A reusable widget that can be used to build a expression string. More...

#include <qgsexpressionbuilderwidget.h>

Inheritance diagram for QgsExpressionBuilderWidget:

Public Slots
void	autosave ()
	Auto save the current Python function code. More...

void	loadAllValues ()
	Load all unique values from the set layer into the sample area. More...

void	loadSampleValues ()
	Load sample values into the sample value area. More...

void	setAutoSave (bool enabled)
	Enabled or disable auto saving. 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...

Public Member Functions
	QgsExpressionBuilderWidget (QWidget *parent=nullptr)
	Create a new expression builder widget with an optional parent. More...

	~QgsExpressionBuilderWidget () override

bool	evalError () const
	Will be set to `true` if the current expression text reported an eval error with the context. More...

QString	expectedOutputFormat ()
	The set expected format string. More...

QgsExpressionContext	expressionContext () const
	Returns the expression context for the widget. More...

QString	expressionText ()
	Gets the expression string that has been set in the expression area. More...

bool	isExpressionValid ()

void	loadCodeFromFile (QString path)
	Load code from the given file into the function editor. More...

void	loadFieldNames ()
	Loads all the field names from the layer. More...

void	loadFieldNames (const QgsFields &fields)

void	loadFieldsAndValues (const QMap< QString, QStringList > &fieldValues)
	Loads field names and values from the specified map. More...

void	loadFunctionCode (const QString &code)
	Load code into the function editor. More...

void	loadRecent (const QString &collection="generic")
	Loads the recent expressions from the given collection. More...

QStandardItemModel *	model ()
	Returns a pointer to the dialog's function item model. More...

void	newFunctionFile (const QString &fileName="scratch")
	Create a new file in the function editor. More...

bool	parserError () const
	Will be set to `true` if the current expression text reports a parser error with the context. More...

QgsProject *	project ()
	Returns the project currently associated with the widget. More...

void	registerItem (const QString &group, const QString &label, const QString &expressionText, const QString &helpText=QString(), QgsExpressionItem::ItemType type=QgsExpressionItem::ExpressionNode, bool highlightedItem=false, int sortOrder=1, QIcon icon=QIcon())
	Registers a node item for the expression builder. More...

void	saveFunctionFile (QString fileName)
	Save the current function editor text to the given file. More...

void	saveToRecent (const QString &collection="generic")
	Adds the current expression to the given collection. More...

void	setExpectedOutputFormat (const QString &expected)
	The set expected format string. More...

void	setExpressionContext (const QgsExpressionContext &context)
	Sets the expression context for the widget. More...

void	setExpressionText (const QString &expression)
	Sets the expression string for the widget. More...

void	setGeomCalculator (const QgsDistanceArea &da)
	Sets geometry calculator used in distance/area calculations. More...

void	setLayer (QgsVectorLayer *layer)
	Sets layer in order to get the fields and values. More...

void	setProject (QgsProject *project)
	Sets the project currently associated with the widget. More...

void	updateFunctionFileList (const QString &path)
	Update the list of function files found at the given path. More...

Protected Member Functions
void	showEvent (QShowEvent *e) override

Detailed Description

A reusable widget that can be used to build a expression string.

See QgsExpressionBuilderDialog for example of usage.

Definition at line 133 of file qgsexpressionbuilderwidget.h.

Constructor & Destructor Documentation

◆ QgsExpressionBuilderWidget()

QgsExpressionBuilderWidget::QgsExpressionBuilderWidget ( QWidget * parent = nullptr )

Create a new expression builder widget with an optional parent.

Definition at line 46 of file qgsexpressionbuilderwidget.cpp.

◆ ~QgsExpressionBuilderWidget()

QgsExpressionBuilderWidget::~QgsExpressionBuilderWidget ( )

override

Definition at line 212 of file qgsexpressionbuilderwidget.cpp.

Member Function Documentation

◆ autosave

void QgsExpressionBuilderWidget::autosave ( )

slot

Auto save the current Python function code.

Definition at line 1132 of file qgsexpressionbuilderwidget.cpp.

◆ evalError()

bool QgsExpressionBuilderWidget::evalError ( ) const

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

Since: QGIS 3.0

Definition at line 875 of file qgsexpressionbuilderwidget.cpp.

◆ evalErrorChanged

void QgsExpressionBuilderWidget::evalErrorChanged ( )

signal

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

Since: QGIS 3.0

◆ expectedOutputFormat()

QString QgsExpressionBuilderWidget::expectedOutputFormat ( )

The set expected format string.

This is pure text format and no expression validation is done against it.

