QgsFields Class Reference

Container of fields for a vector layer. More...

#include <qgsfield.h>

Classes
struct	Field

Public Types
enum	FieldOrigin { OriginUnknown, OriginProvider, OriginJoin, OriginEdit }
typedef struct QgsFields::Field	Field

Public Member Functions
void	clear ()
	Remove all fields. More...
bool	append (const QgsField &field, FieldOrigin origin=OriginProvider, int originIndex=-1)
	Append a field. The field must have unique name, otherwise it is rejected (returns false) More...
void	remove (int fieldIdx)
	Remove a field with the given index. More...
void	extend (const QgsFields &other)
	Extend with fields from another QgsFields container. More...
bool	isEmpty () const
	Check whether the container is empty. More...
int	count () const
	Return number of items. More...
int	size () const
	Return number of items. More...
bool	exists (int i) const
	Return if a field index is valid. More...
const QgsField &	operator[] (int i) const
	Get field at particular index (must be in range 0..N-1) More...
QgsField &	operator[] (int i)
	Get field at particular index (must be in range 0..N-1) More...
const QgsField &	at (int i) const
	Get field at particular index (must be in range 0..N-1) More...
const QgsField &	field (int fieldIdx) const
	Get field at particular index (must be in range 0..N-1) More...
const QgsField &	field (const QString &name) const
	Get field at particular index (must be in range 0..N-1) More...
FieldOrigin	fieldOrigin (int fieldIdx) const
	Get field's origin (value from an enumeration) More...
int	fieldOriginIndex (int fieldIdx) const
	Get field's origin index (its meaning is specific to each type of origin) More...
int	indexFromName (const QString &name) const
	Look up field's index from name. Returns -1 on error. More...
int	fieldNameIndex (const QString &fieldName) const
	Look up field's index from name - case insensitive TODO: sort out case sensitive (indexFromName()) vs insensitive (fieldNameIndex()) calls. More...
QgsAttributeList	allAttributesList () const
	Utility function to get list of attribute indexes. More...
QList< QgsField >	toList () const
	Utility function to return a list of QgsField instances. More...

Protected Attributes
QVector< Field >	mFields
	internal storage of the container More...
QHash< QString, int >	mNameToIndex
	map for quick resolution of name to index More...

Detailed Description

Container of fields for a vector layer.

In addition to storing a list of QgsField instances, it also:

• allows quick lookups of field names to index in the list
• keeps track of where the field definition comes from (vector data provider, joined layer or newly added from an editing operation)

Definition at line 161 of file qgsfield.h.

Member Typedef Documentation

typedef struct QgsFields::Field QgsFields::Field

Member Enumeration Documentation

enum QgsFields::FieldOrigin

Enumerator
OriginUnknown	it has not been specified where the field comes from
OriginProvider	field comes from the underlying data provider of the vector layer (originIndex = index in provider's fields)
OriginJoin	field comes from a joined layer (originIndex / 1000 = index of the join, originIndex % 1000 = index within the join)
OriginEdit	field has been temporarily added in editing mode (originIndex = index in the list of added attributes)

Definition at line 165 of file qgsfield.h.

Member Function Documentation

QgsAttributeList QgsFields::allAttributesList

(

)

const

Utility function to get list of attribute indexes.

Note

added in 2.4

Definition at line 187 of file qgsfield.cpp.

References mFields.

Referenced by QgsVectorDataProvider::attributeIndexes(), QgsVectorLayer::pendingAllAttributesList(), and QgsVectorLayerFeatureIterator::prepareJoins().

bool QgsFields::append	(	const QgsField &	field,
		FieldOrigin	origin = OriginProvider,
		int	originIndex = -1
	)

Append a field. The field must have unique name, otherwise it is rejected (returns false)

Definition at line 140 of file qgsfield.cpp.

References mFields, mNameToIndex, QgsField::name(), and OriginProvider.

Referenced by QgsOverlayAnalyzer::combineFieldLists(), QgsGeometryAnalyzer::convexHull(), QgsPointSample::createRandomPoints(), QgsTransectSample::createSample(), extend(), QgsGeometryAnalyzer::extent(), QgsVectorLayerJoinBuffer::updateFields(), and QgsVectorLayerEditBuffer::updateFields().

const QgsField& QgsFields::at ( int  i ) const

inline

Get field at particular index (must be in range 0..N-1)

Definition at line 208 of file qgsfield.h.

Referenced by extend(), QgsFeature::fieldNameIndex(), QgsRelation::getRelatedFeaturesRequest(), QgsDataDefinedButton::init(), QgsRelationEditorWidget::on_mUnlinkFeatureButton_clicked(), QgsVectorLayerRenderer::prepareDiagrams(), QgsPalLayerSettings::readDataDefinedProperty(), QgsComposerAttributeTable::readXML(), QgsProjectFileTransform::transform0110to1000(), and QgsFieldModel::updateModel().

void QgsFields::clear

(

)

Remove all fields.

