Merge pull request #47053 from nirvn/save_as_gpkg_preserve_array

[vector file writer] Preserve array fields when saving as geopackage
qgis · Jan 30, 2022 · 8860a8a · 8860a8a
2 parents cf92467 + c14de22
commit 8860a8a
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Showing 2 changed files with 91 additions and 8 deletions.
diff --git a/src/core/qgsvectorfilewriter.cpp b/src/core/qgsvectorfilewriter.cpp
@@ -21,6 +21,7 @@
 #include "qgsfeature.h"
 #include "qgsfeatureiterator.h"
 #include "qgsgeometry.h"
+
 #include "qgslogger.h"
 #include "qgsmessagelog.h"
 #include "qgscoordinatereferencesystem.h"
@@ -47,6 +48,7 @@
 #include <QMetaType>
 #include <QMutex>
 #include <QRegularExpression>
+#include <QJsonDocument>
 
 #include <cassert>
 #include <cstdlib> // size_t
@@ -597,6 +599,7 @@ void QgsVectorFileWriter::init( QString vectorFileName,
         }
 
         OGRFieldType ogrType = OFTString; //default to string
+        OGRFieldSubType ogrSubType = OFSTNone;
         int ogrWidth = attrField.length();
         int ogrPrecision = attrField.precision();
         if ( ogrPrecision > 0 )
@@ -629,6 +632,7 @@ void QgsVectorFileWriter::init( QString vectorFileName,
 
           case QVariant::Bool:
             ogrType = OFTInteger;
+            ogrSubType = OFSTBoolean;
             ogrWidth = 1;
             ogrPrecision = 0;
             break;
@@ -679,6 +683,14 @@ void QgsVectorFileWriter::init( QString vectorFileName,
 
           case QVariant::StringList:
           {
+            // handle GPKG conversion to JSON
+            if ( mOgrDriverName == QLatin1String( "GPKG" ) )
+            {
+              ogrType = OFTString;
+              ogrSubType = OFSTJSON;
+              break;
+            }
+
             const char *pszDataTypes = GDALGetMetadataItem( poDriver, GDAL_DMD_CREATIONFIELDDATATYPES, nullptr );
             if ( pszDataTypes && strstr( pszDataTypes, "StringList" ) )
             {
@@ -694,6 +706,14 @@ void QgsVectorFileWriter::init( QString vectorFileName,
           }
 
           case QVariant::List:
+            // handle GPKG conversion to JSON
+            if ( mOgrDriverName == QLatin1String( "GPKG" ) )
+            {
+              ogrType = OFTString;
+              ogrSubType = OFSTJSON;
+              break;
+            }
+
             // fall through to default for other unsupported types
             if ( attrField.subType() == QVariant::String )
             {
@@ -803,14 +823,8 @@ void QgsVectorFileWriter::init( QString vectorFileName,
           OGR_Fld_SetPrecision( fld.get(), ogrPrecision );
         }
 
-        switch ( attrField.type() )
-        {
-          case QVariant::Bool:
-            OGR_Fld_SetSubType( fld.get(), OFSTBoolean );
-            break;
-          default:
-            break;
-        }
+        if ( ogrSubType != OFSTNone )
+          OGR_Fld_SetSubType( fld.get(), ogrSubType );
 
         // create the field
         QgsDebugMsgLevel( "creating field " + attrField.name() +
@@ -2537,6 +2551,19 @@ gdal::ogr_feature_unique_ptr QgsVectorFileWriter::createFeature( const QgsFeatur
 
       case QVariant::StringList:
       {
+        // handle GPKG conversion to JSON
+        if ( mOgrDriverName == QLatin1String( "GPKG" ) )
+        {
+          const QJsonDocument doc = QJsonDocument::fromVariant( attrValue );
+          QString jsonString;
+          if ( !doc.isNull() )
+          {
+            jsonString = QString::fromUtf8( doc.toJson( QJsonDocument::Compact ).constData() );
+          }
+          OGR_F_SetFieldString( poFeature.get(), ogrField, mCodec->fromUnicode( jsonString.constData() ) );
+          break;
+        }
+
         QStringList list = attrValue.toStringList();
         if ( mSupportedListSubTypes.contains( QVariant::String ) )
         {
@@ -2563,6 +2590,19 @@ gdal::ogr_feature_unique_ptr QgsVectorFileWriter::createFeature( const QgsFeatur
       }
 
