Sorting table by its column value in Twig - symfony

Question

I created a method in Twig that will count and display results in table.But I want to sort the table based on results column
{% for island in islands %}
<tr>
<td>{{ island.id }}</td>
<td>{{ island.name }}</td>
<td>{{ number_votes(island.id) }}</td>
</tr>
{% endfor %}
results
id name result
1 name1 3000
2 name2 100
3 name3 5000
4 name4 90
As you can see it is sorted by default based on its id.How to sort based on its result column?
My twig filter
public function getFunctions()
{
return array(
new \Twig_SimpleFunction('number_votes', array($this, 'a'))
);
}
public function getName()
{
return 'app.extension';
}
public function a($id)
{
$qb=$this->em->createQueryBuilder();
$qb->select('count(v.id)')
->from('Bundle:Voters','v')
->join('v.city','c')
->join('c.province','p')
->join('p.region','r')
->join('r.island','i')
->where('i.id = :x')
->setParameter('x',$id);
$count = $qb->getQuery()->getSingleScalarResult();
return $count;
//I tried return sort($count)//not working
}
I also tried
{{ number_votes(island.id)|sort }}/throws an error
I'm afraid I have to create another Twig filter,is there any way to prevent this?

Answer 1

You could avoid a twig filter completely and do something like this so you have your islands and your vote counts in one result set:
$islandsAndVotes = $qb->select('i, count(v.id) as vote_count')
->from('Bundle:Voters','v')
->join('v.city','c')
->join('c.province','p')
->join('p.region','r')
->join('r.island','i')
->groupBy('i')
->orderBy('vote_count', 'DESC')
->getQuery()
->getResult()
;
Each element of $islandsAndVotes will contain an Island entity at index 0 and a vote count at index 1
E.g.
foreach ($islandsAndVotes as $islandVote) {
$island = array_shift($islandVote);
$votecount = array_shift($islandVote);
}
In twig you could use first & last to access the island or the vote count respectively as you iterate over the results.
{% for islandVote in islandsAndVotes %}
{% set island = islandVotes|first %}
{% set voteCount = islandVotes|last %}
<tr>
<td>{{ island.id }}</td>
<td>{{ island.name }}</td>
<td>{{ voteCount }}</td>
</tr>
{% endfor %}