A convenience class for writing vector layers to disk based formats (e.g. More...

#include <qgsvectorfilewriter.h>

Inheritance diagram for QgsVectorFileWriter:

Classes
class	BoolOption
	An available option for configuring file writing for a particular output format, presenting an boolean option. More...
struct	DriverDetails
	Details of available driver formats. More...
class	FieldValueConverter
	Interface to convert raw field values to their user-friendly values. More...
struct	FilterFormatDetails
	Details of available filters and formats. More...
class	HiddenOption
	A hidden option for file writing for a particular output format. More...
class	IntOption
	An available option for configuring file writing for a particular output format, presenting an integer option. More...
struct	MetaData
class	Option
	Describes an available option for configuring file writing for a particular output format. More...
class	SaveVectorOptions
	Options to pass to QgsVectorFileWriter::writeAsVectorFormat(). More...
class	SetOption
	An available option for configuring file writing for a particular output format, presenting a choice of preset values. More...
class	StringOption
	An available option for configuring file writing for a particular output format, presenting a freeform string option. More...

Public Types
enum	ActionOnExistingFile { CreateOrOverwriteFile , CreateOrOverwriteLayer , AppendToLayerNoNewFields , AppendToLayerAddFields }
	Enumeration to describe how to handle existing files. More...
typedef QFlags< EditionCapability >	EditionCapabilities
	Combination of CanAddNewLayer, CanAppendToExistingLayer, CanAddNewFieldsToExistingLayer or CanDeleteLayer.
enum	EditionCapability { CanAddNewLayer = 1 << 0 , CanAppendToExistingLayer = 1 << 1 , CanAddNewFieldsToExistingLayer = 1 << 2 , CanDeleteLayer = 1 << 3 }
	Edition capability flags. More...
enum	FieldNameSource { Original = 0 , PreferAlias }
	Source for exported field names. More...
enum	OptionType { Set , String , Int , Hidden }
enum	VectorFormatOption { SortRecommended = 1 << 1 , SkipNonSpatialFormats = 1 << 2 , SupportsMultipleLayers = 1 << 3 }
	Options for sorting and filtering vector formats. More...
typedef QFlags< VectorFormatOption >	VectorFormatOptions
enum	WriterError { NoError = 0 , ErrDriverNotFound , ErrCreateDataSource , ErrCreateLayer , ErrAttributeTypeUnsupported , ErrAttributeCreationFailed , ErrProjection , ErrFeatureWriteFailed , ErrInvalidLayer , ErrSavingMetadata , Canceled }
Public Types inherited from QgsFeatureSink
enum	Flag { FastInsert = 1 << 1 , RollBackOnErrors = 1 << 2 }
	Flags controlling how features are added to a sink. More...
typedef QFlags< Flag >	Flags
enum	SinkFlag { RegeneratePrimaryKey = 1 << 1 }
	Flags that can be set on a QgsFeatureSink. More...
typedef QFlags< SinkFlag >	SinkFlags

Public Member Functions
	QgsVectorFileWriter (const QgsVectorFileWriter &rh)=delete
Q_DECL_DEPRECATED	QgsVectorFileWriter (const QString &vectorFileName, const QString &fileEncoding, const QgsFields &fields, Qgis::WkbType geometryType, const QgsCoordinateReferenceSystem &srs, const QString &driverName, const QStringList &datasourceOptions, const QStringList &layerOptions, QString newFilename, Qgis::FeatureSymbologyExport symbologyExport, QgsVectorFileWriter::FieldValueConverter fieldValueConverter, const QString &layerName, QgsVectorFileWriter::ActionOnExistingFile action, QString newLayer=nullptr, const QgsCoordinateTransformContext &transformContext=QgsCoordinateTransformContext(), QgsFeatureSink::SinkFlags sinkFlags=QgsFeatureSink::SinkFlags(), FieldNameSource fieldNameSource=Original, bool includeConstraints=false, bool setFieldDomains=true, const QgsAbstractDatabaseProviderConnection sourceDatabaseProviderConnection=nullptr)
	Create a new vector file writer.
Q_DECL_DEPRECATED	QgsVectorFileWriter (const QString &vectorFileName, const QString &fileEncoding, const QgsFields &fields, Qgis::WkbType geometryType, const QgsCoordinateReferenceSystem &srs=QgsCoordinateReferenceSystem(), const QString &driverName="GPKG", const QStringList &datasourceOptions=QStringList(), const QStringList &layerOptions=QStringList(), QString newFilename=nullptr, Qgis::FeatureSymbologyExport symbologyExport=Qgis::FeatureSymbologyExport::NoSymbology, QgsFeatureSink::SinkFlags sinkFlags=QgsFeatureSink::SinkFlags(), QString newLayer=nullptr, const QgsCoordinateTransformContext &transformContext=QgsCoordinateTransformContext(), FieldNameSource fieldNameSource=Original)
	Create a new vector file writer.
	~QgsVectorFileWriter () override
	Close opened shapefile for writing.
bool	addFeature (QgsFeature &feature, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags()) override
	Adds a single feature to the sink.
virtual bool	addFeatures (QgsFeatureIterator &iterator, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags())
	Adds all features from the specified iterator to the sink.
bool	addFeatures (QgsFeatureList &features, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags()) override
	Adds a list of features to the sink.
bool	addFeatureWithStyle (QgsFeature &feature, QgsFeatureRenderer *renderer, Qgis::DistanceUnit outputUnit=Qgis::DistanceUnit::Meters)
	Adds a feature to the currently opened data source, using the style from a specified renderer.
Qgis::VectorFileWriterCapabilities	capabilities () const
	Returns the capabilities supported by the writer.
QString	driver () const
	Returns the GDAL (short) driver name associated with the output file.
QString	driverLongName () const
	Returns the GDAL long driver name associated with the output file.
QString	errorMessage () const
	Retrieves error message.
QgsVectorFileWriter::WriterError	hasError () const
	Checks whether there were any errors in constructor.
QString	lastError () const override
	Returns the most recent error encountered by the sink, e.g.
QgsVectorFileWriter &	operator= (const QgsVectorFileWriter &rh)=delete
void	setSymbologyExport (Qgis::FeatureSymbologyExport symExport)
	Sets the feature symbology export handling for the writer.
void	setSymbologyScale (double scale)
	Set reference scale for output.
QMap< int, int >	sourceFieldIndexToWriterFieldIndex () const
	Returns the map of original source field index to output file field index.
Qgis::FeatureSymbologyExport	symbologyExport () const
	Returns the feature symbology export handling for the writer.
double	symbologyScale () const
	Returns the reference scale for output.
Public Member Functions inherited from QgsFeatureSink
virtual	~QgsFeatureSink ()=default
virtual void	finalize ()
	Finalizes the sink, flushing any buffered features to the destination.
virtual bool	flushBuffer ()
	Flushes any internal buffer which may exist in the sink, causing any buffered features to be added to the sink's destination.

