Utilities for working with OGR features and layers. More...

#include <qgsogrutils.h>

Static Public Member Functions
static OGRFieldDomainH	convertFieldDomain (const QgsFieldDomain *domain)
	Converts a QGIS field domain definition to an OGR field domain equivalent.

static std::unique_ptr< QgsFieldDomain >	convertFieldDomain (OGRFieldDomainH domain)
	Converts an OGR field domain definition to a QgsFieldDomain equivalent.

static gdal::relationship_unique_ptr	convertRelationship (const QgsWeakRelation &relation, QString &error)
	Converts a QGIS relation to a GDAL relationship equivalent.

static QgsWeakRelation	convertRelationship (GDALRelationshipH relationship, const QString &datasetUri)
	Converts an GDAL relationship definition to a QgsWeakRelation equivalent.

static OGRSpatialReferenceH	crsToOGRSpatialReference (const QgsCoordinateReferenceSystem &crs)
	Returns a OGRSpatialReferenceH corresponding to the specified crs object.

static QStringList	cStringListToQStringList (char **stringList)
	Converts a c string list to a QStringList.

static bool	deleteStyleById (GDALDatasetH hDS, const QString &styleId, QString &errCause)
	Helper function for deleting a style by id from ogr/gdal database datasources.

static QVariant	getOgrFeatureAttribute (OGRFeatureH ogrFet, const QgsField &field, int attIndex, QTextCodec encoding, bool ok=nullptr)
	Retrieves an attribute value from an OGR feature, using a provided field definition.

static QVariant	getOgrFeatureAttribute (OGRFeatureH ogrFet, const QgsFields &fields, int attIndex, QTextCodec encoding, bool ok=nullptr)
	Retrieves an attribute value from an OGR feature.

static QString	getStyleById (GDALDatasetH hDS, const QString &styleId, QString &errCause)
	Helper function for getting a style by ID from ogr/gdal database datasources.

static int	listStyles (GDALDatasetH hDS, const QString &layerName, const QString &geomColumn, QStringList &ids, QStringList &names, QStringList &descriptions, QString &errCause)
	Helper function for listing styles in ogr/gdal database datasources.

static QString	loadStoredStyle (GDALDatasetH hDS, const QString &layerName, const QString &geomColumn, QString &styleName, QString &errCause)
	Helper function for loading a stored styles in ogr/gdal database datasources.

static QList< QgsVectorDataProvider::NativeType >	nativeFieldTypesForDriver (GDALDriverH driver)
	Returns the list of native field types supported for a driver.

static QVariant	OGRFieldtoVariant (const OGRField *value, OGRFieldType type)
	Converts an OGRField value of the specified type into a QVariant.

static void	ogrFieldTypeToQVariantType (OGRFieldType ogrType, OGRFieldSubType ogrSubType, QMetaType::Type &variantType, QMetaType::Type &variantSubType)
	Converts an OGR field type and sub type to the best matching QVariant::Type equivalent.

static QgsGeometry	ogrGeometryToQgsGeometry (OGRGeometryH geom)
	Converts an OGR geometry representation to a QgsGeometry object.

static Qgis::WkbType	ogrGeometryTypeToQgsWkbType (OGRwkbGeometryType ogrGeomType)
	Converts a OGRwkbGeometryType to QgsWkbTypes::Type.

static QgsCoordinateReferenceSystem	OGRSpatialReferenceToCrs (OGRSpatialReferenceH srs)
	Returns a QgsCoordinateReferenceSystem corresponding to the specified OGR srs object, or an invalid QgsCoordinateReferenceSystem if srs could not be converted.

static QString	OGRSpatialReferenceToWkt (OGRSpatialReferenceH srs)
	Returns a WKT string corresponding to the specified OGR srs object.

static int	OGRTZFlagFromQt (const QDateTime &datetime)
	Gets the value of OGRField::Date::TZFlag from the timezone of a QDateTime.

static QVariantMap	parseStyleString (const QString &string)
	Parses an OGR style string to a variant map containing the style string components.

