QgsExpressionPreviewWidget Class Reference

QgsExpressionPreviewWidget is a widget to preview an expression result. More...

#include <qgsexpressionpreviewwidget.h>

Inheritance diagram for QgsExpressionPreviewWidget:

Public Slots
void	setCurrentFeature (const QgsFeature &feature)
	sets the current feature used More...

Signals
void	evalErrorChanged ()
	Will be set to true if the current expression text reported an eval error with the context. More...
void	expressionParsed (bool isValid)
	Emitted when the user changes the expression in the widget. More...
void	parserErrorChanged ()
	Will be set to true if the current expression text reported a parser error with the context. More...
void	toolTipChanged (const QString &toolTip)
	Emitted whenever the tool tip changed. More...

Public Member Functions
	QgsExpressionPreviewWidget (QWidget *parent=nullptr)
	Constructor. More...
bool	evalError () const
	Will be set to true if the current expression text reported an eval error with the context. More...
QgsExpressionContext	expressionContext () const
	Returns the expression context for the widget. More...
bool	parserError () const
	Will be set to true if the current expression text reports a parser error with the context. More...
QList< QgsExpression::ParserError >	parserErrors () const
	Returns the expression parser erros. More...
const QgsExpressionNode *	rootNode () const
	Returns the root node of the expression. More...
void	setExpressionContext (const QgsExpressionContext &context)
	Sets the expression context for the widget. More...
void	setExpressionText (const QString &expression)
	Sets the expression. More...
void	setGeomCalculator (const QgsDistanceArea &da)
	Sets geometry calculator used in distance/area calculations. More...
void	setLayer (QgsVectorLayer *layer)
	Sets the layer used in the preview. More...

Detailed Description

QgsExpressionPreviewWidget is a widget to preview an expression result.

If the layer is set, one can browse across features to see the different outputs.

Since

QGIS 3.14

Definition at line 35 of file qgsexpressionpreviewwidget.h.

Constructor & Destructor Documentation

QgsExpressionPreviewWidget()

QgsExpressionPreviewWidget::QgsExpressionPreviewWidget ( QWidget *  parent = nullptr )

explicit

Constructor.

Definition at line 25 of file qgsexpressionpreviewwidget.cpp.

Member Function Documentation

evalError()

bool QgsExpressionPreviewWidget::evalError

(

)

const

Will be set to true if the current expression text reported an eval error with the context.

Definition at line 186 of file qgsexpressionpreviewwidget.cpp.

evalErrorChanged

void QgsExpressionPreviewWidget::evalErrorChanged ( )

signal

Will be set to true if the current expression text reported an eval error with the context.

expressionContext()

QgsExpressionContext QgsExpressionPreviewWidget::expressionContext ( ) const

inline

Returns the expression context for the widget.

The context is used for the expression preview result and for populating the list of available functions and variables.

See also

setExpressionContext

Definition at line 53 of file qgsexpressionpreviewwidget.h.

expressionParsed

void QgsExpressionPreviewWidget::expressionParsed ( bool  isValid )

signal

Emitted when the user changes the expression in the widget.

Users of this widget should connect to this signal to decide if to let the user continue.

Parameters

isValid

Is true if the expression the user has typed is valid.

parserError()

bool QgsExpressionPreviewWidget::parserError

(

)

const

Will be set to true if the current expression text reports a parser error with the context.

Definition at line 172 of file qgsexpressionpreviewwidget.cpp.

parserErrorChanged

void QgsExpressionPreviewWidget::parserErrorChanged ( )

signal

Will be set to true if the current expression text reported a parser error with the context.

parserErrors()

QList<QgsExpression::ParserError> QgsExpressionPreviewWidget::parserErrors ( ) const

inline

Returns the expression parser erros.

Definition at line 81 of file qgsexpressionpreviewwidget.h.

rootNode()

const QgsExpressionNode* QgsExpressionPreviewWidget::rootNode ( ) const

inline

Returns the root node of the expression.

Definition at line 78 of file qgsexpressionpreviewwidget.h.

setCurrentFeature

void QgsExpressionPreviewWidget::setCurrentFeature ( const QgsFeature &  feature )

slot

sets the current feature used

Definition at line 48 of file qgsexpressionpreviewwidget.cpp.

setExpressionContext()

void QgsExpressionPreviewWidget::setExpressionContext

(

const QgsExpressionContext &

context

)

Sets the expression context for the widget.

The context is used for the expression preview result and to populate the list of available functions and variables.

Parameters

context

expression context

Definition at line 62 of file qgsexpressionpreviewwidget.cpp.

setExpressionText()

void QgsExpressionPreviewWidget::setExpressionText

(

const QString &

expression

)

Sets the expression.

Definition at line 42 of file qgsexpressionpreviewwidget.cpp.

setGeomCalculator()

void QgsExpressionPreviewWidget::setGeomCalculator

(

const QgsDistanceArea &

da

)

Sets geometry calculator used in distance/area calculations.

Definition at line 56 of file qgsexpressionpreviewwidget.cpp.

setLayer()

void QgsExpressionPreviewWidget::setLayer

(

QgsVectorLayer *

layer

)

Sets the layer used in the preview.

Definition at line 36 of file qgsexpressionpreviewwidget.cpp.

toolTipChanged

void QgsExpressionPreviewWidget::toolTipChanged ( const QString &  toolTip )

signal

Emitted whenever the tool tip changed.

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

• /build/qgis-3.20.0+99unstable/src/gui/qgsexpressionpreviewwidget.h
• /build/qgis-3.20.0+99unstable/src/gui/qgsexpressionpreviewwidget.cpp