Returns: The expected value format.

Definition at line 704 of file qgsexpressionbuilderwidget.cpp.

◆ expressionContext()

QgsExpressionContext QgsExpressionBuilderWidget::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

Since: QGIS 2.12

Definition at line 197 of file qgsexpressionbuilderwidget.h.

◆ expressionParsed

void QgsExpressionBuilderWidget::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.

◆ expressionText()

QString QgsExpressionBuilderWidget::expressionText ( )

Gets the expression string that has been set in the expression area.

Returns: The expression as a string.

Definition at line 694 of file qgsexpressionbuilderwidget.cpp.

◆ isExpressionValid()

bool QgsExpressionBuilderWidget::isExpressionValid ( )

Definition at line 552 of file qgsexpressionbuilderwidget.cpp.

◆ loadAllValues

void QgsExpressionBuilderWidget::loadAllValues ( )

slot

Load all unique values from the set layer into the sample area.

Definition at line 1110 of file qgsexpressionbuilderwidget.cpp.

◆ loadCodeFromFile()

void QgsExpressionBuilderWidget::loadCodeFromFile ( QString path )

Load code from the given file into the function editor.

Definition at line 367 of file qgsexpressionbuilderwidget.cpp.

◆ loadFieldNames() [1/2]

void QgsExpressionBuilderWidget::loadFieldNames ( )

Loads all the field names from the layer.

Remarks: Should this really be public couldn't we just do this for the user?

Definition at line 396 of file qgsexpressionbuilderwidget.cpp.

◆ loadFieldNames() [2/2]

void QgsExpressionBuilderWidget::loadFieldNames ( const QgsFields & fields )

Definition at line 407 of file qgsexpressionbuilderwidget.cpp.

◆ loadFieldsAndValues()

void QgsExpressionBuilderWidget::loadFieldsAndValues ( const QMap< QString, QStringList > & fieldValues )

Loads field names and values from the specified map.

Note: The field values must be quoted appropriately if they are strings.

Since: QGIS 2.12

Definition at line 427 of file qgsexpressionbuilderwidget.cpp.

◆ loadFunctionCode()

void QgsExpressionBuilderWidget::loadFunctionCode ( const QString & code )

Load code into the function editor.

Definition at line 375 of file qgsexpressionbuilderwidget.cpp.

◆ loadRecent()

void QgsExpressionBuilderWidget::loadRecent ( const QString & collection = "generic" )

Loads the recent expressions from the given collection.

By default it is loaded from the collection "generic".

Definition at line 575 of file qgsexpressionbuilderwidget.cpp.

◆ loadSampleValues

void QgsExpressionBuilderWidget::loadSampleValues ( )

slot

Load sample values into the sample value area.

Definition at line 1097 of file qgsexpressionbuilderwidget.cpp.

◆ model()

QStandardItemModel * QgsExpressionBuilderWidget::model ( )

Returns a pointer to the dialog's function item model.

This method is exposed for testing purposes only - it should not be used to modify the model.

Since: QGIS 3.0

Definition at line 889 of file qgsexpressionbuilderwidget.cpp.

◆ newFunctionFile()

void QgsExpressionBuilderWidget::newFunctionFile ( const QString & fileName = "scratch" )

Create a new file in the function editor.

Definition at line 328 of file qgsexpressionbuilderwidget.cpp.

◆ parserError()

bool QgsExpressionBuilderWidget::parserError ( ) const

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

Since: QGIS 3.0

Definition at line 850 of file qgsexpressionbuilderwidget.cpp.

◆ parserErrorChanged

void QgsExpressionBuilderWidget::parserErrorChanged ( )

signal

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

Since: QGIS 3.0

◆ project()

QgsProject * QgsExpressionBuilderWidget::project ( )

Returns the project currently associated with the widget.

See also: setProject()

Since: QGIS 3.0

Definition at line 894 of file qgsexpressionbuilderwidget.cpp.

◆ registerItem()

void QgsExpressionBuilderWidget::registerItem	(	const QString &	group,
		const QString &	label,
		const QString &	expressionText,
		const QString &	helpText = `QString()`,
		QgsExpressionItem::ItemType	type = `QgsExpressionItem::ExpressionNode`,
		bool	highlightedItem = `false`,
		int	sortOrder = `1`,
		QIcon	icon = `QIcon()`
	)

Registers a node item for the expression builder.

