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

#include <qgsfeature.h>

Collaboration diagram for QgsFeature:

List of all members.

Public Member Functions
	QgsFeature (QgsFeatureId id=QgsFeatureId())
	Constructor.
	QgsFeature (const QgsFields &fields, QgsFeatureId id=QgsFeatureId())
	QgsFeature (const QgsFeature &rhs)
	copy ctor needed due to internal pointer
	~QgsFeature ()
	Destructor.
QVariant	attribute (const QString &name) const
	Lookup attribute value from attribute name.
QVariant	attribute (int fieldIdx) const
	Lookup attribute value from its index.
const QgsAttributes &	attributes () const
QgsAttributes &	attributes ()
void	deleteAttribute (int field)
	Deletes an attribute and its value.
bool	deleteAttribute (const QString &name)
	Remove an attribute value.
int	fieldNameIndex (const QString &fieldName) const
	Utility method to get attribute index from name.
const QgsFields *	fields () const
	Get associated field map.
QgsGeometry *	geometry () const
	Get the geometry object associated with this feature.
QgsGeometry *	geometryAndOwnership ()
	Get the geometry object associated with this feature The caller assumes responsibility for the QgsGeometry*'s destruction.
QgsFeatureId	id () const
	Get the feature id for this feature.
void	initAttributes (int fieldCount)
bool	isValid () const
	Return the validity of this feature.
QgsFeature &	operator= (QgsFeature const &rhs)
	assignment operator needed due to internal pointer
bool	setAttribute (int field, const QVariant &attr)
bool	setAttribute (const QString &name, QVariant value)
	Insert a value into attribute.
void	setAttributes (const QgsAttributes &attrs)
void	setFeatureId (QgsFeatureId id)
	Set the feature id for this feature.
void	setFields (const QgsFields *fields)
	Assign a field map with the feature to allow attribute access by attribute name.
void	setGeometry (const QgsGeometry &geom)
	Set this feature's geometry from another QgsGeometry object (deep copy)
void	setGeometry (QgsGeometry *geom)
	Set this feature's geometry (takes geometry ownership)
void	setGeometryAndOwnership (unsigned char *geom, size_t length)
	Set this feature's geometry from WKB.
void	setValid (bool validity)
	Set the validity of the feature.
Private Attributes
QgsAttributes	mAttributes
	attributes accessed by field index
QgsFeatureId	mFid
	feature id
const QgsFields *	mFields
	Optional field map for name-based attribute lookups.
QgsGeometry *	mGeometry
	pointer to geometry in binary WKB format
bool	mOwnsGeometry
	Indicator if the mGeometry is owned by this QgsFeature.
bool	mValid
	Flag to indicate if this feature is valid.

Detailed Description

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

Encapsulates a spatial feature with attributes.

Author:: Gary E.Sherman

Definition at line 114 of file qgsfeature.h.

Constructor & Destructor Documentation

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

Constructor.

Definition at line 27 of file qgsfeature.cpp.

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

Definition at line 37 of file qgsfeature.cpp.

References QgsFields::count(), and initAttributes().

QgsFeature::QgsFeature ( const QgsFeature & rhs )

copy ctor needed due to internal pointer

Definition at line 47 of file qgsfeature.cpp.

References mGeometry, and setGeometry().

QgsFeature::~QgsFeature ( )

Destructor.

Definition at line 90 of file qgsfeature.cpp.

References mGeometry, and mOwnsGeometry.

Member Function Documentation

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

Lookup attribute value from attribute name.

Returns invalid variant if attribute name could not be converted to index. Field map must be associated to make this work.

Note:: added in 2.0

Definition at line 222 of file qgsfeature.cpp.

References fieldNameIndex(), and mAttributes.

