QgsVectorFileWriter Class Reference

A convenience class for writing vector files to disk. More...

#include <qgsvectorfilewriter.h>

Classes
class	BoolOption
class	HiddenOption
class	IntOption
struct	MetaData
class	Option
class	SetOption
class	StringOption

Public Types
enum	OptionType { Set, String, Int, Hidden }
enum	SymbologyExport { NoSymbology = 0, FeatureSymbology, SymbolLayerSymbology }
enum	WriterError {   NoError = 0, ErrDriverNotFound, ErrCreateDataSource, ErrCreateLayer,   ErrAttributeTypeUnsupported, ErrAttributeCreationFailed, ErrProjection, ErrFeatureWriteFailed,   ErrInvalidLayer }

Public Member Functions
	QgsVectorFileWriter (const QString &vectorFileName, const QString &fileEncoding, const QgsFields &fields, QGis::WkbType geometryType, const QgsCoordinateReferenceSystem *srs, const QString &driverName="ESRI Shapefile", const QStringList &datasourceOptions=QStringList(), const QStringList &layerOptions=QStringList(), QString *newFilename=0, SymbologyExport symbologyExport=NoSymbology)
	create shapefile and initialize it
	~QgsVectorFileWriter ()
	close opened shapefile for writing
bool	addFeature (QgsFeature &feature, QgsFeatureRendererV2 *renderer=0, QGis::UnitType outputUnit=QGis::Meters)
	add feature to the currently opened shapefile
QMap< int, int >	attrIdxToOgrIdx ()
QString	errorMessage ()
	retrieves error message
WriterError	hasError ()
	checks whether there were any errors in constructor
void	setSymbologyExport (SymbologyExport symExport)
void	setSymbologyScaleDenominator (double d)
SymbologyExport	symbologyExport () const
double	symbologyScaleDenominator () const

Static Public Member Functions
static QString	convertCodecNameForEncodingOption (const QString &codecName)
	Converts codec name to string passed to ENCODING layer creation option of OGR Shapefile.
static bool	deleteShapeFile (QString theFileName)
	Delete a shapefile (and its accompanying shx / dbf / prf)
static bool	driverMetadata (const QString &driverName, MetaData &driverMetadata)
static QString	fileFilterString ()
	Returns filter string that can be used for dialogs.
static QString	filterForDriver (const QString &driverName)
	Creates a filter for an OGR driver key.
static QMap< QString, QString >	ogrDriverList ()
	Returns driver list that can be used for dialogs.
static QMap< QString, QString >	supportedFiltersAndFormats ()
	Returns map with format filter string as key and OGR format key as value.
static WriterError	writeAsVectorFormat (QgsVectorLayer *layer, const QString &fileName, const QString &fileEncoding, const QgsCoordinateReferenceSystem *destCRS, const QString &driverName="ESRI Shapefile", bool onlySelected=false, QString *errorMessage=0, const QStringList &datasourceOptions=QStringList(), const QStringList &layerOptions=QStringList(), bool skipAttributeCreation=false, QString *newFilename=0, SymbologyExport symbologyExport=NoSymbology, double symbologyScale=1.0, const QgsRectangle *filterExtent=0)
	Write contents of vector layer to an (OGR supported) vector formt.
static WriterError	writeAsVectorFormat (QgsVectorLayer *layer, const QString &fileName, const QString &fileEncoding, const QgsCoordinateTransform *ct, const QString &driverName="ESRI Shapefile", bool onlySelected=false, QString *errorMessage=0, const QStringList &datasourceOptions=QStringList(), const QStringList &layerOptions=QStringList(), bool skipAttributeCreation=false, QString *newFilename=0, SymbologyExport symbologyExport=NoSymbology, double symbologyScale=1.0, const QgsRectangle *filterExtent=0)

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

Protected Attributes
QMap< int, int >	mAttrIdxToOgrIdx
	map attribute indizes to OGR field indexes
QTextCodec *	mCodec
OGRDataSourceH	mDS
WriterError	mError
	contains error value if construction was not successful
QString	mErrorMessage
QgsFields	mFields
OGRGeometryH	mGeom
OGRLayerH	mLayer
SymbologyExport	mSymbologyExport
double	mSymbologyScaleDenominator
	Scale for symbology export (e.g.
QGis::WkbType	mWkbType
	geometry type which is being used

Detailed Description

A convenience class for writing vector files to disk.

