wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\DataModel\Serializers;

use Serializers\DispatchableSerializer;
use Serializers\Exceptions\SerializationException;
use Serializers\Exceptions\UnsupportedObjectException;
use Serializers\Serializer;
use Wikibase\DataModel\Reference;
use Wikibase\DataModel\Snak\Snak;
use Wikibase\DataModel\Snak\SnakList;

/**
 * Package private
 *
 * @license GPL-2.0-or-later
 * @author Thomas Pellissier Tanon
 */
class ReferenceSerializer implements DispatchableSerializer {

    /**
     * @var Serializer
     */
    private $snaksSerializer;

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

    /**
     * @see Serializer::isSerializerFor
     *
     * @param mixed $object
     *
     * @return bool
     */
    public function isSerializerFor( $object ) {
        return $object instanceof Reference;
    }

    /**
     * @see Serializer::serialize
     *
     * @param Reference $object
     *
     * @throws SerializationException
     * @return array
     */
    public function serialize( $object ) {
        if ( !$this->isSerializerFor( $object ) ) {
            throw new UnsupportedObjectException(
                $object,
                'ReferenceSerializer can only serialize Reference objects'
            );
        }

        return $this->getSerialized( $object );
    }

    private function getSerialized( Reference $reference ) {
        return [
            'hash' => $reference->getHash(),
            'snaks' => $this->snaksSerializer->serialize( $reference->getSnaks() ),
            'snaks-order' => $this->buildSnakListOrderList( $reference->getSnaks() ),
        ];
    }

    private function buildSnakListOrderList( SnakList $snaks ) {
        $list = [];

        /**
         * @var Snak $snak
         */
        foreach ( $snaks as $snak ) {
            $id = $snak->getPropertyId()->getSerialization();
            if ( !in_array( $id, $list ) ) {
                $list[] = $id;
            }
        }

        return $list;
    }

}