Class providing some utility methods to manage auxiliary storage. More...

#include <qgsauxiliarystorage.h>

Public Member Functions
	QgsAuxiliaryStorage (const QgsProject &project, bool copy=true)
	Constructor. More...

	QgsAuxiliaryStorage (const QString &filename=QString(), bool copy=true)
	Constructor. More...

virtual	~QgsAuxiliaryStorage ()
	Destructor. More...

QgsAuxiliaryLayer *	createAuxiliaryLayer (const QgsField &field, QgsVectorLayer *layer) const
	Creates an auxiliary layer for a vector layer. More...

QString	currentFileName () const
	Returns the path of the current database used. More...

QString	errorString () const
	Returns the underlying error string describing potential errors happening in saveAs(). More...

QString	fileName () const
	Returns the target filename of the database. More...

bool	isValid () const
	Returns the status of the auxiliary storage currently defined. More...

bool	save () const
	Saves the current database. More...

bool	saveAs (const QString &filename)
	Saves the current database to a new path. More...

bool	saveAs (const QgsProject &project)
	Saves the current database to a new path for a specific project. More...

Static Public Member Functions
static bool	deleteTable (const QgsDataSourceUri &uri)
	Removes a table from the auxiliary storage. More...

static bool	duplicateTable (const QgsDataSourceUri &uri, const QString &newTable)
	Duplicates a table and its content. More...

static bool	exists (const QgsProject &project)
	Returns true if the auxiliary database yet exists for a project, false otherwise. More...

static QString	extension ()
	Returns the extension used for auxiliary databases. More...

Detailed Description

Class providing some utility methods to manage auxiliary storage.

Since: QGIS 3.0

Definition at line 259 of file qgsauxiliarystorage.h.

Constructor & Destructor Documentation

QgsAuxiliaryStorage::QgsAuxiliaryStorage	(	const QgsProject &	project,
		bool	copy = `true`
	)

Constructor.

The project filename is used to build a database path at the same location, but with a different extension. Then, it's the same logic as described for

See also: QgsAuxiliaryStorage(const QString &, bool copy).

Parameters

project	The project for which the auxiliary storage has to be used
copy	Parameter indicating if a copy of the database has to be used

Definition at line 516 of file qgsauxiliarystorage.cpp.

QgsAuxiliaryStorage::QgsAuxiliaryStorage	(	const QString &	filename = `QString()`,
		bool	copy = `true`
	)

Constructor.

If a valid database path is given in parameter and copy mode is deactivated, then every changes is directly committed on the original database. But if the copy mode is activated, then changes are committed on a copy of the database (a temporary file) and a save action is therefore necessary to keep modifications in the original file.

If an empty string for the database path is given in parameter, then a database is created in a temporary file whatever the copy mode.

If the database path given in parameter is not empty but does not exist, then a database is created at this location when copy mode is deactivated. When copy mode is activated, a temporary database is used instead and a save action will be necessary to create the database at the original location given in parameter.

Parameters

filename	The path of the database
copy	Parameter indicating if a copy of the database has to be used

Definition at line 529 of file qgsauxiliarystorage.cpp.

QgsAuxiliaryStorage::~QgsAuxiliaryStorage ( )

virtual

Destructor.

Definition at line 538 of file qgsauxiliarystorage.cpp.

Member Function Documentation

QgsAuxiliaryLayer * QgsAuxiliaryStorage::createAuxiliaryLayer	(	const QgsField &	field,
		QgsVectorLayer *	layer
	)		const

Creates an auxiliary layer for a vector layer.

A new table is created if necessary. The primary key to use to construct the auxiliary layer is given in parameter.

Parameters

field	The primary key to join
layer	The vector layer for which the auxiliary layer has to be created

Returns: A new auxiliary layer or a nullptr if an error happened.

Definition at line 576 of file qgsauxiliarystorage.cpp.

QString QgsAuxiliaryStorage::currentFileName ( ) const

Returns the path of the current database used.

It may be different from the target filename if the auxiliary storage is opened in copy mode.

Definition at line 822 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::deleteTable ( const QgsDataSourceUri & uri )

static

Removes a table from the auxiliary storage.

Parameters

uri	The uri of the table to remove

Returns: true if the table is well deleted, false otherwise

Definition at line 601 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::duplicateTable	(	const QgsDataSourceUri &	uri,
		const QString &	newTable
	)

static

Duplicates a table and its content.

Parameters

uri	The uri of the table to duplicate
newTable	The name of the new table

Returns: true if the table is well duplicated, false otherwise

Definition at line 624 of file qgsauxiliarystorage.cpp.

QString QgsAuxiliaryStorage::errorString ( ) const

Returns the underlying error string describing potential errors happening in saveAs().

Empty by default.

Since: QGIS 3.4

Definition at line 644 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::exists ( const QgsProject & project )

static

Returns true if the auxiliary database yet exists for a project, false otherwise.

Parameters

project The project for which the database is checked

Since: QGIS 3.2

Definition at line 680 of file qgsauxiliarystorage.cpp.

QString QgsAuxiliaryStorage::extension ( )

static

Returns the extension used for auxiliary databases.

Definition at line 675 of file qgsauxiliarystorage.cpp.

QString QgsAuxiliaryStorage::fileName ( ) const

Returns the target filename of the database.

Definition at line 548 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::isValid ( ) const

Returns the status of the auxiliary storage currently defined.

Returns: true if the auxiliary storage is valid, false otherwise

Definition at line 543 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::save ( ) const

Saves the current database.

Returns: true if everything is saved, false otherwise

Definition at line 553 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::saveAs ( const QString & filename )

Saves the current database to a new path.

Returns: true if everything is saved, false otherwise

Definition at line 649 of file qgsauxiliarystorage.cpp.

bool QgsAuxiliaryStorage::saveAs ( const QgsProject & project )

Saves the current database to a new path for a specific project.

Actually, the current filename of the project is used to deduce the path of the database to save.

Returns: true if everything is saved, false otherwise

Definition at line 670 of file qgsauxiliarystorage.cpp.

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

/build/qgis-3.4.15+24xenial/src/core/qgsauxiliarystorage.h
/build/qgis-3.4.15+24xenial/src/core/qgsauxiliarystorage.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation