QgsExpressionTreeView Class Reference

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:

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. More...

Signals
void	currentExpressionItemChanged (QgsExpressionItem *item)
	Emitter when the current expression item changed. More...
void	expressionItemDoubleClicked (const QString &text)
	Emitted when a expression item is double clicked. More...

Public Member Functions
	QgsExpressionTreeView (QWidget *parent=nullptr)
	Constructor. More...
QgsExpressionItem *	currentItem () const
	Returns the current item or a nullptr. More...
QJsonDocument	exportUserExpressions ()
	Create the expressions JSON document storing all the user expressions to be exported. More...
QgsExpressionContext	expressionContext () const
	Returns the expression context for the widget. More...
const QList< QgsExpressionItem * >	findExpressions (const QString &label)
	Returns the list of expression items matching a label. More...
void	loadExpressionsFromJson (const QJsonDocument &expressionsDocument)
	Load and permanently store the expressions from the expressions JSON document. More...
void	loadFieldNames (const QgsFields &fields)
	This allows loading fields without specifying a layer. More...
void	loadRecent (const QString &collection=QStringLiteral("generic"))
	Loads the recent expressions from the given collection. More...
void	loadUserExpressions ()
	Loads the user expressions. More...
Q_DECL_DEPRECATED QStandardItemModel *	model ()
	Returns a pointer to the dialog's function item model. More...
QgsProject *	project ()
	Returns the project currently associated with the widget. More...
void	refresh ()
	Refreshes the content of the tree. More...
void	removeFromUserExpressions (const QString &label)
	Removes the expression label from the user stored expressions. More...
void	saveToRecent (const QString &expressionText, const QString &collection="generic")
	Adds the current expression to the given collection. More...
void	saveToUserExpressions (const QString &label, const QString &expression, const QString &helpText)
	Stores the user expression with given label and helpText. More...
void	setExpressionContext (const QgsExpressionContext &context)
	Sets the expression context for the tree view. More...
void	setLayer (QgsVectorLayer *layer)
	Sets layer in order to get the fields and values. More...
void	setMenuProvider (MenuProvider *provider)
	Sets the menu provider. More...
void	setProject (QgsProject *project)
	Sets the project currently associated with the widget. More...
QStringList	userExpressionLabels () const
	Returns the user expression labels. More...

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 611 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 797 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 653 of file qgsexpressiontreeview.cpp.

loadFieldNames()

void QgsExpressionTreeView::loadFieldNames

(

const QgsFields &

fields

)

This allows loading fields without specifying a layer.

Definition at line 447 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 513 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 580 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 572 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 537 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 555 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 606 of file qgsexpressiontreeview.cpp.

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

• /build/qgis-3.28.0+99sid/src/gui/qgsexpressiontreeview.h
• /build/qgis-3.28.0+99sid/src/gui/qgsexpressiontreeview.cpp