qgsvectordataprovider.h

Go to the documentation of this file.

/***************************************************************************
    qgsvectordataprovider.h - DataProvider Interface for vector layers
     --------------------------------------
    Date                 : 23-Sep-2004
    Copyright            : (C) 2004 by Marco Hugentobler
    email                : [email protected]
 ***************************************************************************
 *                                                                         *
 *   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 QGSVECTORDATAPROVIDER_H
#define QGSVECTORDATAPROVIDER_H
 
class QTextCodec;
 
#include "qgis_core.h"
 
#include <QHash>
#include <QList>
#include <QMap>
#include <QSet>
 
//QGIS Includes
#include "qgis_sip.h"
#include "qgsdataprovider.h"
#include "qgsfeature.h"
#include "qgsaggregatecalculator.h"
#include "qgsmaplayerdependency.h"
#include "qgsrelation.h"
#include "qgsfeaturesink.h"
#include "qgsfeaturesource.h"
#include "qgsfeaturerequest.h"
#include "qgsvectordataprovidertemporalcapabilities.h"
 
typedef QList<int> QgsAttributeList SIP_SKIP;
typedef QSet<int> QgsAttributeIds SIP_SKIP;
typedef QHash<int, QString> QgsAttrPalIndexNameHash;
 
class QgsFeatureIterator;
class QgsTransaction;
class QgsFeedback;
class QgsFeatureRenderer;
class QgsAbstractVectorLayerLabeling;
 

class CORE_EXPORT QgsVectorDataProvider : public QgsDataProvider, public QgsFeatureSink, public QgsFeatureSource
{
    Q_OBJECT
 
    friend class QgsTransaction;
    friend class QgsVectorLayerEditBuffer;
 
  public:
    static const int EditingCapabilities = static_cast< int >( Qgis::VectorProviderCapability::EditingCapabilities );

    QgsVectorDataProvider(
      const QString &uri = QString(), const QgsDataProvider::ProviderOptions &providerOptions = QgsDataProvider::ProviderOptions(), Qgis::DataProviderReadFlags flags = Qgis::DataProviderReadFlags()
    );

    virtual QgsAbstractFeatureSource *featureSource() const = 0 SIP_FACTORY;

    virtual QString storageType() const;

    QgsFeatureIterator getFeatures( const QgsFeatureRequest &request = QgsFeatureRequest() ) const override = 0;

    Qgis::WkbType wkbType() const override = 0;

    long long featureCount() const override = 0;

    virtual bool empty() const;

    virtual bool isSqlQuery() const;

    virtual Qgis::VectorLayerTypeFlags vectorLayerTypeFlags() const;

    Qgis::FeatureAvailability hasFeatures() const override;

    QgsFields fields() const override = 0;
 
    QgsCoordinateReferenceSystem sourceCrs() const override;
    QgsRectangle sourceExtent() const override;
    QgsBox3D sourceExtent3D() const override;
    QString sourceName() const override { return QString(); }

    QString dataComment() const override;

    QVariant minimumValue( int index ) const override;

    QVariant maximumValue( int index ) const override;

    virtual QStringList uniqueStringsMatching( int index, const QString &substring, int limit = -1, QgsFeedback *feedback = nullptr ) const;

    virtual QVariant aggregate(
      Qgis::Aggregate aggregate, int index, const QgsAggregateCalculator::AggregateParameters &parameters, QgsExpressionContext *context, bool &ok, QgsFeatureIds *fids = nullptr
    ) const;

    virtual void enumValues( int index, QStringList &enumList SIP_OUT ) const
    {
      Q_UNUSED( index )
      enumList.clear();
    }
 
    using QgsFeatureSink::addFeatures;
    bool addFeatures( QgsFeatureList &flist SIP_INOUT, QgsFeatureSink::Flags flags = QgsFeatureSink::Flags() ) override;
    QString lastError() const override;

    virtual bool deleteFeatures( const QgsFeatureIds &id );

    virtual bool truncate();

    virtual bool cancelReload();

    virtual bool addAttributes( const QList<QgsField> &attributes );

    virtual bool deleteAttributes( const QgsAttributeIds &attributes );

    virtual bool renameAttributes( const QgsFieldNameMap &renamedAttributes );

    virtual bool changeAttributeValues( const QgsChangedAttributesMap &attr_map );

    virtual bool changeFeatures( const QgsChangedAttributesMap &attr_map, const QgsGeometryMap &geometry_map );

    virtual QVariant defaultValue( int fieldIndex ) const;

    virtual QString defaultValueClause( int fieldIndex ) const;

    QgsFieldConstraints::Constraints fieldConstraints( int fieldIndex ) const;

    virtual bool skipConstraintCheck( int fieldIndex, QgsFieldConstraints::Constraint constraint, const QVariant &value = QVariant() ) const;

    virtual bool changeGeometryValues( const QgsGeometryMap &geometry_map );

    virtual bool createSpatialIndex();

    virtual bool createAttributeIndex( int field );

    Q_INVOKABLE virtual Qgis::VectorProviderCapabilities capabilities() const;

    QString capabilitiesString() const;

    virtual Qgis::VectorDataProviderAttributeEditCapabilities attributeEditCapabilities() const;

    virtual void setEncoding( const QString &e );

