[api] Add PyQGIS helpers to QgsGeometry.asMultiPoint(), asMultiPolyli…

…ne() and asMultiPolygon() - raise ValueError when these methods are called with null geometries - raise TypeError when these methods are called with incompatible geometry types, instead of silently returning empty lists
qgis · Jan 11, 2019 · 938adb8 · 938adb8
1 parent 2664737
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diff --git a/python/core/auto_generated/geometry/qgsgeometry.sip.in b/python/core/auto_generated/geometry/qgsgeometry.sip.in
@@ -1515,22 +1515,96 @@ will be raised.
     }
 %End
 
-    QgsMultiPointXY asMultiPoint() const;
+
+    SIP_PYOBJECT asMultiPoint() const /TypeHint="QgsMultiPointXY"/;
 %Docstring
-Returns contents of the geometry as a multi point
-if wkbType is WKBMultiPoint, otherwise an empty list
+Returns the contents of the geometry as a multi-point.
+
+Any z or m values present in the geometry will be discarded.
+
+This method works only with multi-point geometry types. If the geometry
+is not a multi-point type, a TypeError will be raised. If the geometry is null, a ValueError
+will be raised.
+%End
+%MethodCode
+    const QgsWkbTypes::Type type = sipCpp->wkbType();
+    if ( sipCpp->isNull() )
+    {
+      PyErr_SetString( PyExc_ValueError, QStringLiteral( "Null geometry cannot be converted to a multipoint." ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else if ( QgsWkbTypes::geometryType( type ) != QgsWkbTypes::PointGeometry || !QgsWkbTypes::isMultiType( type ) )
+    {
+      PyErr_SetString( PyExc_TypeError, QStringLiteral( "%1 geometry cannot be converted to a multipoint. Only multipoint types are permitted." ).arg( QgsWkbTypes::displayString( type ) ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else
+    {
+      const sipMappedType *qvector_type = sipFindMappedType( "QVector< QgsPointXY >" );
+      sipRes = sipConvertFromNewType( new QgsPolylineXY( sipCpp->asMultiPoint() ), qvector_type, Py_None );
+    }
 %End
 
-    QgsMultiPolylineXY asMultiPolyline() const;
+
+    SIP_PYOBJECT asMultiPolyline() const /TypeHint="QgsMultiPolylineXY"/;
 %Docstring
-Returns contents of the geometry as a multi linestring
-if wkbType is WKBMultiLineString, otherwise an empty list
+Returns the contents of the geometry as a multi-linestring.
+
+Any z or m values present in the geometry will be discarded. If the geometry is a curved line type
+(such as a MultiCurve), it will be automatically segmentized.
+
+This method works only with multi-linestring (or multi-curve) geometry types. If the geometry
+is not a multi-linestring type, a TypeError will be raised. If the geometry is null, a ValueError
+will be raised.
+%End
+%MethodCode
+    const QgsWkbTypes::Type type = sipCpp->wkbType();
+    if ( sipCpp->isNull() )
+    {
+      PyErr_SetString( PyExc_ValueError, QStringLiteral( "Null geometry cannot be converted to a multilinestring." ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else if ( QgsWkbTypes::geometryType( type ) != QgsWkbTypes::LineGeometry || !QgsWkbTypes::isMultiType( type ) )
+    {
+      PyErr_SetString( PyExc_TypeError, QStringLiteral( "%1 geometry cannot be converted to a multilinestring. Only multi linestring or curves are permitted." ).arg( QgsWkbTypes::displayString( type ) ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else
+    {
+      const sipMappedType *qvector_type = sipFindMappedType( "QVector<QVector<QgsPointXY>>" );
+      sipRes = sipConvertFromNewType( new QgsMultiPolylineXY( sipCpp->asMultiPolyline() ), qvector_type, Py_None );
+    }
 %End
 
