Port processing combineFields to c++

nyalldawson · nyalldawson · commit c41dca937c3d · 2017-09-22T15:19:32.000+10:00
diff --git a/python/core/processing/qgsprocessingutils.sip b/python/core/processing/qgsprocessingutils.sip
@@ -193,6 +193,15 @@ class QgsProcessingUtils
  :rtype: str
 %End
 
+    static QgsFields combineFields( const QgsFields &fieldsA, const QgsFields &fieldsB );
+%Docstring
+ Combines two field lists, avoiding duplicate field names (in a case-insensitive manner).
+
+ Duplicate field names will be altered to "name_2", "name_3", etc, finding the first
+ non-duplicate name.
+ :rtype: QgsFields
+%End
+
 };
 
 class QgsProcessingFeatureSource : QgsFeatureSource
diff --git a/python/plugins/processing/algs/qgis/HubLines.py b/python/plugins/processing/algs/qgis/HubLines.py
@@ -37,7 +37,8 @@
                        QgsProcessingParameterField,
                        QgsProcessingParameterFeatureSink,
                        QgsProcessingException,
-                       QgsExpression)
+                       QgsExpression,
+                       QgsProcessingUtils)
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
 from processing.tools import vector
 
@@ -89,7 +90,7 @@ def processAlgorithm(self, parameters, context, feedback):
         field_spoke = self.parameterAsString(parameters, self.SPOKE_FIELD, context)
         field_spoke_index = hub_source.fields().lookupField(field_spoke)
 
-        fields = vector.combineFields(hub_source.fields(), spoke_source.fields())
+        fields = QgsProcessingUtils.combineFields(hub_source.fields(), spoke_source.fields())
 
         (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                fields, QgsWkbTypes.LineString, hub_source.sourceCrs())
diff --git a/python/plugins/processing/algs/qgis/JoinAttributes.py b/python/plugins/processing/algs/qgis/JoinAttributes.py
@@ -82,7 +82,7 @@ def processAlgorithm(self, parameters, context, feedback):
         joinField1Index = input.fields().lookupField(field)
         joinField2Index = input2.fields().lookupField(field2)
 
-        outFields = vector.combineFields(input.fields(), input2.fields())
+        outFields = QgsProcessingUtils.combineFields(input.fields(), input2.fields())
 
         (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                outFields, input.wkbType(), input.sourceCrs())
diff --git a/python/plugins/processing/algs/qgis/SpatialJoin.py b/python/plugins/processing/algs/qgis/SpatialJoin.py
@@ -37,6 +37,7 @@
                        QgsFeatureRequest,
                        QgsGeometry,
                        QgsProcessing,
+                       QgsProcessingUtils,
                        QgsProcessingParameterBoolean,
                        QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterEnum,
@@ -148,7 +149,7 @@ def processAlgorithm(self, parameters, context, feedback):
                 if idx >= 0:
                     fields_to_join.append(join_source.fields().at(idx))
 
-        out_fields = vector.combineFields(source_fields, fields_to_join)
+        out_fields = QgsProcessingUtils.combineFields(source_fields, fields_to_join)
 
         (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                out_fields, source.wkbType(), source.sourceCrs())
diff --git a/python/plugins/processing/algs/qgis/SpatialJoinSummary.py b/python/plugins/processing/algs/qgis/SpatialJoinSummary.py
@@ -43,6 +43,7 @@
                        QgsDateTimeStatisticalSummary,
                        QgsStringStatisticalSummary,
                        QgsProcessing,
+                       QgsProcessingUtils,
                        QgsProcessingParameterBoolean,
                        QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterEnum,
@@ -247,7 +248,7 @@ def addField(original, stat, type):
                         else:
                             addFieldKeepType(join_field, f[0])
 
-        out_fields = vector.combineFields(source_fields, fields_to_join)
+        out_fields = QgsProcessingUtils.combineFields(source_fields, fields_to_join)
 
         (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                out_fields, source.wkbType(), source.sourceCrs())
diff --git a/python/plugins/processing/algs/qgis/SymmetricalDifference.py b/python/plugins/processing/algs/qgis/SymmetricalDifference.py
@@ -36,6 +36,7 @@
                        NULL,
                        QgsWkbTypes,
                        QgsMessageLog,
+                       QgsProcessingUtils,
                        QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterFeatureSink,
                        QgsSpatialIndex)
@@ -79,7 +80,7 @@ def processAlgorithm(self, parameters, context, feedback):
         sourceB = self.parameterAsSource(parameters, self.OVERLAY, context)
 
         geomType = QgsWkbTypes.multiType(sourceA.wkbType())
-        fields = vector.combineFields(sourceA.fields(), sourceB.fields())
+        fields = QgsProcessingUtils.combineFields(sourceA.fields(), sourceB.fields())
 
         (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                fields, geomType, sourceA.sourceCrs())
diff --git a/python/plugins/processing/algs/qgis/Union.py b/python/plugins/processing/algs/qgis/Union.py
@@ -34,7 +34,7 @@
                        QgsFeatureSink,
                        QgsGeometry,
                        QgsWkbTypes,
-                       QgsMessageLog,
+                       QgsProcessingUtils,
                        QgsProcessingParameterFeatureSource,
                        QgsProcessingParameterFeatureSink,
                        QgsSpatialIndex)
@@ -79,7 +79,7 @@ def processAlgorithm(self, parameters, context, feedback):
         sourceB = self.parameterAsSource(parameters, self.OVERLAY, context)
 
         geomType = QgsWkbTypes.multiType(sourceA.wkbType())
-        fields = vector.combineFields(sourceA.fields(), sourceB.fields())
+        fields = QgsProcessingUtils.combineFields(sourceA.fields(), sourceB.fields())
 
         (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                                fields, geomType, sourceA.sourceCrs())
diff --git a/python/plugins/processing/tools/vector.py b/python/plugins/processing/tools/vector.py
@@ -174,29 +174,6 @@ def extractPoints(geom):
     return points
 
 
-def combineFields(fieldsA, fieldsB):
-    """Create single field map from two input field maps.
-    """
-    fields = []
-    fields.extend(fieldsA)
-    namesA = [str(f.name()).lower() for f in fieldsA]
-    for field in fieldsB:
-        name = str(field.name()).lower()
-        if name in namesA:
-            idx = 2
-            newName = name + '_' + str(idx)
-            while newName in namesA:
-                idx += 1
-                newName = name + '_' + str(idx)
-            field = QgsField(newName, field.type(), field.typeName())
-        fields.append(field)
-
-    real_fields = QgsFields()
-    for f in fields:
-        real_fields.append(f)
-    return real_fields
-
-
 def checkMinDistance(point, index, distance, points):
     """Check if distance from given point to all other points is greater
     than given value.
diff --git a/src/core/processing/qgsprocessingutils.cpp b/src/core/processing/qgsprocessingutils.cpp
@@ -555,6 +555,41 @@ QString QgsProcessingUtils::convertToCompatibleFormat( const QgsVectorLayer *vl,
   }
 }
 
+QgsFields QgsProcessingUtils::combineFields( const QgsFields &fieldsA, const QgsFields &fieldsB )
+{
+  QgsFields outFields = fieldsA;
+  QSet< QString > usedNames;
+  for ( const QgsField &f : fieldsA )
+  {
+    usedNames.insert( f.name().toLower() );
+  }
+
+  for ( const QgsField &f : fieldsB )
+  {
+    if ( usedNames.contains( f.name().toLower() ) )
+    {
+      int idx = 2;
+      QString newName = f.name() + '_' + QString::number( idx );
+      while ( usedNames.contains( newName.toLower() ) )
+      {
+        idx++;
+        newName = f.name() + '_' + QString::number( idx );
+      }
+      QgsField newField = f;
+      newField.setName( newName );
+      outFields.append( newField );
+      usedNames.insert( newName.toLower() );
+    }
+    else
+    {
+      usedNames.insert( f.name().toLower() );
+      outFields.append( f );
+    }
+  }
+
+  return outFields;
+}
+
 
 //
 // QgsProcessingFeatureSource
diff --git a/src/core/processing/qgsprocessingutils.h b/src/core/processing/qgsprocessingutils.h
@@ -224,6 +224,14 @@ class CORE_EXPORT QgsProcessingUtils
         QgsProcessingContext &context,
         QgsProcessingFeedback *feedback );
 
+    /**
+     * Combines two field lists, avoiding duplicate field names (in a case-insensitive manner).
+     *
+     * Duplicate field names will be altered to "name_2", "name_3", etc, finding the first
+     * non-duplicate name.
+     */
+    static QgsFields combineFields( const QgsFields &fieldsA, const QgsFields &fieldsB );
+
   private:
 
     static bool canUseLayer( const QgsRasterLayer *layer );
diff --git a/tests/src/core/testqgsprocessing.cpp b/tests/src/core/testqgsprocessing.cpp
@@ -352,6 +352,7 @@ class TestQgsProcessing: public QObject
     void tempUtils();
     void convertCompatible();
     void create();
+    void combineFields();
 
   private:
 
@@ -5443,5 +5444,40 @@ void TestQgsProcessing::create()
   QCOMPARE( newInstance->provider(), &p );
 }
 
+void TestQgsProcessing::combineFields()
+{
+  QgsFields a;
+  QgsFields b;
+  // combine empty fields
+  QgsFields res = QgsProcessingUtils::combineFields( a, b );
+  QVERIFY( res.isEmpty() );
+
+  // fields in a
+  a.append( QgsField( "name" ) );
+  res = QgsProcessingUtils::combineFields( a, b );
+  QCOMPARE( res.count(), 1 );
+  QCOMPARE( res.at( 0 ).name(), QStringLiteral( "name" ) );
+  b.append( QgsField( "name" ) );
+  res = QgsProcessingUtils::combineFields( a, b );
+  QCOMPARE( res.count(), 2 );
+  QCOMPARE( res.at( 0 ).name(), QStringLiteral( "name" ) );
+  QCOMPARE( res.at( 1 ).name(), QStringLiteral( "name_2" ) );
+
+  a.append( QgsField( "NEW" ) );
+  res = QgsProcessingUtils::combineFields( a, b );
+  QCOMPARE( res.count(), 3 );
+  QCOMPARE( res.at( 0 ).name(), QStringLiteral( "name" ) );
+  QCOMPARE( res.at( 1 ).name(), QStringLiteral( "NEW" ) );
+  QCOMPARE( res.at( 2 ).name(), QStringLiteral( "name_2" ) );
+
+  b.append( QgsField( "new" ) );
+  res = QgsProcessingUtils::combineFields( a, b );
+  QCOMPARE( res.count(), 4 );
+  QCOMPARE( res.at( 0 ).name(), QStringLiteral( "name" ) );
+  QCOMPARE( res.at( 1 ).name(), QStringLiteral( "NEW" ) );
+  QCOMPARE( res.at( 2 ).name(), QStringLiteral( "name_2" ) );
+  QCOMPARE( res.at( 3 ).name(), QStringLiteral( "new_2" ) );
+}
+
 QGSTEST_MAIN( TestQgsProcessing )
 #include "testqgsprocessing.moc"