Definition at line 134 of file qgsfield.cpp.

References mFields, and mNameToIndex.

int QgsFields::count ( ) const

inline

Return number of items.

Definition at line 195 of file qgsfield.h.

Referenced by QgsVectorLayerEditBuffer::addAttribute(), QgsVectorLayerEditBuffer::addFeature(), QgsVectorLayerFeatureIterator::addJoinedAttributes(), QgsOfflineEditing::applyFeaturesAdded(), QgsVectorLayer::attributeDisplayName(), QgsVectorLayerJoinBuffer::cacheJoinLayer(), QgsVectorLayerEditBuffer::changeAttributeValue(), QgsOverlayAnalyzer::combineFieldLists(), QgsVectorLayerEditBuffer::commitChanges(), QgsOfflineEditing::copyVectorLayer(), QgsFormAnnotationItem::createDesignerWidget(), QgsVectorFileWriter::createFeature(), QgsFieldModel::data(), QgsVectorLayerEditBuffer::deleteAttribute(), QgsAttributeAction::expandAction(), extend(), QgsVectorLayer::fieldEditable(), fieldNameIndex(), QgsVectorDataProvider::fieldNameIndex(), QgsFeature::fieldNameIndex(), QgsVectorDataProvider::fieldNameMap(), QgsVectorDataProvider::fillMinMaxCache(), QgsZonalStatistics::getUniqueFieldName(), QgsVectorLayerImport::importLayer(), QgsFieldModel::indexFromName(), QgsDataDefinedButton::init(), QgsLabel::labelField(), QgsVectorLayer::labelOnTop(), QgsAttributeTableModel::loadAttributes(), QgsExpressionBuilderWidget::loadFieldNames(), QgsVectorLayer::pendingPkAttributesList(), QgsSearchQueryBuilder::populateFields(), QgsQueryBuilder::populateFields(), QgsExpression::NodeColumnRef::prepare(), QgsFeature::QgsFeature(), QgsVectorFileWriter::QgsVectorFileWriter(), QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator(), QgsVectorLayerUndoCommandAddAttribute::QgsVectorLayerUndoCommandAddAttribute(), QgsLabel::readLabelField(), QgsAtlasComposition::readXML(), QgsComposerAttributeTable::resetColumns(), QgsFieldModel::rowCount(), QgsFieldModel::setAllowExpression(), QgsComposerAttributeTable::setDisplayAttributes(), QgsVectorLayer::setDisplayField(), QgsVectorLayer::setFieldEditable(), QgsFeature::setFields(), QgsVectorLayer::setLabelOnTop(), QgsAtlasComposition::setSortKeyAttributeIndex(), QgsProjectFileTransform::transform0110to1000(), QgsVectorLayerJoinBuffer::updateFields(), and QgsFieldModel::updateModel().

bool QgsFields::exists ( int  i ) const

inline

Return if a field index is valid.

Parameters

i	Index of the field which needs to be checked

Returns

True if the field exists

Definition at line 201 of file qgsfield.h.

Referenced by QgsVectorLayerFeatureIterator::prepareJoins(), and QgsComposerAttributeTable::setDisplayAttributes().

void QgsFields::extend

(

const QgsFields &

other

)

Extend with fields from another QgsFields container.

Definition at line 159 of file qgsfield.cpp.

References append(), at(), count(), fieldOrigin(), and fieldOriginIndex().

const QgsField& QgsFields::field ( int  fieldIdx ) const

inline

Get field at particular index (must be in range 0..N-1)

Definition at line 210 of file qgsfield.h.

Referenced by QgsTransectSample::createSample(), fieldNameIndex(), remove(), and QgsVectorLayerJoinBuffer::updateFields().

const QgsField& QgsFields::field ( const QString &  name ) const

inline

Get field at particular index (must be in range 0..N-1)

Definition at line 212 of file qgsfield.h.

int QgsFields::fieldNameIndex

(

const QString &

fieldName

)

const

Look up field's index from name - case insensitive TODO: sort out case sensitive (indexFromName()) vs insensitive (fieldNameIndex()) calls.

Note

added in 2.4

Definition at line 175 of file qgsfield.cpp.

References count(), field(), mFields, and QgsField::name().

Referenced by QgsLegacyHelpers::convertEditType(), QgsVectorLayer::fieldNameIndex(), QgsFeatureRequest::setSubsetOfAttributes(), QgsPointDisplacementRenderer::startRender(), QgsVectorFieldSymbolLayer::startRender(), QgsGraduatedSymbolRendererV2::startRender(), and QgsCategorizedSymbolRendererV2::startRender().

