The feature class encapsulates a single feature including its id, geometry and a list of field/values attributes. More...

#include <qgsfeature.h>

Public Member Functions
	QgsFeature (const QgsFeature &rhs)
	Copy constructor. More...

	QgsFeature (const QgsFields &fields, QgsFeatureId id=FID_NULL)
	Constructor for QgsFeature. More...

	QgsFeature (QgsFeatureId id=FID_NULL)
	Constructor for QgsFeature. More...

virtual	~QgsFeature ()

int	approximateMemoryUsage () const
	Returns the approximate RAM usage of the feature, in bytes. More...

QVariant	attribute (const QString &name) const
	Lookup attribute value from attribute name. More...

QVariant	attribute (int fieldIdx) const
	Lookup attribute value from its index. More...

int	attributeCount () const
	Returns the number of attributes attached to the feature. More...

QgsAttributes	attributes () const
	Returns the feature's attributes. More...

void	clearGeometry ()
	Removes any geometry associated with the feature. More...

bool	deleteAttribute (const QString &name)
	Removes an attribute value by field name. More...

void	deleteAttribute (int field)
	Deletes an attribute and its value. More...

int	fieldNameIndex (const QString &fieldName) const
	Utility method to get attribute index from name. More...

QgsFields	fields () const
	Returns the field map associated with the feature. More...

QgsGeometry	geometry () const
	Returns the geometry associated with this feature. More...

bool	hasGeometry () const
	Returns `true` if the feature has an associated geometry. More...

QgsFeatureId	id () const
	Gets the feature ID for this feature. More...

void	initAttributes (int fieldCount)
	Initialize this feature with the given number of fields. More...

bool	isValid () const
	Returns the validity of this feature. More...

	operator QVariant () const
	Allows direct construction of QVariants from features. More...

bool	operator!= (const QgsFeature &other) const
	Compares two features. More...

QgsFeature &	operator= (const QgsFeature &rhs)
	Assignment operator. More...

bool	operator== (const QgsFeature &other) const
	Compares two features. More...

void	padAttributes (int count)
	Resizes the attributes attached to this feature by appending the specified count of NULL values to the end of the existing attributes. More...

void	resizeAttributes (int fieldCount)
	Resizes the attributes attached to this feature to the given number of fields. More...

bool	setAttribute (const QString &name, const QVariant &value)
	Insert a value into attribute. More...

bool	setAttribute (int field, const QVariant &attr)
	Set an attribute's value by field index. More...

void	setAttributes (const QgsAttributes &attrs)
	Sets the feature's attributes. More...

void	setFields (const QgsFields &fields, bool initAttributes=false)
	Assign a field map with the feature to allow attribute access by attribute name. More...

void	setGeometry (const QgsGeometry &geometry)
	Set the feature's geometry. More...

void	setGeometry (std::unique_ptr< QgsAbstractGeometry > geometry)
	Set the feature's geometry. More...

void	setId (QgsFeatureId id)
	Sets the feature ID for this feature. More...

void	setValid (bool validity)
	Sets the validity of the feature. More...

Properties
QgsAttributes	attributes

QgsFields	fields

QgsGeometry	geometry

Q_GADGET QgsFeatureId	id

Detailed Description

The feature class encapsulates a single feature including its id, geometry and a list of field/values attributes.

Note: QgsFeature objects are implicitly shared.

Definition at line 55 of file qgsfeature.h.

Constructor & Destructor Documentation

◆ QgsFeature() [1/3]

QgsFeature::QgsFeature ( QgsFeatureId id = FID_NULL )

Constructor for QgsFeature.

Parameters

id	feature id

Definition at line 39 of file qgsfeature.cpp.

◆ QgsFeature() [2/3]

QgsFeature::QgsFeature	(	const QgsFields &	fields,
		QgsFeatureId	id = `FID_NULL`
	)

Constructor for QgsFeature.

Parameters

fields	feature's fields
id	feature id

Definition at line 44 of file qgsfeature.cpp.

