add sort by expression algorithm

python/plugins/processing/tests/testdata/expected/order_by_expression.gml

@@ -0,0 +1,61 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation="http://ogr.maptools.org/ order_by_expression.xsd"
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>-1</gml:X><gml:Y>-3</gml:Y></gml:coord>
+      <gml:coord><gml:X>10</gml:X><gml:Y>6</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:order_by_expression fid="polys.1">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>5,5 6,4 4,4 5,5</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:name>Aaaaa</ogr:name>
+      <ogr:intval>-33</ogr:intval>
+      <ogr:floatval>0</ogr:floatval>
+    </ogr:order_by_expression>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:order_by_expression fid="polys.3">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>6,1 10,1 10,-3 6,-3 6,1</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs><gml:innerBoundaryIs><gml:LinearRing><gml:coordinates>7,0 7,-2 9,-2 9,0 7,0</gml:coordinates></gml:LinearRing></gml:innerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:name>ASDF</ogr:name>
+      <ogr:intval>0</ogr:intval>
+      <ogr:floatval xsi:nil="true"/>
+    </ogr:order_by_expression>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:order_by_expression fid="polys.5">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>3,2 6,1 6,-3 2,-1 2,2 3,2</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:name>elim</ogr:name>
+      <ogr:intval>2</ogr:intval>
+      <ogr:floatval>3.33</ogr:floatval>
+    </ogr:order_by_expression>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:order_by_expression fid="polys.0">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>-1,-1 -1,3 3,3 3,2 2,2 2,-1 -1,-1</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:name>aaaaa</ogr:name>
+      <ogr:intval>33</ogr:intval>
+      <ogr:floatval>44.123456</ogr:floatval>
+    </ogr:order_by_expression>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:order_by_expression fid="polys.4">
+      <ogr:name xsi:nil="true"/>
+      <ogr:intval>120</ogr:intval>
+      <ogr:floatval>-100291.43213</ogr:floatval>
+    </ogr:order_by_expression>
+  </gml:featureMember>
+  <gml:featureMember>
+    <ogr:order_by_expression fid="polys.2">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>2,5 2,6 3,6 3,5 2,5</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:name>bbaaa</ogr:name>
+      <ogr:intval xsi:nil="true"/>
+      <ogr:floatval>0.123</ogr:floatval>
+    </ogr:order_by_expression>
+  </gml:featureMember>
+</ogr:FeatureCollection>

python/plugins/processing/tests/testdata/expected/order_by_expression.xsd

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xs:schema targetNamespace="http://ogr.maptools.org/" xmlns:ogr="http://ogr.maptools.org/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" version="1.0">
+<xs:import namespace="http://www.opengis.net/gml" schemaLocation="http://schemas.opengis.net/gml/2.1.2/feature.xsd"/>
+<xs:element name="FeatureCollection" type="ogr:FeatureCollectionType" substitutionGroup="gml:_FeatureCollection"/>
+<xs:complexType name="FeatureCollectionType">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureCollectionType">
+      <xs:attribute name="lockId" type="xs:string" use="optional"/>
+      <xs:attribute name="scope" type="xs:string" use="optional"/>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+<xs:element name="order_by_expression" type="ogr:order_by_expression_Type" substitutionGroup="gml:_Feature"/>
+<xs:complexType name="order_by_expression_Type">
+  <xs:complexContent>
+    <xs:extension base="gml:AbstractFeatureType">
+      <xs:sequence>
+        <xs:element name="geometryProperty" type="gml:PolygonPropertyType" nillable="true" minOccurs="0" maxOccurs="1"/>
+        <xs:element name="name" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:string">
+              <xs:maxLength value="5"/>
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="intval" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:integer">
+              <xs:totalDigits value="10"/>
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+        <xs:element name="floatval" nillable="true" minOccurs="0" maxOccurs="1">
+          <xs:simpleType>
+            <xs:restriction base="xs:decimal">
+            </xs:restriction>
+          </xs:simpleType>
+        </xs:element>
+      </xs:sequence>
+    </xs:extension>
+  </xs:complexContent>
+</xs:complexType>
+</xs:schema>

python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml

@@ -3396,6 +3396,24 @@ tests:
         name: expected/add_field.gml
         type: vector
 
+  - algorithm: native:orderbyexpression
+    name: Order by expression
+    params:
+      ASCENDING: true
+      EXPRESSION: intval
+      INPUT:
+        name: polys.gml
+        type: vector
+      NULLS_FIRST: false
+    results:
+      OUTPUT:
+        name: expected/order_by_expression.gml
+        type: vector
+        compare:
+          fields:
+            __all__:
+              precision: 4
+
   - algorithm: qgis:randompointsinextent
     name: Random point in extent, don't check result
     params:

src/analysis/CMakeLists.txt

@@ -46,6 +46,7 @@ SET(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmmergelines.cpp
   processing/qgsalgorithmminimumenclosingcircle.cpp
   processing/qgsalgorithmmultiparttosinglepart.cpp
+  processing/qgsalgorithmorderbyexpression.cpp
   processing/qgsalgorithmorientedminimumboundingbox.cpp
   processing/qgsalgorithmpackage.cpp
   processing/qgsalgorithmpromotetomultipart.cpp

