QGIS API Documentation  2.15.0-Master (13f053b)
Public Member Functions | List of all members
QgsExpression::StaticFunction Class Reference

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

#include <qgsexpression.h>

Inheritance diagram for QgsExpression::StaticFunction:
Inheritance graph
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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...
 
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, 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...
 
virtual ~Function ()
 
QString group () const
 The group 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...
 
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 ParameterListparameters () 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 630 of file qgsexpression.h.

Constructor & Destructor Documentation

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 634 of file qgsexpression.h.

virtual QgsExpression::StaticFunction::~StaticFunction ( )
inlinevirtual

Definition at line 650 of file qgsexpression.h.

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 654 of file qgsexpression.h.

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 672 of file qgsexpression.h.

Member Function Documentation

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 702 of file qgsexpression.h.

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 5123 of file qgsexpression.cpp.

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

Returns result of evaluating the function.

Parameters
valueslist of values passed to the function
contextcontext expression is being evaluated against
parentparent expression
Returns
result of function

Reimplemented from QgsExpression::Function.

Definition at line 697 of file qgsexpression.h.


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