wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Client\Usage;

use DataValues\UnboundedQuantityValue;
use Wikibase\DataModel\Entity\EntityId;
use Wikibase\DataModel\Entity\EntityIdParser;
use Wikibase\DataModel\Entity\EntityIdParsingException;
use Wikibase\DataModel\Entity\EntityIdValue;
use Wikibase\DataModel\Snak\PropertyValueSnak;
use Wikibase\DataModel\Snak\Snak;
use Wikibase\Lib\Formatters\SnakFormatter;

/**
 * SnakFormatter decorator that records entity usage.
 * This uses an UsageTrackingLanguageFallbackLabelDescriptionLookup internally in order
 * to track label usage.
 *
 * @see UsageAccumulator
 *
 * @license GPL-2.0-or-later
 * @author Daniel Kinzler
 */
class UsageTrackingSnakFormatter implements SnakFormatter {

    /**
     * @var SnakFormatter
     */
    private $snakFormatter;

    /**
     * @var UsageAccumulator
     */
    private $usageAccumulator;

    /**
     * @var EntityIdParser
     */
    private $repoItemUriParser;

    /**
     * @var UsageTrackingLanguageFallbackLabelDescriptionLookup
     */
    private $usageTrackingLabelDescriptionLookup;

    public function __construct(
        SnakFormatter $snakFormatter,
        UsageAccumulator $usageAccumulator,
        EntityIdParser $repoItemUriParser,
        UsageTrackingLanguageFallbackLabelDescriptionLookup $usageTrackingLabelDescriptionLookup
    ) {
        $this->snakFormatter = $snakFormatter;
        $this->usageAccumulator = $usageAccumulator;
        $this->repoItemUriParser = $repoItemUriParser;
        $this->usageTrackingLabelDescriptionLookup = $usageTrackingLabelDescriptionLookup;
    }

    /**
     * @see SnakFormatter::formatSnak
     *
     * @param Snak $snak
     *
     * @return string Either plain text, wikitext or HTML, depending on the SnakFormatter provided.
     */
    public function formatSnak( Snak $snak ) {
        if ( $snak instanceof PropertyValueSnak ) {
            $value = $snak->getDataValue();

            // FIXME: All usage tracking is technically misplaced here, as it repeats knowledge from
            // WikibaseValueFormatterBuilders and what the individual formatters actually use.
            if ( $value instanceof EntityIdValue ) {
                $entityId = $value->getEntityId();
                $this->addLabelUsage( $entityId );

                // This title usage aspect must be kept in sync with what the formatters from
                // WikibaseValueFormatterBuilders::newEntityIdFormatter actually use.
                if ( $this->getFormat() !== SnakFormatter::FORMAT_PLAIN ) {
                    $this->usageAccumulator->addTitleUsage( $entityId );
                }
            } elseif ( $value instanceof UnboundedQuantityValue ) {
                $unit = $value->getUnit();
                try {
                    $entityId = $this->repoItemUriParser->parse( $unit );
                } catch ( EntityIdParsingException $e ) {
                    $entityId = null;
                }
                if ( $entityId ) {
                    $this->addLabelUsage( $entityId );
                }
            }
        }

        return $this->snakFormatter->formatSnak( $snak );
    }

    private function addLabelUsage( EntityId $id ) {
        // Just get the label from UsageTrackingLanguageFallbackLabelDescriptionLookup::getLabel,
        // which will record the appropriate usage(s) for us.
        $this->usageTrackingLabelDescriptionLookup->getLabel( $id );
    }

    /**
     * Returns the format ID of the format this formatter generates.
     * This uses the FORMAT_XXX constants defined in OutputFormatSnakFormatterFactory.
     *
     * @return string One of the SnakFormatter::FORMAT_... constants.
     */
    public function getFormat() {
        return $this->snakFormatter->getFormat();
    }

}