QGIS/python/core/qgstransaction.sip
2017-05-05 15:39:29 +02:00

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/************************************************************************
* This file has been generated automatically from *
* *
* src/core/qgstransaction.h *
* *
* Do not edit manually ! Edit header and run scripts/sipify.pl again *
************************************************************************/
class QgsTransaction : QObject /Abstract/
{
%Docstring
This class allows including a set of layers in a database-side transaction,
provided the layer data providers support transactions and are compatible
with each other.
Only layers which are not in edit mode can be included in a transaction,
and all layers need to be in read-only mode for a transaction to be committed
or rolled back.
Layers cannot only be included in one transaction at a time.
When editing layers which are part of a transaction group, all changes are
sent directly to the data provider (bypassing the undo/redo stack), and the
changes can either be committed or rolled back on the database side via the
QgsTransaction.commit and QgsTransaction.rollback methods.
As long as the transaction is active, the state of all layer features reflects
the current state in the transaction.
Edits on features can get rejected if another conflicting transaction is active.
%End
%TypeHeaderCode
#include "qgstransaction.h"
%End
public:
static QgsTransaction *create( const QString &connString, const QString &providerKey ) /Factory/;
%Docstring
Create a transaction for the specified connection string ``connString``
and provider with ``providerKey``.
:rtype: QgsTransaction
%End
static QgsTransaction *create( const QStringList &layerIds ) /Factory/;
%Docstring
Create a transaction which includes the layers specified with
``layerIds``.
All layers are expected to have the same connection string and data
provider.
:rtype: QgsTransaction
%End
virtual ~QgsTransaction();
bool addLayer( const QString &layerId );
%Docstring
Add the layer with ``layerId`` to the transaction. The layer must not be
in edit mode and the connection string must match.
:rtype: bool
%End
bool addLayer( QgsVectorLayer *layer );
%Docstring
Add the ``layer`` to the transaction. The layer must not be
in edit mode and the connection string must match.
:rtype: bool
%End
bool begin( QString &errorMsg /Out/, int statementTimeout = 20 );
%Docstring
Begin transaction
The ``statementTimeout`` (in seconds) specifies how long an sql statement
is allowed to block QGIS before it is aborted.
Statements can block, if multiple transactions are active and a
statement would produce a conflicting state. In these cases, the
statements block until the conflicting transaction is committed or
rolled back.
Some providers might not honour the statement timeout.
:rtype: bool
%End
bool commit( QString &errorMsg /Out/ );
%Docstring
Commit transaction.
:rtype: bool
%End
bool rollback( QString &errorMsg /Out/ );
%Docstring
Roll back transaction.
:rtype: bool
%End
virtual bool executeSql( const QString &sql, QString &error /Out/ ) = 0;
%Docstring
Execute the ``sql`` string. The result must not be a tuple, so running a
``SELECT`` query will return an error.
:rtype: bool
%End
static bool supportsTransaction( const QgsVectorLayer *layer );
%Docstring
Checks if a the provider of a given ``layer`` supports transactions.
:rtype: bool
%End
signals:
void afterRollback();
%Docstring
Emitted after a rollback
%End
protected:
};
/************************************************************************
* This file has been generated automatically from *
* *
* src/core/qgstransaction.h *
* *
* Do not edit manually ! Edit header and run scripts/sipify.pl again *
************************************************************************/