Referenced by QgsGeometryAnalyzer::addEventLayerFeature(), QgsVectorLayerFeatureIterator::addJoinedAttributes(), QgsGeometryAnalyzer::bufferFeature(), QgsInterpolator::cacheBaseData(), QgsAttributeEditor::createAttributeEditor(), QgsVectorFileWriter::createFeature(), QgsGraduatedSymbolRendererV2::createRenderer(), QgsAttributeTableModel::data(), QgsPalLayerSettings::dataDefinedValue(), QgsAttributeAction::doAction(), QgsExpression::NodeColumnRef::eval(), QgsGeometryAnalyzer::eventLayer(), QgsMapTip::fetchFeature(), QgsLabel::fieldValue(), QgsSearchQueryBuilder::getFieldValues(), QgsTINInterpolator::insertData(), QgsAttributeTableModel::loadAttributes(), QgsLineVectorLayerDirector::makeGraph(), QgsVectorLayer::maximumValue(), QgsVectorLayer::minimumValue(), QgsAttributeTableModel::prefetchColumnData(), QgsVectorLayerUndoCommandDeleteAttribute::QgsVectorLayerUndoCommandDeleteAttribute(), QgsPalLabeling::registerDiagramFeature(), QgsPalLayerSettings::registerFeature(), QgsVectorFieldSymbolLayer::renderPoint(), QgsSingleSymbolRendererV2::symbolForFeature(), QgsVectorLayerUndoCommandChangeAttribute::undo(), QgsVectorDataProvider::uniqueValues(), and QgsVectorLayer::uniqueValues().

QVariant QgsFeature::attribute ( int fieldIdx ) const

Lookup attribute value from its index.

Returns invalid variant if the index does not exist.

Note:: added in 2.0

Definition at line 214 of file qgsfeature.cpp.

References mAttributes.

const QgsAttributes& QgsFeature::attributes ( ) const [inline]

Definition at line 143 of file qgsfeature.h.

Referenced by QgsVectorLayerEditBuffer::addFeature(), QgsVectorLayerImport::addFeature(), QgsVectorLayerFeatureIterator::addJoinedAttributes(), QgsVectorLayerFeatureIterator::FetchJoinInfo::addJoinedAttributesDirect(), QgsOfflineEditing::applyFeaturesAdded(), QgsAtlasComposition::beginRender(), QgsGeometryAnalyzer::bufferFeature(), QgsVectorLayerJoinBuffer::cacheJoinLayer(), QgsGeometryAnalyzer::centroidFeature(), QgsOfflineEditing::copyVectorLayer(), QgsFormAnnotationItem::createDesignerWidget(), QgsVectorDataProvider::fillMinMaxCache(), QgsComposerAttributeTable::getFeatureAttributes(), QgsPointDisplacementRenderer::getLabel(), QgsOverlayAnalyzer::intersectFeature(), QgsAttributeDialog::QgsAttributeDialog(), QgsPalLabeling::registerDiagramFeature(), QgsDualView::saveEditChanges(), QgsGeometryAnalyzer::simplifyFeature(), QgsGraduatedSymbolRendererV2::symbolForFeature(), QgsCategorizedSymbolRendererV2::symbolForFeature(), QgsVectorLayerEditBuffer::updateChangedAttributes(), QgsVectorLayer::updateFeature(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorLayerFeatureIterator::useChangedAttributeFeature().

QgsAttributes& QgsFeature::attributes ( ) [inline]

Definition at line 144 of file qgsfeature.h.

void QgsFeature::deleteAttribute ( int field )

Deletes an attribute and its value.

Definition at line 107 of file qgsfeature.cpp.

References mAttributes.

bool QgsFeature::deleteAttribute ( const QString & name )

Remove an attribute value.

Returns false if attribute name could not be converted to index. Field map must be associated to make this work.

Note:: added in 2.0

Definition at line 204 of file qgsfeature.cpp.

References fieldNameIndex(), and mAttributes.

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

Utility method to get attribute index from name.

Returns -1 if field does not exist or field map is not associated. Field map must be associated to make this work.

Note:: added in 2.0

Definition at line 231 of file qgsfeature.cpp.

References QgsFields::at(), QgsFields::count(), mFields, and QgsField::name().

Referenced by attribute(), deleteAttribute(), and setAttribute().

const QgsFields* QgsFeature::fields ( ) const [inline]

Get associated field map.

may be NULL

Note:: added in 2.0

Definition at line 199 of file qgsfeature.h.