Parameters

group	The group the item will be show in the tree view. If the group doesn't exsit it will be created.
label	The label that is show to the user for the item in the tree.
expressionText	The text that is inserted into the expression area when the user double clicks on the item.
helpText	The help text that the user will see when item is selected.
type	The type of the expression item.
highlightedItem	set to `true` to make the item highlighted, which inserts a bold copy of the item at the top level
sortOrder	sort ranking for item
icon	custom icon to show for item

Definition at line 508 of file qgsexpressionbuilderwidget.cpp.

◆ saveFunctionFile()

void QgsExpressionBuilderWidget::saveFunctionFile ( QString fileName )

Save the current function editor text to the given file.

Definition at line 275 of file qgsexpressionbuilderwidget.cpp.

◆ saveToRecent()

void QgsExpressionBuilderWidget::saveToRecent ( const QString & collection = "generic" )

Adds the current expression to the given collection.

By default it is saved to the collection "generic".

Definition at line 557 of file qgsexpressionbuilderwidget.cpp.

◆ setAutoSave

void QgsExpressionBuilderWidget::setAutoSave ( bool enabled )

inlineslot

Enabled or disable auto saving.

When enabled Python scripts will be auto saved when text changes.

Parameters

enabled true to enable auto saving.

Definition at line 324 of file qgsexpressionbuilderwidget.h.

◆ setExpectedOutputFormat()

void QgsExpressionBuilderWidget::setExpectedOutputFormat ( const QString & expected )

The set expected format string.

This is pure text format and no expression validation is done against it.

Parameters

expected The expected value format for the expression.

Note: Only a UI hint and not used for expression validation.

Definition at line 709 of file qgsexpressionbuilderwidget.cpp.

◆ setExpressionContext()

void QgsExpressionBuilderWidget::setExpressionContext ( const QgsExpressionContext & context )

Sets 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.

Parameters

context expression context

See also: expressionContext

Since: QGIS 2.12

Definition at line 715 of file qgsexpressionbuilderwidget.cpp.

◆ setExpressionText()

void QgsExpressionBuilderWidget::setExpressionText ( const QString & expression )

Sets the expression string for the widget.

Definition at line 699 of file qgsexpressionbuilderwidget.cpp.

◆ setGeomCalculator()

void QgsExpressionBuilderWidget::setGeomCalculator ( const QgsDistanceArea & da )

Sets geometry calculator used in distance/area calculations.

Definition at line 689 of file qgsexpressionbuilderwidget.cpp.

◆ setLayer()

void QgsExpressionBuilderWidget::setLayer ( QgsVectorLayer * layer )

Sets layer in order to get the fields and values.

Note: this needs to be called before calling loadFieldNames().

Definition at line 220 of file qgsexpressionbuilderwidget.cpp.

◆ setProject()

void QgsExpressionBuilderWidget::setProject ( QgsProject * project )

Sets the project currently associated with the widget.

This controls which layers and relations and other project-specific items are shown in the widget.

See also: project()

Since: QGIS 3.0

Definition at line 899 of file qgsexpressionbuilderwidget.cpp.

◆ showEvent()

void QgsExpressionBuilderWidget::showEvent ( QShowEvent * e )

overrideprotected

Definition at line 905 of file qgsexpressionbuilderwidget.cpp.

◆ updateFunctionFileList()

void QgsExpressionBuilderWidget::updateFunctionFileList ( const QString & path )

Update the list of function files found at the given path.

Definition at line 298 of file qgsexpressionbuilderwidget.cpp.

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

/build/qgis-3.10.0+15buster/src/gui/qgsexpressionbuilderwidget.h
/build/qgis-3.10.0+15buster/src/gui/qgsexpressionbuilderwidget.cpp

Public Slots

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QgsExpressionBuilderWidget()

◆ ~QgsExpressionBuilderWidget()

Member Function Documentation

◆ autosave

◆ evalError()

◆ evalErrorChanged

◆ expectedOutputFormat()

◆ expressionContext()

◆ expressionParsed

◆ expressionText()

◆ isExpressionValid()

◆ loadAllValues

◆ loadCodeFromFile()

◆ loadFieldNames() [1/2]

◆ loadFieldNames() [2/2]

◆ loadFieldsAndValues()

◆ loadFunctionCode()

◆ loadRecent()

◆ loadSampleValues

◆ model()

◆ newFunctionFile()

◆ parserError()

◆ parserErrorChanged

◆ project()

◆ registerItem()

◆ saveFunctionFile()

◆ saveToRecent()

◆ setAutoSave

◆ setExpectedOutputFormat()

◆ setExpressionContext()

◆ setExpressionText()

◆ setGeomCalculator()

◆ setLayer()

◆ setProject()

◆ showEvent()

◆ updateFunctionFileList()