    QString encoding() const;

    int fieldNameIndex( const QString &fieldName ) const;

    QMap<QString, int> fieldNameMap() const;

    virtual QgsAttributeList attributeIndexes() const;

    virtual QgsAttributeList pkAttributeIndexes() const;

    virtual QString geometryColumnName() const;

    Q_DECL_DEPRECATED QgsAttrPalIndexNameHash palAttributeIndexNames() const SIP_DEPRECATED;

    bool supportedType( const QgsField &field ) const;
 
    struct NativeType
    {
        NativeType(
          const QString &typeDesc, const QString &typeName, QMetaType::Type type, int minLen = 0, int maxLen = 0, int minPrec = 0, int maxPrec = 0, QMetaType::Type subType = QMetaType::Type::UnknownType
        )
          : mTypeDesc( typeDesc )
          , mTypeName( typeName )
          , mType( type )
          , mMinLen( minLen )
          , mMaxLen( maxLen )
          , mMinPrec( minPrec )
          , mMaxPrec( maxPrec )
          , mSubType( subType )
        {}
 
        Q_DECL_DEPRECATED NativeType(
          const QString &typeDesc, const QString &typeName, QVariant::Type type, int minLen = 0, int maxLen = 0, int minPrec = 0, int maxPrec = 0, QVariant::Type subType = QVariant::Type::Invalid
        )
          : mTypeDesc( typeDesc )
          , mTypeName( typeName )
          , mType( QgsVariantUtils::variantTypeToMetaType( type ) )
          , mMinLen( minLen )
          , mMaxLen( maxLen )
          , mMinPrec( minPrec )
          , mMaxPrec( maxPrec )
          , mSubType( QgsVariantUtils::variantTypeToMetaType( subType ) ) SIP_DEPRECATED
        {}
 
 
        QString mTypeDesc;
        QString mTypeName;
        QMetaType::Type mType;
        int mMinLen;
        int mMaxLen;
        int mMinPrec;
        int mMaxPrec;
        QMetaType::Type mSubType;
    };

    QList< QgsVectorDataProvider::NativeType > nativeTypes() const;

    virtual bool doesStrictFeatureTypeCheck() const { return true; }

    static QStringList availableEncodings();

    bool hasErrors() const;

    void clearErrors();

    QStringList errors() const;

    virtual QgsFeatureRenderer *createRenderer( const QVariantMap &configuration = QVariantMap() ) const SIP_FACTORY;

    virtual QgsAbstractVectorLayerLabeling *createLabeling( const QVariantMap &configuration = QVariantMap() ) const SIP_FACTORY;

    static QVariant convertValue( QMetaType::Type type, const QString &value );

    Q_DECL_DEPRECATED static QVariant convertValue( QVariant::Type type, const QString &value ) SIP_DEPRECATED;

    virtual QgsTransaction *transaction() const;

    Q_DECL_DEPRECATED virtual void forceReload() SIP_DEPRECATED { reloadData(); }

    virtual QSet<QgsMapLayerDependency> dependencies() const;

    virtual QList<QgsRelation> discoverRelations( const QgsVectorLayer *target, const QList<QgsVectorLayer *> &layers ) const;

    virtual QString translateMetadataKey( const QString &mdKey ) const { return mdKey; }

    virtual QString translateMetadataValue( const QString &mdKey, const QVariant &value ) const
    {
      Q_UNUSED( mdKey )
      return value.toString();
    }

    virtual bool hasMetadata() const { return true; }

    virtual void handlePostCloneOperations( QgsVectorDataProvider *source );
 
    QgsVectorDataProviderTemporalCapabilities *temporalCapabilities() override;
    const QgsVectorDataProviderTemporalCapabilities *temporalCapabilities() const override SIP_SKIP;
 
    QgsDataProviderElevationProperties *elevationProperties() override;
    const QgsDataProviderElevationProperties *elevationProperties() const override SIP_SKIP;
 
  signals:

    void raiseError( const QString &msg ) const;
 
  protected:
    void clearMinMaxCache();

    void fillMinMaxCache() const;

    void pushError( const QString &msg ) const;

    QgsGeometry convertToProviderType( const QgsGeometry &geom ) const;

    void setNativeTypes( const QList<QgsVectorDataProvider::NativeType> &nativeTypes );
 
#ifdef SIP_PYQT5_RUN

    QTextCodec *textEncoding() const;
#endif

    static QgsGeometry convertToProviderType( const QgsGeometry &geometry, Qgis::WkbType providerGeometryType );
 
 
  private:
    mutable bool mCacheMinMaxDirty = true;
    mutable QMap<int, QVariant> mCacheMinValues, mCacheMaxValues;

    QTextCodec *mEncoding = nullptr;

    QgsAttributeList mAttributesToFetch;

    QList< NativeType > mNativeTypes;

    mutable QStringList mErrors;
 
    std::unique_ptr< QgsVectorDataProviderTemporalCapabilities > mTemporalCapabilities;
    std::unique_ptr< QgsDataProviderElevationProperties > mElevationProperties;
 
    static QStringList sEncodings;

    virtual void setTransaction( QgsTransaction * /*transaction*/ ) {}
};
 
#endif