QGIS API Documentation  2.99.0-Master (c42dad3)
Public Member Functions | Properties | List of all members
QgsFeature Class Reference

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 (QgsFeatureId id=QgsFeatureId())
 Constructor for QgsFeature. More...
 
 QgsFeature (const QgsFields &fields, QgsFeatureId id=QgsFeatureId())
 Constructor for QgsFeature. More...
 
 QgsFeature (const QgsFeature &rhs)
 Copy constructor. More...
 
virtual ~QgsFeature ()
 Destructor. 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...
 
QgsAttributes attributes () const
 Returns the feature's attributes. More...
 
void clearGeometry ()
 Removes any geometry associated with the feature. More...
 
void deleteAttribute (int field)
 Deletes an attribute and its value. More...
 
bool deleteAttribute (const QString &name)
 Removes an attribute value by field name. 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
 Get 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...
 
QgsFeatureoperator= (const QgsFeature &rhs)
 Assignment operator. More...
 
bool operator== (const QgsFeature &other) const
 Compares two features. More...
 
bool setAttribute (int field, const QVariant &attr)
 Set an attribute's value by field index. More...
 
bool setAttribute (const QString &name, const QVariant &value)
 Insert a value into attribute. More...
 
void setAttributes (const QgsAttributes &attrs)
 Sets the feature's attributes. More...
 
void setFeatureId (QgsFeatureId id)
 Sets the feature ID for this feature. 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 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
 
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.
Author
Gary E.Sherman

Definition at line 135 of file qgsfeature.h.

Constructor & Destructor Documentation

§ QgsFeature() [1/3]

QgsFeature::QgsFeature ( QgsFeatureId  id = QgsFeatureId())

Constructor for QgsFeature.

Parameters
idfeature id

Definition at line 49 of file qgsfeature.cpp.

§ QgsFeature() [2/3]

QgsFeature::QgsFeature ( const QgsFields fields,
QgsFeatureId  id = QgsFeatureId() 
)

Constructor for QgsFeature.

Parameters
fieldsfeature's fields
idfeature id

Definition at line 54 of file qgsfeature.cpp.

§ QgsFeature() [3/3]

QgsFeature::QgsFeature ( const QgsFeature rhs)

Copy constructor.

Definition at line 61 of file qgsfeature.cpp.

§ ~QgsFeature()

QgsFeature::~QgsFeature ( )
virtual

Destructor.

Definition at line 92 of file qgsfeature.cpp.

Member Function Documentation

§ 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
nameThe 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 field is not found
See also
setFields

Definition at line 277 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
fieldIdxThe 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 field is not found
See also
setFields

Definition at line 269 of file qgsfeature.cpp.

§ attributes()

QgsAttributes QgsFeature::attributes ( ) const

Returns the feature's attributes.

attributes method.

Returns
list of feature's attributes
See also
setAttributes
Note
added in QGIS 2.9

§ clearGeometry()

void QgsFeature::clearGeometry ( )

Removes any geometry associated with the feature.

See also
setGeometry()
hasGeometry()
Note
added in QGIS 3.0

Definition at line 168 of file qgsfeature.cpp.

§ deleteAttribute() [1/2]

void QgsFeature::deleteAttribute ( int  field)

Deletes an attribute and its value.

Parameters
fieldthe index of the field
See also
setAttribute
Note
For Python: raises a KeyError exception if the field is not found

Definition at line 107 of file qgsfeature.cpp.

§ deleteAttribute() [2/2]

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
nameThe 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
See also
setFields

Definition at line 258 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
fieldNamename 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 292 of file qgsfeature.cpp.

§ fields()

QgsFields QgsFeature::fields ( ) const

Returns the field map associated with the feature.

See also
setFields

§ 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 113 of file qgsfeature.cpp.

§ hasGeometry()

bool QgsFeature::hasGeometry ( ) const

Returns true if the feature has an associated geometry.

See also
geometry()
Note
added in QGIS 3.0.

Definition at line 214 of file qgsfeature.cpp.

§ id()

QgsFeatureId QgsFeature::id ( ) const

Get the feature ID for this feature.

Returns
feature ID
See also
setFeatureId

§ initAttributes()

void QgsFeature::initAttributes ( int  fieldCount)

Initialize this feature with the given number of fields.

Discard any previously set attribute data.

Parameters
fieldCountNumber of fields to initialize

Definition at line 219 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 200 of file qgsfeature.cpp.

§ operator QVariant()

QgsFeature::operator QVariant ( ) const
inline

Allows direct construction of QVariants from features.

Definition at line 333 of file qgsfeature.h.

§ operator!=()

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

Compares two features.

Definition at line 87 of file qgsfeature.cpp.

§ operator=()

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

Assignment operator.

Definition at line 66 of file qgsfeature.cpp.

§ operator==()

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

Compares two features.

Definition at line 72 of file qgsfeature.cpp.

§ setAttribute() [1/2]

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

Set an attribute's value by field index.

Parameters
fieldthe index of the field to set
attrthe value of the attribute
Returns
false, if the field index does not exist
Note
For Python: raises a KeyError exception instead of returning false
See also
setAttributes

Definition at line 228 of file qgsfeature.cpp.

§ setAttribute() [2/2]

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.

Parameters
nameThe name of the field to set
valueThe 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
See also
setFields

Definition at line 247 of file qgsfeature.cpp.

§ setAttributes()

void QgsFeature::setAttributes ( const QgsAttributes attrs)

Sets the feature's attributes.

Parameters
attrsattribute list
See also
setAttribute
attributes

Definition at line 153 of file qgsfeature.cpp.

§ setFeatureId()

void QgsFeature::setFeatureId ( QgsFeatureId  id)

Sets the feature ID for this feature.

Parameters
idfeature id
See also
id

Definition at line 124 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
fieldsThe attribute fields which this feature holds
initAttributesIf true, attributes are initialized. Clears any data previously assigned. C++: Defaults to false Python: Defaults to true
Note
added in QGIS 2.9
See also
fields

Definition at line 179 of file qgsfeature.cpp.

§ setGeometry()

void QgsFeature::setGeometry ( const QgsGeometry geometry)

Set the feature's geometry.

Parameters
geometrynew feature geometry
See also
geometry()
clearGeometry()

Definition at line 162 of file qgsfeature.cpp.

§ setId()

void QgsFeature::setId ( QgsFeatureId  id)

Sets the feature ID for this feature.

Parameters
idfeature id
See also
id

Definition at line 139 of file qgsfeature.cpp.

§ setValid()

void QgsFeature::setValid ( bool  validity)

Sets the validity of the feature.

Parameters
validityset to true if feature is valid
See also
isValid

Definition at line 205 of file qgsfeature.cpp.

Property Documentation

§ attributes

QgsAttributes QgsFeature::attributes
readwrite

Definition at line 140 of file qgsfeature.h.

§ fields

QgsFields QgsFeature::fields
readwrite

Definition at line 141 of file qgsfeature.h.

§ id

QgsFeatureId QgsFeature::id
readwrite

Definition at line 139 of file qgsfeature.h.


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