apply_filter: manipulating QueryBuilder directly vs. returning a Condition?

[spackmat]

Hi,

I have to filter for the existence of related entities. An elegant way to do this is using the is empty expression of DQL. Since I don't know a way to use is empty within Expr contexts, my working code for now is:

'apply_filter' => function (QueryInterface $filterQuery, $field, $values) {
    $query = $filterQuery->getQueryBuilder();
    if ($values['value'] == 'true') {
        $query->andWhere('e.relatedEntities is not empty');
    }
    elseif ($values['value'] == 'false') {
        $query->andWhere('e.relatedEntities is empty');
    }

    return null;
},

This works, but I have a strong feeling, that manipulating the QueryBuilder directly is bad practice and I should find a way to express this using Expr-constructs instead.

So any opnions on this?

Or an idea how I can solve this with the Expressions-interface?

Greets,
spackmat

[cedric-g]

Hi :), since I've added the filter_condition_builder option you can simply return a condition object in the apply_filter closure:

'apply_filter' => function (QueryInterface $filterQuery, $field, $values) {
    if ($values['value'] == 'true') {
        return $filterQuery->createCondition('e.relatedEntities is not empty');
    }
    elseif ($values['value'] == 'false') {
        return $filterQuery->createCondition('e.relatedEntities is empty');
    }

    return null;
},

[spackmat]

@cedric-g cool, this makes my life easier, thanks.

But for the record: Is it bad practice to manipulate the QueryBuilder directly? Why? What's the difference, if any?

[rvanlaak]

Manipulate directly? That actually is the idea of the library right, or how do you see this as a bad practice? You can also pass it as callable / callback if I'm right.

[cedric-g]

It depends on the way you work with the bundle. The fact is, if you choose to add some expressions directly to the doctrine query builder in the apply_filter it will work. But these expressions won't be handled by the filter_condition_builder as the expression won't be associatied to the field but straight to the doctrine query builder.

[spackmat]

@cedric-g so now if I have a filter, which has no corresponding field/property, but uses a Repository-method to add a complex andWhere() expression to the queryBuilder instead, the following would be fine?

'apply_filter' => function (QueryInterface $filterQuery, $field, $values) {
    if (empty($values['value'])) {
        return null;
    }

    $this->myInjectedRepository->addQbMyComplexFilter($filterQuery->getQueryBuilder(), $values['value']);
    return null;
},

And in the repository to be complete:

public function addQbMyComplexFilter(QueryBuilder $qb, string $myFilterValue): QueryBuilder
{
    $qb
        ->andWhere(
            // create some complex filter expressions
        )
        ->setParameter('myFIlterValue', $myFilterValue)
    ;
    return $qb;
}

This works, but I still have a feeling, that this direct manipulation could have side effects. What are the the downsides of "But these expressions won't be handled by the filter_condition_builder"?