-    QgsMultiPolygonXY asMultiPolygon() const;
+
+    SIP_PYOBJECT asMultiPolygon() const /TypeHint="QgsMultiPolygonXY"/;
 %Docstring
-Returns contents of the geometry as a multi polygon
-if wkbType is WKBMultiPolygon, otherwise an empty list
+Returns the contents of the geometry as a multi-polygon.
+
+Any z or m values present in the geometry will be discarded. If the geometry is a curved polygon type
+(such as a MultiSurface), it will be automatically segmentized.
+
+This method works only with multi-polygon (or multi-curve polygon) geometry types. If the geometry
+is not a multi-polygon type, a TypeError will be raised. If the geometry is null, a ValueError
+will be raised.
+%End
+%MethodCode
+    const QgsWkbTypes::Type type = sipCpp->wkbType();
+    if ( sipCpp->isNull() )
+    {
+      PyErr_SetString( PyExc_ValueError, QStringLiteral( "Null geometry cannot be converted to a multipolygon." ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else if ( QgsWkbTypes::geometryType( type ) != QgsWkbTypes::PolygonGeometry || !QgsWkbTypes::isMultiType( type ) )
+    {
+      PyErr_SetString( PyExc_TypeError, QStringLiteral( "%1 geometry cannot be converted to a multipolygon. Only multi polygon or curves are permitted." ).arg( QgsWkbTypes::displayString( type ) ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else
+    {
+      const sipMappedType *qvector_type = sipFindMappedType( "QVector<QVector<QVector<QgsPointXY>>>" );
+      sipRes = sipConvertFromNewType( new QgsMultiPolygonXY( sipCpp->asMultiPolygon() ), qvector_type, Py_None );
+    }
 %End
 
     QVector<QgsGeometry> asGeometryCollection() const;

diff --git a/src/core/geometry/qgsgeometry.h b/src/core/geometry/qgsgeometry.h
@@ -1552,23 +1552,135 @@ class CORE_EXPORT QgsGeometry
     % End
 #endif
 
+#ifndef SIP_RUN
+
     /**
-     * Returns contents of the geometry as a multi point
-     * if wkbType is WKBMultiPoint, otherwise an empty list
+     * Returns the contents of the geometry as a multi-point.
+     *
+     * Any z or m values present in the geometry will be discarded.
+     *
+     * \warning If the geometry is not a multi-point type, an empty list will be returned.
      */
     QgsMultiPointXY asMultiPoint() const;
+#else
+
+    /**
+     * Returns the contents of the geometry as a multi-point.
+     *
+     * Any z or m values present in the geometry will be discarded.
+     *
+     * This method works only with multi-point geometry types. If the geometry
+     * is not a multi-point type, a TypeError will be raised. If the geometry is null, a ValueError
+     * will be raised.
+     */
+    SIP_PYOBJECT asMultiPoint() const SIP_TYPEHINT( QgsMultiPointXY );
+    % MethodCode
+    const QgsWkbTypes::Type type = sipCpp->wkbType();
+    if ( sipCpp->isNull() )
+    {
+      PyErr_SetString( PyExc_ValueError, QStringLiteral( "Null geometry cannot be converted to a multipoint." ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else if ( QgsWkbTypes::geometryType( type ) != QgsWkbTypes::PointGeometry || !QgsWkbTypes::isMultiType( type ) )
+    {
+      PyErr_SetString( PyExc_TypeError, QStringLiteral( "%1 geometry cannot be converted to a multipoint. Only multipoint types are permitted." ).arg( QgsWkbTypes::displayString( type ) ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else
+    {
+      const sipMappedType *qvector_type = sipFindMappedType( "QVector< QgsPointXY >" );
+      sipRes = sipConvertFromNewType( new QgsPolylineXY( sipCpp->asMultiPoint() ), qvector_type, Py_None );
+    }
+    % End
+#endif
+
+#ifndef SIP_RUN
 
     /**
-     * Returns contents of the geometry as a multi linestring
-     * if wkbType is WKBMultiLineString, otherwise an empty list
+     * Returns the contents of the geometry as a multi-linestring.
+     *
+     * Any z or m values present in the geometry will be discarded. If the geometry is a curved line type
+     * (such as a MultiCurve), it will be automatically segmentized.
+     *
+     * \warning If the geometry is not a multi-linestring (or multi-curve linestring) type, an empty list will be returned.
      */
     QgsMultiPolylineXY asMultiPolyline() const;
+#else
 
     /**
-     * Returns contents of the geometry as a multi polygon
-     * if wkbType is WKBMultiPolygon, otherwise an empty list
+     * Returns the contents of the geometry as a multi-linestring.
+     *
+     * Any z or m values present in the geometry will be discarded. If the geometry is a curved line type
+     * (such as a MultiCurve), it will be automatically segmentized.
+     *
+     * This method works only with multi-linestring (or multi-curve) geometry types. If the geometry
+     * is not a multi-linestring type, a TypeError will be raised. If the geometry is null, a ValueError
+     * will be raised.
+     */
+    SIP_PYOBJECT asMultiPolyline() const SIP_TYPEHINT( QgsMultiPolylineXY );
+    % MethodCode
+    const QgsWkbTypes::Type type = sipCpp->wkbType();
+    if ( sipCpp->isNull() )
+    {
+      PyErr_SetString( PyExc_ValueError, QStringLiteral( "Null geometry cannot be converted to a multilinestring." ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else if ( QgsWkbTypes::geometryType( type ) != QgsWkbTypes::LineGeometry || !QgsWkbTypes::isMultiType( type ) )
+    {
+      PyErr_SetString( PyExc_TypeError, QStringLiteral( "%1 geometry cannot be converted to a multilinestring. Only multi linestring or curves are permitted." ).arg( QgsWkbTypes::displayString( type ) ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else
+    {
+      const sipMappedType *qvector_type = sipFindMappedType( "QVector<QVector<QgsPointXY>>" );
+      sipRes = sipConvertFromNewType( new QgsMultiPolylineXY( sipCpp->asMultiPolyline() ), qvector_type, Py_None );
+    }
+    % End
+#endif
+
+#ifndef SIP_RUN
+
+    /**
+     * Returns the contents of the geometry as a multi-polygon.
+     *
+     * Any z or m values present in the geometry will be discarded. If the geometry is a curved polygon type
+     * (such as a MultiSurface), it will be automatically segmentized.
+     *
+     * \warning If the geometry is not a multi-polygon (or multi-curve polygon) type, an empty list will be returned.
      */
     QgsMultiPolygonXY asMultiPolygon() const;
+#else
+
+    /**
+     * Returns the contents of the geometry as a multi-polygon.
+     *
+     * Any z or m values present in the geometry will be discarded. If the geometry is a curved polygon type
+     * (such as a MultiSurface), it will be automatically segmentized.
+     *
+     * This method works only with multi-polygon (or multi-curve polygon) geometry types. If the geometry
+     * is not a multi-polygon type, a TypeError will be raised. If the geometry is null, a ValueError
+     * will be raised.
+     */
+    SIP_PYOBJECT asMultiPolygon() const SIP_TYPEHINT( QgsMultiPolygonXY );
+    % MethodCode
+    const QgsWkbTypes::Type type = sipCpp->wkbType();
+    if ( sipCpp->isNull() )
+    {
+      PyErr_SetString( PyExc_ValueError, QStringLiteral( "Null geometry cannot be converted to a multipolygon." ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else if ( QgsWkbTypes::geometryType( type ) != QgsWkbTypes::PolygonGeometry || !QgsWkbTypes::isMultiType( type ) )
+    {
+      PyErr_SetString( PyExc_TypeError, QStringLiteral( "%1 geometry cannot be converted to a multipolygon. Only multi polygon or curves are permitted." ).arg( QgsWkbTypes::displayString( type ) ).toUtf8().constData() );
+      sipIsErr = 1;
+    }
+    else
+    {
+      const sipMappedType *qvector_type = sipFindMappedType( "QVector<QVector<QVector<QgsPointXY>>>" );
+      sipRes = sipConvertFromNewType( new QgsMultiPolygonXY( sipCpp->asMultiPolygon() ), qvector_type, Py_None );
+    }
+    % End
+#endif
 
     /**
      * Returns contents of the geometry as a list of geometries

diff --git a/tests/src/python/test_qgsgeometry.py b/tests/src/python/test_qgsgeometry.py
@@ -601,6 +601,69 @@ def testPointXY(self):
         with self.assertRaises(ValueError):
             QgsGeometry().asPolygon()
 
