qgsvectorfilewriter.h

Go to the documentation of this file.

/***************************************************************************
                          qgsvectorfilewriter.h
                          generic vector file writer
                             -------------------
    begin                : Jun 6 2004
    copyright            : (C) 2004 by Tim Sutton
    email                : tim at linfiniti.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSVECTORFILEWRITER_H
#define QGSVECTORFILEWRITER_H

#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsfields.h"
#include "qgsfeedback.h"
#include "qgssymbol.h"
#include "qgstaskmanager.h"
#include "qgsogrutils.h"
#include "qgsrenderer.h"
#include "qgsgeometryengine.h"
#include "qgsfeaturesink.h"
#include <ogr_api.h>

class QgsSymbolLayer;
class QTextCodec;
class QgsFeatureIterator;

class CORE_EXPORT QgsVectorFileWriter : public QgsFeatureSink
{
  public:
    enum OptionType
    {
      Set,
      String,
      Int,
      Hidden
    };

    class Option
    {
      public:
        Option( const QString &docString, QgsVectorFileWriter::OptionType type )
          : docString( docString )
          , type( type ) {}
        virtual ~Option() = default;

        QString docString;
        QgsVectorFileWriter::OptionType type;
    };

    class SetOption : public QgsVectorFileWriter::Option
    {
      public:
        SetOption( const QString &docString, const QStringList &values, const QString &defaultValue, bool allowNone = false )
          : Option( docString, Set )
          , values( values.toSet() )
          , defaultValue( defaultValue )
          , allowNone( allowNone )
        {}

        QSet<QString> values;
        QString defaultValue;
        bool allowNone;
    };

    class StringOption: public QgsVectorFileWriter::Option
    {
      public:
        StringOption( const QString &docString, const QString &defaultValue = QString() )
          : Option( docString, String )
          , defaultValue( defaultValue )
        {}

        QString defaultValue;
    };

    class IntOption: public QgsVectorFileWriter::Option
    {
      public:
        IntOption( const QString &docString, int defaultValue )
          : Option( docString, Int )
          , defaultValue( defaultValue )
        {}

        int defaultValue;
    };

    class BoolOption : public QgsVectorFileWriter::SetOption
    {
      public:
        BoolOption( const QString &docString, bool defaultValue )
          : SetOption( docString, QStringList() << QStringLiteral( "YES" ) << QStringLiteral( "NO" ), defaultValue ? "YES" : "NO" )
        {}
    };

    class HiddenOption : public QgsVectorFileWriter::Option
    {
      public:
        explicit HiddenOption( const QString &value )
          : Option( QString(), Hidden )
          , mValue( value )
        {}

        QString mValue;
    };

    struct MetaData
    {
      MetaData() = default;

      MetaData( const QString &longName, const QString &trLongName, const QString &glob, const QString &ext, const QMap<QString, QgsVectorFileWriter::Option *> &driverOptions, const QMap<QString, QgsVectorFileWriter::Option *> &layerOptions, const QString &compulsoryEncoding = QString() )
        : longName( longName )
        , trLongName( trLongName )
        , glob( glob )
        , ext( ext )
        , driverOptions( driverOptions )
        , layerOptions( layerOptions )
        , compulsoryEncoding( compulsoryEncoding )
      {}

      QString longName;
      QString trLongName;
      QString glob;
      QString ext;
      QMap<QString, QgsVectorFileWriter::Option *> driverOptions;
      QMap<QString, QgsVectorFileWriter::Option *> layerOptions;
      QString compulsoryEncoding;
    };

    enum WriterError
    {
      NoError = 0,
      ErrDriverNotFound,
      ErrCreateDataSource,
      ErrCreateLayer,
      ErrAttributeTypeUnsupported,
      ErrAttributeCreationFailed,
      ErrProjection,
      ErrFeatureWriteFailed,
      ErrInvalidLayer,
      Canceled, 
    };

    enum SymbologyExport
    {
      NoSymbology = 0, //export only data
      FeatureSymbology, //Keeps the number of features and export symbology per feature
      SymbolLayerSymbology //Exports one feature per symbol layer (considering symbol levels)
    };


    enum VectorFormatOption
    {
      SortRecommended = 1 << 1, 
      SkipNonSpatialFormats = 1 << 2, 
    };
    Q_DECLARE_FLAGS( VectorFormatOptions, VectorFormatOption )

    
    class CORE_EXPORT FieldValueConverter
    {
      public:
        FieldValueConverter() = default;

        virtual ~FieldValueConverter() = default;

        virtual QgsField fieldDefinition( const QgsField &field );

        virtual QVariant convert( int fieldIdxInLayer, const QVariant &value );

        virtual QgsVectorFileWriter::FieldValueConverter *clone() const SIP_FACTORY;
    };

    enum EditionCapability
    {
      CanAddNewLayer                 = 1 << 0,

      CanAppendToExistingLayer       = 1 << 1,

      CanAddNewFieldsToExistingLayer = 1 << 2,

      CanDeleteLayer                 = 1 << 3
    };

    Q_DECLARE_FLAGS( EditionCapabilities, EditionCapability )

    
    enum ActionOnExistingFile
    {
      CreateOrOverwriteFile,

      CreateOrOverwriteLayer,

      AppendToLayerNoNewFields,

      AppendToLayerAddFields
    };

#ifndef SIP_RUN

#else

#endif
    static QgsVectorFileWriter::WriterError writeAsVectorFormat( QgsVectorLayer *layer,
        const QString &fileName,
        const QString &fileEncoding,
        const QgsCoordinateReferenceSystem &destCRS = QgsCoordinateReferenceSystem(),
        const QString &driverName = "GPKG",
        bool onlySelected = false,
        QString *errorMessage SIP_OUT = nullptr,
        const QStringList &datasourceOptions = QStringList(),
        const QStringList &layerOptions = QStringList(),
        bool skipAttributeCreation = false,
        QString *newFilename = nullptr,
        QgsVectorFileWriter::SymbologyExport symbologyExport = QgsVectorFileWriter::NoSymbology,
        double symbologyScale = 1.0,
        const QgsRectangle *filterExtent = nullptr,
        QgsWkbTypes::Type overrideGeometryType = QgsWkbTypes::Unknown,
        bool forceMulti = false,
        bool includeZ = false,
        const QgsAttributeList &attributes = QgsAttributeList(),
        QgsVectorFileWriter::FieldValueConverter *fieldValueConverter = nullptr
#ifndef SIP_RUN
            , QString *newLayer = nullptr );
#else
                                                               );
#endif

#ifndef SIP_RUN

#else

#endif
    static QgsVectorFileWriter::WriterError writeAsVectorFormat( QgsVectorLayer *layer,
        const QString &fileName,
        const QString &fileEncoding,
        const QgsCoordinateTransform &ct,
        const QString &driverName = "GPKG",
        bool onlySelected = false,
        QString *errorMessage SIP_OUT = nullptr,
        const QStringList &datasourceOptions = QStringList(),
        const QStringList &layerOptions = QStringList(),
        bool skipAttributeCreation = false,
        QString *newFilename = nullptr,
        QgsVectorFileWriter::SymbologyExport symbologyExport = QgsVectorFileWriter::NoSymbology,
        double symbologyScale = 1.0,
        const QgsRectangle *filterExtent = nullptr,
        QgsWkbTypes::Type overrideGeometryType = QgsWkbTypes::Unknown,
        bool forceMulti = false,
        bool includeZ = false,
        const QgsAttributeList &attributes = QgsAttributeList(),
        QgsVectorFileWriter::FieldValueConverter *fieldValueConverter = nullptr
#ifndef SIP_RUN
            , QString *newLayer = nullptr );
#else
                                                               );
#endif

    class CORE_EXPORT SaveVectorOptions
    {
      public:
        SaveVectorOptions();

        virtual ~SaveVectorOptions() = default;

        QString driverName;

        QString layerName;

        QgsVectorFileWriter::ActionOnExistingFile actionOnExistingFile = CreateOrOverwriteFile;

        QString fileEncoding;

        QgsCoordinateTransform ct;

        bool onlySelectedFeatures = false;

        QStringList datasourceOptions;

        QStringList layerOptions;

        bool skipAttributeCreation = false;

        QgsAttributeList attributes;

        QgsVectorFileWriter::SymbologyExport symbologyExport = NoSymbology;

        double symbologyScale = 1.0;

        QgsRectangle filterExtent;

        QgsWkbTypes::Type overrideGeometryType = QgsWkbTypes::Unknown;

        bool forceMulti = false;

        bool includeZ = false;

        QgsVectorFileWriter::FieldValueConverter *fieldValueConverter = nullptr;

        QgsFeedback *feedback = nullptr;
    };

#ifndef SIP_RUN

#else

#endif
    static QgsVectorFileWriter::WriterError writeAsVectorFormat( QgsVectorLayer *layer,
        const QString &fileName,
        const QgsVectorFileWriter::SaveVectorOptions &options,
        QString *newFilename = nullptr,
        QString *errorMessage SIP_OUT = nullptr
#ifndef SIP_RUN
                                        , QString *newLayer = nullptr );
#else
                                                               );
#endif

