c++ helper class for defining QgsExpression functions. More...

#include <qgsexpression.h>

Inheritance diagram for QgsExpression::StaticFunction:

Public Member Functions
Q_DECL_DEPRECATED	StaticFunction (const QString &fnname, int params, FcnEval fcn, const QString &group, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, const QStringList &aliases=QStringList(), bool handlesNull=false)

	StaticFunction (const QString &fnname, int params, FcnEvalContext fcn, const QString &group, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, const QStringList &aliases=QStringList(), bool handlesNull=false)
	Static function for evaluation against a QgsExpressionContext, using an unnamed list of parameter values. More...

	StaticFunction (const QString &fnname, const ParameterList &params, FcnEvalContext fcn, const QString &group, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, const QStringList &aliases=QStringList(), bool handlesNull=false)
	Static function for evaluation against a QgsExpressionContext, using a named list of parameter values. More...

	StaticFunction (const QString &fnname, const ParameterList &params, FcnEvalContext fcn, const QStringList &groups, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, const QStringList &aliases=QStringList(), bool handlesNull=false)
	Static function for evaluation against a QgsExpressionContext, using a named list of parameter values and list of groups. More...

virtual	~StaticFunction ()

virtual QStringList	aliases () const override
	Returns a list of possible aliases for the function. More...

virtual Q_DECL_DEPRECATED QVariant	func (const QVariantList &values, const QgsFeature f, QgsExpression parent) override

virtual QVariant	func (const QVariantList &values, const QgsExpressionContext context, QgsExpression parent) override
	Returns result of evaluating the function. More...

Public Member Functions inherited from QgsExpression::Function
	Function (const QString &fnname, int params, const QString &group, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, bool handlesNull=false, bool isContextual=false)
	Constructor for function which uses unnamed parameters. More...

	Function (const QString &fnname, int params, const QStringList &groups, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, bool handlesNull=false, bool isContextual=false)
	Constructor for function which uses unnamed parameters and group list. More...

	Function (const QString &fnname, const ParameterList &params, const QString &group, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, bool handlesNull=false, bool isContextual=false)
	Constructor for function which uses named parameter list. More...

	Function (const QString &fnname, const ParameterList &params, const QStringList &groups, const QString &helpText=QString(), bool usesGeometry=false, const QStringList &referencedColumns=QStringList(), bool lazyEval=false, bool handlesNull=false, bool isContextual=false)
	Constructor for function which uses named parameter list and group list. More...

virtual	~Function ()

QString	group () const
	Returns the first group which the function belongs to. More...

QStringList	groups () const
	Returns a list of the groups the function belongs to. More...

virtual bool	handlesNull () const

const QString	helptext () const
	The help text for the function. More...

bool	isContextual () const
	Returns whether the function is only available if provided by a QgsExpressionContext object. More...

virtual bool	isDeprecated () const
	Returns true if the function is deprecated and should not be presented as a valid option to users in expression builders. More...

bool	lazyEval () const
	True if this function should use lazy evaluation. More...

int	minParams () const
	The mininum number of parameters this function takes. More...

QString	name () const
	The name of the function. More...

bool	operator== (const Function &other) const

const ParameterList &	parameters () const
	Returns the list of named parameters for the function, if set. More...

int	params () const
	The number of parameters this function takes. More...

virtual QStringList	referencedColumns () const

bool	usesgeometry () const
	Does this function use a geometry object. More...

Detailed Description

c++ helper class for defining QgsExpression functions.

Note: not available in Python bindings

Definition at line 728 of file qgsexpression.h.

Constructor & Destructor Documentation

◆ StaticFunction() [1/4]

Q_DECL_DEPRECATED QgsExpression::StaticFunction::StaticFunction	(	const QString &	fnname,
		int	params,
		FcnEval	fcn,
		const QString &	group,
		const QString &	helpText = `QString()`,
		bool	usesGeometry = `false`,
		const QStringList &	referencedColumns = `QStringList()`,
		bool	lazyEval = `false`,
		const QStringList &	aliases = `QStringList()`,
		bool	handlesNull = `false`
	)

inline

Deprecated:: use QgsExpressionContext variant instead

Definition at line 732 of file qgsexpression.h.