Static Public Member Functions
static bool	areThereNewFieldsToCreate (const QString &datasetName, const QString &layerName, QgsVectorLayer *layer, const QgsAttributeList &attributes)
	Returns whether there are among the attributes specified some that do not exist yet in the layer.
static QString	convertCodecNameForEncodingOption (const QString &codecName)
	Converts codec name to string passed to ENCODING layer creation option of OGR Shapefile.
static QgsVectorFileWriter *	create (const QString &fileName, const QgsFields &fields, Qgis::WkbType geometryType, const QgsCoordinateReferenceSystem &srs, const QgsCoordinateTransformContext &transformContext, const QgsVectorFileWriter::SaveVectorOptions &options, QgsFeatureSink::SinkFlags sinkFlags=QgsFeatureSink::SinkFlags(), QString newFilename=nullptr, QString newLayer=nullptr)
	Create a new vector file writer.
static QStringList	defaultDatasetOptions (const QString &driverName)
	Returns a list of the default dataset options for a specified driver.
static QStringList	defaultLayerOptions (const QString &driverName)
	Returns a list of the default layer options for a specified driver.
static bool	deleteShapeFile (const QString &fileName)
	Delete a shapefile (and its accompanying shx / dbf / prj / qix / qpj / cpg / sbn / sbx / idm / ind).
static QString	driverForExtension (const QString &extension)
	Returns the OGR driver name for a specified file extension.
static bool	driverMetadata (const QString &driverName, MetaData &driverMetadata)
static QgsVectorFileWriter::EditionCapabilities	editionCapabilities (const QString &datasetName)
	Returns edition capabilities for an existing dataset name.
static QString	fileFilterString (VectorFormatOptions options=SortRecommended)
	Returns filter string that can be used for dialogs.
static QString	filterForDriver (const QString &driverName)
	Creates a filter for an OGR driver key.
static QList< QgsVectorFileWriter::DriverDetails >	ogrDriverList (VectorFormatOptions options=SortRecommended)
	Returns the driver list that can be used for dialogs.
static OGRwkbGeometryType	ogrTypeFromWkbType (Qgis::WkbType type)
	Gets the ogr geometry type from an internal QGIS wkb type enum.
static QList< QgsVectorFileWriter::FilterFormatDetails >	supportedFiltersAndFormats (VectorFormatOptions options=SortRecommended)
	Returns a list or pairs, with format filter string as first element and OGR format key as second element.
static QStringList	supportedFormatExtensions (VectorFormatOptions options=SortRecommended)
	Returns a list of file extensions for supported formats, e.g "shp", "gpkg".
static bool	supportsFeatureStyles (const QString &driverName)
	Returns `true` if the specified driverName supports feature styles.
static bool	targetLayerExists (const QString &datasetName, const QString &layerName)
	Returns whether the target layer already exists.
static Q_DECL_DEPRECATED QgsVectorFileWriter::WriterError	writeAsVectorFormat (QgsVectorLayer layer, const QString &fileName, const QgsVectorFileWriter::SaveVectorOptions &options, QString newFilename=nullptr, QString errorMessage=nullptr, QString newLayer=nullptr)
	Writes a layer out to a vector file.
static Q_DECL_DEPRECATED QgsVectorFileWriter::WriterError	writeAsVectorFormat (QgsVectorLayer layer, const QString &fileName, const QString &fileEncoding, const QgsCoordinateReferenceSystem &destCRS=QgsCoordinateReferenceSystem(), const QString &driverName="GPKG", bool onlySelected=false, QString errorMessage=nullptr, const QStringList &datasourceOptions=QStringList(), const QStringList &layerOptions=QStringList(), bool skipAttributeCreation=false, QString newFilename=nullptr, Qgis::FeatureSymbologyExport symbologyExport=Qgis::FeatureSymbologyExport::NoSymbology, double symbologyScale=1.0, const QgsRectangle filterExtent=nullptr, Qgis::WkbType overrideGeometryType=Qgis::WkbType::Unknown, bool forceMulti=false, bool includeZ=false, const QgsAttributeList &attributes=QgsAttributeList(), QgsVectorFileWriter::FieldValueConverter fieldValueConverter=nullptr, QString newLayer=nullptr)
	Write contents of vector layer to an (OGR supported) vector format.
static Q_DECL_DEPRECATED QgsVectorFileWriter::WriterError	writeAsVectorFormat (QgsVectorLayer layer, const QString &fileName, const QString &fileEncoding, const QgsCoordinateTransform &ct, const QString &driverName="GPKG", bool onlySelected=false, QString errorMessage=nullptr, const QStringList &datasourceOptions=QStringList(), const QStringList &layerOptions=QStringList(), bool skipAttributeCreation=false, QString newFilename=nullptr, Qgis::FeatureSymbologyExport symbologyExport=Qgis::FeatureSymbologyExport::NoSymbology, double symbologyScale=1.0, const QgsRectangle filterExtent=nullptr, Qgis::WkbType overrideGeometryType=Qgis::WkbType::Unknown, bool forceMulti=false, bool includeZ=false, const QgsAttributeList &attributes=QgsAttributeList(), QgsVectorFileWriter::FieldValueConverter fieldValueConverter=nullptr, QString newLayer=nullptr)
	Writes a layer out to a vector file.
static Q_DECL_DEPRECATED QgsVectorFileWriter::WriterError	writeAsVectorFormatV2 (QgsVectorLayer layer, const QString &fileName, const QgsCoordinateTransformContext &transformContext, const QgsVectorFileWriter::SaveVectorOptions &options, QString newFilename=nullptr, QString newLayer=nullptr, QString errorMessage=nullptr)
	Writes a layer out to a vector file.
static QgsVectorFileWriter::WriterError	writeAsVectorFormatV3 (QgsVectorLayer layer, const QString &fileName, const QgsCoordinateTransformContext &transformContext, const QgsVectorFileWriter::SaveVectorOptions &options, QString errorMessage=nullptr, QString newFilename=nullptr, QString newLayer=nullptr)
	Writes a layer out to a vector file.