static QgsFeature	readOgrFeature (OGRFeatureH ogrFet, const QgsFields &fields, QTextCodec *encoding)
	Reads an OGR feature and converts it to a QgsFeature.

static bool	readOgrFeatureAttributes (OGRFeatureH ogrFet, const QgsFields &fields, QgsFeature &feature, QTextCodec *encoding)
	Reads all attributes from an OGR feature into a QgsFeature.

static bool	readOgrFeatureGeometry (OGRFeatureH ogrFet, QgsFeature &feature)
	Reads the geometry from an OGR feature into a QgsFeature.

static QgsFields	readOgrFields (OGRFeatureH ogrFet, QTextCodec *encoding)
	Reads an OGR feature and returns a corresponding fields collection.

static QString	readShapefileEncoding (const QString &path)
	Reads the encoding of the shapefile at the specified path (where path is the location of the ".shp" file).

static QString	readShapefileEncodingFromCpg (const QString &path)
	Reads the encoding of the shapefile at the specified path (where path is the location of the ".shp" file), from the CPG specified encoding.

static QString	readShapefileEncodingFromLdid (const QString &path)
	Reads the encoding of the shapefile at the specified path (where path is the location of the ".shp" file), from the DBF LDID encoding.

static bool	saveStyle (GDALDatasetH hDS, const QString &layerName, const QString &geomColumn, const QString &qmlStyle, const QString &sldStyle, const QString &styleName, const QString &styleDescription, const QString &uiFileContent, bool useAsDefault, QString &errCause)
	Helper function for saving a style to ogr/gdal database datasources.

static QgsFeatureList	stringToFeatureList (const QString &string, const QgsFields &fields, QTextCodec *encoding)
	Attempts to parse a string representing a collection of features using OGR.

static QgsFields	stringToFields (const QString &string, QTextCodec *encoding)
	Attempts to retrieve the fields from a string representing a collection of features using OGR.

static QVariant	stringToVariant (OGRFieldType type, OGRFieldSubType subType, const QString &string)
	Converts a string to a variant, using the provider OGR field type and subType to determine the most appropriate variant type.

static bool	styleExists (GDALDatasetH hDS, const QString &layerName, const QString &geomColumn, const QString &styleId, QString &errorCause)
	Helper function for checking whether a style exists in ogr/gdal database datasources.

static std::unique_ptr< QgsSymbol >	symbolFromStyleString (const QString &string, Qgis::SymbolType type)
	Creates a new QgsSymbol matching an OGR style string.

static std::unique_ptr< OGRField >	variantToOGRField (const QVariant &value, OGRFieldType type)
	Converts a QVariant to an OGRField value of specified type.

static void	variantTypeToOgrFieldType (QMetaType::Type variantType, OGRFieldType &ogrType, OGRFieldSubType &ogrSubType)
	Converts an QVariant type to the best matching OGR field type and sub type.

Detailed Description

Utilities for working with OGR features and layers.

Contains helper utilities for assisting work with both OGR features and layers.

Note: not available in Python bindings

Definition at line 191 of file qgsogrutils.h.

Member Function Documentation

◆ convertFieldDomain() [1/2]

OGRFieldDomainH QgsOgrUtils::convertFieldDomain ( const QgsFieldDomain * domain )

static

Converts a QGIS field domain definition to an OGR field domain equivalent.

Note: Requires GDAL >= 3.3; Not available in Python bindings

Since: QGIS 3.26

Definition at line 2272 of file qgsogrutils.cpp.

◆ convertFieldDomain() [2/2]

std::unique_ptr< QgsFieldDomain > QgsOgrUtils::convertFieldDomain ( OGRFieldDomainH domain )

static

Converts an OGR field domain definition to a QgsFieldDomain equivalent.

Note: Requires GDAL >= 3.3; Not available in Python bindings

Since: QGIS 3.26

Definition at line 2179 of file qgsogrutils.cpp.

◆ convertRelationship() [1/2]

gdal::relationship_unique_ptr QgsOgrUtils::convertRelationship	(	const QgsWeakRelation &	relation,
		QString &	error
	)

static

Converts a QGIS relation to a GDAL relationship equivalent.

Note: Requires GDAL >= 3.6; Not available in Python bindings

Since: QGIS 3.30

Definition at line 2508 of file qgsogrutils.cpp.

◆ convertRelationship() [2/2]

QgsWeakRelation QgsOgrUtils::convertRelationship	(	GDALRelationshipH	relationship,
		const QString &	datasetUri
	)

static

Converts an GDAL relationship definition to a QgsWeakRelation equivalent.

Note: Requires GDAL >= 3.6; Not available in Python bindings

Since: QGIS 3.30

Definition at line 2384 of file qgsogrutils.cpp.

◆ crsToOGRSpatialReference()

OGRSpatialReferenceH QgsOgrUtils::crsToOGRSpatialReference ( const QgsCoordinateReferenceSystem & crs )

static

Returns a OGRSpatialReferenceH corresponding to the specified crs object.

Note: Caller must release the returned object with OSRRelease.

Since: QGIS 3.22

Definition at line 1236 of file qgsogrutils.cpp.

◆ cStringListToQStringList()

QStringList QgsOgrUtils::cStringListToQStringList ( char ** stringList )

static

Converts a c string list to a QStringList.

Presumes a null terminated string list.

Since: QGIS 3.2

Definition at line 1172 of file qgsogrutils.cpp.

◆ deleteStyleById()

bool QgsOgrUtils::deleteStyleById	(	GDALDatasetH	hDS,
		const QString &	styleId,
		QString &	errCause
	)

static

Helper function for deleting a style by id from ogr/gdal database datasources.

Since: QGIS 3.34

Definition at line 2819 of file qgsogrutils.cpp.

◆ getOgrFeatureAttribute() [1/2]

QVariant QgsOgrUtils::getOgrFeatureAttribute	(	OGRFeatureH	ogrFet,
		const QgsField &	field,
		int	attIndex,
		QTextCodec *	encoding,
		bool *	ok = `nullptr`
	)

static

Retrieves an attribute value from an OGR feature, using a provided field definition.

Parameters

ogrFet	OGR feature handle
field	definition of corresponding field
attIndex	index of attribute to retrieve from ogrFet
encoding	text encoding
ok	optional storage for success of retrieval

Returns: attribute converted to a QVariant object

See also: readOgrFeatureAttributes()

Since: QGIS 3.10.1

Definition at line 519 of file qgsogrutils.cpp.

◆ getOgrFeatureAttribute() [2/2]

QVariant QgsOgrUtils::getOgrFeatureAttribute	(	OGRFeatureH	ogrFet,
		const QgsFields &	fields,
		int	attIndex,
		QTextCodec *	encoding,
		bool *	ok = `nullptr`
	)

static

Retrieves an attribute value from an OGR feature.

Parameters

ogrFet	OGR feature handle
fields	fields collection corresponding to feature
attIndex	index of attribute to retrieve
encoding	text encoding
ok	optional storage for success of retrieval

Returns: attribute converted to a QVariant object

See also: readOgrFeatureAttributes()

Definition at line 506 of file qgsogrutils.cpp.

◆ getStyleById()

QString QgsOgrUtils::getStyleById	(	GDALDatasetH	hDS,
		const QString &	styleId,
		QString &	errCause
	)

static

Helper function for getting a style by ID from ogr/gdal database datasources.

Since: QGIS 3.34

Definition at line 2785 of file qgsogrutils.cpp.

◆ listStyles()

int QgsOgrUtils::listStyles	(	GDALDatasetH	hDS,
		const QString &	layerName,
		const QString &	geomColumn,
		QStringList &	ids,
		QStringList &	names,
		QStringList &	descriptions,
		QString &	errCause
	)

static

Helper function for listing styles in ogr/gdal database datasources.

Since: QGIS 3.34

Definition at line 2667 of file qgsogrutils.cpp.

◆ loadStoredStyle()

QString QgsOgrUtils::loadStoredStyle	(	GDALDatasetH	hDS,
		const QString &	layerName,
		const QString &	geomColumn,
		QString &	styleName,
		QString &	errCause
	)

static

Helper function for loading a stored styles in ogr/gdal database datasources.

