Class providing some utility methods to manage auxiliary storage.
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#include <qgsauxiliarystorage.h>
Class providing some utility methods to manage auxiliary storage.
- Since
- QGIS 3.0
Definition at line 291 of file qgsauxiliarystorage.h.
◆ QgsAuxiliaryStorage() [1/2]
| 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 |
◆ QgsAuxiliaryStorage() [2/2]
| 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 |
◆ ~QgsAuxiliaryStorage()
| virtual QgsAuxiliaryStorage::~QgsAuxiliaryStorage |
( |
| ) |
|
|
virtual |
◆ createAuxiliaryLayer()
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
nullptr if an error happened.
◆ currentFileName()
| 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.
◆ deleteTable()
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
◆ duplicateTable()
| static 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
◆ errorString()
| QString QgsAuxiliaryStorage::errorString |
( |
| ) |
const |
Returns the underlying error string describing potential errors happening in saveAs().
Empty by default.
- Since
- QGIS 3.4
◆ exists()
| static 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
◆ extension()
| static QString QgsAuxiliaryStorage::extension |
( |
| ) |
|
|
static |
Returns the extension used for auxiliary databases.
◆ fileName()
| QString QgsAuxiliaryStorage::fileName |
( |
| ) |
const |
Returns the target filename of the database.
◆ isValid()
| bool QgsAuxiliaryStorage::isValid |
( |
| ) |
const |
Returns the status of the auxiliary storage currently defined.
- Returns
true if the auxiliary storage is valid, false otherwise
◆ save()
| bool QgsAuxiliaryStorage::save |
( |
| ) |
const |
Saves the current database.
- Returns
true if everything is saved, false otherwise
◆ saveAs() [1/2]
| 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
◆ saveAs() [2/2]
| bool QgsAuxiliaryStorage::saveAs |
( |
const QString & |
filename | ) |
|
Saves the current database to a new path.
- Returns
true if everything is saved, false otherwise
The documentation for this class was generated from the following file:
