Add utility function QgsMapLayerUtils::layerSourceMatchesPath

Tests whether a layer has a source which matches a specified file path
qgis · Jul 28, 2021 · 216925a · 216925a
1 parent 8285a15
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diff --git a/python/core/auto_generated/qgsmaplayerutils.sip.in b/python/core/auto_generated/qgsmaplayerutils.sip.in
@@ -34,6 +34,15 @@ The ``crs`` argument specifies the desired coordinate reference system for the c
 Creates and returns the (possibly ``None``) database connection for a ``layer``.
 Ownership is transferred to the caller.
 
+.. versionadded:: 3.22
+%End
+
+    static bool layerSourceMatchesPath( const QgsMapLayer *layer, const QString &path );
+%Docstring
+Returns ``True`` if the source of the specified ``layer`` matches the given ``path``.
+
+This method can be used to test whether a layer is associated with a file path.
+
 .. versionadded:: 3.22
 %End
 

diff --git a/src/core/qgsmaplayerutils.cpp b/src/core/qgsmaplayerutils.cpp
@@ -112,3 +112,12 @@ QgsAbstractDatabaseProviderConnection *QgsMapLayerUtils::databaseConnection( con
     return nullptr;
   }
 }
+
+bool QgsMapLayerUtils::layerSourceMatchesPath( const QgsMapLayer *layer, const QString &path )
+{
+  if ( !layer || path.isEmpty() )
+    return false;
+
+  const QVariantMap parts = QgsProviderRegistry::instance()->decodeUri( layer->providerType(), layer->source() );
+  return parts.value( QStringLiteral( "path" ) ).toString() == path;
+}
diff --git a/src/core/qgsmaplayerutils.h b/src/core/qgsmaplayerutils.h
@@ -51,6 +51,15 @@ class CORE_EXPORT QgsMapLayerUtils
      */
     static QgsAbstractDatabaseProviderConnection *databaseConnection( const QgsMapLayer *layer ) SIP_FACTORY;
 
+    /**
+     * Returns TRUE if the source of the specified \a layer matches the given \a path.
+     *
+     * This method can be used to test whether a layer is associated with a file path.
+     *
+     * \since QGIS 3.22
+     */
+    static bool layerSourceMatchesPath( const QgsMapLayer *layer, const QString &path );
+
 };
 
 #endif // QGSMAPLAYERUTILS_H

diff --git a/tests/src/python/test_qgsmaplayerutils.py b/tests/src/python/test_qgsmaplayerutils.py
@@ -64,6 +64,33 @@ def testCombinedExtent(self):
                                                  QgsCoordinateTransformContext())
         self.assertEqual(extent.toString(0), '-13234651,2607875 : 2008833,5921203')
 
+    def test_layerSourceMatchesPath(self):
+        """
+        Test QgsMapLayerUtils.layerSourceMatchesPath()
+        """
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(None, ''))
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(None, 'aaaaa'))
+
+        # shapefile
+        layer1 = QgsVectorLayer(unitTestDataPath() + '/points.shp', 'l1')
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(layer1, ''))
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(layer1, 'aaaaa'))
+        self.assertTrue(QgsMapLayerUtils.layerSourceMatchesPath(layer1, unitTestDataPath() + '/points.shp'))
+
+        # geopackage with layers
+        layer1 = QgsVectorLayer(unitTestDataPath() + '/mixed_layers.gpkg|layername=lines', 'l1')
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(layer1, ''))
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(layer1, 'aaaaa'))
+        self.assertTrue(QgsMapLayerUtils.layerSourceMatchesPath(layer1, unitTestDataPath() + '/mixed_layers.gpkg'))
+        layer2 = QgsVectorLayer(unitTestDataPath() + '/mixed_layers.gpkg|layername=points', 'l1')
+        self.assertTrue(QgsMapLayerUtils.layerSourceMatchesPath(layer2, unitTestDataPath() + '/mixed_layers.gpkg'))
+
+        # raster layer from gpkg
+        rl = QgsRasterLayer(f'GPKG:{unitTestDataPath()}/mixed_layers.gpkg:band1')
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(rl, ''))
+        self.assertFalse(QgsMapLayerUtils.layerSourceMatchesPath(rl, 'aaaaa'))
+        self.assertTrue(QgsMapLayerUtils.layerSourceMatchesPath(rl, unitTestDataPath() + '/mixed_layers.gpkg'))
+
 
 if __name__ == '__main__':
     unittest.main()