+        # as multipoint
+        self.assertEqual(QgsGeometry.fromWkt('MultiPoint(11 13,14 15)').asMultiPoint(), [QgsPointXY(11, 13), QgsPointXY(14, 15)])
+        self.assertEqual(QgsGeometry.fromWkt('MultiPointZ(11 13 1,14 15 2)').asMultiPoint(), [QgsPointXY(11, 13), QgsPointXY(14, 15)])
+        self.assertEqual(QgsGeometry.fromWkt('MultiPointM(11 13 1,14 15 2)').asMultiPoint(), [QgsPointXY(11, 13), QgsPointXY(14, 15)])
+        self.assertEqual(QgsGeometry.fromWkt('MultiPointZM(11 13 1 2,14 15 3 4)').asMultiPoint(), [QgsPointXY(11, 13), QgsPointXY(14, 15)])
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('Point(11 13)').asMultiPoint()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('LineString(11 13,14 15)').asMultiPoint()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('MultiLineString((11 13, 14 15),(1 2, 3 4))').asMultiPoint()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('Polygon((11 13,14 15, 14 13, 11 13))').asMultiPoint()
+        with self.assertRaises(ValueError):
+            QgsGeometry().asMultiPoint()
+
+        # as multilinestring
+        self.assertEqual(QgsGeometry.fromWkt('MultiLineString((11 13,14 15, 11 15, 11 13))').asMultiPolyline(),
+                         [[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]])
+        self.assertEqual(QgsGeometry.fromWkt('MultiLineStringZ((11 13 1,14 15 2, 11 15 3, 11 13 1))').asMultiPolyline(),
+                         [[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]])
+        self.assertEqual(QgsGeometry.fromWkt('MultiLineStringM((11 13 1,14 15 2, 11 15 3, 11 13 1))').asMultiPolyline(),
+                         [[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]])
+        self.assertEqual(QgsGeometry.fromWkt('MultiLineStringZM((11 13 1 11,14 15 2 12 , 11 15 3 13 , 11 13 1 11))').asMultiPolyline(),
+                         [[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]])
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('Point(11 13)').asMultiPolyline()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('MultiPoint(11 13,14 15)').asMultiPolyline()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('Polygon((11 13, 14 15, 17 18, 11 13))').asMultiPolyline()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('LineString(11 13,14 15)').asPolygon()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('MultiPolygon(((11 13,14 15, 11 15, 11 13)))').asMultiPolyline()
+        with self.assertRaises(ValueError):
+            QgsGeometry().asPolygon()
+
+        # as multipolygon
+        self.assertEqual(QgsGeometry.fromWkt('MultiPolygon(((11 13,14 15, 11 15, 11 13)))').asMultiPolygon(),
+                         [[[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]]])
+        self.assertEqual(
+            QgsGeometry.fromWkt('MultiPolygonZ(((11 13 1,14 15 2, 11 15 3 , 11 13 1)))').asMultiPolygon(),
+            [[[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]]])
+        self.assertEqual(
+            QgsGeometry.fromWkt('MultiPolygonM(((11 13 1,14 15 2, 11 15 3 , 11 13 1)))').asMultiPolygon(),
+            [[[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]]])
+        self.assertEqual(QgsGeometry.fromWkt(
+            'MultiPolygonZM(((11 13 1 11,14 15 2 12, 11 15 3 13, 11 13 1 11)))').asMultiPolygon(),
+            [[[QgsPointXY(11, 13), QgsPointXY(14, 15), QgsPointXY(11, 15), QgsPointXY(11, 13)]]])
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('Point(11 13)').asMultiPolygon()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('MultiPoint(11 13,14 15)').asMultiPolygon()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('Polygon((11 13, 14 15, 17 18, 11 13))').asMultiPolygon()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('LineString(11 13,14 15)').asPolygon()
+        with self.assertRaises(TypeError):
+            QgsGeometry.fromWkt('MultiLineString((11 13,14 15, 11 15, 11 13))').asMultiPolygon()
+        with self.assertRaises(ValueError):
+            QgsGeometry().asPolygon()
+
     def testReferenceGeometry(self):
         """ Test parsing a whole range of valid reference wkt formats and variants, and checking
         expected values such as length, area, centroids, bounding boxes, etc of the resultant geometry.