Protected Member Functions
OGRGeometryH	createEmptyGeometry (Qgis::WkbType wkbType)

Protected Attributes
QMap< int, int >	mAttrIdxToOgrLayerIdx
	Map attribute indices to OGR layer field indexes such as they are on the current mLayer instance.
QMap< int, int >	mAttrIdxToProviderIdx
	Map attribute indices to OGR provider field indexes such as they are after the OGR provider has been created.
QTextCodec *	mCodec = nullptr
gdal::ogr_datasource_unique_ptr	mDS
WriterError	mError
	Contains error value if construction was not successful.
QString	mErrorMessage
QgsFields	mFields
FieldValueConverter *	mFieldValueConverter = nullptr
	Field value converter.
bool	mIncludeConstraints = false
	Whether to transfer field constraints to output.
OGRLayerH	mLayer = nullptr
QString	mOgrDriverLongName
QString	mOgrDriverName
OGRSpatialReferenceH	mOgrRef = nullptr
bool	mSetFieldDomains = true
	Whether to set field domains to output.
QMap< QgsSymbolLayer *, QString >	mSymbolLayerTable
Qgis::FeatureSymbologyExport	mSymbologyExport = Qgis::FeatureSymbologyExport::NoSymbology
double	mSymbologyScale
	Scale for symbology export (e.g. for symbols units in map units).
Qgis::WkbType	mWkbType
	Geometry type which is being used.

Friends
class	QgsVectorFileWriterTask
class	TestQgsVectorFileWriter

Detailed Description

A convenience class for writing vector layers to disk based formats (e.g.

Shapefiles, GeoPackage).

There are two possibilities how to use this class:

A static call to QgsVectorFileWriter::writeAsVectorFormat(...) which saves the whole vector layer.
Create an instance of the class and issue calls to addFeature(...).

Definition at line 52 of file qgsvectorfilewriter.h.

Member Typedef Documentation

◆ EditionCapabilities

typedef QFlags< EditionCapability > QgsVectorFileWriter::EditionCapabilities

Combination of CanAddNewLayer, CanAppendToExistingLayer, CanAddNewFieldsToExistingLayer or CanDeleteLayer.

Definition at line 271 of file qgsvectorfilewriter.h.

◆ VectorFormatOptions

typedef QFlags< VectorFormatOption > QgsVectorFileWriter::VectorFormatOptions

Definition at line 215 of file qgsvectorfilewriter.h.

Member Enumeration Documentation

◆ ActionOnExistingFile

enum QgsVectorFileWriter::ActionOnExistingFile

Enumeration to describe how to handle existing files.

Enumerator
CreateOrOverwriteFile	Create or overwrite file.
CreateOrOverwriteLayer	Create or overwrite layer.
AppendToLayerNoNewFields	Append features to existing layer, but do not create new fields.
AppendToLayerAddFields	Append features to existing layer, and create new fields if needed.

Definition at line 276 of file qgsvectorfilewriter.h.

◆ EditionCapability

enum QgsVectorFileWriter::EditionCapability

Edition capability flags.

Enumerator
CanAddNewLayer	Flag to indicate that a new layer can be added to the dataset.
CanAppendToExistingLayer	Flag to indicate that new features can be added to an existing layer.
CanAddNewFieldsToExistingLayer	Flag to indicate that new fields can be added to an existing layer. Imply CanAppendToExistingLayer.
CanDeleteLayer	Flag to indicate that an existing layer can be deleted.

Definition at line 253 of file qgsvectorfilewriter.h.

◆ FieldNameSource

enum QgsVectorFileWriter::FieldNameSource

Source for exported field names.

Since: QGIS 3.18

Enumerator
Original	Use original field names.
PreferAlias	Use the field alias as the exported field name, wherever one is set. Otherwise use the original field names.

Definition at line 200 of file qgsvectorfilewriter.h.

◆ OptionType

enum QgsVectorFileWriter::OptionType

Enumerator
Set
String
Int
Hidden

Definition at line 55 of file qgsvectorfilewriter.h.

◆ VectorFormatOption

enum QgsVectorFileWriter::VectorFormatOption

Options for sorting and filtering vector formats.

Enumerator

SortRecommended

Use recommended sort order, with extremely commonly used formats listed first.

SkipNonSpatialFormats

Filter out any formats which do not have spatial support (e.g. those which cannot save geometries).

SupportsMultipleLayers

Filter to only formats which support multiple layers.

Since: QGIS 3.32

Definition at line 209 of file qgsvectorfilewriter.h.

◆ WriterError

enum QgsVectorFileWriter::WriterError

Enumerator
NoError
ErrDriverNotFound
ErrCreateDataSource
ErrCreateLayer
ErrAttributeTypeUnsupported
ErrAttributeCreationFailed
ErrProjection
ErrFeatureWriteFailed
ErrInvalidLayer
ErrSavingMetadata	Metadata saving failed.
Canceled	Writing was interrupted by manual cancellation.

Definition at line 180 of file qgsvectorfilewriter.h.