Since: QGIS 3.34

Definition at line 2846 of file qgsogrutils.cpp.

◆ nativeFieldTypesForDriver()

QList< QgsVectorDataProvider::NativeType > QgsOgrUtils::nativeFieldTypesForDriver ( GDALDriverH driver )

static

Returns the list of native field types supported for a driver.

Since: QGIS 3.28

Definition at line 2059 of file qgsogrutils.cpp.

◆ OGRFieldtoVariant()

QVariant QgsOgrUtils::OGRFieldtoVariant	(	const OGRField *	value,
		OGRFieldType	type
	)

static

Converts an OGRField value of the specified type into a QVariant.

Since: QGIS 3.20

Definition at line 144 of file qgsogrutils.cpp.

◆ ogrFieldTypeToQVariantType()

void QgsOgrUtils::ogrFieldTypeToQVariantType	(	OGRFieldType	ogrType,
		OGRFieldSubType	ogrSubType,
		QMetaType::Type &	variantType,
		QMetaType::Type &	variantSubType
	)

static

Converts an OGR field type and sub type to the best matching QVariant::Type equivalent.

Parameters

ogrType	OGR field type
ogrSubType	OGR field sub type
variantType	will be set to matching QVariant type
variantSubType	will be set to matching QVariant sub type, for list, map and other complex OGR field types.

Note: Not available in Python bindings

Since: QGIS 3.26

Definition at line 1883 of file qgsogrutils.cpp.

◆ ogrGeometryToQgsGeometry()

QgsGeometry QgsOgrUtils::ogrGeometryToQgsGeometry ( OGRGeometryH geom )

static

Converts an OGR geometry representation to a QgsGeometry object.

Parameters

geom	OGR geometry handle

Returns: QgsGeometry object. If conversion was not successful the geometry will be empty.

See also: readOgrFeatureGeometry()

Definition at line 961 of file qgsogrutils.cpp.

◆ ogrGeometryTypeToQgsWkbType()

Qgis::WkbType QgsOgrUtils::ogrGeometryTypeToQgsWkbType ( OGRwkbGeometryType ogrGeomType )

static

Converts a OGRwkbGeometryType to QgsWkbTypes::Type.

Since: QGIS 3.4.9

Definition at line 875 of file qgsogrutils.cpp.

◆ OGRSpatialReferenceToCrs()

QgsCoordinateReferenceSystem QgsOgrUtils::OGRSpatialReferenceToCrs ( OGRSpatialReferenceH srs )

static

Returns a QgsCoordinateReferenceSystem corresponding to the specified OGR srs object, or an invalid QgsCoordinateReferenceSystem if srs could not be converted.

Since: QGIS 3.10.1

Definition at line 1203 of file qgsogrutils.cpp.

◆ OGRSpatialReferenceToWkt()

QString QgsOgrUtils::OGRSpatialReferenceToWkt ( OGRSpatialReferenceH srs )

static

Returns a WKT string corresponding to the specified OGR srs object.

The WKT string format will be selected using the most appropriate format (usually WKT2 if GDAL 3 is available).

Since: QGIS 3.10.1

Definition at line 1187 of file qgsogrutils.cpp.

◆ OGRTZFlagFromQt()

int QgsOgrUtils::OGRTZFlagFromQt ( const QDateTime & datetime )

static

Gets the value of OGRField::Date::TZFlag from the timezone of a QDateTime.

Since: QGIS 3.30

Definition at line 229 of file qgsogrutils.cpp.

◆ parseStyleString()

QVariantMap QgsOgrUtils::parseStyleString ( const QString & string )

static

Parses an OGR style string to a variant map containing the style string components.

Since: QGIS 3.20

Definition at line 1317 of file qgsogrutils.cpp.

◆ readOgrFeature()

QgsFeature QgsOgrUtils::readOgrFeature	(	OGRFeatureH	ogrFet,
		const QgsFields &	fields,
		QTextCodec *	encoding
	)

static

Reads an OGR feature and converts it to a QgsFeature.

Parameters

ogrFet	OGR feature handle
fields	fields collection corresponding to feature
encoding	text encoding

Returns: valid feature if read was successful

Definition at line 424 of file qgsogrutils.cpp.

◆ readOgrFeatureAttributes()

bool QgsOgrUtils::readOgrFeatureAttributes	(	OGRFeatureH	ogrFet,
		const QgsFields &	fields,
		QgsFeature &	feature,
		QTextCodec *	encoding
	)

static

Reads all attributes from an OGR feature into a QgsFeature.

Parameters

ogrFet	OGR feature handle
fields	fields collection corresponding to feature
feature	QgsFeature to store attributes in
encoding	text encoding

Returns: true if attribute read was successful

See also: getOgrFeatureAttribute()

Definition at line 745 of file qgsogrutils.cpp.

◆ readOgrFeatureGeometry()

bool QgsOgrUtils::readOgrFeatureGeometry	(	OGRFeatureH	ogrFet,
		QgsFeature &	feature
	)

static

Reads the geometry from an OGR feature into a QgsFeature.

Parameters

ogrFet	OGR feature handle
feature	QgsFeature to store geometry in

Returns: true if geometry read was successful

See also: readOgrFeatureAttributes(); ogrGeometryToQgsGeometry()

Definition at line 766 of file qgsogrutils.cpp.

◆ readOgrFields()

QgsFields QgsOgrUtils::readOgrFields	(	OGRFeatureH	ogrFet,
		QTextCodec *	encoding
	)

static

Reads an OGR feature and returns a corresponding fields collection.

Parameters

ogrFet	OGR feature handle
encoding	text encoding

Returns: fields collection if read was successful

Definition at line 449 of file qgsogrutils.cpp.

◆ readShapefileEncoding()

QString QgsOgrUtils::readShapefileEncoding ( const QString & path )

static

Reads the encoding of the shapefile at the specified path (where path is the location of the ".shp" file).

This method considers both the CPG specified encoding and the DBF LDID encoding (priority goes to CPG based encoding)

See also: readShapefileEncodingFromCpg(); readShapefileEncodingFromLdid()

Since: QGIS 3.12

Definition at line 1294 of file qgsogrutils.cpp.

◆ readShapefileEncodingFromCpg()

QString QgsOgrUtils::readShapefileEncodingFromCpg ( const QString & path )

static

Reads the encoding of the shapefile at the specified path (where path is the location of the ".shp" file), from the CPG specified encoding.

Return an empty string if CPG based encoding was not found.

See also: readShapefileEncoding()

Since: QGIS 3.12

Definition at line 1303 of file qgsogrutils.cpp.

◆ readShapefileEncodingFromLdid()

QString QgsOgrUtils::readShapefileEncodingFromLdid ( const QString & path )

static

Reads the encoding of the shapefile at the specified path (where path is the location of the ".shp" file), from the DBF LDID encoding.

Return an empty string if LDID based encoding was not found.

See also: readShapefileEncoding()

Since: QGIS 3.12

Definition at line 1310 of file qgsogrutils.cpp.

◆ saveStyle()

bool QgsOgrUtils::saveStyle	(	GDALDatasetH	hDS,
		const QString &	layerName,
		const QString &	geomColumn,
		const QString &	qmlStyle,
		const QString &	sldStyle,
		const QString &	styleName,
		const QString &	styleDescription,
		const QString &	uiFileContent,
		bool	useAsDefault,
		QString &	errCause
	)

static

Helper function for saving a style to ogr/gdal database datasources.

Since: QGIS 3.34

Definition at line 2901 of file qgsogrutils.cpp.

◆ stringToFeatureList()

QgsFeatureList QgsOgrUtils::stringToFeatureList	(	const QString &	string,
		const QgsFields &	fields,
		QTextCodec *	encoding
	)

static

Attempts to parse a string representing a collection of features using OGR.

For example, this method can be used to convert a GeoJSON encoded collection to a list of QgsFeatures.

Parameters

string	string to parse
fields	fields collection to use for parsed features (

See also: stringToFields())

Parameters

encoding text encoding

Returns: list of parsed features, or an empty list if no features could be parsed

See also: stringToFields()

Definition at line 1090 of file qgsogrutils.cpp.

