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

#include <qgsfields.h>

Classes
struct	Field

Public Types
typedef struct QgsFields::Field	Field

enum	FieldOrigin { OriginUnknown, OriginProvider, OriginJoin, OriginEdit, OriginExpression }

Public Member Functions
	QgsFields ()
	Constructor for an empty field container. More...

	QgsFields (const QgsFields &other)
	Copy constructor. More...

virtual	~QgsFields ()

QgsAttributeList	allAttributesList () const
	Utility function to get list of attribute indexes. 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...

QgsField	at (int i) const
	Get field at particular index (must be in range 0..N-1) More...

const_iterator	begin () const noexcept
	Returns a const STL-style iterator pointing to the first item in the list. More...

iterator	begin ()
	Returns an STL-style iterator pointing to the first item in the list. More...

void	clear ()
	Remove all fields. More...

const_iterator	constBegin () const noexcept
	Returns a const STL-style iterator pointing to the first item in the list. More...

const_iterator	constEnd () const noexcept
	Returns a const STL-style iterator pointing to the imaginary item after the last item in the list. More...

int	count () const
	Return number of items. More...

const_iterator	end () const noexcept
	Returns a const STL-style iterator pointing to the imaginary item after the last item in the list. More...

iterator	end ()
	Returns an STL-style iterator pointing to the imaginary item after the last item in the list. More...

bool	exists (int i) const
	Return if a field index is valid. More...

void	extend (const QgsFields &other)
	Extend with fields from another QgsFields container. More...

QgsField	field (int fieldIdx) const
	Get field at particular index (must be in range 0..N-1) More...

QgsField	field (const QString &name) const
	Get field with matching name. 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...

QIcon	iconForField (int fieldIdx) const
	Returns an icon corresponding to a field index, based on the field's type and source. More...

int	indexFromName (const QString &fieldName) const
	Get the field index from the field name. More...

int	indexOf (const QString &fieldName) const
	Get the field index from the field name. More...

bool	isEmpty () const
	Check whether the container is empty. More...

int	lookupField (const QString &fieldName) const
	Look up field's index from the field name. More...

QStringList	names () const
	Returns a list with field names. More...

	operator QVariant () const
	Allows direct construction of QVariants from fields. More...

bool	operator!= (const QgsFields &other) const

QgsFields &	operator= (const QgsFields &other)
	Assignment operator. More...

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

void	remove (int fieldIdx)
	Remove a field with the given index. More...

int	size () const
	Return number of items. More...

QList< QgsField >	toList () const
	Utility function to return a list of QgsField instances. 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)
Note
QgsFields objects are implicitly shared.

Definition at line 42 of file qgsfields.h.

Member Typedef Documentation

◆ Field

typedef struct QgsFields::Field QgsFields::Field

Member Enumeration Documentation

◆ FieldOrigin

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.

Definition at line 46 of file qgsfields.h.

Constructor & Destructor Documentation

◆ QgsFields() [1/2]

QgsFields::QgsFields ( )

Constructor for an empty field container.

Definition at line 28 of file qgsfields.cpp.

◆ QgsFields() [2/2]

QgsFields::QgsFields ( const QgsFields & other )

Copy constructor.

Definition at line 33 of file qgsfields.cpp.

◆ ~QgsFields()

QgsFields::~QgsFields ( )

virtual

Definition at line 44 of file qgsfields.cpp.

Member Function Documentation

◆ allAttributesList()

QgsAttributeList QgsFields::allAttributesList ( ) const

Utility function to get list of attribute indexes.

Since: QGIS 2.4

Definition at line 326 of file qgsfields.cpp.

◆ append()

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 59 of file qgsfields.cpp.

◆ appendExpressionField()

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 72 of file qgsfields.cpp.

◆ at()

QgsField QgsFields::at ( int i ) const

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

Definition at line 145 of file qgsfields.cpp.

◆ begin() [1/2]

QgsFields::const_iterator QgsFields::begin ( ) const

noexcept

Returns a const STL-style iterator pointing to the first item in the list.

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 223 of file qgsfields.cpp.

◆ begin() [2/2]

QgsFields::iterator QgsFields::begin ( )

Returns an STL-style iterator pointing to the first item in the list.

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 239 of file qgsfields.cpp.

◆ clear()

void QgsFields::clear ( )

Remove all fields.

Definition at line 47 of file qgsfields.cpp.

◆ constBegin()

QgsFields::const_iterator QgsFields::constBegin ( ) const

noexcept

Returns a const STL-style iterator pointing to the first item in the list.

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 207 of file qgsfields.cpp.

◆ constEnd()

QgsFields::const_iterator QgsFields::constEnd ( ) const

noexcept

Returns a const STL-style iterator pointing to the imaginary item after the last item in the list.

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 215 of file qgsfields.cpp.

◆ count()

int QgsFields::count ( ) const

Return number of items.

Definition at line 115 of file qgsfields.cpp.

◆ end() [1/2]

QgsFields::const_iterator QgsFields::end ( ) const

noexcept

Returns a const STL-style iterator pointing to the imaginary item after the last item in the list.

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 231 of file qgsfields.cpp.