Constructor & Destructor Documentation

◆ QgsVectorFileWriter() [1/3]

QgsVectorFileWriter::QgsVectorFileWriter	(	const QString &	vectorFileName,
		const QString &	fileEncoding,
		const QgsFields &	fields,
		Qgis::WkbType	geometryType,
		const QgsCoordinateReferenceSystem &	srs = QgsCoordinateReferenceSystem(),
		const QString &	driverName = "GPKG",
		const QStringList &	datasourceOptions = QStringList(),
		const QStringList &	layerOptions = QStringList(),
		QString *	newFilename = nullptr,
		Qgis::FeatureSymbologyExport	symbologyExport = Qgis::FeatureSymbologyExport::NoSymbology,
		QgsFeatureSink::SinkFlags	sinkFlags = QgsFeatureSink::SinkFlags(),
		QString *	newLayer = nullptr,
		const QgsCoordinateTransformContext &	transformContext = QgsCoordinateTransformContext(),
		FieldNameSource	fieldNameSource = Original )

Create a new vector file writer.

Deprecated: QGIS 3.40. Use create() instead.

Definition at line 78 of file qgsvectorfilewriter.cpp.

◆ QgsVectorFileWriter() [2/3]

QgsVectorFileWriter::QgsVectorFileWriter	(	const QString &	vectorFileName,
		const QString &	fileEncoding,
		const QgsFields &	fields,
		Qgis::WkbType	geometryType,
		const QgsCoordinateReferenceSystem &	srs,
		const QString &	driverName,
		const QStringList &	datasourceOptions,
		const QStringList &	layerOptions,
		QString *	newFilename,
		Qgis::FeatureSymbologyExport	symbologyExport,
		QgsVectorFileWriter::FieldValueConverter *	fieldValueConverter,
		const QString &	layerName,
		QgsVectorFileWriter::ActionOnExistingFile	action,
		QString *	newLayer = nullptr,
		const QgsCoordinateTransformContext &	transformContext = QgsCoordinateTransformContext(),
		QgsFeatureSink::SinkFlags	sinkFlags = QgsFeatureSink::SinkFlags(),
		FieldNameSource	fieldNameSource = Original,
		bool	includeConstraints = false,
		bool	setFieldDomains = true,
		const QgsAbstractDatabaseProviderConnection *	sourceDatabaseProviderConnection = nullptr )

Create a new vector file writer.

Parameters

vectorFileName	file name to write to
fileEncoding	encoding to use
fields	fields to write
geometryType	geometry type of output file
srs	spatial reference system of output file
driverName	OGR driver to use
datasourceOptions	list of OGR data source creation options
layerOptions	list of OGR layer creation options
newFilename	potentially modified file name (output parameter)
symbologyExport	symbology to export
fieldValueConverter	field value converter (added in QGIS 2.16)
layerName	layer name. If let empty, it will be derived from the filename (added in QGIS 3.0)
action	action on existing file (added in QGIS 3.0)
newLayer	potentially modified layer name (output parameter) (added in QGIS 3.4)
transformContext	transform context, needed if the output file srs is forced to specific crs (added in QGIS 3.10.3)
sinkFlags	feature sink flags (added in QGIS 3.10.3)
fieldNameSource	source for field names (since QGIS 3.18)
includeConstraints	set to `true` to copy field constraints to the destination layer (since QGIS 3.34)
setFieldDomains	set to `true` to copy field domains (since QGIS 3.36)
sourceDatabaseProviderConnection	source database provider connection, for field domains (since QGIS 3.36)

Note: not available in Python bindings

Deprecated: QGIS 3.40. Use create() instead.

Definition at line 102 of file qgsvectorfilewriter.cpp.

◆ QgsVectorFileWriter() [3/3]

QgsVectorFileWriter::QgsVectorFileWriter ( const QgsVectorFileWriter & rh )

delete

◆ ~QgsVectorFileWriter()

QgsVectorFileWriter::~QgsVectorFileWriter ( )

override

Close opened shapefile for writing.

Definition at line 3368 of file qgsvectorfilewriter.cpp.

Member Function Documentation

◆ addFeature()

bool QgsVectorFileWriter::addFeature	(	QgsFeature &	feature,
		QgsFeatureSink::Flags	flags = QgsFeatureSink::Flags() )

overridevirtual

Adds a single feature to the sink.

Feature addition behavior is controlled by the specified flags.

See also: addFeatures()

Returns: true in case of success and false in case of failure

Reimplemented from QgsFeatureSink.

Definition at line 2737 of file qgsvectorfilewriter.cpp.

◆ addFeatures() [1/2]

bool QgsFeatureSink::addFeatures	(	QgsFeatureIterator &	iterator,
		QgsFeatureSink::Flags	flags = QgsFeatureSink::Flags() )

virtual

Adds all features from the specified iterator to the sink.

Feature addition behavior is controlled by the specified flags.

Returns: true if all features were added successfully, or false if any feature could not be added

Reimplemented from QgsFeatureSink.

Definition at line 108 of file qgsfeaturesink.cpp.

◆ addFeatures() [2/2]

bool QgsVectorFileWriter::addFeatures	(	QgsFeatureList &	features,
		QgsFeatureSink::Flags	flags = QgsFeatureSink::Flags() )

overridevirtual

Adds a list of features to the sink.

Feature addition behavior is controlled by the specified flags.

See also: addFeature()

Returns: true in case of success and false in case of failure

Implements QgsFeatureSink.

Definition at line 2742 of file qgsvectorfilewriter.cpp.

◆ addFeatureWithStyle()

bool QgsVectorFileWriter::addFeatureWithStyle	(	QgsFeature &	feature,
		QgsFeatureRenderer *	renderer,
		Qgis::DistanceUnit	outputUnit = Qgis::DistanceUnit::Meters )

Adds a feature to the currently opened data source, using the style from a specified renderer.

Definition at line 2758 of file qgsvectorfilewriter.cpp.

