void QgsFieldCalculator::accept()
{
builder->saveToRecent( "fieldcalc" );
if ( !mVectorLayer )
return;
// Set up QgsDistanceArea each time we (re-)calculate
QgsDistanceArea myDa;
myDa.setSourceCrs( mVectorLayer->crs().srsid() );
myDa.setEllipsoidalMode( QgisApp::instance()->mapCanvas()->mapSettings().hasCrsTransformEnabled() );
myDa.setEllipsoid( QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE ) );
QString calcString = builder->expressionText();
QgsExpression exp( calcString );
exp.setGeomCalculator( myDa );
QgsExpressionContext expContext;
expContext << QgsExpressionContextUtils::globalScope()
<< QgsExpressionContextUtils::projectScope()
<< QgsExpressionContextUtils::layerScope( mVectorLayer );
if ( !exp.prepare( &expContext ) )
{
QMessageBox::critical( 0, tr( "Evaluation error" ), exp.evalErrorString() );
return;
}
// Test for creating expression field based on ! mUpdateExistingGroupBox checked rather
// than on mNewFieldGroupBox checked, as if the provider does not support adding attributes
// then mUpdateExistingGroupBox is set to not checkable, and hence is not checked. This
// is a minimum fix to resolve this - better would be some GUI redesign...
if ( ! mUpdateExistingGroupBox->isChecked() && mCreateVirtualFieldCheckbox->isChecked() )
{
mVectorLayer->addExpressionField( calcString, fieldDefinition() );
}
else
{
if ( !mVectorLayer->isEditable() )
mVectorLayer->startEditing();
QApplication::setOverrideCursor( Qt::WaitCursor );
mVectorLayer->beginEditCommand( "Field calculator" );
//update existing field
if ( mUpdateExistingGroupBox->isChecked() || !mNewFieldGroupBox->isEnabled() )
{
QMap<QString, int>::const_iterator fieldIt = mFieldMap.find( mExistingFieldComboBox->currentText() );
if ( fieldIt != mFieldMap.end() )
{
mAttributeId = fieldIt.value();
}
}
else
{
//create new field
const QgsField newField = fieldDefinition();
if ( !mVectorLayer->addAttribute( newField ) )
{
QApplication::restoreOverrideCursor();
QMessageBox::critical( 0, tr( "Provider error" ), tr( "Could not add the new field to the provider." ) );
mVectorLayer->destroyEditCommand();
return;
}
//get index of the new field
const QgsFields& fields = mVectorLayer->fields();
for ( int idx = 0; idx < fields.count(); ++idx )
{
if ( fields[idx].name() == mOutputFieldNameLineEdit->text() )
{
mAttributeId = idx;
break;
}
}
//update expression context with new fields
expContext.setFields( mVectorLayer->fields() );
if ( ! exp.prepare( &expContext ) )
{
QApplication::restoreOverrideCursor();
QMessageBox::critical( 0, tr( "Evaluation error" ), exp.evalErrorString() );
return;
}
}
if ( mAttributeId == -1 )
{
mVectorLayer->destroyEditCommand();
QApplication::restoreOverrideCursor();
return;
}
//go through all the features and change the new attribute
QgsFeature feature;
bool calculationSuccess = true;
QString error;
bool onlySelected = mOnlyUpdateSelectedCheckBox->isChecked();
QgsFeatureIds selectedIds = mVectorLayer->selectedFeaturesIds();
bool useGeometry = exp.needsGeometry();
int rownum = 1;
QgsField field = mVectorLayer->fields()[mAttributeId];
bool newField = !mUpdateExistingGroupBox->isChecked();
QVariant emptyAttribute;
if ( newField )
emptyAttribute = QVariant( field.type() );
QgsFeatureIterator fit = mVectorLayer->getFeatures( QgsFeatureRequest().setFlags( useGeometry ? QgsFeatureRequest::NoFlags : QgsFeatureRequest::NoGeometry ) );
while ( fit.nextFeature( feature ) )
{
if ( onlySelected )
{
if ( !selectedIds.contains( feature.id() ) )
{
continue;
}
}
expContext.setFeature( feature );
expContext.lastScope()->setVariable( QString( "row_number" ), rownum );
QVariant value = exp.evaluate( &expContext );
field.convertCompatible( value );
if ( exp.hasEvalError() )
{
calculationSuccess = false;
error = exp.evalErrorString();
break;
}
else
{
mVectorLayer->changeAttributeValue( feature.id(), mAttributeId, value, newField ? emptyAttribute : feature.attributes().value( mAttributeId ) );
}
rownum++;
}
QApplication::restoreOverrideCursor();
if ( !calculationSuccess )
{
QMessageBox::critical( 0, tr( "Error" ), tr( "An error occured while evaluating the calculation string:\n%1" ).arg( error ) );
mVectorLayer->destroyEditCommand();
return;
}
mVectorLayer->endEditCommand();
}
QDialog::accept();
}
void QgsFieldCalculator::accept()
{
builder->saveToRecent( QStringLiteral( "fieldcalc" ) );
if ( !mVectorLayer )
return;
// Set up QgsDistanceArea each time we (re-)calculate
QgsDistanceArea myDa;
myDa.setSourceCrs( mVectorLayer->crs().srsid() );
myDa.setEllipsoidalMode( true );
myDa.setEllipsoid( QgsProject::instance()->ellipsoid() );
QString calcString = builder->expressionText();
QgsExpression exp( calcString );
exp.setGeomCalculator( &myDa );
exp.setDistanceUnits( QgsProject::instance()->distanceUnits() );
exp.setAreaUnits( QgsProject::instance()->areaUnits() );
QgsExpressionContext expContext( QgsExpressionContextUtils::globalProjectLayerScopes( mVectorLayer ) );
if ( !exp.prepare( &expContext ) )
{
QMessageBox::critical( nullptr, tr( "Evaluation error" ), exp.evalErrorString() );
return;
}
bool updatingGeom = false;
// Test for creating expression field based on ! mUpdateExistingGroupBox checked rather
// than on mNewFieldGroupBox checked, as if the provider does not support adding attributes
// then mUpdateExistingGroupBox is set to not checkable, and hence is not checked. This
// is a minimum fix to resolve this - better would be some GUI redesign...
if ( ! mUpdateExistingGroupBox->isChecked() && mCreateVirtualFieldCheckbox->isChecked() )
{
mVectorLayer->addExpressionField( calcString, fieldDefinition() );
}
else
{
if ( !mVectorLayer->isEditable() )
mVectorLayer->startEditing();
QApplication::setOverrideCursor( Qt::WaitCursor );
mVectorLayer->beginEditCommand( QStringLiteral( "Field calculator" ) );
//update existing field
if ( mUpdateExistingGroupBox->isChecked() || !mNewFieldGroupBox->isEnabled() )
{
if ( mExistingFieldComboBox->currentData().toString() == QLatin1String( "geom" ) )
{
//update geometry
mAttributeId = -1;
updatingGeom = true;
}
else
{
QMap<QString, int>::const_iterator fieldIt = mFieldMap.constFind( mExistingFieldComboBox->currentText() );
if ( fieldIt != mFieldMap.constEnd() )
{
mAttributeId = fieldIt.value();
}
}
}
else
{
//create new field
const QgsField newField = fieldDefinition();
if ( !mVectorLayer->addAttribute( newField ) )
{
QApplication::restoreOverrideCursor();
QMessageBox::critical( nullptr, tr( "Provider error" ), tr( "Could not add the new field to the provider." ) );
mVectorLayer->destroyEditCommand();
return;
}
//get index of the new field
const QgsFields& fields = mVectorLayer->fields();
for ( int idx = 0; idx < fields.count(); ++idx )
{
if ( fields.at( idx ).name() == mOutputFieldNameLineEdit->text() )
{
mAttributeId = idx;
break;
}
}
//update expression context with new fields
expContext.setFields( mVectorLayer->fields() );
if ( ! exp.prepare( &expContext ) )
{
QApplication::restoreOverrideCursor();
QMessageBox::critical( nullptr, tr( "Evaluation error" ), exp.evalErrorString() );
return;
}
}
if ( mAttributeId == -1 && !updatingGeom )
{
mVectorLayer->destroyEditCommand();
QApplication::restoreOverrideCursor();
return;
}
//go through all the features and change the new attribute
QgsFeature feature;
bool calculationSuccess = true;
QString error;
bool useGeometry = exp.needsGeometry();
int rownum = 1;
QgsField field = !updatingGeom ? mVectorLayer->fields().at( mAttributeId ) : QgsField();
bool newField = !mUpdateExistingGroupBox->isChecked();
QVariant emptyAttribute;
if ( newField )
emptyAttribute = QVariant( field.type() );
QgsFeatureRequest req = QgsFeatureRequest().setFlags( useGeometry ? QgsFeatureRequest::NoFlags : QgsFeatureRequest::NoGeometry );
if ( mOnlyUpdateSelectedCheckBox->isChecked() )
{
req.setFilterFids( mVectorLayer->selectedFeatureIds() );
}
QgsFeatureIterator fit = mVectorLayer->getFeatures( req );
while ( fit.nextFeature( feature ) )
{
expContext.setFeature( feature );
expContext.lastScope()->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "row_number" ), rownum, true ) );
QVariant value = exp.evaluate( &expContext );
if ( exp.hasEvalError() )
{
calculationSuccess = false;
error = exp.evalErrorString();
break;
}
else if ( updatingGeom )
{
if ( value.canConvert< QgsGeometry >() )
{
QgsGeometry geom = value.value< QgsGeometry >();
mVectorLayer->changeGeometry( feature.id(), geom );
}
}
else
{
field.convertCompatible( value );
mVectorLayer->changeAttributeValue( feature.id(), mAttributeId, value, newField ? emptyAttribute : feature.attributes().value( mAttributeId ) );
}
rownum++;
}
QApplication::restoreOverrideCursor();
if ( !calculationSuccess )
{
QMessageBox::critical( nullptr, tr( "Error" ), tr( "An error occurred while evaluating the calculation string:\n%1" ).arg( error ) );
mVectorLayer->destroyEditCommand();
return;
}
mVectorLayer->endEditCommand();
}
QDialog::accept();
}
