Class ExpressionEvaluator

The ExpressionEvaluator class enables evaluation of expression strings and expression templates.

#include <expressionevaluator.h>

Inherits the following classes: QObject

Public Types

Type	Name
enum	Mode Expression evaluator modes.

Public Properties

Type	Name
property AppExpressionContextScopesGenerator *	appExpressionContextScopesGenerator
property QString	expressionText
property QgsFeature	feature
property QgsMapLayer *	layer
property QgsQuickMapSettings *	mapSettings
property Mode	mode
property QgsProject *	project
property QVariantMap	variables

Public Signals

Type	Name
signal void	appExpressionContextScopesGeneratorChanged
signal void	expressionTextChanged
signal void	featureChanged
signal void	layerChanged
signal void	mapSettingsChanged
signal void	modeChanged
signal void	projectChanged
signal void	variablesChanged

Public Functions

Type	Name
	ExpressionEvaluator (QObject * parent=nullptr)
AppExpressionContextScopesGenerator *	appExpressionContextScopesGenerator () const Returns the application expression context scopes generator object.
Q_INVOKABLE QVariant	evaluate () Returns the evaluated expression text value.
QString	expressionText () Returns the expression text used when evaluating.
QgsFeature	feature () const Returns the feature attached to the expression context.
QgsMapLayer *	layer () const Returns the map layer attached to the expression context.
QgsQuickMapSettings *	mapSettings () const Returns the map settings attached to the expression context.
Mode	mode () const Returns the expression evaluator mode.
QgsProject *	project () const Returns the project attached to the expression context.
void	setAppExpressionContextScopesGenerator (AppExpressionContextScopesGenerator * generator) Sets the application expression context scopes generator object.
void	setExpressionText (const QString & expressionText) Sets the expression text used when evaluating.
void	setFeature (const QgsFeature & feature) Sets the feature attached to the expression context.
void	setLayer (QgsMapLayer * layer) Sets the map layer attached to the expression context.
void	setMapSettings (QgsQuickMapSettings * mapSettings) Sets the map settings attached to the expression context.
void	setMode (Mode mode) Sets the expression evaluator mode .
void	setProject (QgsProject * project) Sets the project attached to the expression context.
void	setVariables (const QVariantMap & variables) Sets the map of variables injected into the expression context when evaluating.
QVariantMap	variables () const Returns the map of variables injected into the expression context when evaluating.

Public Types Documentation

enum Mode

Expression evaluator modes.

enum ExpressionEvaluator::Mode {
    ExpressionMode,
    ExpressionTemplateMode
};

Public Properties Documentation

property appExpressionContextScopesGenerator [1/2]

AppExpressionContextScopesGenerator * ExpressionEvaluator::appExpressionContextScopesGenerator;

property expressionText [1/2]

QString ExpressionEvaluator::expressionText;

property feature [1/2]

QgsFeature ExpressionEvaluator::feature;

property layer [1/2]

QgsMapLayer * ExpressionEvaluator::layer;

property mapSettings [1/2]

QgsQuickMapSettings * ExpressionEvaluator::mapSettings;

property mode [1/2]

Mode ExpressionEvaluator::mode;

property project [1/2]

QgsProject * ExpressionEvaluator::project;

property variables [1/2]

QVariantMap ExpressionEvaluator::variables;

Public Signals Documentation

signal appExpressionContextScopesGeneratorChanged

void ExpressionEvaluator::appExpressionContextScopesGeneratorChanged;

signal expressionTextChanged

void ExpressionEvaluator::expressionTextChanged;

signal featureChanged

void ExpressionEvaluator::featureChanged;

signal layerChanged

void ExpressionEvaluator::layerChanged;

signal mapSettingsChanged

void ExpressionEvaluator::mapSettingsChanged;

signal modeChanged

void ExpressionEvaluator::modeChanged;

signal projectChanged

void ExpressionEvaluator::projectChanged;

signal variablesChanged

void ExpressionEvaluator::variablesChanged;

Public Functions Documentation

function ExpressionEvaluator

explicit ExpressionEvaluator::ExpressionEvaluator (
    QObject * parent=nullptr
)

function appExpressionContextScopesGenerator [2/2]

Returns the application expression context scopes generator object.

AppExpressionContextScopesGenerator * ExpressionEvaluator::appExpressionContextScopesGenerator () const

function evaluate

Returns the evaluated expression text value.

Q_INVOKABLE QVariant ExpressionEvaluator::evaluate ()

function expressionText [2/2]

Returns the expression text used when evaluating.

inline QString ExpressionEvaluator::expressionText ()

function feature [2/2]

Returns the feature attached to the expression context.

inline QgsFeature ExpressionEvaluator::feature () const

function layer [2/2]

Returns the map layer attached to the expression context.

inline QgsMapLayer * ExpressionEvaluator::layer () const

function mapSettings [2/2]

Returns the map settings attached to the expression context.

inline QgsQuickMapSettings * ExpressionEvaluator::mapSettings () const

function mode [2/2]

Returns the expression evaluator mode.

inline Mode ExpressionEvaluator::mode () const

function project [2/2]

Returns the project attached to the expression context.

inline QgsProject * ExpressionEvaluator::project () const

function setAppExpressionContextScopesGenerator

Sets the application expression context scopes generator object.

void ExpressionEvaluator::setAppExpressionContextScopesGenerator (
    AppExpressionContextScopesGenerator * generator
)

function setExpressionText

Sets the expression text used when evaluating.

void ExpressionEvaluator::setExpressionText (
    const QString & expressionText
)

function setFeature

Sets the feature attached to the expression context.

void ExpressionEvaluator::setFeature (
    const QgsFeature & feature
)

function setLayer

Sets the map layer attached to the expression context.

void ExpressionEvaluator::setLayer (
    QgsMapLayer * layer
)

function setMapSettings

Sets the map settings attached to the expression context.

void ExpressionEvaluator::setMapSettings (
    QgsQuickMapSettings * mapSettings
)

function setMode

Sets the expression evaluator mode .

void ExpressionEvaluator::setMode (
    Mode mode
)

function setProject

Sets the project attached to the expression context.

void ExpressionEvaluator::setProject (
    QgsProject * project
)

function setVariables

Sets the map of variables injected into the expression context when evaluating.

void ExpressionEvaluator::setVariables (
    const QVariantMap & variables
)

function variables [2/2]

Returns the map of variables injected into the expression context when evaluating.

inline QVariantMap ExpressionEvaluator::variables () const

The documentation for this class was generated from the following file src/core/expressionevaluator.h