QVariant QgsSymbolLayerV2::evaluateDataDefinedProperty( const QString &property, const QgsFeature* feature, const QVariant& defaultVal, bool *ok ) const
{
if ( ok )
*ok = false;
QgsDataDefined* dd = getDataDefinedProperty( property );
if ( !dd || !dd->isActive() )
return defaultVal;
if ( dd->useExpression() )
{
if ( dd->expression() )
{
QgsExpressionContext context = feature ? QgsExpressionContextUtils::createFeatureBasedContext( *feature, QgsFields() ) : QgsExpressionContext();
QVariant result = dd->expression()->evaluate( &context );
if ( result.isValid() )
{
if ( ok )
*ok = true;
return result;
}
else
return defaultVal;
}
else
{
return defaultVal;
}
}
else if ( feature && !dd->field().isEmpty() && !mFields.isEmpty() )
{
int attributeIndex = mFields.fieldNameIndex( dd->field() );
if ( attributeIndex >= 0 )
{
if ( ok )
*ok = true;
return feature->attribute( attributeIndex );
}
}
return defaultVal;
}
QVariant QgsSymbolLayerV2::evaluateDataDefinedProperty( const QString& property, const QgsSymbolV2RenderContext& context, const QVariant& defaultVal, bool* ok ) const
{
if ( ok )
*ok = false;
QgsDataDefined* dd = getDataDefinedProperty( property );
if ( !dd || !dd->isActive() )
return defaultVal;
if ( dd->useExpression() )
{
if ( dd->expression() )
{
QVariant result = dd->expression()->evaluate( &context.renderContext().expressionContext() );
if ( result.isValid() )
{
if ( ok )
*ok = true;
return result;
}
else
return defaultVal;
}
else
{
return defaultVal;
}
}
else if ( context.feature() && !dd->field().isEmpty() && !mFields.isEmpty() )
{
int attributeIndex = mFields.fieldNameIndex( dd->field() );
if ( attributeIndex >= 0 )
{
if ( ok )
*ok = true;
return context.feature()->attribute( attributeIndex );
}
}
return defaultVal;
}
QgsExpression* QgsSymbolLayerV2::expression( const QString& property ) const
{
QgsDataDefined* dd = getDataDefinedProperty( property );
return dd ? dd->expression() : nullptr;
}