QgsGeometry * QgsFeature::geometry ( ) const

Get the geometry object associated with this feature.

Definition at line 113 of file qgsfeature.cpp.

References mGeometry.

Referenced by QgsVectorLayerImport::addFeature(), QgsVectorLayerEditUtils::addPart(), QgsVectorLayerEditUtils::addRing(), QgsVectorLayer::boundingBoxOfSelected(), QgsGeometryAnalyzer::bufferFeature(), QgsInterpolator::cacheBaseData(), QgsGml::calculateExtentFromFeatures(), QgsZonalStatistics::calculateStatistics(), QgsGeometryAnalyzer::centroidFeature(), QgsGeometryAnalyzer::convexFeature(), QgsPointDisplacementRenderer::createDisplacementGroups(), QgsVectorFileWriter::createFeature(), QgsGeometryAnalyzer::dissolveFeature(), QgsVectorLayer::drawRendererV2(), QgsVectorLayer::drawRendererV2Levels(), QgsGeometryAnalyzer::eventLayer(), QgsVectorFileWriter::exportFeaturesSymbolLevels(), QgsVectorLayer::extent(), fcnGeomArea(), fcnGeometry(), fcnGeomLength(), fcnGeomPerimeter(), QgsMapToolIdentify::featureDerivedAttributes(), QgsSpatialIndex::featureInfo(), QgsVectorLayerImport::importLayer(), QgsTINInterpolator::insertData(), QgsOverlayAnalyzer::intersectFeature(), QgsLabel::labelPoint(), QgsLineVectorLayerDirector::makeGraph(), QgsAtlasComposition::prepareForFeature(), QgsAttributeDialog::QgsAttributeDialog(), QgsVectorLayerUndoCommandAddFeature::redo(), QgsPalLabeling::registerDiagramFeature(), QgsPalLayerSettings::registerFeature(), QgsVectorLayer::removePolygonIntersections(), QgsPointDisplacementRenderer::renderFeature(), QgsFeatureRendererV2::renderFeatureWithSymbol(), QgsGeometryAnalyzer::simplifyFeature(), QgsVectorLayer::snapWithContext(), QgsVectorLayerEditUtils::translateFeature(), QgsVectorLayerUndoCommandAddFeature::undo(), QgsVectorLayerUndoCommandChangeGeometry::undo(), QgsVectorLayer::updateFeature(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorFileWriter::writeAsVectorFormat().

QgsGeometry * QgsFeature::geometryAndOwnership ( )

Get the geometry object associated with this feature The caller assumes responsibility for the QgsGeometry*'s destruction.

Definition at line 118 of file qgsfeature.cpp.

References mGeometry, and mOwnsGeometry.

QgsFeatureId QgsFeature::id ( ) const

Get the feature id for this feature.

Returns:: Feature id

Definition at line 101 of file qgsfeature.cpp.

References mFid.