◆ stringToFields()

QgsFields QgsOgrUtils::stringToFields	(	const QString &	string,
		QTextCodec *	encoding
	)

static

Attempts to retrieve the fields from a string representing a collection of features using OGR.

Parameters

string	string to parse
encoding	text encoding

Returns: retrieved fields collection, or an empty list if no fields could be determined from the string

See also: stringToFeatureList()

Definition at line 1132 of file qgsogrutils.cpp.

◆ stringToVariant()

QVariant QgsOgrUtils::stringToVariant	(	OGRFieldType	type,
		OGRFieldSubType	subType,
		const QString &	string
	)

static

Converts a string to a variant, using the provider OGR field type and subType to determine the most appropriate variant type.

Note: Not available in Python bindings

Since: QGIS 3.26

Definition at line 2008 of file qgsogrutils.cpp.

◆ styleExists()

bool QgsOgrUtils::styleExists	(	GDALDatasetH	hDS,
		const QString &	layerName,
		const QString &	geomColumn,
		const QString &	styleId,
		QString &	errorCause
	)

static

Helper function for checking whether a style exists in ogr/gdal database datasources.

Since: QGIS 3.34

Definition at line 2756 of file qgsogrutils.cpp.

◆ symbolFromStyleString()

std::unique_ptr< QgsSymbol > QgsOgrUtils::symbolFromStyleString	(	const QString &	string,
		Qgis::SymbolType	type
	)

static

Creates a new QgsSymbol matching an OGR style string.

Since: QGIS 3.20

Definition at line 1364 of file qgsogrutils.cpp.

◆ variantToOGRField()

std::unique_ptr< OGRField > QgsOgrUtils::variantToOGRField	(	const QVariant &	value,
		OGRFieldType	type
	)

static

Converts a QVariant to an OGRField value of specified type.

Returns nullptr in case of error

Since: QGIS 3.26

Definition at line 236 of file qgsogrutils.cpp.

◆ variantTypeToOgrFieldType()

void QgsOgrUtils::variantTypeToOgrFieldType	(	QMetaType::Type	variantType,
		OGRFieldType &	ogrType,
		OGRFieldSubType &	ogrSubType
	)

static

Converts an QVariant type to the best matching OGR field type and sub type.

Parameters

variantType	QVariant field type
ogrType	will be set to matching OGR type
ogrSubType	will be set to matching OGR sub type

Note: Not available in Python bindings

Since: QGIS 3.26

Definition at line 1956 of file qgsogrutils.cpp.

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

/home/fischer/src/qgis-3.38/src/core/qgsogrutils.h
/home/fischer/src/qgis-3.38/src/core/qgsogrutils.cpp

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ convertFieldDomain() [1/2]

◆ convertFieldDomain() [2/2]

◆ convertRelationship() [1/2]

◆ convertRelationship() [2/2]

◆ crsToOGRSpatialReference()

◆ cStringListToQStringList()

◆ deleteStyleById()

◆ getOgrFeatureAttribute() [1/2]

◆ getOgrFeatureAttribute() [2/2]

◆ getStyleById()

◆ listStyles()

◆ loadStoredStyle()

◆ nativeFieldTypesForDriver()

◆ OGRFieldtoVariant()

◆ ogrFieldTypeToQVariantType()

◆ ogrGeometryToQgsGeometry()

◆ ogrGeometryTypeToQgsWkbType()

◆ OGRSpatialReferenceToCrs()

◆ OGRSpatialReferenceToWkt()

◆ OGRTZFlagFromQt()

◆ parseStyleString()

◆ readOgrFeature()

◆ readOgrFeatureAttributes()

◆ readOgrFeatureGeometry()

◆ readOgrFields()

◆ readShapefileEncoding()

◆ readShapefileEncodingFromCpg()

◆ readShapefileEncodingFromLdid()

◆ saveStyle()

◆ stringToFeatureList()

◆ stringToFields()

◆ stringToVariant()

◆ styleExists()

◆ symbolFromStyleString()

◆ variantToOGRField()

◆ variantTypeToOgrFieldType()