◆ QgsFeature() [3/3]

QgsFeature::QgsFeature ( const QgsFeature & rhs )

Copy constructor.

Definition at line 51 of file qgsfeature.cpp.

◆ ~QgsFeature()

QgsFeature::~QgsFeature ( )

virtual

Definition at line 82 of file qgsfeature.cpp.

Member Function Documentation

◆ approximateMemoryUsage()

int QgsFeature::approximateMemoryUsage ( ) const

Returns the approximate RAM usage of the feature, in bytes.

This method takes into account the size of variable elements (strings, geometry, ...), but the value returned should be considered as a lower bound estimation.

Since: QGIS 3.16

Definition at line 334 of file qgsfeature.cpp.

◆ attribute() [1/2]

QVariant QgsFeature::attribute ( const QString & name ) const

Lookup attribute value from attribute name.

Field map must be associated using setFields() before this method can be used.

Parameters

name	The name of the attribute to get

Returns: The value of the attribute (C++: Invalid variant if no such name exists )

Note: For Python: raises a KeyError exception if the field is not found; Alternatively in Python:
feature[name]

See also: setFields

Definition at line 287 of file qgsfeature.cpp.

◆ attribute() [2/2]

QVariant QgsFeature::attribute ( int fieldIdx ) const

Lookup attribute value from its index.

Field map must be associated using setFields() before this method can be used.

Parameters

fieldIdx The index of the attribute to get

Returns: The value of the attribute (C++: Invalid variant if no such index exists )

Note: For Python: raises a KeyError exception if the field is not found; Alternatively in Python:
feature[fieldIdx]

See also: setFields

Definition at line 279 of file qgsfeature.cpp.

◆ attributeCount()

int QgsFeature::attributeCount ( ) const

Returns the number of attributes attached to the feature.

Since: QGIS 3.18

Definition at line 129 of file qgsfeature.cpp.

◆ attributes()

QgsAttributes QgsFeature::attributes ( ) const

Returns the feature's attributes.

Returns: list of feature's attributes

See also: setAttributes

Note: Alternatively in Python: iterate feature, eg.
[attr for attr in feature]

Since: QGIS 2.9

Definition at line 124 of file qgsfeature.cpp.

◆ clearGeometry()

void QgsFeature::clearGeometry ( )

Removes any geometry associated with the feature.

See also: setGeometry(); hasGeometry()

Since: QGIS 3.0

Definition at line 158 of file qgsfeature.cpp.

◆ deleteAttribute() [1/2]

bool QgsFeature::deleteAttribute ( const QString & name )

Removes an attribute value by field name.

Field map must be associated using setFields() before this method can be used.

Parameters

name	The name of the field to delete

Returns: false if attribute name could not be converted to index (C++ only)

Note: For Python: raises a KeyError exception instead of returning false; Alternatively in Python:
del feature[name]

See also: setFields

Definition at line 268 of file qgsfeature.cpp.

◆ deleteAttribute() [2/2]

void QgsFeature::deleteAttribute ( int field )

Deletes an attribute and its value.

Parameters

field the index of the field

See also: setAttribute

Note: For Python: raises a KeyError exception if the field is not found; Alternatively in Python:
del feature[field]

field
const QgsField & field
Definition: qgsfield.h:472

Definition at line 97 of file qgsfeature.cpp.

◆ fieldNameIndex()

int QgsFeature::fieldNameIndex ( const QString & fieldName ) const

Utility method to get attribute index from name.

Field map must be associated using setFields() before this method can be used.

Parameters

fieldName name of field to get attribute index of

Returns: -1 if field does not exist or field map is not associated.

See also: setFields

Definition at line 302 of file qgsfeature.cpp.

◆ fields()

QgsFields QgsFeature::fields ( ) const

Returns the field map associated with the feature.

See also: setFields

Definition at line 179 of file qgsfeature.cpp.

◆ geometry()

QgsGeometry QgsFeature::geometry ( ) const

Returns the geometry associated with this feature.

