Doctrine\ORM\Tools\Pagination\Paginator

Complexity

Total Complexity

27

Size/Duplication

Total Lines	248
Duplicated Lines	0 %

Test Coverage

Coverage

90.91%

Importance

Changes

0

12 Methods

Rating	Name	Duplication	Size	Complexity
A	getFetchJoinCollection()	0	3	1
A	appendTreeWalker()	0	10	2
A	__construct()	0	8	2
B	getIterator()	0	43	4
A	getPagesCount()	0	5	2
A	useOutputWalker()	0	7	2
A	getUseOutputWalkers()	0	3	1
B	getCountQuery()	0	40	6
A	cloneQuery()	0	13	2
A	getQuery()	0	3	1
A	setUseOutputWalkers()	0	5	1
A	count()	0	11	3

<?php

declare(strict_types=1);

namespace Doctrine\ORM\Tools\Pagination;

use Doctrine\Common\Collections\Collection;
use Doctrine\DBAL\Types\Type;
use Doctrine\ORM\NoResultException;
use Doctrine\ORM\Query;
use Doctrine\ORM\Query\Parameter;
use Doctrine\ORM\Query\Parser;
use Doctrine\ORM\Query\ResultSetMapping;
use Doctrine\ORM\QueryBuilder;
use function array_key_exists;
use function array_map;
use function array_sum;
use function ceil;
use function count;

/**
 * The paginator can handle various complex scenarios with DQL.
 */
class Paginator implements \Countable, \IteratorAggregate
{
    /** @var Query */
    private $query;

    /** @var bool */
    private $fetchJoinCollection;

    /** @var bool|null */
    private $useOutputWalkers;

    /** @var int */
    private $count;

    /**
     * @param Query|QueryBuilder $query               A Doctrine ORM query or query builder.
     * @param bool               $fetchJoinCollection Whether the query joins a collection (true by default).
     */
    public function __construct($query, $fetchJoinCollection = true)
    {
        if ($query instanceof QueryBuilder) {
            $query = $query->getQuery();
        }

        $this->query               = $query;
        $this->fetchJoinCollection = (bool) $fetchJoinCollection;
    }

    /**
     * Returns the query.
     *
     * @return Query
     */
    public function getQuery()
    {
        return $this->query;
    }

    /**
     * Returns whether the query joins a collection.
     *
     * @return bool Whether the query joins a collection.
     */
    public function getFetchJoinCollection()
    {
        return $this->fetchJoinCollection;
    }

    /**
     * Returns whether the paginator will use an output walker.
     *
     * @return bool|null
     */
    public function getUseOutputWalkers()
    {
        return $this->useOutputWalkers;
    }

    /**
     * Sets whether the paginator will use an output walker.
     *
     * @param bool|null $useOutputWalkers
     *
     * @return $this
     */
    public function setUseOutputWalkers($useOutputWalkers)
    {
        $this->useOutputWalkers = $useOutputWalkers;

        return $this;
    }

    /**
     * {@inheritdoc}
     */
    public function count()
    {
        if ($this->count === null) {
            try {
                $this->count = array_sum(array_map('current', $this->getCountQuery()->getScalarResult()));
            } catch (NoResultException $e) {
                $this->count = 0;
            }
        }

        return $this->count;
    }

    /**
     * Returns number of pages
     *
     * @return int|null
     */
    public function getPagesCount()
    {
        $maxResults = $this->query->getMaxResults();

        return $maxResults !== null ? (int) ceil($this->count() / $maxResults) : null;
    }

    /**
     * {@inheritdoc}
     */
    public function getIterator()
    {
        $offset = $this->query->getFirstResult();
        $length = $this->query->getMaxResults();

        if ($this->fetchJoinCollection) {
            $subQuery = $this->cloneQuery($this->query);

            if ($this->useOutputWalker($subQuery)) {
                $subQuery->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, LimitSubqueryOutputWalker::class);
            } else {
                $this->appendTreeWalker($subQuery, LimitSubqueryWalker::class);
            }

