Automatically restore layer metadata on loading a gpkg if present

in the gpkg_metadata table
qgis · May 3, 2021 · 207ed26 · 207ed26
1 parent d589690
commit 207ed26
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Showing 3 changed files with 101 additions and 42 deletions.
diff --git a/src/core/providers/ogr/qgsogrprovider.cpp b/src/core/providers/ogr/qgsogrprovider.cpp
@@ -617,48 +617,7 @@ QgsOgrProvider::QgsOgrProvider( QString const &uri, const ProviderOptions &optio
   bool supportsBoolean = false;
 
   // layer metadata
-  if ( mOgrOrigLayer )
-  {
-#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
-    QMutex *mutex = nullptr;
-#else
-    QRecursiveMutex *mutex = nullptr;
-#endif
-    OGRLayerH layer = mOgrOrigLayer->getHandleAndMutex( mutex );
-    QMutexLocker locker( mutex );
-    if ( ( mGDALDriverName == QLatin1String( "FileGDB" ) || mGDALDriverName == QLatin1String( "OpenFileGDB" ) ) )
-    {
-      // read layer metadata
-
-      // important -- this ONLY works if the layer name is NOT quoted!!
-      QByteArray sql = "GetLayerMetadata " + mOgrOrigLayer->name();
-      if ( QgsOgrLayerUniquePtr l = mOgrOrigLayer->ExecuteSQL( sql ) )
-      {
-        gdal::ogr_feature_unique_ptr f( l->GetNextFeature() );
-        if ( f )
-        {
-          bool ok = false;
-          QVariant res = QgsOgrUtils::getOgrFeatureAttribute( f.get(), QgsField( QString(), QVariant::String ), 0, textEncoding(), &ok );
-          if ( ok )
-          {
-            QDomDocument metadataDoc;
-            metadataDoc.setContent( res.toString() );
-            mLayerMetadata = QgsMetadataUtils::convertFromEsri( metadataDoc );
-          }
-        }
-      }
-    }
-    else
-    {
-      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 );
-    }
-  }
-  mLayerMetadata.setType( QStringLiteral( "dataset" ) );
+  loadMetadata();
 
   if ( mOgrOrigLayer )
   {
@@ -1461,6 +1420,76 @@ void QgsOgrProvider::loadFields()
   }
 }
 
+void QgsOgrProvider::loadMetadata()
+{
+  if ( mOgrOrigLayer )
+  {
+#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
+    QMutex *mutex = nullptr;
+#else
+    QRecursiveMutex *mutex = nullptr;
+#endif
+    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 ( mGDALDriverName == QLatin1String( "GPKG" ) )
+    {
+      // read Geopackage layer metadata - scan gpkg_metadata table for QGIS metadata
+      const QString sql = QStringLiteral( "SELECT metadata from gpkg_metadata LEFT JOIN gpkg_metadata_reference ON "
+                                          "(gpkg_metadata_reference.table_name = %1 AND gpkg_metadata.id = gpkg_metadata_reference.md_file_id) "
+                                          "WHERE md_standard_uri = %2 and reference_scope = %3" ).arg(
+                            QgsSqliteUtils::quotedString( mOgrOrigLayer->name() ),
+                            QgsSqliteUtils::quotedString( QStringLiteral( "http://mrcc.com/qgis.dtd" ) ),
+                            QgsSqliteUtils::quotedString( QStringLiteral( "table" ) ) );                                                         ;
+
+      if ( QgsOgrLayerUniquePtr l = mOgrOrigLayer->ExecuteSQL( sql.toLocal8Bit().constData() ) )
+      {
+        gdal::ogr_feature_unique_ptr f( l->GetNextFeature() );
+        if ( f )
+        {
+          bool ok = false;
+          QVariant res = QgsOgrUtils::getOgrFeatureAttribute( f.get(), QgsField( QString(), QVariant::String ), 0, nullptr, &ok );
+          if ( ok )
+          {
+            QDomDocument doc;
+            doc.setContent( res.toString() );
+            mLayerMetadata.readMetadataXml( doc.documentElement() );
+          }
+        }
+      }
+    }
+    else if ( ( mGDALDriverName == QLatin1String( "FileGDB" ) || mGDALDriverName == QLatin1String( "OpenFileGDB" ) ) )
+    {
+      // read ESRI FileGeodatabase layer metadata
+
+      // important -- this ONLY works if the layer name is NOT quoted!!
+      QByteArray sql = "GetLayerMetadata " + mOgrOrigLayer->name();
+      if ( QgsOgrLayerUniquePtr l = mOgrOrigLayer->ExecuteSQL( sql ) )
+      {
+        gdal::ogr_feature_unique_ptr f( l->GetNextFeature() );
+        if ( f )
+        {
+          bool ok = false;
+          QVariant res = QgsOgrUtils::getOgrFeatureAttribute( f.get(), QgsField( QString(), QVariant::String ), 0, textEncoding(), &ok );
+          if ( ok )
+          {
+            QDomDocument metadataDoc;
+            metadataDoc.setContent( res.toString() );
+            mLayerMetadata = QgsMetadataUtils::convertFromEsri( metadataDoc );
+          }
+        }
+      }
+    }
+  }
+  mLayerMetadata.setType( QStringLiteral( "dataset" ) );
+}
 
