[ogr] Read Geopackage layer identifier and description into QGIS

nyalldawson · nyalldawson · commit 5ced04e400b7 · 2019-02-18T17:56:01.000+10:00
layer metadata automatically Fixes #21293
diff --git a/src/providers/ogr/qgsogrprovider.cpp b/src/providers/ogr/qgsogrprovider.cpp
@@ -525,6 +525,21 @@ QgsOgrProvider::QgsOgrProvider( QString const &uri, const ProviderOptions &optio
 
   bool supportsBoolean = false;
 
+  // layer metadata
+  mLayerMetadata.setType( QStringLiteral( "dataset" ) );
+  if ( mOgrOrigLayer )
+  {
+    QMutex *mutex = nullptr;
+    OGRLayerH layer = mOgrOrigLayer->getHandleAndMutex( mutex );
+    QMutexLocker locker( mutex );
+    const QString identifier = GDALGetMetadataItem( layer, "IDENTIFIER", nullptr );
+    if ( !identifier.isEmpty() )
+      mLayerMetadata.setTitle( identifier ); // see geopackage specs -- "'identifier' is analogous to 'title'"
+    const QString abstract = GDALGetMetadataItem( layer, "DESCRIPTION", nullptr );
+    if ( !abstract.isEmpty() )
+      mLayerMetadata.setAbstract( abstract );
+  }
+
 #if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,3,0)
   if ( mOgrOrigLayer )
   {
@@ -855,6 +870,11 @@ QStringList QgsOgrProvider::subLayers() const
   return _subLayers( true );
 }
 
+QgsLayerMetadata QgsOgrProvider::layerMetadata() const
+{
+  return mLayerMetadata;
+}
+
 QStringList QgsOgrProvider::subLayersWithoutFeatureCount() const
 {
   return _subLayers( false );
@@ -2617,6 +2637,8 @@ void QgsOgrProvider::computeCapabilities()
     }
   }
 
+  ability |= ReadLayerMetadata;
+
   if ( updateModeActivated )
     leaveUpdateMode();
 
diff --git a/src/providers/ogr/qgsogrprovider.h b/src/providers/ogr/qgsogrprovider.h
@@ -100,6 +100,7 @@ class QgsOgrProvider : public QgsVectorDataProvider
 
     QgsCoordinateReferenceSystem crs() const override;
     QStringList subLayers() const override;
+    QgsLayerMetadata layerMetadata() const override;
     QStringList subLayersWithoutFeatureCount() const;
     QString storageType() const override;
     QgsFeatureIterator getFeatures( const QgsFeatureRequest &request ) const override;
@@ -248,6 +249,8 @@ class QgsOgrProvider : public QgsVectorDataProvider
     //! Original layer (not a SQL result layer)
     QgsOgrLayerUniquePtr mOgrOrigLayer;
 
+    QgsLayerMetadata mLayerMetadata;
+
     //! path to filename
     QString mFilePath;
 
diff --git a/tests/src/python/test_provider_ogr_gpkg.py b/tests/src/python/test_provider_ogr_gpkg.py
@@ -1303,6 +1303,25 @@ def test_quote_identifier(self):
         for i in range(1, len(vl.fields())):
             self.assertEqual(vl.uniqueValues(i), {'a', 'b', 'c'})
 
+    def testGeopackageLayerMetadata(self):
+        """
+        Geopackage layer description and identifier should be read into layer metadata automatically
+        """
+        tmpfile = os.path.join(self.basetestpath, 'testGeopackageLayerMetadata.gpkg')
+        ds = ogr.GetDriverByName('GPKG').CreateDataSource(tmpfile)
+        lyr = ds.CreateLayer('layer1', geom_type=ogr.wkbPoint)
+        lyr.SetMetadataItem('DESCRIPTION', "my desc")
+        lyr.SetMetadataItem('IDENTIFIER', "my title")  # see geopackage specs -- "'identifier' is analogous to 'title'"
+        lyr.CreateField(ogr.FieldDefn('attr', ogr.OFTInteger))
+        f = ogr.Feature(lyr.GetLayerDefn())
+        f.SetGeometry(ogr.CreateGeometryFromWkt('POINT(0 0)'))
+        lyr.CreateFeature(f)
+        f = None
+        vl1 = QgsVectorLayer(u'{}'.format(tmpfile) + "|layername=" + "layer1", 'test', u'ogr')
+        self.assertTrue(vl1.isValid())
+        self.assertEqual(vl1.metadata().title(), 'my title')
+        self.assertEqual(vl1.metadata().abstract(), 'my desc')
+
 
 if __name__ == '__main__':
     unittest.main()