Referenced by QgsVectorLayerEditUtils::addRing(), QgsAttributeTableModel::attributeValueChanged(), QgsAtlasComposition::beginRender(), QgsVectorLayer::boundingBoxOfSelected(), QgsVectorLayerCache::cacheFeature(), QgsZonalStatistics::calculateStatistics(), QgsOfflineEditing::copyVectorLayer(), QgsPointDisplacementRenderer::createDisplacementGroups(), QgsVectorFileWriter::createFeature(), QgsFeatureListModel::data(), QgsAttributeTableModel::data(), QgsVectorLayer::drawRendererV2(), QgsVectorLayer::drawRendererV2Levels(), QgsGml::endElement(), QgsGeometryAnalyzer::eventLayer(), fcnFeatureId(), QgsSpatialIndex::featureInfo(), QgsAttributeTableFilterModel::generateListOfVisibleFeatures(), QgsVectorLayerImport::importLayer(), QgsVectorLayer::invertSelection(), QgsVectorLayer::invertSelectionInRectangle(), QgsAttributeTableModel::loadLayer(), QgsVectorLayerFeatureIterator::nextFeature(), QgsCachedFeatureWriterIterator::nextFeature(), QgsExpressionSelectionDialog::on_mActionAddToSelection_triggered(), QgsExpressionSelectionDialog::on_mActionRemoveFromSelection_triggered(), QgsExpressionSelectionDialog::on_mActionSelect_triggered(), QgsExpressionSelectionDialog::on_mActionSelectInstersect_triggered(), QgsAttributeTableModel::prefetchColumnData(), QgsAttributeDialog::QgsAttributeDialog(), QgsVectorLayerUndoCommandDeleteAttribute::QgsVectorLayerUndoCommandDeleteAttribute(), QgsVectorLayerUndoCommandAddFeature::redo(), QgsPalLabeling::registerDiagramFeature(), QgsPalLayerSettings::registerFeature(), QgsVectorLayer::removePolygonIntersections(), QgsPointDisplacementRenderer::renderFeature(), QgsFeatureRendererV2::renderFeatureWithSymbol(), QgsDualView::saveEditChanges(), QgsVectorLayer::select(), QgsVectorLayer::selectAll(), QgsFormAnnotationItem::setFeatureForMapPosition(), QgsHtmlAnnotationItem::setFeatureForMapPosition(), setFeatureId(), QgsVectorLayer::snapWithContext(), QgsVectorLayerUndoCommandAddFeature::undo(), QgsVectorLayerUndoCommandDeleteFeature::undo(), QgsVectorLayerUndoCommandDeleteAttribute::undo(), QgsVectorLayerEditBuffer::updateChangedAttributes(), QgsVectorLayer::updateFeature(), QgsVectorLayerEditBuffer::updateFeatureGeometry(), QgsOfflineEditing::updateFidLookup(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorFileWriter::writeAsVectorFormat().

void QgsFeature::initAttributes ( int fieldCount )

Definition at line 173 of file qgsfeature.cpp.

References mAttributes.

Referenced by QgsVectorLayerImport::addFeature(), QgsAttributeTableModel::feature(), QgsVectorLayerImport::importLayer(), QgsFeature(), and QgsVectorFileWriter::writeAsVectorFormat().

bool QgsFeature::isValid ( ) const

Return 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.

Definition at line 163 of file qgsfeature.cpp.

References mValid.

Referenced by QgsAttributeTableModel::data(), QgsDualView::on_mFeatureList_currentEditSelectionChanged(), and QgsExpressionBuilderWidget::on_txtExpressionString_textChanged().

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

assignment operator needed due to internal pointer

Definition at line 64 of file qgsfeature.cpp.

References mAttributes, mFid, mFields, mGeometry, mOwnsGeometry, mValid, and setGeometry().

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

Definition at line 182 of file qgsfeature.cpp.

References QgsMessageLog::logMessage(), mAttributes, tr, and QgsMessageLog::WARNING.

Referenced by QgsAttributeDialog::accept(), QgsVectorLayerImport::addFeature(), QgsVectorLayerFeatureIterator::FetchJoinInfo::addJoinedAttributesCached(), QgsVectorLayerFeatureIterator::FetchJoinInfo::addJoinedAttributesDirect(), QgsVectorLayerCache::attributeValueChanged(), QgsGml::endElement(), QgsAttributeTableModel::feature(), and QgsVectorLayerUndoCommandDeleteAttribute::undo().

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

Insert a value into attribute.

Returns false if attribute name could not be converted to index. Field map must be associated to make this work.

Note:: added in 2.0

Definition at line 194 of file qgsfeature.cpp.

References fieldNameIndex(), and mAttributes.

void QgsFeature::setAttributes ( const QgsAttributes & attrs ) [inline]

Definition at line 145 of file qgsfeature.h.