If the feature has no geometry, an empty QgsGeometry object will be returned.

See also: hasGeometry(); setGeometry()

Definition at line 103 of file qgsfeature.cpp.

◆ hasGeometry()

bool QgsFeature::hasGeometry ( ) const

Returns true if the feature has an associated geometry.

See also: geometry()

Since: QGIS 3.0.

Definition at line 204 of file qgsfeature.cpp.

◆ id()

QgsFeatureId QgsFeature::id ( ) const

Gets the feature ID for this feature.

Returns: feature ID

See also: setId()

Definition at line 92 of file qgsfeature.cpp.

◆ initAttributes()

void QgsFeature::initAttributes ( int fieldCount )

Initialize this feature with the given number of fields.

Discard any previously set attribute data.

Parameters

fieldCount Number of fields to initialize

See also: resizeAttributes()

Definition at line 209 of file qgsfeature.cpp.

◆ isValid()

bool QgsFeature::isValid ( ) const

Returns the validity of this feature.

This is normally set by the provider to indicate some problem that makes the feature invalid or to indicate a null feature.

See also: setValid

Definition at line 190 of file qgsfeature.cpp.

◆ operator QVariant()

QgsFeature::operator QVariant ( ) const

inline

Allows direct construction of QVariants from features.

Definition at line 582 of file qgsfeature.h.

◆ operator!=()

bool QgsFeature::operator!= ( const QgsFeature & other ) const

Compares two features.

Definition at line 77 of file qgsfeature.cpp.

◆ operator=()

QgsFeature & QgsFeature::operator= ( const QgsFeature & rhs )

Assignment operator.

Definition at line 56 of file qgsfeature.cpp.

◆ operator==()

bool QgsFeature::operator== ( const QgsFeature & other ) const

Compares two features.

Definition at line 62 of file qgsfeature.cpp.

◆ padAttributes()

void QgsFeature::padAttributes ( int count )

Resizes the attributes attached to this feature by appending the specified count of NULL values to the end of the existing attributes.

See also: resizeAttributes()

Since: QGIS 3.18

Definition at line 227 of file qgsfeature.cpp.

◆ resizeAttributes()

void QgsFeature::resizeAttributes ( int fieldCount )

Resizes the attributes attached to this feature to the given number of fields.

If the new fieldCount is greater than the original number of fields then the additional attributes will be filled with NULL values. All existing attributes will remain unchanged.

If the new fieldCount is less than the original number of fields then the unwanted values will be discarded from the end of the existing attributes.

See also: initAttributes(); padAttributes()

Since: QGIS 3.18

Definition at line 218 of file qgsfeature.cpp.

◆ setAttribute() [1/2]

bool QgsFeature::setAttribute	(	const QString &	name,
		const QVariant &	value
	)

Insert a value into attribute.

Returns false if attribute name could not be converted to index. Field map must be associated using setFields() before this method can be used. The feature will be valid if it was successful

Parameters

name	The name of the field to set
value	The value to set

Returns: false if attribute name could not be converted to index (C++ only)

Note: For Python: raises a KeyError exception instead of returning false; Alternatively in Python:
feature[name] = attr

See also: setFields

Definition at line 256 of file qgsfeature.cpp.

◆ setAttribute() [2/2]

bool QgsFeature::setAttribute	(	int	field,
		const QVariant &	attr
	)

Set an attribute's value by field index.

The feature will be valid if it was successful.

Parameters

field	the index of the field to set
attr	the value of the attribute

Returns: false, if the field index does not exist

Note: For Python: raises a KeyError exception instead of returning false; Alternatively in Python:
feature[field] = attr

See also: setAttributes

Definition at line 236 of file qgsfeature.cpp.

◆ setAttributes()

void QgsFeature::setAttributes ( const QgsAttributes & attrs )

Sets the feature's attributes.

The feature will be valid after.

Parameters

attrs attribute list

See also: setAttribute; attributes

Definition at line 134 of file qgsfeature.cpp.

