wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Repo\Rdf;

use Psr\Log\LoggerInterface;
use Psr\Log\NullLogger;
use Wikibase\DataModel\Snak\PropertyValueSnak;
use Wikimedia\Assert\Assert;
use Wikimedia\Purtle\RdfWriter;

/**
 * Dispatching implementation of ValueSnakRdfBuilder. This allows extensions to register
 * ValueSnakRdfBuilders for custom data types.
 *
 * @license GPL-2.0-or-later
 * @author Daniel Kinzler
 */
class DispatchingValueSnakRdfBuilder implements ValueSnakRdfBuilder {

    /**
     * @var ValueSnakRdfBuilder[]
     */
    private $valueBuilders;

    /** @var LoggerInterface */
    private $logger;

    /**
     * @param ValueSnakRdfBuilder[] $valueBuilders ValueSnakRdfBuilder objects keyed by data type
     * (with prefix "PT:") or value type (with prefix "VT:").
     * @param LoggerInterface|null $logger Used to log a warning
     * when encountering a value without a builder in $valueBuilders.
     */
    public function __construct( array $valueBuilders, LoggerInterface $logger = null ) {
        Assert::parameterElementType( ValueSnakRdfBuilder::class, $valueBuilders, '$valueBuilders' );

        $this->valueBuilders = $valueBuilders;
        $this->logger = $logger ?: new NullLogger();
    }

    /**
     * Adds specific value
     *
     * @param RdfWriter $writer
     * @param string $propertyValueNamespace Property value relation namespace
     * @param string $propertyValueLName Property value relation name
     * @param string $dataType Property data type
     * @param string $snakNamespace
     * @param PropertyValueSnak $snak
     */
    public function addValue(
        RdfWriter $writer,
        $propertyValueNamespace,
        $propertyValueLName,
        $dataType,
        $snakNamespace,
        PropertyValueSnak $snak
    ) {
        $valueType = $snak->getDataValue()->getType();
        $builder = $this->getValueBuilder( $dataType, $valueType );

        if ( $builder ) {
            $builder->addValue( $writer, $propertyValueNamespace, $propertyValueLName, $dataType, $snakNamespace, $snak );
        }
    }

    /**
     * @param string|null $dataTypeId
     * @param string $dataValueType
     *
     * @return null|ValueSnakRdfBuilder
     */
    private function getValueBuilder( $dataTypeId, $dataValueType ) {
        if ( $dataTypeId !== null ) {
            if ( isset( $this->valueBuilders["PT:$dataTypeId"] ) ) {
                return $this->valueBuilders["PT:$dataTypeId"];
            }
        }

        if ( isset( $this->valueBuilders["VT:$dataValueType"] ) ) {
            return $this->valueBuilders["VT:$dataValueType"];
        }

        if ( $dataTypeId !== null ) {
            $this->logger->warning(
                __METHOD__ . ': No RDF builder defined for data type ' .
                '{dataTypeId} nor for value type {dataValueType}.',
                [
                    'dataTypeId' => $dataTypeId,
                    'dataValueType' => $dataValueType,
                ]
            );
        } else {
            $this->logger->warning(
                __METHOD__ . ': No RDF builder defined for value type {dataValueType}.',
                [
                    'dataValueType' => $dataValueType,
                ]
            );
        }

        return null;
    }

}