Referenced by QgsOfflineEditing::applyFeaturesAdded(), QgsGeometryAnalyzer::bufferFeature(), QgsGeometryAnalyzer::centroidFeature(), QgsGeometryAnalyzer::convexHull(), QgsOfflineEditing::copyVectorLayer(), QgsGeometryAnalyzer::dissolve(), QgsGeometryAnalyzer::extent(), QgsOverlayAnalyzer::intersectFeature(), QgsGeometryAnalyzer::simplifyFeature(), QgsVectorLayerEditUtils::splitFeatures(), QgsGml::startElement(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorLayerFeatureIterator::useChangedAttributeFeature().

void QgsFeature::setFeatureId ( QgsFeatureId id )

Set the feature id for this feature.

Set the feature id.

Parameters:

id	Feature id

Definition at line 129 of file qgsfeature.cpp.

References id(), and mFid.

Referenced by QgsAttributeTableModel::feature(), QgsAttributeTableModel::QgsAttributeTableModel(), QgsVectorLayerUndoCommandAddFeature::QgsVectorLayerUndoCommandAddFeature(), QgsAttributeTableModel::reload(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorLayerFeatureIterator::useChangedAttributeFeature().

void QgsFeature::setFields ( const QgsFields * fields ) [inline]

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

Note:: added in 2.0

Definition at line 194 of file qgsfeature.h.

Referenced by QgsVectorLayerFeatureIterator::nextFeature(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorLayerFeatureIterator::useChangedAttributeFeature().

void QgsFeature::setGeometry ( const QgsGeometry & geom )

Set this feature's geometry from another QgsGeometry object (deep copy)

Definition at line 135 of file qgsfeature.cpp.

void QgsFeature::setGeometry ( QgsGeometry * geom )

Set this feature's geometry (takes geometry ownership)

Note:: not available in python bindings

Definition at line 140 of file qgsfeature.cpp.

References mGeometry, and mOwnsGeometry.

void QgsFeature::setGeometryAndOwnership	(	unsigned char *	geom,
		size_t	length
	)

Set this feature's geometry from WKB.

Set the pointer to the feature geometry.

This feature assumes responsibility for destroying geom.

Definition at line 155 of file qgsfeature.cpp.

References QgsGeometry::fromWkb(), and setGeometry().

Referenced by QgsGml::endElement().

void QgsFeature::setValid ( bool validity )

Set the validity of the feature.

Definition at line 168 of file qgsfeature.cpp.

References mValid.

Referenced by QgsAttributeTableModel::attributeValueChanged(), QgsGml::endElement(), QgsVectorLayerFeatureIterator::nextFeature(), QgsVectorLayerFeatureIterator::useAddedFeature(), and QgsVectorLayerFeatureIterator::useChangedAttributeFeature().

Member Data Documentation

QgsAttributes QgsFeature::mAttributes [private]

attributes accessed by field index

Definition at line 236 of file qgsfeature.h.

Referenced by attribute(), deleteAttribute(), initAttributes(), operator=(), and setAttribute().

QgsFeatureId QgsFeature::mFid [private]

feature id

Definition at line 233 of file qgsfeature.h.

Referenced by id(), operator=(), and setFeatureId().

const QgsFields* QgsFeature::mFields [private]

Optional field map for name-based attribute lookups.

Definition at line 253 of file qgsfeature.h.

Referenced by fieldNameIndex(), and operator=().

QgsGeometry* QgsFeature::mGeometry [private]

pointer to geometry in binary WKB format

This is usually set by a call to OGRGeometry::exportToWkb()

Definition at line 242 of file qgsfeature.h.

Referenced by geometry(), geometryAndOwnership(), operator=(), QgsFeature(), setGeometry(), and ~QgsFeature().

bool QgsFeature::mOwnsGeometry [private]

Indicator if the mGeometry is owned by this QgsFeature.

If so, this QgsFeature takes responsibility for the mGeometry's destruction.

Definition at line 247 of file qgsfeature.h.

Referenced by geometryAndOwnership(), operator=(), setGeometry(), and ~QgsFeature().

bool QgsFeature::mValid [private]

Flag to indicate if this feature is valid.

Definition at line 250 of file qgsfeature.h.

Referenced by isValid(), operator=(), and setValid().

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

src/core/qgsfeature.h
src/core/qgsfeature.cpp

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation