QGIS API Documentation  3.17.0-Master (57c5a6fc26)
Public Slots | Signals | Public Member Functions | List of all members
QgsExpressionPreviewWidget Class Reference

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

#include <qgsexpressionpreviewwidget.h>

Inheritance diagram for QgsExpressionPreviewWidget:
Inheritance graph
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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::ParserErrorparserErrors () const
 Returns the expression parser erros. More...
 
const QgsExpressionNoderootNode () 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 175 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
isValidIs 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 161 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
contextexpression 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.


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