◆ areThereNewFieldsToCreate()

bool QgsVectorFileWriter::areThereNewFieldsToCreate	(	const QString &	datasetName,
		const QString &	layerName,
		QgsVectorLayer *	layer,
		const QgsAttributeList &	attributes )

static

Returns whether there are among the attributes specified some that do not exist yet in the layer.

Definition at line 4705 of file qgsvectorfilewriter.cpp.

◆ capabilities()

Qgis::VectorFileWriterCapabilities QgsVectorFileWriter::capabilities ( ) const

Returns the capabilities supported by the writer.

Since: QGIS 3.32

Definition at line 2732 of file qgsvectorfilewriter.cpp.

◆ convertCodecNameForEncodingOption()

QString QgsVectorFileWriter::convertCodecNameForEncodingOption ( const QString & codecName )

static

Converts codec name to string passed to ENCODING layer creation option of OGR Shapefile.

Definition at line 4306 of file qgsvectorfilewriter.cpp.

◆ create()

QgsVectorFileWriter * QgsVectorFileWriter::create	(	const QString &	fileName,
		const QgsFields &	fields,
		Qgis::WkbType	geometryType,
		const QgsCoordinateReferenceSystem &	srs,
		const QgsCoordinateTransformContext &	transformContext,
		const QgsVectorFileWriter::SaveVectorOptions &	options,
		QgsFeatureSink::SinkFlags	sinkFlags = QgsFeatureSink::SinkFlags(),
		QString *	newFilename = nullptr,
		QString *	newLayer = nullptr )

static

Create a new vector file writer.

Parameters

fileName	file name to write to
fields	fields to write
geometryType	geometry type of output file
srs	spatial reference system of output file
transformContext	coordinate transform context
options	save options
sinkFlags	feature sink flags
newFilename	potentially modified file name (output parameter)
newLayer	potentially modified layer name (output parameter)

Since: QGIS 3.10.3

Definition at line 134 of file qgsvectorfilewriter.cpp.

◆ createEmptyGeometry()

OGRGeometryH QgsVectorFileWriter::createEmptyGeometry ( Qgis::WkbType wkbType )

protected

Note: not available in Python bindings

Definition at line 1088 of file qgsvectorfilewriter.cpp.

◆ defaultDatasetOptions()

QStringList QgsVectorFileWriter::defaultDatasetOptions ( const QString & driverName )

static

Returns a list of the default dataset options for a specified driver.

Parameters

driverName name of OGR driver

See also: defaultLayerOptions()

Definition at line 2689 of file qgsvectorfilewriter.cpp.

◆ defaultLayerOptions()

QStringList QgsVectorFileWriter::defaultLayerOptions ( const QString & driverName )

static

Returns a list of the default layer options for a specified driver.

Parameters

driverName name of OGR driver

See also: defaultDatasetOptions()

Definition at line 2698 of file qgsvectorfilewriter.cpp.

◆ deleteShapeFile()

bool QgsVectorFileWriter::deleteShapeFile ( const QString & fileName )

static

Delete a shapefile (and its accompanying shx / dbf / prj / qix / qpj / cpg / sbn / sbx / idm / ind).

Parameters

fileName /path/to/file.shp

Returns: bool true if the file was deleted successfully

Definition at line 3953 of file qgsvectorfilewriter.cpp.

◆ driver()

QString QgsVectorFileWriter::driver ( ) const

Returns the GDAL (short) driver name associated with the output file.

See also: driverLongName()

Since: QGIS 3.32

Definition at line 2722 of file qgsvectorfilewriter.cpp.

◆ driverForExtension()

QString QgsVectorFileWriter::driverForExtension ( const QString & extension )

static

Returns the OGR driver name for a specified file extension.

E.g. the driver name for the ".shp" extension is "ESRI Shapefile". If no suitable drivers are found then an empty string is returned.

Definition at line 4246 of file qgsvectorfilewriter.cpp.

◆ driverLongName()

QString QgsVectorFileWriter::driverLongName ( ) const

Returns the GDAL long driver name associated with the output file.

See also: driver()

Since: QGIS 3.32

Definition at line 2727 of file qgsvectorfilewriter.cpp.

◆ driverMetadata()

bool QgsVectorFileWriter::driverMetadata	(	const QString &	driverName,
		QgsVectorFileWriter::MetaData &	driverMetadata )

static

Definition at line 2665 of file qgsvectorfilewriter.cpp.

◆ editionCapabilities()

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

static

Returns edition capabilities for an existing dataset name.

Definition at line 4650 of file qgsvectorfilewriter.cpp.

◆ errorMessage()

QString QgsVectorFileWriter::errorMessage ( ) const

Retrieves error message.

Definition at line 2717 of file qgsvectorfilewriter.cpp.

◆ fileFilterString()

QString QgsVectorFileWriter::fileFilterString ( VectorFormatOptions options = SortRecommended )

static

Returns filter string that can be used for dialogs.

The options argument can be used to control the sorting and filtering of returned drivers.

Definition at line 4281 of file qgsvectorfilewriter.cpp.

◆ filterForDriver()

QString QgsVectorFileWriter::filterForDriver ( const QString & driverName )

static

Creates a filter for an OGR driver key.

Definition at line 4295 of file qgsvectorfilewriter.cpp.

◆ hasError()

QgsVectorFileWriter::WriterError QgsVectorFileWriter::hasError ( ) const

Checks whether there were any errors in constructor.

Definition at line 2712 of file qgsvectorfilewriter.cpp.

◆ lastError()

QString QgsVectorFileWriter::lastError ( ) const

overridevirtual

Returns the most recent error encountered by the sink, e.g.

when a call to addFeatures() returns false.

Since: QGIS 3.16

Reimplemented from QgsFeatureSink.

Definition at line 2753 of file qgsvectorfilewriter.cpp.

◆ ogrDriverList()

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

static

Returns the driver list that can be used for dialogs.

It contains all OGR drivers plus some additional internal QGIS driver names to distinguish between more supported formats of the same OGR driver.

The returned list consists of structs containing the driver long name (e.g. user-friendly display name for the format) and internal driver short name.

