Sylius: How to sort product by variant.sku - sylius

Question

I would like to sort the products by its sku. How would that be possible ?
I tried to add in ProductRepository.php:
...
$queryBuilder = $this->getCollectionQueryBuilder();
$queryBuilder
->innerJoin('product.taxons', 'taxon')
->innerJoin('product.variants', 'variant')
->andWhere('taxon = :taxon')
->setParameter('taxon', $taxon)
;
foreach ($criteria as $attributeName => $value) {
$queryBuilder
->andWhere('product.'.$attributeName.' IN (:'.$attributeName.')')
->setParameter($attributeName, $value)
;
}
$queryBuilder->orderBy('variant.sku');
...
but got:
Cannot select distinct identifiers from query with LIMIT and ORDER BY
on a column from a fetch joined to-many association. Use output
walkers.

Answer 1

Finally what I did: Sorted the products just before output in a custom twig function:
macros.html.twig
{% set products = skusort(products) %}
In my SkusortExtenstion.php (as of PHP 5.3)
$product->getIterator()->uasort(function($a, $b){
return $a->getMasterVariant()->getSku() > $b->getMasterVariant()->getSku();
});
return $product;
Was afraid of performance issue as there's a lot of products but seems to be very fast.

Answer 2

Another way is to reload method getPaginator() of class Sylius\Bundle\ResourceBundle\Doctrine\ORM\EntityRepository. In that case we must instantinate DoctrineORMAdapter with $useOutputWalkers flag (the latest constructor argument).
So, put the folowing code in your ProductRepository.php:
/**
* {#inheritdoc}
*/
public function getPaginator(QueryBuilder $queryBuilder)
{
return new Pagerfanta(new DoctrineORMAdapter($queryBuilder, true, true));
}