    QgsVectorFileWriter( const QString &vectorFileName,
                         const QString &fileEncoding,
                         const QgsFields &fields,
                         QgsWkbTypes::Type geometryType,
                         const QgsCoordinateReferenceSystem &srs = QgsCoordinateReferenceSystem(),
                         const QString &driverName = "GPKG",
                         const QStringList &datasourceOptions = QStringList(),
                         const QStringList &layerOptions = QStringList(),
                         QString *newFilename = nullptr,
                         QgsVectorFileWriter::SymbologyExport symbologyExport = QgsVectorFileWriter::NoSymbology,
                         QgsFeatureSink::SinkFlags sinkFlags = nullptr
#ifndef SIP_RUN
                             , QString *newLayer = nullptr
#endif
                       );

    QgsVectorFileWriter( const QString &vectorFileName,
                         const QString &fileEncoding,
                         const QgsFields &fields,
                         QgsWkbTypes::Type geometryType,
                         const QgsCoordinateReferenceSystem &srs,
                         const QString &driverName,
                         const QStringList &datasourceOptions,
                         const QStringList &layerOptions,
                         QString *newFilename,
                         QgsVectorFileWriter::SymbologyExport symbologyExport,
                         QgsVectorFileWriter::FieldValueConverter *fieldValueConverter,
                         const QString &layerName,
                         QgsVectorFileWriter::ActionOnExistingFile action,
                         QString *newLayer = nullptr
                       ) SIP_SKIP;

    QgsVectorFileWriter( const QgsVectorFileWriter &rh ) = delete;
    QgsVectorFileWriter &operator=( const QgsVectorFileWriter &rh ) = delete;

    struct FilterFormatDetails
    {
      QString driverName;

      QString filterString;

      QStringList globs;
    };

    static QList< QgsVectorFileWriter::FilterFormatDetails > supportedFiltersAndFormats( VectorFormatOptions options = SortRecommended );

    static QStringList supportedFormatExtensions( VectorFormatOptions options = SortRecommended );

    static bool supportsFeatureStyles( const QString &driverName );

    struct DriverDetails
    {
      QString longName;

      QString driverName;
    };

    static QList< QgsVectorFileWriter::DriverDetails > ogrDriverList( VectorFormatOptions options = SortRecommended );

    static QString driverForExtension( const QString &extension );

    static QString fileFilterString( VectorFormatOptions options = SortRecommended );

    static QString filterForDriver( const QString &driverName );

    static QString convertCodecNameForEncodingOption( const QString &codecName );

    QgsVectorFileWriter::WriterError hasError();

    QString errorMessage();

    bool addFeature( QgsFeature &feature, QgsFeatureSink::Flags flags = nullptr ) override;
    bool addFeatures( QgsFeatureList &features, QgsFeatureSink::Flags flags = nullptr ) override;

    bool addFeatureWithStyle( QgsFeature &feature, QgsFeatureRenderer *renderer, QgsUnitTypes::DistanceUnit outputUnit = QgsUnitTypes::DistanceMeters );

    QMap<int, int> attrIdxToOgrIdx() { return mAttrIdxToOgrIdx; } SIP_SKIP

    ~QgsVectorFileWriter() override;

    static bool deleteShapeFile( const QString &fileName );

    QgsVectorFileWriter::SymbologyExport symbologyExport() const { return mSymbologyExport; }
    void setSymbologyExport( QgsVectorFileWriter::SymbologyExport symExport ) { mSymbologyExport = symExport; }

    double symbologyScale() const { return mSymbologyScale; }

    void setSymbologyScale( double scale );

    static bool driverMetadata( const QString &driverName, MetaData &driverMetadata );

    static QStringList defaultDatasetOptions( const QString &driverName );

    static QStringList defaultLayerOptions( const QString &driverName );

    static OGRwkbGeometryType ogrTypeFromWkbType( QgsWkbTypes::Type type ) SIP_SKIP;

    static QgsVectorFileWriter::EditionCapabilities editionCapabilities( const QString &datasetName );

    static bool targetLayerExists( const QString &datasetName,
                                   const QString &layerName );

    static bool areThereNewFieldsToCreate( const QString &datasetName,
                                           const QString &layerName,
                                           QgsVectorLayer *layer,
                                           const QgsAttributeList &attributes );

  protected:
    OGRGeometryH createEmptyGeometry( QgsWkbTypes::Type wkbType ) SIP_SKIP;

    gdal::ogr_datasource_unique_ptr mDS;
    OGRLayerH mLayer = nullptr;
    OGRSpatialReferenceH mOgrRef = nullptr;

