EntityRepository::applyFilter(Filter $filter)

EntityRepository_applyFilter.php

class EntityRepository
{
    public function applyFilter(Filter $filter)
    {
        $qb = $this->createQueryBuilder('e');

        $filter->apply($qb);

        return $qb->getQuery()->getResult();
    }
}


interface Filter
{
    public function apply(QueryBuilder $qb);
}


class FilterChain implements Filter
{
    // This could be a SplPriorityQueue too
    private $filters = array();

    public function add(Filter $filter)
    {
        $this->filters[] = $filter;
    }

    public function apply(QueryBuilder $qb)
    {
        foreach ($this->filters as $filter) {
            $filter->apply($qb);
        }
    }
}


namespace Filters\Group;

class GroupNameFilter implements Filter
{
    private $name;

    public function __construct($name)
    {
        $this->name = $name;
    }

    public function apply(QueryBuilder $qb)
    {
        $qb->addSelect('g')
           ->innerJoin($qb->getRootAlias() . '.Group', 'g', Expr\Join::WITH, 'g.name = :groupName')
           ->setParameter('groupName', $this->name);
    }
}

For userland code why not, but that doesnt help as a generic ways as its only for QueryBuilder and doesnt help with persister queries