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

#include <qgsvectorfilewriter.h>

Inheritance diagram for QgsVectorFileWriter:

Classes
class	BoolOption

struct	DriverDetails
	Details of available driver formats. More...

class	FieldValueConverter
	Interface to convert raw field values to their user-friendly value. More...

struct	FilterFormatDetails
	Details of available filters and formats. More...

class	HiddenOption

class	IntOption

struct	MetaData

class	Option

class	SaveVectorOptions
	Options to pass to writeAsVectorFormat() More...

class	SetOption

class	StringOption

Public Types
enum	ActionOnExistingFile { CreateOrOverwriteFile , CreateOrOverwriteLayer , AppendToLayerNoNewFields , AppendToLayerAddFields }
	Combination of CanAddNewLayer, CanAppendToExistingLayer, CanAddNewFieldsToExistingLayer or CanDeleteLayer. More...

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	SymbologyExport { NoSymbology = 0 , FeatureSymbology , SymbolLayerSymbology }

enum	VectorFormatOption { SortRecommended = 1 << 1 , SkipNonSpatialFormats = 1 << 2 }
	Options for sorting and filtering vector formats. More...

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...

enum	SinkFlag { RegeneratePrimaryKey = 1 << 1 }
	Flags that can be set on a QgsFeatureSink. More...

Public Member Functions
	QgsVectorFileWriter (const QgsVectorFileWriter &rh)=delete
	QgsVectorFileWriter cannot be copied. More...

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, QgsVectorFileWriter::SymbologyExport 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)
	Create a new vector file writer. More...

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, QgsVectorFileWriter::SymbologyExport symbologyExport=QgsVectorFileWriter::NoSymbology, QgsFeatureSink::SinkFlags sinkFlags=QgsFeatureSink::SinkFlags(), QString newLayer=nullptr, const QgsCoordinateTransformContext &transformContext=QgsCoordinateTransformContext(), FieldNameSource fieldNameSource=Original)
	Create a new vector file writer. More...

	~QgsVectorFileWriter () override
	Close opened shapefile for writing. More...

bool	addFeature (QgsFeature &feature, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags()) override
	Adds a single feature to the sink. More...

bool	addFeatures (QgsFeatureList &features, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags()) override
	Adds a list of features to the sink. More...

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. More...

QMap< int, int >	attrIdxToOgrIdx () const

QString	errorMessage () const
	Retrieves error message. More...

QgsVectorFileWriter::WriterError	hasError () const
	Checks whether there were any errors in constructor. More...

QString	lastError () const override
	Returns the most recent error encountered by the sink, e.g. More...

QgsVectorFileWriter &	operator= (const QgsVectorFileWriter &rh)=delete
	QgsVectorFileWriter cannot be copied. More...

void	setSymbologyExport (QgsVectorFileWriter::SymbologyExport symExport)

void	setSymbologyScale (double scale)
	Set reference scale for output. More...

QgsVectorFileWriter::SymbologyExport	symbologyExport () const

double	symbologyScale () const
	Returns the reference scale for output. More...

Public Member Functions inherited from QgsFeatureSink
virtual	~QgsFeatureSink ()=default

virtual bool	addFeature (QgsFeature &feature, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags())
	Adds a single feature to the sink. More...

virtual bool	addFeatures (QgsFeatureIterator &iterator, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags())
	Adds all features from the specified iterator to the sink. More...

virtual bool	addFeatures (QgsFeatureList &features, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags())=0
	Adds a list of features to the sink. More...

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. More...

virtual QString	lastError () const
	Returns the most recent error encountered by the sink, e.g. More...

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. More...

static QString	convertCodecNameForEncodingOption (const QString &codecName)
	Converts codec name to string passed to ENCODING layer creation option of OGR Shapefile. More...

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. More...

static QStringList	defaultDatasetOptions (const QString &driverName)
	Returns a list of the default dataset options for a specified driver. More...

static QStringList	defaultLayerOptions (const QString &driverName)
	Returns a list of the default layer options for a specified driver. More...

static bool	deleteShapeFile (const QString &fileName)
	Delete a shapefile (and its accompanying shx / dbf / prj / qix / qpj / cpg / sbn / sbx / idm / ind) More...

static QString	driverForExtension (const QString &extension)
	Returns the OGR driver name for a specified file extension. More...

