QgsExpressionTreeView is a tree view to list all expressions functions, variables and fields that can be used in an expression. More...

#include <qgsexpressiontreeview.h>

Inheritance diagram for QgsExpressionTreeView:

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Classes
class	MenuProvider
	Implementation of this interface can be implemented to allow QgsExpressionTreeView instance to provide custom context menus (opened upon right-click). More...

Public Slots
void	setSearchText (const QString &text)
	Sets the text to filter the expression tree.

Signals
void	currentExpressionItemChanged (QgsExpressionItem *item)
	Emitter when the current expression item changed.

void	expressionItemDoubleClicked (const QString &text)
	Emitted when a expression item is double clicked.

Public Member Functions
	QgsExpressionTreeView (QWidget *parent=nullptr)
	Constructor.

QgsExpressionItem *	currentItem () const
	Returns the current item or a nullptr.

QJsonDocument	exportUserExpressions ()
	Create the expressions JSON document storing all the user expressions to be exported.

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

const QList< QgsExpressionItem * >	findExpressions (const QString &label)
	Returns the list of expression items matching a label.

void	loadExpressionsFromJson (const QJsonDocument &expressionsDocument)
	Load and permanently store the expressions from the expressions JSON document.

void	loadFieldNames (const QgsFields &fields)
	This allows loading fields without specifying a layer.

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

void	loadUserExpressions ()
	Loads the user expressions.

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

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

void	refresh ()
	Refreshes the content of the tree.

void	removeFromUserExpressions (const QString &label)
	Removes the expression label from the user stored expressions.

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

void	saveToUserExpressions (const QString &label, const QString &expression, const QString &helpText)
	Stores the user expression with given label and helpText.

void	setExpressionContext (const QgsExpressionContext &context)
	Sets the expression context for the tree view.

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

void	setMenuProvider (MenuProvider *provider)
	Sets the menu provider.

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

QStringList	userExpressionLabels () const
	Returns the user expression labels.

Detailed Description

QgsExpressionTreeView is a tree view to list all expressions functions, variables and fields that can be used in an expression.

See also: QgsExpressionBuilderWidget

Since: QGIS 3.14

Definition at line 150 of file qgsexpressiontreeview.h.

Constructor & Destructor Documentation

◆ QgsExpressionTreeView()

QgsExpressionTreeView::QgsExpressionTreeView ( QWidget * parent = nullptr )

Constructor.

Definition at line 108 of file qgsexpressiontreeview.cpp.

Member Function Documentation

◆ currentExpressionItemChanged

void QgsExpressionTreeView::currentExpressionItemChanged ( QgsExpressionItem * item )

signal

Emitter when the current expression item changed.

◆ currentItem()

QgsExpressionItem * QgsExpressionTreeView::currentItem ( ) const

Returns the current item or a nullptr.

Definition at line 171 of file qgsexpressiontreeview.cpp.

◆ exportUserExpressions()

QJsonDocument QgsExpressionTreeView::exportUserExpressions ( )

Create the expressions JSON document storing all the user expressions to be exported.

Returns: the created expressions JSON file

Definition at line 617 of file qgsexpressiontreeview.cpp.

◆ expressionContext()

QgsExpressionContext QgsExpressionTreeView::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 199 of file qgsexpressiontreeview.h.

◆ expressionItemDoubleClicked

void QgsExpressionTreeView::expressionItemDoubleClicked ( const QString & text )

signal

Emitted when a expression item is double clicked.

◆ findExpressions()

const QList< QgsExpressionItem * > QgsExpressionTreeView::findExpressions ( const QString & label )

Returns the list of expression items matching a label.

Definition at line 803 of file qgsexpressiontreeview.cpp.

◆ loadExpressionsFromJson()

void QgsExpressionTreeView::loadExpressionsFromJson ( const QJsonDocument & expressionsDocument )

Load and permanently store the expressions from the expressions JSON document.

Parameters

expressionsDocument the parsed expressions JSON file

Definition at line 659 of file qgsexpressiontreeview.cpp.

◆ loadFieldNames()

void QgsExpressionTreeView::loadFieldNames ( const QgsFields & fields )

This allows loading fields without specifying a layer.

Definition at line 453 of file qgsexpressiontreeview.cpp.

◆ loadRecent()

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

Loads the recent expressions from the given collection.

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

Definition at line 519 of file qgsexpressiontreeview.cpp.

◆ loadUserExpressions()

void QgsExpressionTreeView::loadUserExpressions ( )

Loads the user expressions.

This is done on request since it can be very slow if there are thousands of user expressions

Definition at line 586 of file qgsexpressiontreeview.cpp.

◆ model()

QStandardItemModel * QgsExpressionTreeView::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

Note: will be removed in QGIS 4

Deprecated:: since QGIS 3.14

Definition at line 178 of file qgsexpressiontreeview.cpp.

◆ project()

QgsProject * QgsExpressionTreeView::project ( )

Returns the project currently associated with the widget.

See also: setProject()

Definition at line 183 of file qgsexpressiontreeview.cpp.

◆ refresh()

void QgsExpressionTreeView::refresh ( )

Refreshes the content of the tree.

Definition at line 163 of file qgsexpressiontreeview.cpp.

◆ removeFromUserExpressions()

void QgsExpressionTreeView::removeFromUserExpressions ( const QString & label )

Removes the expression label from the user stored expressions.

Definition at line 578 of file qgsexpressiontreeview.cpp.

◆ saveToRecent()

void QgsExpressionTreeView::saveToRecent	(	const QString &	expressionText,
		const QString &	collection = `"generic"`
	)

Adds the current expression to the given collection.

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

Definition at line 543 of file qgsexpressiontreeview.cpp.

◆ saveToUserExpressions()

void QgsExpressionTreeView::saveToUserExpressions	(	const QString &	label,
		const QString &	expression,
		const QString &	helpText
	)

Stores the user expression with given label and helpText.

Definition at line 561 of file qgsexpressiontreeview.cpp.

◆ setExpressionContext()

void QgsExpressionTreeView::setExpressionContext ( const QgsExpressionContext & context )

Sets the expression context for the tree view.

The context is used to populate the list of available functions and variables.

Parameters

context expression context

See also: expressionContext

Definition at line 149 of file qgsexpressiontreeview.cpp.

◆ setLayer()

void QgsExpressionTreeView::setLayer ( QgsVectorLayer * layer )

Sets layer in order to get the fields and values.

Definition at line 137 of file qgsexpressiontreeview.cpp.

◆ setMenuProvider()

void QgsExpressionTreeView::setMenuProvider ( QgsExpressionTreeView::MenuProvider * provider )

Sets the menu provider.

This does not take ownership of the provider

Definition at line 158 of file qgsexpressiontreeview.cpp.

◆ setProject()

void QgsExpressionTreeView::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()

Definition at line 188 of file qgsexpressiontreeview.cpp.

◆ setSearchText

void QgsExpressionTreeView::setSearchText ( const QString & text )

slot

Sets the text to filter the expression tree.

Definition at line 195 of file qgsexpressiontreeview.cpp.

◆ userExpressionLabels()

QStringList QgsExpressionTreeView::userExpressionLabels ( ) const

Returns the user expression labels.

Definition at line 612 of file qgsexpressiontreeview.cpp.

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

/home/fischer/src/qgis-3.38/src/gui/qgsexpressiontreeview.h
/home/fischer/src/qgis-3.38/src/gui/qgsexpressiontreeview.cpp

Classes

Public Slots

Signals

Public Member Functions