gml:featureMember>
   <gml:featureMember>