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

static QgsVectorFileWriter::EditionCapabilities	editionCapabilities (const QString &datasetName)
	Returns edition capabilities for an existing dataset name. More...

static QString	fileFilterString (VectorFormatOptions options=SortRecommended)
	Returns filter string that can be used for dialogs. More...

static QString	filterForDriver (const QString &driverName)
	Creates a filter for an OGR driver key. More...

static QList< QgsVectorFileWriter::DriverDetails >	ogrDriverList (VectorFormatOptions options=SortRecommended)
	Returns the driver list that can be used for dialogs. More...

static OGRwkbGeometryType	ogrTypeFromWkbType (Qgis::WkbType type)
	Gets the ogr geometry type from an internal QGIS wkb type enum. More...

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. More...

static QStringList	supportedFormatExtensions (VectorFormatOptions options=SortRecommended)
	Returns a list of file extensions for supported formats, e.g "shp", "gpkg". More...

static bool	supportsFeatureStyles (const QString &driverName)
	Returns `true` if the specified driverName supports feature styles. More...

static bool	targetLayerExists (const QString &datasetName, const QString &layerName)
	Returns whether the target layer already exists. More...

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. More...

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, QgsVectorFileWriter::SymbologyExport symbologyExport=QgsVectorFileWriter::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. More...

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, QgsVectorFileWriter::SymbologyExport symbologyExport=QgsVectorFileWriter::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. More...

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. More...

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. More...

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

Protected Attributes
QMap< int, int >	mAttrIdxToOgrIdx
	Map attribute indizes to OGR field indexes. More...

QTextCodec *	mCodec = nullptr

gdal::ogr_datasource_unique_ptr	mDS

WriterError	mError
	Contains error value if construction was not successful. More...

QString	mErrorMessage

QgsFields	mFields

FieldValueConverter *	mFieldValueConverter = nullptr
	Field value converter. More...

OGRLayerH	mLayer = nullptr

QString	mOgrDriverName

OGRSpatialReferenceH	mOgrRef = nullptr

QMap< QgsSymbolLayer *, QString >	mSymbolLayerTable

SymbologyExport	mSymbologyExport

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

Qgis::WkbType	mWkbType
	Geometry type which is being used. More...

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 46 of file qgsvectorfilewriter.h.

Member Enumeration Documentation

◆ ActionOnExistingFile

enum QgsVectorFileWriter::ActionOnExistingFile

Combination of CanAddNewLayer, CanAppendToExistingLayer, CanAddNewFieldsToExistingLayer or CanDeleteLayer.

Since: QGIS 3.0. Enumeration to describe how to handle existing files; QGIS 3.0

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 275 of file qgsvectorfilewriter.h.

◆ EditionCapability

enum QgsVectorFileWriter::EditionCapability

Edition capability flags.

Since: QGIS 3.0

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 250 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 195 of file qgsvectorfilewriter.h.

◆ OptionType

enum QgsVectorFileWriter::OptionType

Enumerator
Set
String
Int
Hidden

Definition at line 49 of file qgsvectorfilewriter.h.

◆ SymbologyExport

enum QgsVectorFileWriter::SymbologyExport

Enumerator
NoSymbology
FeatureSymbology
SymbolLayerSymbology

Definition at line 183 of file qgsvectorfilewriter.h.

◆ VectorFormatOption

enum QgsVectorFileWriter::VectorFormatOption

Options for sorting and filtering vector formats.

Since: QGIS 3.0

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)

Definition at line 205 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 168 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`,
		QgsVectorFileWriter::SymbologyExport	symbologyExport = `QgsVectorFileWriter::NoSymbology`,
		QgsFeatureSink::SinkFlags	sinkFlags = `QgsFeatureSink::SinkFlags()`,
		QString *	newLayer = `nullptr`,
		const QgsCoordinateTransformContext &	transformContext = `QgsCoordinateTransformContext()`,
		FieldNameSource	fieldNameSource = `Original`
	)

Create a new vector file writer.

Deprecated:: Use create() instead.

Definition at line 71 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,
		QgsVectorFileWriter::SymbologyExport	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`
	)

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)

Note: not available in Python bindings

Deprecated:: Use create() instead.

Definition at line 97 of file qgsvectorfilewriter.cpp.

◆ QgsVectorFileWriter() [3/3]

QgsVectorFileWriter::QgsVectorFileWriter ( const QgsVectorFileWriter & rh )

delete

QgsVectorFileWriter cannot be copied.

◆ ~QgsVectorFileWriter()

QgsVectorFileWriter::~QgsVectorFileWriter ( )

override

Close opened shapefile for writing.

Definition at line 3094 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 2530 of file qgsvectorfilewriter.cpp.

◆ addFeatures()

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 2535 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.