There are two possibilities how to use this class:

1. static call to QgsVectorFileWriter::writeAsShapefile(...) which saves the whole vector layer
2. create an instance of the class and issue calls to addFeature(...)

Currently supports only writing to shapefiles, but shouldn't be a problem to add capability to support other OGR-writable formats.

Definition at line 42 of file qgsvectorfilewriter.h.

Member Enumeration Documentation

enum QgsVectorFileWriter::OptionType

Enumerator:

Set
String
Int
Hidden

Definition at line 45 of file qgsvectorfilewriter.h.

enum QgsVectorFileWriter::SymbologyExport

Enumerator:

NoSymbology
FeatureSymbology
SymbolLayerSymbology

Definition at line 156 of file qgsvectorfilewriter.h.

enum QgsVectorFileWriter::WriterError

Enumerator:

NoError
ErrDriverNotFound
ErrCreateDataSource
ErrCreateLayer
ErrAttributeTypeUnsupported
ErrAttributeCreationFailed
ErrProjection
ErrFeatureWriteFailed
ErrInvalidLayer

Definition at line 143 of file qgsvectorfilewriter.h.

Constructor & Destructor Documentation

QgsVectorFileWriter::QgsVectorFileWriter	(	const QString &	vectorFileName,
		const QString &	fileEncoding,
		const QgsFields &	fields,
		QGis::WkbType	geometryType,
		const QgsCoordinateReferenceSystem *	srs,
		const QString &	driverName = "ESRI Shapefile",
		const QStringList &	datasourceOptions = QStringList(),
		const QStringList &	layerOptions = QStringList(),
		QString *	newFilename = 0,
		SymbologyExport	symbologyExport = NoSymbology
	)

create shapefile and initialize it

Definition at line 57 of file qgsvectorfilewriter.cpp.

QgsVectorFileWriter::~QgsVectorFileWriter

(

)

close opened shapefile for writing

Definition at line 1783 of file qgsvectorfilewriter.cpp.

Member Function Documentation

bool QgsVectorFileWriter::addFeature	(	QgsFeature &	feature,
		QgsFeatureRendererV2 *	renderer = 0,
		QGis::UnitType	outputUnit = QGis::Meters
	)

add feature to the currently opened shapefile

Definition at line 1560 of file qgsvectorfilewriter.cpp.

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

inline

Note

not available in python bindings

Definition at line 253 of file qgsvectorfilewriter.h.

QString QgsVectorFileWriter::convertCodecNameForEncodingOption ( const QString &  codecName )

static

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

Definition at line 2205 of file qgsvectorfilewriter.cpp.

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

protected

Note

not available in python bindings

Definition at line 493 of file qgsvectorfilewriter.cpp.

bool QgsVectorFileWriter::deleteShapeFile ( QString  theFileName )

static

Delete a shapefile (and its accompanying shx / dbf / prf)

Parameters

theFileName

/path/to/file.shp

Returns

bool true if the file was deleted successfully

Definition at line 2054 of file qgsvectorfilewriter.cpp.

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

static

Definition at line 1531 of file qgsvectorfilewriter.cpp.

QString QgsVectorFileWriter::errorMessage

(

)

retrieves error message

Definition at line 1555 of file qgsvectorfilewriter.cpp.

QString QgsVectorFileWriter::fileFilterString ( )

static

Returns filter string that can be used for dialogs.

Definition at line 2178 of file qgsvectorfilewriter.cpp.

QString QgsVectorFileWriter::filterForDriver ( const QString &  driverName )

static

Creates a filter for an OGR driver key.

Definition at line 2193 of file qgsvectorfilewriter.cpp.

QgsVectorFileWriter::WriterError QgsVectorFileWriter::hasError

(

)

checks whether there were any errors in constructor

Definition at line 1550 of file qgsvectorfilewriter.cpp.

QMap< QString, QString > QgsVectorFileWriter::ogrDriverList ( )

static

Returns driver list that can be used for dialogs.

