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

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

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)

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)
OriginExpression	field is calculated from an expression

Member Function Documentation

QgsAttributeList QgsFields::allAttributesList

(

)

const

Utility function to get list of attribute indexes.

Note

added in 2.4

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)

bool QgsFields::appendExpressionField	(	const QgsField &	field,
		int	originIndex
	)

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

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

inline

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

void QgsFields::clear

(

)

Remove all fields.

int QgsFields::count ( ) const

inline

Return number of items.

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

void QgsFields::extend

(

const QgsFields &

other

)

Extend with fields from another QgsFields container.

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

inline

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

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

inline

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

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

FieldOrigin QgsFields::fieldOrigin ( int  fieldIdx ) const

inline

Get field's origin (value from an enumeration)

int QgsFields::fieldOriginIndex ( int  fieldIdx ) const

inline

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

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

inline

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

bool QgsFields::isEmpty ( ) const

inline

Check whether the container is empty.

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

inline

Note

added in 2.6

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

inline

Note

added in 2.6

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

inline

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

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

inline

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

void QgsFields::remove

(

int

fieldIdx

)

Remove a field with the given index.

int QgsFields::size ( ) const

inline

Return number of items.

QList< QgsField > QgsFields::toList

(

)

const

Utility function to return a list of QgsField instances.

Member Data Documentation

QVector<Field> QgsFields::mFields

protected

internal storage of the container

QHash<QString, int> QgsFields::mNameToIndex

protected

map for quick resolution of name to index

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

• /tmp/buildd/qgis-2.6.0+wheezy1/src/core/qgsfield.h
• /tmp/buildd/qgis-2.6.0+wheezy1/src/core/qgsfield.cpp