◆ ~StaticFunction()

virtual QgsExpression::StaticFunction::~StaticFunction ( )

inlinevirtual

Definition at line 748 of file qgsexpression.h.

◆ StaticFunction() [2/4]

QgsExpression::StaticFunction::StaticFunction	(	const QString &	fnname,
		int	params,
		FcnEvalContext	fcn,
		const QString &	group,
		const QString &	helpText = `QString()`,
		bool	usesGeometry = `false`,
		const QStringList &	referencedColumns = `QStringList()`,
		bool	lazyEval = `false`,
		const QStringList &	aliases = `QStringList()`,
		bool	handlesNull = `false`
	)

inline

Static function for evaluation against a QgsExpressionContext, using an unnamed list of parameter values.

Definition at line 752 of file qgsexpression.h.

◆ StaticFunction() [3/4]

QgsExpression::StaticFunction::StaticFunction	(	const QString &	fnname,
		const ParameterList &	params,
		FcnEvalContext	fcn,
		const QString &	group,
		const QString &	helpText = `QString()`,
		bool	usesGeometry = `false`,
		const QStringList &	referencedColumns = `QStringList()`,
		bool	lazyEval = `false`,
		const QStringList &	aliases = `QStringList()`,
		bool	handlesNull = `false`
	)

inline

Static function for evaluation against a QgsExpressionContext, using a named list of parameter values.

Definition at line 770 of file qgsexpression.h.

◆ StaticFunction() [4/4]

QgsExpression::StaticFunction::StaticFunction	(	const QString &	fnname,
		const ParameterList &	params,
		FcnEvalContext	fcn,
		const QStringList &	groups,
		const QString &	helpText = `QString()`,
		bool	usesGeometry = `false`,
		const QStringList &	referencedColumns = `QStringList()`,
		bool	lazyEval = `false`,
		const QStringList &	aliases = `QStringList()`,
		bool	handlesNull = `false`
	)

inline

Static function for evaluation against a QgsExpressionContext, using a named list of parameter values and list of groups.

Definition at line 789 of file qgsexpression.h.

Member Function Documentation

◆ aliases()

virtual QStringList QgsExpression::StaticFunction::aliases ( ) const

inlineoverridevirtual

Returns a list of possible aliases for the function.

These include other permissible names for the function, eg deprecated names.

Returns: list of known aliases

Note: added in QGIS 2.9

Reimplemented from QgsExpression::Function.

Definition at line 819 of file qgsexpression.h.

◆ func() [1/2]

QVariant QgsExpression::StaticFunction::func	(	const QVariantList &	values,
		const QgsFeature *	f,
		QgsExpression *	parent
	)

overridevirtual

Deprecated:: use QgsExpressionContext variant instead

Reimplemented from QgsExpression::Function.

Definition at line 5320 of file qgsexpression.cpp.

◆ func() [2/2]

virtual QVariant QgsExpression::StaticFunction::func	(	const QVariantList &	values,
		const QgsExpressionContext *	context,
		QgsExpression *	parent
	)

inlineoverridevirtual

Returns result of evaluating the function.

Parameters

values	list of values passed to the function
context	context expression is being evaluated against
parent	parent expression

Returns: result of function

Reimplemented from QgsExpression::Function.

Definition at line 814 of file qgsexpression.h.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsexpression.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsexpression.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ StaticFunction() [1/4]

◆ ~StaticFunction()

◆ StaticFunction() [2/4]

◆ StaticFunction() [3/4]

◆ StaticFunction() [4/4]

Member Function Documentation

◆ aliases()

◆ func() [1/2]

◆ func() [2/2]