It contains all OGR drivers

• some additional internal QGIS driver names to distinguish between more supported formats of the same OGR driver

Definition at line 2106 of file qgsvectorfilewriter.cpp.

void QgsVectorFileWriter::setSymbologyExport ( SymbologyExport  symExport )

inline

Definition at line 265 of file qgsvectorfilewriter.h.

void QgsVectorFileWriter::setSymbologyScaleDenominator ( double  d )

inline

Definition at line 268 of file qgsvectorfilewriter.h.

QMap< QString, QString > QgsVectorFileWriter::supportedFiltersAndFormats ( )

static

Returns map with format filter string as key and OGR format key as value.

Definition at line 2079 of file qgsvectorfilewriter.cpp.

SymbologyExport QgsVectorFileWriter::symbologyExport ( ) const

inline

Definition at line 264 of file qgsvectorfilewriter.h.

double QgsVectorFileWriter::symbologyScaleDenominator ( ) const

inline

Definition at line 267 of file qgsvectorfilewriter.h.

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormat ( QgsVectorLayer *  layer, const QString &  fileName, const QString &  fileEncoding, const QgsCoordinateReferenceSystem *  destCRS, const QString &  driverName = "ESRI Shapefile", bool  onlySelected = false, QString *  errorMessage = 0, const QStringList &  datasourceOptions = QStringList(), const QStringList &  layerOptions = QStringList(), bool  skipAttributeCreation = false, QString *  newFilename = 0, SymbologyExport  symbologyExport = NoSymbology, double  symbologyScale = 1.0, const QgsRectangle *  filterExtent = 0  )

static

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

Parameters

layer	layer to write
fileName	file name to write to
fileEncoding	encoding to use
destCRS	pointer to CRS to reproject exported geometries to
driverName	OGR driver to use
onlySelected	write only selected features of layer
errorMessage	pointer to buffer fo error message
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 a null pointer, only features intersecting the extent will be saved

Definition at line 1797 of file qgsvectorfilewriter.cpp.

QgsVectorFileWriter::WriterError QgsVectorFileWriter::writeAsVectorFormat ( QgsVectorLayer *  layer, const QString &  fileName, const QString &  fileEncoding, const QgsCoordinateTransform *  ct, const QString &  driverName = "ESRI Shapefile", bool  onlySelected = false, QString *  errorMessage = 0, const QStringList &  datasourceOptions = QStringList(), const QStringList &  layerOptions = QStringList(), bool  skipAttributeCreation = false, QString *  newFilename = 0, SymbologyExport  symbologyExport = NoSymbology, double  symbologyScale = 1.0, const QgsRectangle *  filterExtent = 0  )

static

Note

added in v2.2

Definition at line 1824 of file qgsvectorfilewriter.cpp.

Member Data Documentation

QMap<int, int> QgsVectorFileWriter::mAttrIdxToOgrIdx

protected

map attribute indizes to OGR field indexes

Definition at line 292 of file qgsvectorfilewriter.h.

QTextCodec* QgsVectorFileWriter::mCodec

protected

Definition at line 286 of file qgsvectorfilewriter.h.

OGRDataSourceH QgsVectorFileWriter::mDS

protected

Definition at line 276 of file qgsvectorfilewriter.h.

WriterError QgsVectorFileWriter::mError

protected

contains error value if construction was not successful

Definition at line 283 of file qgsvectorfilewriter.h.

QString QgsVectorFileWriter::mErrorMessage

protected

Definition at line 284 of file qgsvectorfilewriter.h.

QgsFields QgsVectorFileWriter::mFields

protected

Definition at line 280 of file qgsvectorfilewriter.h.

OGRGeometryH QgsVectorFileWriter::mGeom

protected

Definition at line 278 of file qgsvectorfilewriter.h.

OGRLayerH QgsVectorFileWriter::mLayer

protected

Definition at line 277 of file qgsvectorfilewriter.h.

SymbologyExport QgsVectorFileWriter::mSymbologyExport

protected

Definition at line 294 of file qgsvectorfilewriter.h.

double QgsVectorFileWriter::mSymbologyScaleDenominator

protected

Scale for symbology export (e.g.

for symbols units in map units)

Definition at line 301 of file qgsvectorfilewriter.h.

QGis::WkbType QgsVectorFileWriter::mWkbType

protected

geometry type which is being used

Definition at line 289 of file qgsvectorfilewriter.h.

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

• /tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsvectorfilewriter.h
• /tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsvectorfilewriter.cpp