       case QVariant::List:
+        // handle GPKG conversion to JSON
+        if ( mOgrDriverName == QLatin1String( "GPKG" ) )
+        {
+          const QJsonDocument doc = QJsonDocument::fromVariant( attrValue );
+          QString jsonString;
+          if ( !doc.isNull() )
+          {
+            jsonString = QString::fromUtf8( doc.toJson( QJsonDocument::Compact ).data() );
+          }
+          OGR_F_SetFieldString( poFeature.get(), ogrField, mCodec->fromUnicode( jsonString.constData() ) );
+          break;
+        }
+
         // fall through to default for unsupported types
         if ( field.subType() == QVariant::String )
         {

diff --git a/tests/src/core/testqgsvectorfilewriter.cpp b/tests/src/core/testqgsvectorfilewriter.cpp
@@ -92,6 +92,8 @@ class TestQgsVectorFileWriter: public QObject
     void prepareWriteAsVectorFormat();
     //! Test regression #21714 (Exported GeoPackages have wrong field definitions)
     void testTextFieldLength();
+    //! Test export of array fields to GeoPackages
+    void testExportArrayToGpkg();
     //! Test https://github.com/qgis/QGIS/issues/29819
     void testExportToGpxPoint();
     //! Test https://github.com/qgis/QGIS/issues/29819
@@ -535,6 +537,47 @@ void TestQgsVectorFileWriter::testTextFieldLength()
 
 }
 
+void TestQgsVectorFileWriter::testExportArrayToGpkg()
+{
+  QTemporaryFile tmpFile( QDir::tempPath() +  "/test_qgsvectorfilewriter3_XXXXXX.gpkg" );
+  tmpFile.open();
+  const QString fileName( tmpFile.fileName( ) );
+  QgsVectorLayer vl( "Point?field=arrayfield:integerlist&field=arrayfield2:stringlist", "test", "memory" );
+  QCOMPARE( vl.fields().at( 0 ).type(), QVariant::List );
+  QCOMPARE( vl.fields().at( 0 ).subType(), QVariant::Int );
+  QCOMPARE( vl.fields().at( 1 ).type(), QVariant::StringList );
+  QCOMPARE( vl.fields().at( 1 ).subType(), QVariant::String );
+  QgsFeature f { vl.fields() };
+  f.setAttribute( 0, QVariantList() << 1 << 2 << 3 );
+  f.setAttribute( 1, QStringList() << "a" << "b" << "c" );
+  f.setGeometry( QgsGeometry::fromWkt( QStringLiteral( "point(9 45)" ) ) );
+  QVERIFY( vl.startEditing() );
+  QVERIFY( vl.addFeature( f ) );
+  QgsVectorFileWriter::SaveVectorOptions options;
+  options.driverName = "GPKG";
+  options.layerName = "test";
+  QString newFilename;
+  const QgsVectorFileWriter::WriterError error( QgsVectorFileWriter::writeAsVectorFormatV3(
+        &vl,
+        fileName,
+        vl.transformContext(),
+        options, nullptr,
+        &newFilename ) );
+  QCOMPARE( error, QgsVectorFileWriter::WriterError::NoError );
+  QCOMPARE( newFilename, fileName );
+  const QgsVectorLayer vl2( QStringLiteral( "%1|layername=test" ).arg( fileName ), "src_test", "ogr" );
+  QVERIFY( vl2.isValid() );
+  QCOMPARE( vl2.featureCount(), 1L );
+  QCOMPARE( vl2.fields().at( 1 ).type(), QVariant::Map );
+  QCOMPARE( vl2.fields().at( 1 ).subType(), QVariant::String );
+  QCOMPARE( vl2.fields().at( 1 ).typeName(), QStringLiteral( "JSON" ) );
+  QCOMPARE( vl2.fields().at( 2 ).type(), QVariant::Map );
+  QCOMPARE( vl2.fields().at( 2 ).subType(), QVariant::String );
+  QCOMPARE( vl2.fields().at( 2 ).typeName(), QStringLiteral( "JSON" ) );
+  QCOMPARE( vl2.getFeature( 1 ).attribute( 1 ).toList(), QVariantList() << 1 << 2 << 3 );
+  QCOMPARE( vl2.getFeature( 1 ).attribute( 2 ).toStringList(), QStringList() << "a" << "b" << "c" );
+}
+
 void TestQgsVectorFileWriter::_testExportToGpx( const QString &geomTypeName,
     const QString &wkt,
     const QString &expectedLayerName,