Since: QGIS 3.0

Definition at line 2551 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.

Since: QGIS 3.0

Definition at line 4360 of file qgsvectorfilewriter.cpp.

◆ attrIdxToOgrIdx()

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

inline

Note: not available in Python bindings

Definition at line 839 of file qgsvectorfilewriter.h.

◆ 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 3968 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 126 of file qgsvectorfilewriter.cpp.

◆ createEmptyGeometry()

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

protected

Note: not available in Python bindings

Definition at line 905 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()

Since: QGIS 3.0

Definition at line 2490 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()

Since: QGIS 3.0

Definition at line 2499 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 3656 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.

Since: QGIS 3.0

Definition at line 3908 of file qgsvectorfilewriter.cpp.

◆ driverMetadata()

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

static

Definition at line 2466 of file qgsvectorfilewriter.cpp.

◆ editionCapabilities()

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

static

Returns edition capabilities for an existing dataset name.

Since: QGIS 3.0

Definition at line 4305 of file qgsvectorfilewriter.cpp.

◆ errorMessage()

QString QgsVectorFileWriter::errorMessage ( ) const

Retrieves error message.

Definition at line 2525 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 3943 of file qgsvectorfilewriter.cpp.

◆ filterForDriver()

QString QgsVectorFileWriter::filterForDriver ( const QString & driverName )

static

Creates a filter for an OGR driver key.

Definition at line 3957 of file qgsvectorfilewriter.cpp.

◆ hasError()

QgsVectorFileWriter::WriterError QgsVectorFileWriter::hasError ( ) const

Checks whether there were any errors in constructor.

Definition at line 2520 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 2546 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 3814 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 2508 of file qgsvectorfilewriter.cpp.

◆ operator=()

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

delete

QgsVectorFileWriter cannot be copied.

◆ setSymbologyExport()

void QgsVectorFileWriter::setSymbologyExport ( QgsVectorFileWriter::SymbologyExport symExport )

inline

Definition at line 852 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()

Since: QGIS 3.0

Definition at line 3682 of file qgsvectorfilewriter.cpp.

◆ 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 3688 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()

Since: QGIS 3.0

Definition at line 3772 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.

Since: QGIS 3.0

Definition at line 146 of file qgsvectorfilewriter.cpp.

◆ symbologyExport()

QgsVectorFileWriter::SymbologyExport QgsVectorFileWriter::symbologyExport ( ) const

inline

Definition at line 851 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()

Since: QGIS 3.0

Definition at line 860 of file qgsvectorfilewriter.h.

◆ targetLayerExists()

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

static

Returns whether the target layer already exists.

Since: QGIS 3.0

Definition at line 4344 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	QString pointer which will contain 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	QString pointer which will contain the new layer name created (in case it is different to the provided layer name) (added in QGIS 3.4, not available in python)

Since: QGIS 3.0

Deprecated:: Use writeAsVectorFormatV2() instead.

Definition at line 3615 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`,
		QgsVectorFileWriter::SymbologyExport	symbologyExport = `QgsVectorFileWriter::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	QString pointer which will contain 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 multi* 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	QString pointer which will contain the new layer name created (in case it is different to the provided layer name) (added in QGIS 3.4, not available in python)

Deprecated:: Use writeAsVectorFormatV2() instead.

Definition at line 3112 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`,
		QgsVectorFileWriter::SymbologyExport	symbologyExport = `QgsVectorFileWriter::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	QString pointer which will contain 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 multi* 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	QString pointer which will contain the new layer name created (in case it is different to the provided layer name) (added in QGIS 3.4, not available in python)

Since: QGIS 2.2

Deprecated:: Use writeAsVectorFormatV2() instead.

Definition at line 3159 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:: since QGIS 3.20, use writeAsVectorFormatV3 instead

Definition at line 3630 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 3646 of file qgsvectorfilewriter.cpp.

Friends And Related Function Documentation

◆ QgsVectorFileWriterTask

friend class QgsVectorFileWriterTask

friend

Definition at line 1062 of file qgsvectorfilewriter.h.

◆ TestQgsVectorFileWriter

friend class TestQgsVectorFileWriter

friend

Definition at line 1063 of file qgsvectorfilewriter.h.

Member Data Documentation

◆ mAttrIdxToOgrIdx

QMap<int, int> QgsVectorFileWriter::mAttrIdxToOgrIdx

protected

Map attribute indizes to OGR field indexes.

Definition at line 938 of file qgsvectorfilewriter.h.