    QgsFields mFields;

    WriterError mError;
    QString mErrorMessage;

    QTextCodec *mCodec = nullptr;

    QgsWkbTypes::Type mWkbType;

    QMap<int, int> mAttrIdxToOgrIdx;

    SymbologyExport mSymbologyExport;

    QMap< QgsSymbolLayer *, QString > mSymbolLayerTable;

    double mSymbologyScale;

    QString mOgrDriverName;

    FieldValueConverter *mFieldValueConverter = nullptr;

  private:
#ifdef SIP_RUN
    QgsVectorFileWriter( const QgsVectorFileWriter &rh );
#endif

    struct PreparedWriterDetails
    {
      std::unique_ptr< QgsFeatureRenderer > renderer;
      QgsCoordinateReferenceSystem sourceCrs;
      QgsWkbTypes::Type sourceWkbType = QgsWkbTypes::Unknown;
      QgsFields sourceFields;
      QString providerType;
      long featureCount = 0;
      QgsFeatureIds selectedFeatureIds;
      QString dataSourceUri;
      QString storageType;
      QgsFeatureIterator geometryTypeScanIterator;
      QgsExpressionContext expressionContext;
      QSet< int > fieldsToConvertToInt;
      QgsRenderContext renderContext;
      bool shallTransform = false;
      QgsCoordinateReferenceSystem outputCrs;
      QgsWkbTypes::Type destWkbType = QgsWkbTypes::Unknown;
      QgsAttributeList attributes;
      QgsFields outputFields;
      QgsFeatureIterator sourceFeatureIterator;
      QgsGeometry filterRectGeometry;
      std::unique_ptr< QgsGeometryEngine  > filterRectEngine;
      QVariantMap providerUriParams;
    };

    static QgsVectorFileWriter::WriterError prepareWriteAsVectorFormat( QgsVectorLayer *layer,
        const QgsVectorFileWriter::SaveVectorOptions &options,
        PreparedWriterDetails &details );

    static QgsVectorFileWriter::WriterError writeAsVectorFormat( PreparedWriterDetails &details,
        const QString &fileName,
        const QgsVectorFileWriter::SaveVectorOptions &options,
        QString *newFilename = nullptr,
        QString *errorMessage SIP_OUT = nullptr,
        QString *newLayer = nullptr );

    void init( QString vectorFileName, QString fileEncoding, const QgsFields &fields,
               QgsWkbTypes::Type geometryType, QgsCoordinateReferenceSystem srs,
               const QString &driverName, QStringList datasourceOptions,
               QStringList layerOptions, QString *newFilename,
               QgsVectorFileWriter::FieldValueConverter *fieldValueConverter,
               const QString &layerName,
               QgsVectorFileWriter::ActionOnExistingFile action, QString *newLayer, QgsFeatureSink::SinkFlags sinkFlags );
    void resetMap( const QgsAttributeList &attributes );

    std::unique_ptr< QgsFeatureRenderer > mRenderer;
    QgsRenderContext mRenderContext;

    bool mUsingTransaction = false;
    bool supportsStringList = false;

    void createSymbolLayerTable( QgsVectorLayer *vl, const QgsCoordinateTransform &ct, OGRDataSourceH ds );
    gdal::ogr_feature_unique_ptr createFeature( const QgsFeature &feature );
    bool writeFeature( OGRLayerH layer, OGRFeatureH feature );

    QgsVectorFileWriter::WriterError exportFeaturesSymbolLevels( const PreparedWriterDetails &details, QgsFeatureIterator &fit, const QgsCoordinateTransform &ct, QString *errorMessage = nullptr );
    double mmScaleFactor( double scale, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits );
    double mapUnitScaleFactor( double scale, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits );

    void startRender( QgsFeatureRenderer *sourceRenderer, const QgsFields &fields );
    void stopRender();
    std::unique_ptr< QgsFeatureRenderer > createSymbologyRenderer( QgsFeatureRenderer *sourceRenderer ) const;
    static void addRendererAttributes( QgsFeatureRenderer *renderer, QgsRenderContext &context, const QgsFields &fields, QgsAttributeList &attList );
    static QMap<QString, MetaData> sDriverMetadata;

    static QStringList concatenateOptions( const QMap<QString, Option *> &options );

    friend class QgsVectorFileWriterTask;
    friend class TestQgsVectorFileWriter;
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsVectorFileWriter::EditionCapabilities )
Q_DECLARE_OPERATORS_FOR_FLAGS( QgsVectorFileWriter::VectorFormatOptions )

// clazy:excludeall=qstring-allocations

#endif