FieldOrigin QgsFields::fieldOrigin ( int  fieldIdx ) const

inline

Get field's origin (value from an enumeration)

Definition at line 215 of file qgsfield.h.

Referenced by QgsOfflineEditing::applyFeaturesAdded(), QgsVectorLayerEditBuffer::changeAttributeValue(), QgsVectorLayerEditBuffer::deleteAttribute(), extend(), QgsVectorLayer::fieldEditable(), QgsVectorLayerJoinBuffer::joinForFieldIndex(), QgsVectorLayer::maximumValue(), QgsVectorLayer::minimumValue(), QgsVectorLayer::pendingPkAttributesList(), QgsVectorLayerFeatureIterator::prepareJoins(), QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator(), QgsVectorLayerUndoCommandAddAttribute::QgsVectorLayerUndoCommandAddAttribute(), QgsVectorLayerUndoCommandDeleteAttribute::QgsVectorLayerUndoCommandDeleteAttribute(), and QgsVectorLayer::uniqueValues().

int QgsFields::fieldOriginIndex ( int  fieldIdx ) const

inline

Get field's origin index (its meaning is specific to each type of origin)

Definition at line 217 of file qgsfield.h.

Referenced by QgsOfflineEditing::applyFeaturesAdded(), QgsVectorLayerEditBuffer::deleteAttribute(), extend(), QgsVectorLayerJoinBuffer::joinForFieldIndex(), QgsVectorLayer::pendingPkAttributesList(), QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator(), QgsVectorLayerUndoCommandDeleteAttribute::QgsVectorLayerUndoCommandDeleteAttribute(), and QgsVectorLayerUndoCommandAddAttribute::undo().

int QgsFields::indexFromName ( const QString &  name ) const

inline

Look up field's index from name. Returns -1 on error.

Definition at line 220 of file qgsfield.h.

Referenced by QgsVectorLayerJoinBuffer::cacheJoinLayer(), QgsPalLayerSettings::dataDefinedValue(), QgsRelation::getRelatedFeaturesRequest(), QgsFieldModel::indexFromName(), QgsFieldModel::isField(), QgsRelationEditorWidget::on_mAddFeatureButton_clicked(), and QgsVectorLayerFeatureIterator::prepareJoins().

bool QgsFields::isEmpty ( ) const

inline

Check whether the container is empty.

Definition at line 193 of file qgsfield.h.

Referenced by QgsExpressionBuilderWidget::loadFieldNames().

const QgsField& QgsFields::operator[] ( int  i ) const

inline

Get field at particular index (must be in range 0..N-1)

Definition at line 204 of file qgsfield.h.

QgsField& QgsFields::operator[] ( int  i )

inline

Get field at particular index (must be in range 0..N-1)

Definition at line 206 of file qgsfield.h.

void QgsFields::remove

(

int

fieldIdx

)

Remove a field with the given index.

Definition at line 153 of file qgsfield.cpp.

References field(), mFields, mNameToIndex, and QgsField::name().

Referenced by QgsVectorLayerEditBuffer::updateFields(), and QgsFieldModel::updateModel().

int QgsFields::size ( ) const

inline

Return number of items.

Definition at line 197 of file qgsfield.h.

Referenced by QgsVectorLayerEditBuffer::commitChanges(), QgsVectorLayer::metadata(), QgsGml::QgsGml(), QgsVectorFileWriter::QgsVectorFileWriter(), QgsPalLayerSettings::readDataDefinedProperty(), and QgsVectorLayer::setDisplayField().

QList< QgsField > QgsFields::toList

(

)

const

Utility function to return a list of QgsField instances.

Definition at line 167 of file qgsfield.cpp.

References mFields.

Referenced by QgsDualView::columnBoxInit(), QgsAttributeForm::createWrappers(), QgsGeometryAnalyzer::eventLayer(), QgsAttributeForm::init(), QgsRelationAddDlg::loadLayerAttributes(), and QgsFieldModel::updateModel().

Member Data Documentation

QVector<Field> QgsFields::mFields

protected

internal storage of the container

Definition at line 236 of file qgsfield.h.

Referenced by allAttributesList(), append(), clear(), fieldNameIndex(), remove(), and toList().

QHash<QString, int> QgsFields::mNameToIndex

protected

map for quick resolution of name to index

Definition at line 239 of file qgsfield.h.

Referenced by append(), clear(), and remove().

---

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

• /tmp/buildd/qgis-2.4.0+unstable1/src/core/qgsfield.h
• /tmp/buildd/qgis-2.4.0+unstable1/src/core/qgsfield.cpp