如果提供条件，则Doctrine为createQueryBuilder添加条件

Question

I have following function:

public function latestNews($tags = array(), $categories = array(), $authors = array(), $lang = 'en', $source = '', $limit = 20) {
    return $this->createQueryBuilder('News')
    ->field('tags')->in($tags)
    ->field('categories')->in($category)
    ->field('authors')->in($authors)
    ->field('lang')->equals($lang)
    ->sort('date' -> 'DESC')
    ->field('source')->equals($source)
    ->limit($limit)
    ->getQuery()
    ->execute();
}

I want if variables such as $tags, $categories, $authors or $source provided by function caller this variables affect on the createQueryBuilder, but if each of them does not provide by the function caller(variable with default value) they don't affect createQueryBuilder and make this condition neutral on query. One way is I make the query with many if condition but it is very messy. Is there any better solution?

Answer 1

Something like this should do the trick:

public function latestNews($tags = array(), $categories = array(), authors = array(), $lang = 'en', $source = '', $limit = 20) {
    $inClauses = ['tags', 'categories', 'authors'];
    $equalClauses = ['lang', 'source'];
    $qb = $this->createQueryBuilder('News');

    foreach ($inClauses as $field) {
        $realVar = ${$field};

        if (!empty($realVar)) {
            $qb->field($field)->in($realVar);
        }
    }

    foreach ($equalClauses as $field) {
        $realVar = ${$field};

        if ($realVar) {
            $qb->field($field)->equals($realVar);
        }
    }

    return $qb
        ->sort('date' -> 'DESC')
        ->limit($limit)
        ->getQuery()
        ->execute();
}

A bit ugly, but I don't see any better alternative.