 QString QgsOgrProvider::storageType() const
 {

diff --git a/src/core/providers/ogr/qgsogrprovider.h b/src/core/providers/ogr/qgsogrprovider.h
@@ -181,6 +181,9 @@ class QgsOgrProvider final: public QgsVectorDataProvider
     //! Loads fields from input file to member attributeFields
     void loadFields();
 
+    //! Loads metadata for the layer
+    void loadMetadata();
+
     //! Find out the number of features of the whole layer
     void recalculateFeatureCount() const;
 

diff --git a/tests/src/python/test_provider_ogr_gpkg.py b/tests/src/python/test_provider_ogr_gpkg.py
@@ -1690,6 +1690,33 @@ def testGeopackageSaveMetadata(self):
         self.assertEqual(metadata3.licenses(), ['l1', 'l2'])
         self.assertEqual(metadata3.history(), ['h1', 'h2'])
 
+    def testGeopackageRestoreMetadata(self):
+        """
+        Test that metadata saved to gpkg_metadata is automatically restored on layer load
+        """
+        tmpfile = os.path.join(self.basetestpath, 'testGeopackageRestoreMetadata.gpkg')
+        ds = ogr.GetDriverByName('GPKG').CreateDataSource(tmpfile)
+        lyr = ds.CreateLayer('test', geom_type=ogr.wkbPolygon)
+        lyr.CreateField(ogr.FieldDefn('str_field', ogr.OFTString))
+        lyr.CreateField(ogr.FieldDefn('str_field2', ogr.OFTString))
+        f = None
+        ds = None
+
+        # now save some metadata
+        metadata = QgsLayerMetadata()
+        metadata.setAbstract('my abstract')
+        metadata.setIdentifier('my identifier')
+        metadata.setLicenses(['l1', 'l2'])
+        ok, err = QgsProviderRegistry.instance().saveLayerMetadata('ogr', QgsProviderRegistry.instance().encodeUri('ogr', {'path': tmpfile, 'layerName': 'test'}), metadata)
+        self.assertTrue(ok)
+
+        vl = QgsVectorLayer(tmpfile, 'test')
+        self.assertTrue(vl.isValid())
+        metadata2 = vl.metadata()
+        self.assertEqual(metadata2.abstract(), 'my abstract')
+        self.assertEqual(metadata2.identifier(), 'my identifier')
+        self.assertEqual(metadata2.licenses(), ['l1', 'l2'])
+
     def testUniqueValuesOnFidColumn(self):
         """Test regression #21311 OGR provider returns an empty set for GPKG uniqueValues"""