add is_multipart expression

qgis · Apr 21, 2020 · a2cbd9c · a2cbd9c
1 parent 45bead2
commit a2cbd9c
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Showing 3 changed files with 25 additions and 1 deletion.
diff --git a/resources/function_help/json/is_multipart b/resources/function_help/json/is_multipart
@@ -0,0 +1,8 @@
+{
+  "name": "is_multipart",
+  "type": "function",
+  "description": "Returns true if the geometry is of Multi type.",
+  "arguments": [ {"arg":"geometry","description":"a geometry"} ],
+  "examples": [ { "expression":"is_multipart(geom_from_wkt('MULTIPOINT ((0 0),(1 1),(2 2))'))", "returns":"true"},
+                { "expression":"is_multipart(geom_from_wkt('POINT (0 0)'))", "returns":"false"}]
+}
diff --git a/src/core/expression/qgsexpressionfunction.cpp b/src/core/expression/qgsexpressionfunction.cpp
@@ -3138,6 +3138,15 @@ static QVariant fcnGeomNumGeometries( const QVariantList &values, const QgsExpre
   return QVariant( geom.constGet()->partCount() );
 }
 
+static QVariant fcnGeomIsMultipart( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )
+{
+  QgsGeometry geom = QgsExpressionUtils::getGeometry( values.at( 0 ), parent );
+  if ( geom.isNull() )
+    return QVariant();
+
+  return QVariant( geom.isMultipart() );
+}
+
 static QVariant fcnGeomNumInteriorRings( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )
 {
   QgsGeometry geom = QgsExpressionUtils::getGeometry( values.at( 0 ), parent );
@@ -5927,7 +5936,10 @@ const QList<QgsExpressionFunction *> &QgsExpression::Functions()
         << new QgsStaticExpressionFunction( QStringLiteral( "extrude" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geom" ) )
                                             << QgsExpressionFunction::Parameter( QStringLiteral( "x" ) )
                                             << QgsExpressionFunction::Parameter( QStringLiteral( "y" ) ),
-                                            fcnExtrude, QStringLiteral( "GeometryGroup" ), QString() );
+                                            fcnExtrude, QStringLiteral( "GeometryGroup" ), QString() )
+        << new QgsStaticExpressionFunction( QStringLiteral( "is_multipart" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geometry" ) ),
+                                            fcnGeomIsMultipart, QStringLiteral( "GeometryGroup" ) );
+
 
     QgsStaticExpressionFunction *orderPartsFunc = new QgsStaticExpressionFunction( QStringLiteral( "order_parts" ), QgsExpressionFunction::ParameterList() << QgsExpressionFunction::Parameter( QStringLiteral( "geom" ) )
         << QgsExpressionFunction::Parameter( QStringLiteral( "orderby" ) )

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -1180,6 +1180,10 @@ class TestQgsExpression: public QObject
       QTest::newRow( "rotate line fixed multi point" ) << "geom_to_wkt(rotate(geom_from_wkt('LineString(0 0, 10 0, 10 10)'),90, geom_from_wkt('MULTIPOINT((-5 -3))')))" << false << QVariant( "LineString (-2 -8, -2 -18, 8 -18)" );
       QTest::newRow( "rotate line fixed multi point multiple" ) << "geom_to_wkt(rotate(geom_from_wkt('LineString(0 0, 10 0, 10 10)'),90, geom_from_wkt('MULTIPOINT(-5 -3,1 2)')))" << true << QVariant();
       QTest::newRow( "rotate polygon centroid" ) << "geom_to_wkt(rotate(geom_from_wkt('Polygon((0 0, 10 0, 10 10, 0 0))'),-90))" << false << QVariant( "Polygon ((10 0, 10 10, 0 10, 10 0))" );
+      QTest::newRow( "is_multipart true" ) << "is_multipart(geom_from_wkt('MULTIPOINT ((0 0),(1 1),(2 2))'))" << false << QVariant( true );
+      QTest::newRow( "is_multipart false" ) << "is_multipart(geom_from_wkt('POINT (0 0)'))" << false << QVariant( false );
+      QTest::newRow( "is_multipart false empty geometry" ) << "is_multipart(geom_from_wkt('POINT EMPTY'))" << false << QVariant( false );
+      QTest::newRow( "is_multipart null" ) << "is_multipart(NULL)" << false << QVariant();
 
       // string functions
       QTest::newRow( "format_number" ) << "format_number(1999.567,2)" << false << QVariant( "1,999.57" );