            $subQuery->setFirstResult($offset)->setMaxResults($length);

            $ids = array_map('current', $subQuery->getScalarResult());

            $whereInQuery = $this->cloneQuery($this->query);

            // don't do this for an empty id array
            if (count($ids) === 0) {
                return new \ArrayIterator([]);
            }

            $this->appendTreeWalker($whereInQuery, WhereInWalker::class);

            $whereInQuery->setHint(WhereInWalker::HINT_PAGINATOR_ID_COUNT, count($ids));
            $whereInQuery->setFirstResult(null)->setMaxResults(null);
            $whereInQuery->setParameter(WhereInWalker::PAGINATOR_ID_ALIAS, $ids);
            $whereInQuery->setCacheable($this->query->isCacheable());

            $result = $whereInQuery->getResult($this->query->getHydrationMode());
        } else {
            $result = $this->cloneQuery($this->query)
                ->setMaxResults($length)
                ->setFirstResult($offset)
                ->setCacheable($this->query->isCacheable())
                ->getResult($this->query->getHydrationMode())
            ;
        }

        return new \ArrayIterator($result);
    }

    /**
     * Clones a query.
     *
     * @param Query $query The query.
     *
     * @return Query The cloned query.
     */
    private function cloneQuery(Query $query)
    {
        /** @var Query $cloneQuery */
        $cloneQuery = clone $query;

        $cloneQuery->setParameters(clone $query->getParameters());
        $cloneQuery->setCacheable(false);

        foreach ($query->getHints() as $name => $value) {
            $cloneQuery->setHint($name, $value);
        }

        return $cloneQuery;
    }

    /**
     * Determines whether to use an output walker for the query.
     *
     * @param Query $query The query.
     *
     * @return bool
     */
    private function useOutputWalker(Query $query)
    {
        if ($this->useOutputWalkers === null) {
            return (bool) $query->getHint(Query::HINT_CUSTOM_OUTPUT_WALKER) === false;
        }

        return $this->useOutputWalkers;
    }

    /**
     * Appends a custom tree walker to the tree walkers hint.
     *
     * @param string $walkerClass
     */
    private function appendTreeWalker(Query $query, $walkerClass)
    {
        $hints = $query->getHint(Query::HINT_CUSTOM_TREE_WALKERS);

        if ($hints === false) {
            $hints = [];
        }

        $hints[] = $walkerClass;
        $query->setHint(Query::HINT_CUSTOM_TREE_WALKERS, $hints);
    }

    /**
     * Returns Query prepared to count.
     *
     * @return Query
     */
    private function getCountQuery()
    {
        /** @var Query $countQuery */
        $countQuery = $this->cloneQuery($this->query);

        if (! $countQuery->hasHint(CountWalker::HINT_DISTINCT)) {
            $countQuery->setHint(CountWalker::HINT_DISTINCT, true);
        }

        if ($this->useOutputWalker($countQuery)) {
            $platform = $countQuery->getEntityManager()->getConnection()->getDatabasePlatform(); // law of demeter win

            $rsm = new ResultSetMapping();

            $rsm->addScalarResult($platform->getSQLResultCasing('dctrn_count'), 'count', Type::getType('integer'));

            $countQuery->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, CountOutputWalker::class);
            $countQuery->setResultSetMapping($rsm);
        } else {
            $this->appendTreeWalker($countQuery, CountWalker::class);
        }

        $countQuery->setFirstResult(null)->setMaxResults(null);

        $parser            = new Parser($countQuery);
        $parameterMappings = $parser->parse()->getParameterMappings();
        /** @var Collection|Parameter[] $parameters */
        $parameters = $countQuery->getParameters();

        foreach ($parameters as $key => $parameter) {
            $parameterName = $parameter->getName();

            if (! (isset($parameterMappings[$parameterName]) || array_key_exists($parameterName, $parameterMappings))) {
                unset($parameters[$key]);
            }
        }

        $countQuery->setParameters($parameters);

        return $countQuery;
    }
}