The options argument can be used to control the sorting and filtering of returned drivers.

Definition at line 4144 of file qgsvectorfilewriter.cpp.

◆ ogrTypeFromWkbType()

OGRwkbGeometryType QgsVectorFileWriter::ogrTypeFromWkbType ( Qgis::WkbType type )

static

Gets the ogr geometry type from an internal QGIS wkb type enum.

Will drop M values and convert Z to 2.5D where required.

Note: not available in Python bindings

Definition at line 2707 of file qgsvectorfilewriter.cpp.

◆ operator=()

QgsVectorFileWriter & QgsVectorFileWriter::operator= ( const QgsVectorFileWriter & rh )

delete

◆ setSymbologyExport()

void QgsVectorFileWriter::setSymbologyExport ( Qgis::FeatureSymbologyExport symExport )

inline

Sets the feature symbology export handling for the writer.

See also: symbologyExport()

Definition at line 926 of file qgsvectorfilewriter.h.

◆ setSymbologyScale()

void QgsVectorFileWriter::setSymbologyScale ( double scale )

Set reference scale for output.

The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.

See also: symbologyScale()

Definition at line 3979 of file qgsvectorfilewriter.cpp.

◆ sourceFieldIndexToWriterFieldIndex()

QMap< int, int > QgsVectorFileWriter::sourceFieldIndexToWriterFieldIndex ( ) const

inline

Returns the map of original source field index to output file field index.

Since: QGIS 3.44

Definition at line 902 of file qgsvectorfilewriter.h.

◆ supportedFiltersAndFormats()

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

static

Returns a list or pairs, with format filter string as first element and OGR format key as second element.

The options argument can be used to control the sorting and filtering of returned formats.

See also: supportedFormatExtensions()

Definition at line 4012 of file qgsvectorfilewriter.cpp.

◆ supportedFormatExtensions()

QStringList QgsVectorFileWriter::supportedFormatExtensions ( VectorFormatOptions options = SortRecommended )

static

Returns a list of file extensions for supported formats, e.g "shp", "gpkg".

The options argument can be used to control the sorting and filtering of returned formats.

See also: supportedFiltersAndFormats()

Definition at line 4102 of file qgsvectorfilewriter.cpp.

◆ supportsFeatureStyles()

bool QgsVectorFileWriter::supportsFeatureStyles ( const QString & driverName )

static

Returns true if the specified driverName supports feature styles.

The driverName argument must be a valid GDAL driver name.

Definition at line 154 of file qgsvectorfilewriter.cpp.

◆ symbologyExport()

Qgis::FeatureSymbologyExport QgsVectorFileWriter::symbologyExport ( ) const

inline

Returns the feature symbology export handling for the writer.

See also: setSymbologyExport()

Definition at line 919 of file qgsvectorfilewriter.h.

◆ symbologyScale()

double QgsVectorFileWriter::symbologyScale ( ) const

inline

Returns the reference scale for output.

The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.

See also: setSymbologyScale()

Definition at line 933 of file qgsvectorfilewriter.h.

◆ targetLayerExists()

bool QgsVectorFileWriter::targetLayerExists	(	const QString &	datasetName,
		const QString &	layerName )

static

Returns whether the target layer already exists.

Definition at line 4689 of file qgsvectorfilewriter.cpp.

◆ writeAsVectorFormat() [1/3]

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormat	(	QgsVectorLayer *	layer,
		const QString &	fileName,
		const QgsVectorFileWriter::SaveVectorOptions &	options,
		QString *	newFilename = nullptr,
		QString *	errorMessage = nullptr,
		QString *	newLayer = nullptr )

static

Writes a layer out to a vector file.

Parameters

layer	source layer to write
fileName	file name to write to
options	options.
newFilename	will be set to the new file name created (in case it is different to fileName).
errorMessage	will be set to the error message text, if an error occurs while writing the layer
newLayer	will be set to the new layer name created (in case it is different to the provided layer name) (added in QGIS 3.4, not available in python)

Returns: QgsVectorFileWriter::WriterError::NoError in case of success, or error code in case of error

Deprecated: QGIS 3.40. Use writeAsVectorFormatV2() instead.

Definition at line 3912 of file qgsvectorfilewriter.cpp.

◆ writeAsVectorFormat() [2/3]

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormat	(	QgsVectorLayer *	layer,
		const QString &	fileName,
		const QString &	fileEncoding,
		const QgsCoordinateReferenceSystem &	destCRS = QgsCoordinateReferenceSystem(),
		const QString &	driverName = "GPKG",
		bool	onlySelected = false,
		QString *	errorMessage = nullptr,
		const QStringList &	datasourceOptions = QStringList(),
		const QStringList &	layerOptions = QStringList(),
		bool	skipAttributeCreation = false,
		QString *	newFilename = nullptr,
		Qgis::FeatureSymbologyExport	symbologyExport = Qgis::FeatureSymbologyExport::NoSymbology,
		double	symbologyScale = 1.0,
		const QgsRectangle *	filterExtent = nullptr,
		Qgis::WkbType	overrideGeometryType = Qgis::WkbType::Unknown,
		bool	forceMulti = false,
		bool	includeZ = false,
		const QgsAttributeList &	attributes = QgsAttributeList(),
		QgsVectorFileWriter::FieldValueConverter *	fieldValueConverter = nullptr,
		QString *	newLayer = nullptr )

static

Write contents of vector layer to an (OGR supported) vector format.