◆ mCodec

QTextCodec* QgsVectorFileWriter::mCodec = nullptr

protected

Definition at line 932 of file qgsvectorfilewriter.h.

◆ mDS

gdal::ogr_datasource_unique_ptr QgsVectorFileWriter::mDS

protected

Definition at line 922 of file qgsvectorfilewriter.h.

◆ mError

WriterError QgsVectorFileWriter::mError

protected

Contains error value if construction was not successful.

Definition at line 929 of file qgsvectorfilewriter.h.

◆ mErrorMessage

QString QgsVectorFileWriter::mErrorMessage

protected

Definition at line 930 of file qgsvectorfilewriter.h.

◆ mFields

QgsFields QgsVectorFileWriter::mFields

protected

Definition at line 926 of file qgsvectorfilewriter.h.

◆ mFieldValueConverter

FieldValueConverter* QgsVectorFileWriter::mFieldValueConverter = nullptr

protected

Field value converter.

Definition at line 950 of file qgsvectorfilewriter.h.

◆ mLayer

OGRLayerH QgsVectorFileWriter::mLayer = nullptr

protected

Definition at line 923 of file qgsvectorfilewriter.h.

◆ mOgrDriverName

QString QgsVectorFileWriter::mOgrDriverName

protected

Definition at line 947 of file qgsvectorfilewriter.h.

◆ mOgrRef

OGRSpatialReferenceH QgsVectorFileWriter::mOgrRef = nullptr

protected

Definition at line 924 of file qgsvectorfilewriter.h.

◆ mSymbolLayerTable

QMap< QgsSymbolLayer *, QString > QgsVectorFileWriter::mSymbolLayerTable

protected

Definition at line 942 of file qgsvectorfilewriter.h.

◆ mSymbologyExport

SymbologyExport QgsVectorFileWriter::mSymbologyExport

protected

Definition at line 940 of file qgsvectorfilewriter.h.

◆ mSymbologyScale

double QgsVectorFileWriter::mSymbologyScale

protected

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

Definition at line 945 of file qgsvectorfilewriter.h.

◆ mWkbType

Qgis::WkbType QgsVectorFileWriter::mWkbType

protected

Geometry type which is being used.

Definition at line 935 of file qgsvectorfilewriter.h.

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

/build/qgis-3.30.0+99sid/src/core/qgsvectorfilewriter.h
/build/qgis-3.30.0+99sid/src/core/qgsvectorfilewriter.cpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Enumeration Documentation

◆ ActionOnExistingFile

◆ EditionCapability

◆ FieldNameSource

◆ OptionType

◆ SymbologyExport

◆ VectorFormatOption

◆ WriterError

Constructor & Destructor Documentation

◆ QgsVectorFileWriter() [1/3]

◆ QgsVectorFileWriter() [2/3]

◆ QgsVectorFileWriter() [3/3]

◆ ~QgsVectorFileWriter()

Member Function Documentation

◆ addFeature()

◆ addFeatures()

◆ addFeatureWithStyle()

◆ areThereNewFieldsToCreate()

◆ attrIdxToOgrIdx()

◆ convertCodecNameForEncodingOption()

◆ create()

◆ createEmptyGeometry()

◆ defaultDatasetOptions()

◆ defaultLayerOptions()

◆ deleteShapeFile()

◆ driverForExtension()

◆ driverMetadata()

◆ editionCapabilities()

◆ errorMessage()

◆ fileFilterString()

◆ filterForDriver()

◆ hasError()

◆ lastError()

◆ ogrDriverList()

◆ ogrTypeFromWkbType()

◆ operator=()

◆ setSymbologyExport()

◆ setSymbologyScale()

◆ supportedFiltersAndFormats()

◆ supportedFormatExtensions()

◆ supportsFeatureStyles()

◆ symbologyExport()

◆ symbologyScale()

◆ targetLayerExists()

◆ writeAsVectorFormat() [1/3]

◆ writeAsVectorFormat() [2/3]

◆ writeAsVectorFormat() [3/3]

◆ writeAsVectorFormatV2()

◆ writeAsVectorFormatV3()

Friends And Related Function Documentation

◆ QgsVectorFileWriterTask

◆ TestQgsVectorFileWriter

Member Data Documentation

◆ mAttrIdxToOgrIdx

◆ mCodec

◆ mDS

◆ mError

◆ mErrorMessage

◆ mFields

◆ mFieldValueConverter

◆ mLayer

◆ mOgrDriverName

◆ mOgrRef

◆ mSymbolLayerTable

◆ mSymbologyExport

◆ mSymbologyScale

◆ mWkbType