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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,
  OriginExpression
}
 
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...
 
bool appendExpressionField (const QgsField &field, int originIndex)
 Append an expression 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 QgsFieldoperator[] (int i) const
 Get field at particular index (must be in range 0..N-1) More...
 
QgsFieldoperator[] (int i)
 Get field at particular index (must be in range 0..N-1) More...
 
const QgsFieldat (int i) const
 Get field at particular index (must be in range 0..N-1) More...
 
const QgsFieldfield (int fieldIdx) const
 Get field at particular index (must be in range 0..N-1) More...
 
const QgsFieldfield (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< QgsFieldtoList () const
 Utility function to return a list of QgsField instances. More...
 

Protected Attributes

QVector< FieldmFields
 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:

Definition at line 163 of file qgsfield.h.

Member Typedef Documentation

Member Enumeration Documentation

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)

OriginExpression 

field is calculated from an expression

Definition at line 167 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 198 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 
)
bool QgsFields::appendExpressionField ( const QgsField field,
int  originIndex 
)

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

Definition at line 153 of file qgsfield.cpp.

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

Referenced by QgsExpressionFieldBuffer::updateFields().

const QgsField& QgsFields::at ( int  i) const
inline
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 200 of file qgsfield.h.

Referenced by QgsVectorLayerEditBuffer::addAttribute(), QgsVectorLayerEditBuffer::addFeature(), QgsVectorLayerFeatureIterator::addVirtualAttributes(), 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(), QgsRendererV2DataDefinedMenus::populateMenu(), QgsExpression::NodeColumnRef::prepare(), QgsVectorLayerFeatureIterator::prepareExpressions(), QgsFeature::QgsFeature(), QgsPointDisplacementRendererWidget::QgsPointDisplacementRendererWidget(), QgsVectorFieldSymbolLayerWidget::QgsVectorFieldSymbolLayerWidget(), 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(), QgsFieldModel::updateModel(), and QgsEditorWidgetRegistry::writeMapLayer().

bool QgsFields::exists ( int  i) const
inline

Return if a field index is valid.

Parameters
iIndex of the field which needs to be checked
Returns
True if the field exists

Definition at line 206 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 170 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 215 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 217 of file qgsfield.h.

int QgsFields::fieldNameIndex ( const QString &  fieldName) const
FieldOrigin QgsFields::fieldOrigin ( int  fieldIdx) const
inline
int QgsFields::fieldOriginIndex ( int  fieldIdx) const
inline
int QgsFields::indexFromName ( const QString &  name) const
inline
bool QgsFields::isEmpty ( ) const
inline

Check whether the container is empty.

Definition at line 198 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 209 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 211 of file qgsfield.h.

void QgsFields::remove ( int  fieldIdx)

Remove a field with the given index.

Definition at line 164 of file qgsfield.cpp.

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

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

int QgsFields::size ( ) const
inline
QList< QgsField > QgsFields::toList ( ) const

Member Data Documentation

QVector<Field> QgsFields::mFields
protected

internal storage of the container

Definition at line 243 of file qgsfield.h.

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

QHash<QString, int> QgsFields::mNameToIndex
protected

map for quick resolution of name to index

Definition at line 246 of file qgsfield.h.

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


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