Handles exporting QgsFeature features to GeoJSON features. More...

#include <qgsjsonutils.h>

Public Member Functions
	QgsJsonExporter (QgsVectorLayer *vectorLayer=nullptr, int precision=6)
	Constructor for QgsJsonExporter.

bool	attributeDisplayName () const
	Returns whether original names of attributes or aliases are printed.

QgsAttributeList	attributes () const
	Returns the list of attributes which will be included in the JSON exports, or an empty list if all attributes will be included.

QgsAttributeList	excludedAttributes () const
	Returns a list of attributes which will be specifically excluded from the JSON exports.

QString	exportFeature (const QgsFeature &feature, const QVariantMap &extraProperties=QVariantMap(), const QVariant &id=QVariant(), int indent=-1) const
	Returns a GeoJSON string representation of a feature.

QString	exportFeatures (const QgsFeatureList &features, int indent=-1) const
	Returns a GeoJSON string representation of a list of features (feature collection).

json	exportFeaturesToJsonObject (const QgsFeatureList &features) const
	Returns a JSON object representation of a list of features (feature collection).

json	exportFeatureToJsonObject (const QgsFeature &feature, const QVariantMap &extraProperties=QVariantMap(), const QVariant &id=QVariant()) const
	Returns a QJsonObject representation of a feature.

bool	includeAttributes () const
	Returns whether attributes will be included in the JSON exports.

bool	includeGeometry () const
	Returns whether geometry will be included in the JSON exports.

bool	includeRelated () const
	Returns whether attributes of related (child) features will be included in the JSON exports.

int	precision () const
	Returns the maximum number of decimal places to use in geometry coordinates.

void	setAttributeDisplayName (bool displayName)
	Sets whether to print original names of attributes or aliases if defined.

void	setAttributes (const QgsAttributeList &attributes)
	Sets the list of attributes to include in the JSON exports.

void	setDestinationCrs (const QgsCoordinateReferenceSystem &destinationCrs)
	Set the destination CRS for feature geometry transformation to destinationCrs, this defaults to EPSG:4326 and it is only effective when the automatic geometry transformation is active (it is by default).

void	setExcludedAttributes (const QgsAttributeList &attributes)
	Sets a list of attributes to specifically exclude from the JSON exports.

void	setIncludeAttributes (bool includeAttributes)
	Sets whether to include attributes in the JSON exports.

void	setIncludeGeometry (bool includeGeometry)
	Sets whether to include geometry in the JSON exports.

void	setIncludeRelated (bool includeRelated)
	Sets whether to include attributes of features linked via references in the JSON exports.

void	setPrecision (int precision)
	Sets the maximum number of decimal places to use in geometry coordinates.

void	setSourceCrs (const QgsCoordinateReferenceSystem &crs)
	Sets the source CRS for feature geometries.

void	setTransformGeometries (bool activate)
	Sets whether geometries should be transformed in EPSG 4326 (default behavior) or just keep as it is.

void	setUseFieldFormatters (bool useFieldFormatters)
	Sets whether field formatters (of type KeyValue, List, ValueRelation, ValueMap) are used to export raw values as displayed values.

void	setVectorLayer (QgsVectorLayer *vectorLayer)
	Sets the associated vector layer (required for related attribute export).

QgsCoordinateReferenceSystem	sourceCrs () const
	Returns the source CRS for feature geometries.

bool	useFieldFormatters () const
	Returned whether field formatters (of type KeyValue, List, ValueRelation, ValueMap) are used to export raw values as displayed values.

QgsVectorLayer *	vectorLayer () const
	Returns the associated vector layer, if set.

Detailed Description

Handles exporting QgsFeature features to GeoJSON features.

Note that geometries will be automatically reprojected to WGS84 to match GeoJSON spec if either the source vector layer or source CRS is set.

Definition at line 44 of file qgsjsonutils.h.

Constructor & Destructor Documentation

◆ QgsJsonExporter()

QgsJsonExporter::QgsJsonExporter	(	QgsVectorLayer *	vectorLayer = `nullptr`,
		int	precision = `6`
	)

Constructor for QgsJsonExporter.

Parameters

vectorLayer	associated vector layer (required for related attribute export)
precision	maximum number of decimal places to use for geometry coordinates, the RFC 7946 GeoJSON specification recommends limiting coordinate precision to 6

Definition at line 42 of file qgsjsonutils.cpp.

Member Function Documentation

◆ attributeDisplayName()

bool QgsJsonExporter::attributeDisplayName ( ) const

inline

Returns whether original names of attributes or aliases are printed.

Since: QGIS 3.6

Definition at line 123 of file qgsjsonutils.h.

◆ attributes()

QgsAttributeList QgsJsonExporter::attributes ( ) const

inline

Returns the list of attributes which will be included in the JSON exports, or an empty list if all attributes will be included.

See also: setAttributes(); excludedAttributes()

Note: Attributes excluded via excludedAttributes() take precedence over attributes returned by this method.