src/analysis/processing/qgsalgorithmorderbyexpression.cpp

@@ -0,0 +1,106 @@
+/***************************************************************************
+                         qgsalgorithmorderbyexpression.h
+                         ---------------------
+    begin                : November 2017
+    copyright            : (C) 2017 by Etienne Trimaille
+    email                : etienne dot trimaille 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 "qgsalgorithmorderbyexpression.h"
+#include "qgsfeaturerequest.h"
+
+
+///@cond PRIVATE
+
+QString QgsOrderByExpressionAlgorithm::name() const
+{
+  return QStringLiteral( "orderbyexpression" );
+}
+
+QString QgsOrderByExpressionAlgorithm::displayName() const
+{
+  return QObject::tr( "Order by expression" );
+}
+
+QStringList QgsOrderByExpressionAlgorithm::tags() const
+{
+  return QObject::tr( "orderby,sort,expression,field" ).split( ',' );
+}
+
+QString QgsOrderByExpressionAlgorithm::group() const
+{
+  return QObject::tr( "Vector general" );
+}
+
+void QgsOrderByExpressionAlgorithm::initAlgorithm( const QVariantMap & )
+{
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ) ) );
+  addParameter( new QgsProcessingParameterExpression( QStringLiteral( "EXPRESSION" ), QObject::tr( "Expression" ), QVariant(), QStringLiteral( "INPUT" ) ) );
+  addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "ASCENDING" ), QObject::tr( "Ascending" ), true ) );
+  addParameter( new QgsProcessingParameterBoolean( QStringLiteral( "NULLS_FIRST" ), QObject::tr( "Nulls first" ), false ) );
+
+  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Output layer" ) ) );
+}
+
+QString QgsOrderByExpressionAlgorithm::shortHelpString() const
+{
+  return QObject::tr( "This algorithm sorts a vector layer according to an expression." );
+}
+
+QgsOrderByExpressionAlgorithm *QgsOrderByExpressionAlgorithm::createInstance() const
+{
+  return new QgsOrderByExpressionAlgorithm();
+}
+
+QVariantMap QgsOrderByExpressionAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
+{
+  std::unique_ptr< QgsFeatureSource > source( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
+  if ( !source )
+    return QVariantMap();
+
+  QString expressionString = parameterAsExpression( parameters, QStringLiteral( "EXPRESSION" ), context );
+
+  bool ascending = parameterAsBool( parameters, QStringLiteral( "ASCENDING" ), context );
+  bool nullsFirst = parameterAsBool( parameters, QStringLiteral( "NULLS_FIRST" ), context );
+
+  QString sinkId;
+  std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, sinkId, source->fields(), source->wkbType(), source->sourceCrs() ) );
+  if ( !sink )
+    return QVariantMap();
+
+  long count = source->featureCount();
+  double step = count > 0 ? 100.0 / count : 1;
+  int current = 0;
+
+  QgsFeatureRequest request;
+  request.addOrderBy( expressionString, ascending, nullsFirst );
+
+  QgsFeature inFeature;
+  QgsFeatureIterator features = source->getFeatures( request );
+  while ( features.nextFeature( inFeature ) )
+  {
+    if ( feedback->isCanceled() )
+    {
+      break;
+    }
+    sink->addFeature( inFeature );
+    feedback->setProgress( current * step );
+    current++;
+  }
+
+  QVariantMap outputs;
+  outputs.insert( QStringLiteral( "OUTPUT" ), sinkId );
+  return outputs;
+}
+
+///@endcond

src/analysis/processing/qgsalgorithmorderbyexpression.h

@@ -0,0 +1,53 @@
+/***************************************************************************
+                         qgsalgorithmorderbyexpression.h
+                         ---------------------
+    begin                : November 2017
+    copyright            : (C) 2017 by Etienne Trimaille
+    email                : etienne dot trimaille 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 QGSALGORITHMORDERBYEXPRESSION_H
+#define QGSALGORITHMORDERBYEXPRESSION_H
+
+#define SIP_NO_FILE
+
+#include "qgis.h"
+#include "qgsprocessingalgorithm.h"
+
+///@cond PRIVATE
+
+/**
+ * Native order by expression algorithm.
+ */
+class QgsOrderByExpressionAlgorithm : public QgsProcessingAlgorithm
+{
+  public:
+    QgsOrderByExpressionAlgorithm() = default;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    virtual QStringList tags() const override;
+    QString group() const override;
+    QString shortHelpString() const override;
+    QgsOrderByExpressionAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    virtual QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                          QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMORDERBYEXPRESSION_H

src/analysis/processing/qgsnativealgorithms.cpp

@@ -43,6 +43,7 @@
 #include "qgsalgorithmmergelines.h"
 #include "qgsalgorithmminimumenclosingcircle.h"
 #include "qgsalgorithmmultiparttosinglepart.h"
+#include "qgsalgorithmorderbyexpression.h"
 #include "qgsalgorithmorientedminimumboundingbox.h"
 #include "qgsalgorithmpackage.h"
 #include "qgsalgorithmpromotetomultipart.h"
@@ -122,6 +123,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsMergeLinesAlgorithm() );
   addAlgorithm( new QgsMinimumEnclosingCircleAlgorithm() );
   addAlgorithm( new QgsMultipartToSinglepartAlgorithm() );
+  addAlgorithm( new QgsOrderByExpressionAlgorithm() );
   addAlgorithm( new QgsOrientedMinimumBoundingBoxAlgorithm() );
   addAlgorithm( new QgsPackageAlgorithm() );
   addAlgorithm( new QgsPromoteToMultipartAlgorithm() );