bool QgsTransaction::addLayer( QgsVectorLayer* layer )
{
if ( !layer )
return false;
if ( layer->isEditable() )
return false;
//test if provider supports transactions
if ( !layer->dataProvider() || ( layer->dataProvider()->capabilities() & QgsVectorDataProvider::TransactionSupport ) == 0 )
return false;
if ( layer->dataProvider()->transaction() )
return false;
//connection string not compatible
if ( QgsDataSourceURI( layer->source() ).connectionInfo( false ) != mConnString )
{
QgsDebugMsg( QString( "Couldn't start transaction because connection string for layer %1 : '%2' does not match '%3'" ).arg(
layer->id(), QgsDataSourceURI( layer->source() ).connectionInfo( false ), mConnString ) );
return false;
}
connect( this, SIGNAL( afterRollback() ), layer->dataProvider(), SIGNAL( dataChanged() ) );
connect( QgsMapLayerRegistry::instance(), SIGNAL( layersWillBeRemoved( QStringList ) ), this, SLOT( onLayersDeleted( QStringList ) ) );
mLayers.insert( layer );
if ( mTransactionActive )
layer->dataProvider()->setTransaction( this );
return true;
}
bool QgsTransaction::rollback( QString& errorMsg )
{
if ( !mTransactionActive )
{
return false;
}
Q_FOREACH ( QgsVectorLayer* l, mLayers )
{
if ( l->isEditable() )
{
return false;
}
}
if ( !rollbackTransaction( errorMsg ) )
{
return false;
}
setLayerTransactionIds( 0 );
mTransactionActive = false;
emit afterRollback();
return true;
}
bool QgsTransaction::rollback( QString& errorMsg )
{
if ( !mTransactionActive )
return false;
if ( !rollbackTransaction( errorMsg ) )
return false;
setLayerTransactionIds( nullptr );
mTransactionActive = false;
emit afterRollback();
return true;
}