Definition at line 181 of file qgsjsonutils.h.

◆ excludedAttributes()

QgsAttributeList QgsJsonExporter::excludedAttributes ( ) const

inline

Returns a list of attributes which will be specifically excluded from the JSON exports.

Excluded attributes take precedence over attributes included via attributes().

See also: setExcludedAttributes(); attributes()

Definition at line 198 of file qgsjsonutils.h.

◆ exportFeature()

QString QgsJsonExporter::exportFeature	(	const QgsFeature &	feature,
		const QVariantMap &	extraProperties = `QVariantMap()`,
		const QVariant &	id = `QVariant()`,
		int	indent = `-1`
	)		const

Returns a GeoJSON string representation of a feature.

Parameters

feature	feature to convert
extraProperties	map of extra attributes to include in feature's properties
id	optional ID to use as GeoJSON feature's ID instead of input feature's ID. If omitted, feature's ID is used.
indent	number of indentation spaces for generated JSON (defaults to none)

Returns: GeoJSON string

See also: exportFeatures(); exportFeatureToJsonObject()

Definition at line 83 of file qgsjsonutils.cpp.

◆ exportFeatures()

QString QgsJsonExporter::exportFeatures	(	const QgsFeatureList &	features,
		int	indent = `-1`
	)		const

Returns a GeoJSON string representation of a list of features (feature collection).

Parameters

features	features to convert
indent	number of indentation spaces for generated JSON (defaults to none)

Returns: GeoJSON string

See also: exportFeature()

Definition at line 237 of file qgsjsonutils.cpp.

◆ exportFeaturesToJsonObject()

json QgsJsonExporter::exportFeaturesToJsonObject ( const QgsFeatureList & features ) const

Returns a JSON object representation of a list of features (feature collection).

Parameters

features features to convert

Returns: json object

See also: exportFeatures()

Since: QGIS 3.10

Definition at line 242 of file qgsjsonutils.cpp.

◆ exportFeatureToJsonObject()

json QgsJsonExporter::exportFeatureToJsonObject	(	const QgsFeature &	feature,
		const QVariantMap &	extraProperties = `QVariantMap()`,
		const QVariant &	id = `QVariant()`
	)		const

Returns a QJsonObject representation of a feature.

Parameters

feature	feature to convert
extraProperties	map of extra attributes to include in feature's properties
id	optional ID to use as GeoJSON feature's ID instead of input feature's ID. If omitted, feature's ID is used.

Returns: json object

See also: exportFeatures()

Definition at line 89 of file qgsjsonutils.cpp.

◆ includeAttributes()

bool QgsJsonExporter::includeAttributes ( ) const

inline

Returns whether attributes will be included in the JSON exports.

See also: setIncludeAttributes()

Definition at line 94 of file qgsjsonutils.h.

◆ includeGeometry()

bool QgsJsonExporter::includeGeometry ( ) const

inline

Returns whether geometry will be included in the JSON exports.

See also: setIncludeGeometry()

Definition at line 81 of file qgsjsonutils.h.

◆ includeRelated()

bool QgsJsonExporter::includeRelated ( ) const

inline

Returns whether attributes of related (child) features will be included in the JSON exports.

See also: setIncludeRelated()

Definition at line 109 of file qgsjsonutils.h.

◆ precision()

int QgsJsonExporter::precision ( ) const

inline

Returns the maximum number of decimal places to use in geometry coordinates.

See also: setPrecision()

Definition at line 68 of file qgsjsonutils.h.

◆ setAttributeDisplayName()

void QgsJsonExporter::setAttributeDisplayName ( bool displayName )

inline

Sets whether to print original names of attributes or aliases if defined.

Since: QGIS 3.6

Definition at line 116 of file qgsjsonutils.h.

◆ setAttributes()

void QgsJsonExporter::setAttributes ( const QgsAttributeList & attributes )

inline

Sets the list of attributes to include in the JSON exports.

Parameters

attributes list of attribute indexes, or an empty list to include all attributes

See also: attributes(); setExcludedAttributes()

Note: Attributes excluded via setExcludedAttributes() take precedence over attributes specified by this method.

Definition at line 171 of file qgsjsonutils.h.

◆ setDestinationCrs()

void QgsJsonExporter::setDestinationCrs ( const QgsCoordinateReferenceSystem & destinationCrs )

Set the destination CRS for feature geometry transformation to destinationCrs, this defaults to EPSG:4326 and it is only effective when the automatic geometry transformation is active (it is by default).

See also: setTransformGeometries(); setSourceCrs()

Since: QGIS 3.30

Definition at line 259 of file qgsjsonutils.cpp.

◆ setExcludedAttributes()

void QgsJsonExporter::setExcludedAttributes ( const QgsAttributeList & attributes )

inline

Sets a list of attributes to specifically exclude from the JSON exports.

Excluded attributes take precedence over attributes included via setAttributes().

Parameters

attributes list of attribute indexes to exclude

See also: excludedAttributes(); setAttributes()

Definition at line 190 of file qgsjsonutils.h.

◆ setIncludeAttributes()

void QgsJsonExporter::setIncludeAttributes ( bool includeAttributes )

inline

Sets whether to include attributes in the JSON exports.

Parameters

includeAttributes set to false to prevent attribute inclusion

See also: includeAttributes()

Definition at line 88 of file qgsjsonutils.h.

◆ setIncludeGeometry()

void QgsJsonExporter::setIncludeGeometry ( bool includeGeometry )

inline

Sets whether to include geometry in the JSON exports.

Parameters

includeGeometry set to false to prevent geometry inclusion

See also: includeGeometry()

Definition at line 75 of file qgsjsonutils.h.

◆ setIncludeRelated()

void QgsJsonExporter::setIncludeRelated ( bool includeRelated )

inline

Sets whether to include attributes of features linked via references in the JSON exports.

Parameters

includeRelated set to true to include attributes for any related child features within the exported properties element.

Note: associated vector layer must be set with setVectorLayer()

See also: includeRelated()

Definition at line 103 of file qgsjsonutils.h.

◆ setPrecision()

void QgsJsonExporter::setPrecision ( int precision )

inline

Sets the maximum number of decimal places to use in geometry coordinates.

The RFC 7946 GeoJSON specification recommends limiting coordinate precision to 6

Parameters

precision number of decimal places

See also: precision()

Definition at line 62 of file qgsjsonutils.h.

◆ setSourceCrs()

void QgsJsonExporter::setSourceCrs ( const QgsCoordinateReferenceSystem & crs )

Sets the source CRS for feature geometries.

The source CRS must be set if geometries are to be correctly automatically reprojected to WGS 84, to match GeoJSON specifications.

Parameters

crs	source CRS for input feature geometries

Note: the source CRS will be overwritten when a vector layer is specified via setVectorLayer()

See also: sourceCrs()

Definition at line 72 of file qgsjsonutils.cpp.

◆ setTransformGeometries()

void QgsJsonExporter::setTransformGeometries ( bool activate )

inline

Sets whether geometries should be transformed in EPSG 4326 (default behavior) or just keep as it is.

Since: QGIS 3.12

Definition at line 160 of file qgsjsonutils.h.

◆ setUseFieldFormatters()

void QgsJsonExporter::setUseFieldFormatters ( bool useFieldFormatters )

inline

Sets whether field formatters (of type KeyValue, List, ValueRelation, ValueMap) are used to export raw values as displayed values.

The default is true.

Since: QGIS 3.40

Definition at line 206 of file qgsjsonutils.h.

◆ setVectorLayer()

void QgsJsonExporter::setVectorLayer ( QgsVectorLayer * vectorLayer )

Sets the associated vector layer (required for related attribute export).

This will automatically update the sourceCrs() to match.

Parameters

vectorLayer vector layer

See also: vectorLayer()

Definition at line 57 of file qgsjsonutils.cpp.

◆ sourceCrs()

QgsCoordinateReferenceSystem QgsJsonExporter::sourceCrs ( ) const

Returns the source CRS for feature geometries.

The source CRS must be set if geometries are to be correctly automatically reprojected to WGS 84, to match GeoJSON specifications.

See also: setSourceCrs()

Definition at line 78 of file qgsjsonutils.cpp.

◆ useFieldFormatters()

bool QgsJsonExporter::useFieldFormatters ( ) const

inline

Returned whether field formatters (of type KeyValue, List, ValueRelation, ValueMap) are used to export raw values as displayed values.

Since: QGIS 3.40

Definition at line 214 of file qgsjsonutils.h.

◆ vectorLayer()

QgsVectorLayer * QgsJsonExporter::vectorLayer ( ) const

Returns the associated vector layer, if set.

See also: setVectorLayer()

Definition at line 67 of file qgsjsonutils.cpp.

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

/build/qgis-3.41.0+git20241122+3440c17df1d+99sid/src/core/qgsjsonutils.h
/build/qgis-3.41.0+git20241122+3440c17df1d+99sid/src/core/qgsjsonutils.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QgsJsonExporter()

Member Function Documentation

◆ attributeDisplayName()

◆ attributes()

◆ excludedAttributes()

◆ exportFeature()

◆ exportFeatures()

◆ exportFeaturesToJsonObject()

◆ exportFeatureToJsonObject()

◆ includeAttributes()

◆ includeGeometry()

◆ includeRelated()

◆ precision()

◆ setAttributeDisplayName()

◆ setAttributes()

◆ setDestinationCrs()

◆ setExcludedAttributes()

◆ setIncludeAttributes()

◆ setIncludeGeometry()

◆ setIncludeRelated()

◆ setPrecision()

◆ setSourceCrs()

◆ setTransformGeometries()

◆ setUseFieldFormatters()

◆ setVectorLayer()

◆ sourceCrs()

◆ useFieldFormatters()

◆ vectorLayer()