◆ setFields()

void QgsFeature::setFields	(	const QgsFields &	fields,
		bool	initAttributes = `false`
	)

Assign a field map with the feature to allow attribute access by attribute name.

Parameters

fields	The attribute fields which this feature holds
initAttributes	If `true`, attributes are initialized. Clears any data previously assigned. C++: Defaults to `false` Python: Defaults to `true`

See also: fields

Since: QGIS 2.9

Definition at line 169 of file qgsfeature.cpp.

◆ setGeometry() [1/2]

void QgsFeature::setGeometry ( const QgsGeometry & geometry )

Set the feature's geometry.

The feature will be valid after.

Parameters

geometry new feature geometry

See also: geometry(); clearGeometry()

Definition at line 144 of file qgsfeature.cpp.

◆ setGeometry() [2/2]

void QgsFeature::setGeometry ( std::unique_ptr< QgsAbstractGeometry > geometry )

Set the feature's geometry.

Ownership of the geometry is transferred to the feature. The feature will be made valid after calling this method.

This method is a shortcut for calling:

feature.setGeometry( QgsGeometry( geometry ) )

QgsGeometry

A geometry is the spatial representation of a feature.

Definition: qgsgeometry.h:124

Example

# Sets a feature's geometry to a point geometry
feature.setGeometry( QgsPoint( 210, 41 ) )
print(feature.geometry())
# output: <QgsGeometry: Point (210 41)>
 
# Sets a feature's geometry to a line string
feature.setGeometry( QgsLineString( [ QgsPoint( 210, 41 ), QgsPoint( 301, 55 ) ] ) )
print(feature.geometry())
# output: <QgsGeometry: LineString (210 41, 301 55)>

See also: geometry(); clearGeometry()

Since: QGIS 3.6

Definition at line 151 of file qgsfeature.cpp.

◆ setId()

void QgsFeature::setId ( QgsFeatureId id )

Sets the feature ID for this feature.

Parameters

id	feature id

See also: id

Definition at line 114 of file qgsfeature.cpp.

◆ setValid()

void QgsFeature::setValid ( bool validity )

Sets the validity of the feature.

Parameters

validity set to true if feature is valid

See also: isValid

Definition at line 195 of file qgsfeature.cpp.

Property Documentation

◆ attributes

QgsAttributes QgsFeature::attributes

readwrite

Definition at line 62 of file qgsfeature.h.

◆ fields

QgsFields QgsFeature::fields

readwrite

Definition at line 62 of file qgsfeature.h.

◆ geometry

QgsGeometry QgsFeature::geometry

readwrite

Definition at line 62 of file qgsfeature.h.

◆ id

Q_GADGET QgsFeatureId QgsFeature::id

readwrite

Definition at line 62 of file qgsfeature.h.

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

/build/qgis-3.18.1+99unstable/src/core/qgsfeature.h
/build/qgis-3.18.1+99unstable/src/core/qgsfeature.cpp

Public Member Functions

Properties

Detailed Description

Constructor & Destructor Documentation

◆ QgsFeature() [1/3]

◆ QgsFeature() [2/3]

◆ QgsFeature() [3/3]

◆ ~QgsFeature()

Member Function Documentation

◆ approximateMemoryUsage()

◆ attribute() [1/2]

◆ attribute() [2/2]

◆ attributeCount()

◆ attributes()

◆ clearGeometry()

◆ deleteAttribute() [1/2]

◆ deleteAttribute() [2/2]

◆ fieldNameIndex()

◆ fields()

◆ geometry()

◆ hasGeometry()

◆ id()

◆ initAttributes()

◆ isValid()

◆ operator QVariant()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ padAttributes()

◆ resizeAttributes()

◆ setAttribute() [1/2]

◆ setAttribute() [2/2]

◆ setAttributes()

◆ setFields()

◆ setGeometry() [1/2]

◆ setGeometry() [2/2]

Example

◆ setId()

◆ setValid()

Property Documentation

◆ attributes

◆ fields

◆ geometry

◆ id