Parameters

layer	layer to write
fileName	file name to write to
fileEncoding	encoding to use
destCRS	CRS to reproject exported geometries to, or invalid CRS for no reprojection
driverName	OGR driver to use
onlySelected	write only selected features of layer
errorMessage	will be set to the error message text, if an error occurs while writing the layer
datasourceOptions	list of OGR data source creation options
layerOptions	list of OGR layer creation options
skipAttributeCreation	only write geometries
newFilename	will be set to the new file name created (in case it is different to fileName).
symbologyExport	symbology to export
symbologyScale	scale of symbology
filterExtent	if not `nullptr`, only features intersecting the extent will be saved (added in QGIS 2.4)
overrideGeometryType	set to a valid geometry type to override the default geometry type for the layer. This parameter allows for conversion of geometryless tables to null geometries, etc (added in QGIS 2.14)
forceMulti	set to `true` to force creation of multipart geometries (added in QGIS 2.14)
includeZ	set to `true` to include z dimension in output. This option is only valid if overrideGeometryType is set. (added in QGIS 2.14)
attributes	attributes to export (empty means all unless skipAttributeCreation is set)
fieldValueConverter	field value converter (added in QGIS 2.16)
newLayer	will be set to the new layer name created (in case it is different to the provided layer name) (added in QGIS 3.4, not available in python)

Returns: QgsVectorFileWriter::WriterError::NoError in case of success, or error code in case of error

Deprecated: QGIS 3.40. Use writeAsVectorFormatV2() instead.

Definition at line 3386 of file qgsvectorfilewriter.cpp.

◆ writeAsVectorFormat() [3/3]

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormat	(	QgsVectorLayer *	layer,
		const QString &	fileName,
		const QString &	fileEncoding,
		const QgsCoordinateTransform &	ct,
		const QString &	driverName = "GPKG",
		bool	onlySelected = false,
		QString *	errorMessage = nullptr,
		const QStringList &	datasourceOptions = QStringList(),
		const QStringList &	layerOptions = QStringList(),
		bool	skipAttributeCreation = false,
		QString *	newFilename = nullptr,
		Qgis::FeatureSymbologyExport	symbologyExport = Qgis::FeatureSymbologyExport::NoSymbology,
		double	symbologyScale = 1.0,
		const QgsRectangle *	filterExtent = nullptr,
		Qgis::WkbType	overrideGeometryType = Qgis::WkbType::Unknown,
		bool	forceMulti = false,
		bool	includeZ = false,
		const QgsAttributeList &	attributes = QgsAttributeList(),
		QgsVectorFileWriter::FieldValueConverter *	fieldValueConverter = nullptr,
		QString *	newLayer = nullptr )

static

Writes a layer out to a vector file.

Parameters

layer	layer to write
fileName	file name to write to
fileEncoding	encoding to use
ct	coordinate transform to reproject exported geometries with, or invalid transform for no transformation
driverName	OGR driver to use
onlySelected	write only selected features of layer
errorMessage	will be set to the error message text, if an error occurs while writing the layer
datasourceOptions	list of OGR data source creation options
layerOptions	list of OGR layer creation options
skipAttributeCreation	only write geometries
newFilename	will be set to the new file name created (in case it is different to fileName).
symbologyExport	symbology to export
symbologyScale	scale of symbology
filterExtent	if not `nullptr`, only features intersecting the extent will be saved (added in QGIS 2.4)
overrideGeometryType	set to a valid geometry type to override the default geometry type for the layer. This parameter allows for conversion of geometryless tables to null geometries, etc (added in QGIS 2.14)
forceMulti	set to `true` to force creation of multipart geometries (added in QGIS 2.14)
includeZ	set to `true` to include z dimension in output. This option is only valid if overrideGeometryType is set. (added in QGIS 2.14)
attributes	attributes to export (empty means all unless skipAttributeCreation is set)
fieldValueConverter	field value converter (added in QGIS 2.16)
newLayer	will be set to the new layer name created (in case it is different to the provided layer name) (added in QGIS 3.4, not available in python)

Returns: QgsVectorFileWriter::WriterError::NoError in case of success, or error code in case of error

Deprecated: QGIS 3.40. Use writeAsVectorFormatV2() instead.

Definition at line 3438 of file qgsvectorfilewriter.cpp.

◆ writeAsVectorFormatV2()

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormatV2	(	QgsVectorLayer *	layer,
		const QString &	fileName,
		const QgsCoordinateTransformContext &	transformContext,
		const QgsVectorFileWriter::SaveVectorOptions &	options,
		QString *	newFilename = nullptr,
		QString *	newLayer = nullptr,
		QString *	errorMessage = nullptr )

static

Writes a layer out to a vector file.

Parameters

layer	source layer to write
fileName	file name to write to
transformContext	coordinate transform context
options	save options
newFilename	potentially modified file name (output parameter)
newLayer	potentially modified layer name (output parameter)
errorMessage	will be set to the error message text, if an error occurs while writing the layer

Returns: Error message code, or QgsVectorFileWriter.NoError if the write operation was successful

Deprecated: QGIS 3.20. Use writeAsVectorFormatV3() instead.

Definition at line 3927 of file qgsvectorfilewriter.cpp.

◆ writeAsVectorFormatV3()

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormatV3	(	QgsVectorLayer *	layer,
		const QString &	fileName,
		const QgsCoordinateTransformContext &	transformContext,
		const QgsVectorFileWriter::SaveVectorOptions &	options,
		QString *	errorMessage = nullptr,
		QString *	newFilename = nullptr,
		QString *	newLayer = nullptr )

static

Writes a layer out to a vector file.

Parameters

layer	source layer to write
fileName	file name to write to
transformContext	coordinate transform context
options	save options
newFilename	potentially modified file name (output parameter)
newLayer	potentially modified layer name (output parameter)
errorMessage	will be set to the error message text, if an error occurs while writing the layer

Returns: Error message code, or QgsVectorFileWriter.NoError if the write operation was successful

Since: QGIS 3.20

Definition at line 3943 of file qgsvectorfilewriter.cpp.

◆ QgsVectorFileWriterTask

friend class QgsVectorFileWriterTask

friend

Definition at line 1146 of file qgsvectorfilewriter.h.

◆ TestQgsVectorFileWriter

friend class TestQgsVectorFileWriter

friend

Definition at line 1147 of file qgsvectorfilewriter.h.

Member Data Documentation

◆ mAttrIdxToOgrLayerIdx

QMap<int, int> QgsVectorFileWriter::mAttrIdxToOgrLayerIdx

protected

Map attribute indices to OGR layer field indexes such as they are on the current mLayer instance.