◆ end() [2/2]

QgsFields::iterator QgsFields::end ( )

Returns an STL-style iterator pointing to the imaginary item after the last item in the list.

Since: QGIS 2.16

Note: not available in Python bindings

Definition at line 248 of file qgsfields.cpp.

◆ exists()

bool QgsFields::exists ( int i ) const

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 135 of file qgsfields.cpp.

◆ extend()

void QgsFields::extend ( const QgsFields & other )

Extend with fields from another QgsFields container.

Definition at line 96 of file qgsfields.cpp.

◆ field() [1/2]

QgsField QgsFields::field ( int fieldIdx ) const

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

Definition at line 150 of file qgsfields.cpp.

◆ field() [2/2]

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

Get field with matching name.

Definition at line 155 of file qgsfields.cpp.

◆ fieldOrigin()

QgsFields::FieldOrigin QgsFields::fieldOrigin ( int fieldIdx ) const

Get field's origin (value from an enumeration)

Definition at line 171 of file qgsfields.cpp.

◆ fieldOriginIndex()

int QgsFields::fieldOriginIndex ( int fieldIdx ) const

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

Definition at line 179 of file qgsfields.cpp.

◆ iconForField()

QIcon QgsFields::iconForField ( int fieldIdx ) const

Returns an icon corresponding to a field index, based on the field's type and source.

Since: QGIS 2.14

Definition at line 257 of file qgsfields.cpp.

◆ indexFromName()

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

Get the field index from the field name.

This method is case sensitive and only matches the data source name of the field. Alias for indexOf

Parameters

fieldName The name of the field.

Returns: The field index if found or -1 in case it cannot be found.

See also: lookupField For a more tolerant alternative.

Definition at line 184 of file qgsfields.cpp.

◆ indexOf()

int QgsFields::indexOf ( const QString & fieldName ) const

Get the field index from the field name.

This method is case sensitive and only matches the data source name of the field.

Parameters

fieldName The name of the field.

Returns: The field index if found or -1 in case it cannot be found.

See also: lookupField For a more tolerant alternative.

Since: QGIS 3.0

Definition at line 189 of file qgsfields.cpp.

◆ isEmpty()

bool QgsFields::isEmpty ( ) const

Check whether the container is empty.

Definition at line 110 of file qgsfields.cpp.

◆ lookupField()

int QgsFields::lookupField ( const QString & fieldName ) const

Look up field's index from the field name.

This method matches in the following order:

The exact field name taking case sensitivity into account
Looks for the field name by case insensitive comparison
The field alias (case insensitive)

Parameters

fieldName The name to look for.

Returns: The field index if found or -1 in case it cannot be found.

See also: indexFromName For a more performant and precise but less tolerant alternative.

Since: QGIS 2.4

Definition at line 299 of file qgsfields.cpp.

◆ names()

QStringList QgsFields::names ( ) const

Returns a list with field names.

Since: QGIS 3.0

Definition at line 125 of file qgsfields.cpp.

◆ operator QVariant()

QgsFields::operator QVariant ( ) const

inline

Allows direct construction of QVariants from fields.

Definition at line 328 of file qgsfields.h.

◆ operator!=()

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

inline

Since: QGIS 2.6

Definition at line 306 of file qgsfields.h.

◆ operator=()

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

Assignment operator.

Definition at line 38 of file qgsfields.cpp.

◆ operator==()

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

Since: QGIS 2.6

Definition at line 202 of file qgsfields.cpp.

◆ operator[]() [1/2]

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

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

Definition at line 166 of file qgsfields.cpp.

◆ operator[]() [2/2]

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

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

Definition at line 140 of file qgsfields.cpp.

◆ remove()

void QgsFields::remove ( int fieldIdx )

Remove a field with the given index.

Definition at line 83 of file qgsfields.cpp.

◆ size()

int QgsFields::size ( ) const

Return number of items.

Definition at line 120 of file qgsfields.cpp.

◆ toList()

QList< QgsField > QgsFields::toList ( ) const

Utility function to return a list of QgsField instances.

Definition at line 194 of file qgsfields.cpp.

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

/tmp/buildd/qgis-3.0.2+14stretch/src/core/qgsfields.h
/tmp/buildd/qgis-3.0.2+14stretch/src/core/qgsfields.cpp

Classes

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ Field

Member Enumeration Documentation

◆ FieldOrigin

Constructor & Destructor Documentation

◆ QgsFields() [1/2]

◆ QgsFields() [2/2]

◆ ~QgsFields()

Member Function Documentation

◆ allAttributesList()

◆ append()

◆ appendExpressionField()

◆ at()

◆ begin() [1/2]

◆ begin() [2/2]

◆ clear()

◆ constBegin()

◆ constEnd()

◆ count()

◆ end() [1/2]

◆ end() [2/2]

◆ exists()

◆ extend()

◆ field() [1/2]

◆ field() [2/2]

◆ fieldOrigin()

◆ fieldOriginIndex()

◆ iconForField()

◆ indexFromName()

◆ indexOf()

◆ isEmpty()

◆ lookupField()

◆ names()

◆ operator QVariant()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ remove()

◆ size()

◆ toList()