[processing] port Split vector layer algorithm to C++

python/plugins/processing/algs/qgis/QgisAlgorithmProvider.py

@@ -95,7 +95,6 @@
 from .VectorLayerHistogram import VectorLayerHistogram
 from .VectorLayerScatterplot import VectorLayerScatterplot
 from .VectorLayerScatterplot3D import VectorLayerScatterplot3D
-from .VectorSplit import VectorSplit
 from .VoronoiPolygons import VoronoiPolygons
 
 
@@ -177,7 +176,6 @@ def getAlgs(self):
                 VectorLayerHistogram(),
                 VectorLayerScatterplot(),
                 VectorLayerScatterplot3D(),
-                VectorSplit(),
                 VoronoiPolygons(),
                 ]
 

src/analysis/CMakeLists.txt

@@ -155,6 +155,7 @@ SET(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmsplitfeaturesbyattributecharacter.cpp
   processing/qgsalgorithmsplitlineantimeridian.cpp
   processing/qgsalgorithmsplitlinesbylength.cpp
+  processing/qgsalgorithmsplitvectorlayer.cpp
   processing/qgsalgorithmsplitwithlines.cpp
   processing/qgsalgorithmstringconcatenation.cpp
   processing/qgsalgorithmswapxy.cpp

src/analysis/processing/qgsalgorithmsplitvectorlayer.cpp

@@ -0,0 +1,130 @@
+/***************************************************************************
+                         qgsalgorithmsplitvectorlayer.cpp
+                         ---------------------
+    begin                : May 2020
+    copyright            : (C) 2020 by Alexander Bruy
+    email                : alexander dot bruy at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsalgorithmsplitvectorlayer.h"
+#include "qgsvectorfilewriter.h"
+
+///@cond PRIVATE
+
+QString QgsSplitVectorLayerAlgorithm::name() const
+{
+  return QStringLiteral( "splitvectorlayer" );
+}
+
+QString QgsSplitVectorLayerAlgorithm::displayName() const
+{
+  return QObject::tr( "Split vector layer" );
+}
+
+QStringList QgsSplitVectorLayerAlgorithm::tags() const
+{
+  return QObject::tr( "vector,split,field,unique" ).split( ',' );
+}
+
+QString QgsSplitVectorLayerAlgorithm::group() const
+{
+  return QObject::tr( "Vector general" );
+}
+
+QString QgsSplitVectorLayerAlgorithm::groupId() const
+{
+  return QStringLiteral( "vectorgeneral" );
+}
+
+QString QgsSplitVectorLayerAlgorithm::shortHelpString() const
+{
+  return QObject::tr( "Splits input vector layer into multiple layers by specified unique ID field." );
+}
+
+QgsSplitVectorLayerAlgorithm *QgsSplitVectorLayerAlgorithm::createInstance() const
+{
+  return new QgsSplitVectorLayerAlgorithm();
+}
+
+void QgsSplitVectorLayerAlgorithm::initAlgorithm( const QVariantMap & )
+{
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ) ) );
+  addParameter( new QgsProcessingParameterField( QStringLiteral( "FIELD" ), QObject::tr( "Unique ID field" ),
+                QVariant(), QStringLiteral( "INPUT" ) ) );
+  addParameter( new QgsProcessingParameterFolderDestination( QStringLiteral( "OUTPUT" ), QObject::tr( "Output directory" ) ) );
+  addOutput( new QgsProcessingOutputMultipleLayers( QStringLiteral( "OUTPUT_LAYERS" ), QObject::tr( "Output layers" ) ) );
+}
+
+QVariantMap QgsSplitVectorLayerAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
+{
+  std::unique_ptr< QgsFeatureSource > source( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
+  if ( !source )
+    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
+
+  QString fieldName = parameterAsString( parameters, QStringLiteral( "FIELD" ), context );
+  QString outputDir = parameterAsString( parameters, QStringLiteral( "OUTPUT" ), context );
+
+  if ( !QDir().mkpath( outputDir ) )
+    throw QgsProcessingException( QStringLiteral( "Failed to create output directory." ) );
+
+  QgsFields fields = source->fields();
+  QgsCoordinateReferenceSystem crs = source->sourceCrs();
+  QgsWkbTypes::Type geometryType = source->wkbType();
+  int fieldIndex = fields.lookupField( fieldName );
+  QSet< QVariant > uniqueValues = source->uniqueValues( fieldIndex );
+  QString baseName = outputDir + QDir::separator() + fieldName;
+  QString outputFormat = context.preferredVectorFormat();
+  if ( !QgsVectorFileWriter::supportedFormatExtensions().contains( outputFormat, Qt::CaseInsensitive ) )
+    outputFormat = QStringLiteral( "gpkg" );
+
+  int current = 0;
+  double step = uniqueValues.size() > 0 ? 100.0 / uniqueValues.size() : 1;
+
+  int count = 0;
+  QgsFeature feat;
+  QStringList outputLayers;
+  std::unique_ptr< QgsFeatureSink > sink;
+
+  for ( auto it = uniqueValues.constBegin(); it != uniqueValues.constEnd(); ++it )
+  {
+    if ( feedback->isCanceled() )
+      break;
+
+    QString fileName = QStringLiteral( "%1_%2.%3" ).arg( baseName ).arg( current ).arg( outputFormat );
+    feedback->pushInfo( QObject::tr( "Creating layer: %1" ).arg( fileName ) );
+
+    sink.reset( QgsProcessingUtils::createFeatureSink( fileName, context, fields, geometryType, crs ) );
+    QString expr = QStringLiteral( "%1 = %2" ).arg( QgsExpression::quotedColumnRef( fieldName ), QgsExpression::quotedValue( *it ) );
+    QgsFeatureIterator features = source->getFeatures( QgsFeatureRequest().setFilterExpression( expr ) );
+    while ( features.nextFeature( feat ) )
+    {
+      if ( feedback->isCanceled() )
+        break;
+
+      sink->addFeature( feat, QgsFeatureSink::FastInsert );
+      count += 1;
+    }
+
+    feedback->pushInfo( QObject::tr( "Added %1 features to layer" ).arg( count ) );
+    outputLayers << fileName;
+
+    current += 1;
+    feedback->setProgress( current * step );
+  }
+
+  QVariantMap outputs;
+  outputs.insert( QStringLiteral( "OUTPUT" ), outputDir );
+  outputs.insert( QStringLiteral( "OUTPUT_LAYERS" ), outputLayers );
+  return outputs;
+}
+
+///@endcond

src/analysis/processing/qgsalgorithmsplitvectorlayer.h

@@ -0,0 +1,57 @@
+/***************************************************************************
+                         qgsalgorithmsplitvectorlayer.h
+                         ------------------------------
+    begin                : May 2020
+    copyright            : (C) 2020 by Alexander Bruy
+    email                : alexander dot bruy at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSALGORITHMSPLITVECTORLAYER_H
+#define QGSALGORITHMSPLITVECTORLAYER_H
+
+#define SIP_NO_FILE
+
+#include "qgis_sip.h"
+#include "qgsapplication.h"
+#include "qgsprocessingalgorithm.h"
+
+///@cond PRIVATE
+
+/**
+ * Native split vector layer algorithm.
+ */
+class QgsSplitVectorLayerAlgorithm : public QgsProcessingAlgorithm
+{
+
+  public:
+
+    QgsSplitVectorLayerAlgorithm() = default;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    QString shortHelpString() const override;
+    QIcon icon() const override { return QgsApplication::getThemeIcon( QStringLiteral( "/algorithms/mAlgorithmSplitLayer.svg" ) ); }
+    QString svgIconPath() const override { return QgsApplication::iconPath( QStringLiteral( "/algorithms/mAlgorithmSplitLayer.svg" ) ); }
+    QgsSplitVectorLayerAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMSPLITVECTORLAYER_H

src/analysis/processing/qgsnativealgorithms.cpp

@@ -146,10 +146,11 @@
 #include "qgsalgorithmsmooth.h"
 #include "qgsalgorithmsnaptogrid.h"
 #include "qgsalgorithmspatialindex.h"
+#include "qgsalgorithmsplitfeaturesbyattributecharacter.h"
 #include "qgsalgorithmsplitlineantimeridian.h"
 #include "qgsalgorithmsplitlinesbylength.h"
+#include "qgsalgorithmsplitvectorlayer.h"
 #include "qgsalgorithmsplitwithlines.h"
-#include "qgsalgorithmsplitfeaturesbyattributecharacter.h"
 #include "qgsalgorithmstringconcatenation.h"
 #include "qgsalgorithmsubdivide.h"
 #include "qgsalgorithmsumlinelength.h"
@@ -369,6 +370,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsSplitFeaturesByAttributeCharacterAlgorithm() );
   addAlgorithm( new QgsSplitGeometryAtAntimeridianAlgorithm() );
   addAlgorithm( new QgsSplitLinesByLengthAlgorithm() );
+  addAlgorithm( new QgsSplitVectorLayerAlgorithm() );
   addAlgorithm( new QgsSplitWithLinesAlgorithm() );
   addAlgorithm( new QgsStringConcatenationAlgorithm() );
   addAlgorithm( new QgsStyleFromProjectAlgorithm() );