QgsDataDefined Class Reference

A container class for data source field mapping or expression. More...

#include <qgsdatadefined.h>

Public Member Functions
	QgsDataDefined (bool active=false, bool useexpr=false, const QString &expr=QString(), const QString &field=QString())
	Construct a new data defined object.
	QgsDataDefined (const QgsExpression *expression)
	Construct a new data defined object, analyse the expression to determine if it's a simple field.
	~QgsDataDefined ()
QgsExpression *	expression ()
bool	expressionIsPrepared () const
QMap< QString, QVariant >	expressionParams () const
QString	expressionString () const
QString	field () const
bool	hasDefaultValues () const
	Returns whether the data defined container is set to all the default values, ie, disabled, with empty expression and no assigned field.
void	insertExpressionParam (QString key, QVariant param)
bool	isActive () const
bool	operator!= (const QgsDataDefined &other) const
bool	operator== (const QgsDataDefined &other) const
bool	prepareExpression (QgsVectorLayer *layer)
QStringList	referencedColumns (QgsVectorLayer *layer)
void	setActive (bool active)
void	setExpressionParams (QMap< QString, QVariant > params)
void	setExpressionString (const QString &expr)
void	setField (const QString &field)
bool	setFromXmlElement (const QDomElement &element)
	Sets the properties of the data defined container from an XML element.
void	setUseExpression (bool use)
QMap< QString, QString >	toMap ()
QDomElement	toXmlElement (QDomDocument &document, const QString &elementName) const
	Returns a DOM element containing the properties of the data defined container.
bool	useExpression () const

Detailed Description

A container class for data source field mapping or expression.

Definition at line 31 of file qgsdatadefined.h.

Constructor & Destructor Documentation

QgsDataDefined::QgsDataDefined	(	bool	active = false,
		bool	useexpr = false,
		const QString &	expr = QString(),
		const QString &	field = QString()
	)

Construct a new data defined object.

Parameters

active	Whether the current data defined is active
useexpr	Whether to use expression instead of field
expr	Expression string
field	Field name string

Definition at line 23 of file qgsdatadefined.cpp.

QgsDataDefined::QgsDataDefined ( const QgsExpression *  expression )

explicit

Construct a new data defined object, analyse the expression to determine if it's a simple field.

Parameters

expression

can be null

Definition at line 36 of file qgsdatadefined.cpp.

QgsDataDefined::~QgsDataDefined

(

)

Definition at line 46 of file qgsdatadefined.cpp.

Member Function Documentation

QgsExpression* QgsDataDefined::expression ( )

inline

Definition at line 82 of file qgsdatadefined.h.

bool QgsDataDefined::expressionIsPrepared ( ) const

inline

Definition at line 80 of file qgsdatadefined.h.

QMap<QString, QVariant> QgsDataDefined::expressionParams ( ) const

inline

Definition at line 74 of file qgsdatadefined.h.

QString QgsDataDefined::expressionString ( ) const

inline

Definition at line 70 of file qgsdatadefined.h.

QString QgsDataDefined::field ( ) const

inline

Definition at line 85 of file qgsdatadefined.h.

bool QgsDataDefined::hasDefaultValues

(

)

const

Returns whether the data defined container is set to all the default values, ie, disabled, with empty expression and no assigned field.

Returns

true if data defined container is set to default values

Note

added in QGIS 2.7

Definition at line 52 of file qgsdatadefined.cpp.

void QgsDataDefined::insertExpressionParam	(	QString	key,
		QVariant	param
	)

Definition at line 134 of file qgsdatadefined.cpp.

bool QgsDataDefined::isActive ( ) const

inline

Definition at line 64 of file qgsdatadefined.h.

bool QgsDataDefined::operator!=

(

const QgsDataDefined &

other

)

const

Definition at line 180 of file qgsdatadefined.cpp.

bool QgsDataDefined::operator==

(

const QgsDataDefined &

other

)

const

Definition at line 174 of file qgsdatadefined.cpp.

bool QgsDataDefined::prepareExpression

(

QgsVectorLayer *

layer

)

Definition at line 63 of file qgsdatadefined.cpp.

QStringList QgsDataDefined::referencedColumns

(

QgsVectorLayer *

layer

)

Definition at line 112 of file qgsdatadefined.cpp.

void QgsDataDefined::setActive ( bool  active )

inline

Definition at line 65 of file qgsdatadefined.h.

void QgsDataDefined::setExpressionParams ( QMap< QString, QVariant >  params )

inline

Definition at line 76 of file qgsdatadefined.h.

void QgsDataDefined::setExpressionString

(

const QString &

expr

)

Definition at line 57 of file qgsdatadefined.cpp.

void QgsDataDefined::setField ( const QString &  field )

inline

Definition at line 86 of file qgsdatadefined.h.

bool QgsDataDefined::setFromXmlElement

(

const QDomElement &

element

)

Sets the properties of the data defined container from an XML element.

Calling this will overwrite all the current properties of the container.

Parameters

element

DOM element

Returns

true if properties were successfully read from element

Note

added in QGIS 2.7

See Also

toXmlElement

Definition at line 160 of file qgsdatadefined.cpp.

void QgsDataDefined::setUseExpression ( bool  use )

inline

Definition at line 68 of file qgsdatadefined.h.

QMap< QString, QString > QgsDataDefined::toMap

(

)

Definition at line 139 of file qgsdatadefined.cpp.

QDomElement QgsDataDefined::toXmlElement	(	QDomDocument &	document,
		const QString &	elementName
	)		const

Returns a DOM element containing the properties of the data defined container.

Parameters

document	DOM document
elementName	name for DOM element

Returns

DOM element corresponding to data defined container

Note

added in QGIS 2.7

See Also

setFromXmlElement

Definition at line 150 of file qgsdatadefined.cpp.

bool QgsDataDefined::useExpression ( ) const

inline

Definition at line 67 of file qgsdatadefined.h.

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

• /tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsdatadefined.h
• /tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsdatadefined.cpp