Definition at line 1009 of file qgsvectorfilewriter.h.

◆ mAttrIdxToProviderIdx

QMap<int, int> QgsVectorFileWriter::mAttrIdxToProviderIdx

protected

Map attribute indices to OGR provider field indexes such as they are after the OGR provider has been created.

Definition at line 1006 of file qgsvectorfilewriter.h.

◆ mCodec

QTextCodec* QgsVectorFileWriter::mCodec = nullptr

protected

Definition at line 999 of file qgsvectorfilewriter.h.

◆ mDS

gdal::ogr_datasource_unique_ptr QgsVectorFileWriter::mDS

protected

Definition at line 989 of file qgsvectorfilewriter.h.

◆ mError

WriterError QgsVectorFileWriter::mError

protected

Contains error value if construction was not successful.

Definition at line 996 of file qgsvectorfilewriter.h.

◆ mErrorMessage

QString QgsVectorFileWriter::mErrorMessage

protected

Definition at line 997 of file qgsvectorfilewriter.h.

◆ mFields

QgsFields QgsVectorFileWriter::mFields

protected

Definition at line 993 of file qgsvectorfilewriter.h.

◆ mFieldValueConverter

FieldValueConverter* QgsVectorFileWriter::mFieldValueConverter = nullptr

protected

Field value converter.

Definition at line 1022 of file qgsvectorfilewriter.h.

◆ mIncludeConstraints

bool QgsVectorFileWriter::mIncludeConstraints = false

protected

Whether to transfer field constraints to output.

Definition at line 1025 of file qgsvectorfilewriter.h.

◆ mLayer

OGRLayerH QgsVectorFileWriter::mLayer = nullptr

protected

Definition at line 990 of file qgsvectorfilewriter.h.

◆ mOgrDriverLongName

QString QgsVectorFileWriter::mOgrDriverLongName

protected

Definition at line 1019 of file qgsvectorfilewriter.h.

◆ mOgrDriverName

QString QgsVectorFileWriter::mOgrDriverName

protected

Definition at line 1018 of file qgsvectorfilewriter.h.

◆ mOgrRef

OGRSpatialReferenceH QgsVectorFileWriter::mOgrRef = nullptr

protected

Definition at line 991 of file qgsvectorfilewriter.h.

◆ mSetFieldDomains

bool QgsVectorFileWriter::mSetFieldDomains = true

protected

Whether to set field domains to output.

Definition at line 1028 of file qgsvectorfilewriter.h.

◆ mSymbolLayerTable

QMap< QgsSymbolLayer *, QString > QgsVectorFileWriter::mSymbolLayerTable

protected

Definition at line 1013 of file qgsvectorfilewriter.h.

◆ mSymbologyExport

Qgis::FeatureSymbologyExport QgsVectorFileWriter::mSymbologyExport = Qgis::FeatureSymbologyExport::NoSymbology

protected

Definition at line 1011 of file qgsvectorfilewriter.h.

◆ mSymbologyScale

double QgsVectorFileWriter::mSymbologyScale

protected

Scale for symbology export (e.g. for symbols units in map units).

Definition at line 1016 of file qgsvectorfilewriter.h.

◆ mWkbType

Qgis::WkbType QgsVectorFileWriter::mWkbType

protected

Geometry type which is being used.

Definition at line 1002 of file qgsvectorfilewriter.h.

The documentation for this class was generated from the following files:

/build/qgis-3.99.0+git20260215+1d785854362+99sid/src/core/qgsvectorfilewriter.h
/build/qgis-3.99.0+git20260215+1d785854362+99sid/src/core/qgsvectorfilewriter.cpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ EditionCapabilities

◆ VectorFormatOptions

Member Enumeration Documentation

◆ ActionOnExistingFile

◆ EditionCapability

◆ FieldNameSource

◆ OptionType

◆ VectorFormatOption

◆ WriterError

Constructor & Destructor Documentation

◆ QgsVectorFileWriter() [1/3]

◆ QgsVectorFileWriter() [2/3]

◆ QgsVectorFileWriter() [3/3]

◆ ~QgsVectorFileWriter()

Member Function Documentation

◆ addFeature()

◆ addFeatures() [1/2]

◆ addFeatures() [2/2]

◆ addFeatureWithStyle()

◆ areThereNewFieldsToCreate()

◆ capabilities()

◆ convertCodecNameForEncodingOption()

◆ create()

◆ createEmptyGeometry()

◆ defaultDatasetOptions()

◆ defaultLayerOptions()

◆ deleteShapeFile()

◆ driver()

◆ driverForExtension()

◆ driverLongName()

◆ driverMetadata()

◆ editionCapabilities()

◆ errorMessage()

◆ fileFilterString()

◆ filterForDriver()

◆ hasError()

◆ lastError()

◆ ogrDriverList()

◆ ogrTypeFromWkbType()

◆ operator=()

◆ setSymbologyExport()

◆ setSymbologyScale()

◆ sourceFieldIndexToWriterFieldIndex()

◆ supportedFiltersAndFormats()

◆ supportedFormatExtensions()

◆ supportsFeatureStyles()

◆ symbologyExport()

◆ symbologyScale()

◆ targetLayerExists()

◆ writeAsVectorFormat() [1/3]

◆ writeAsVectorFormat() [2/3]

◆ writeAsVectorFormat() [3/3]

◆ writeAsVectorFormatV2()

◆ writeAsVectorFormatV3()

Friends And Related Symbol Documentation

◆ QgsVectorFileWriterTask

◆ TestQgsVectorFileWriter

Member Data Documentation

◆ mAttrIdxToOgrLayerIdx

◆ mAttrIdxToProviderIdx

◆ mCodec

◆ mDS

◆ mError

◆ mErrorMessage

◆ mFields

◆ mFieldValueConverter

◆ mIncludeConstraints

◆ mLayer

◆ mOgrDriverLongName

◆ mOgrDriverName

◆ mOgrRef