wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Lib\Formatters;

use Wikibase\DataModel\Snak\PropertyValueSnak;
use Wikibase\DataModel\Snak\Snak;
use Wikibase\Lib\SnakUrlExpander;
use Wikimedia\Assert\Assert;
use Wikimedia\Assert\ParameterTypeException;

/**
 * A formatter for PropertyValueSnaks that contain a StringValue that is
 * interpreted as an external identifier. The identifier is rendered as an wikitext link to some
 * resource about the wikitext. The link is created based on a URL pattern associated with the
 * snak's property id via a SnakUrlExpander.
 *
 * @license GPL-2.0-or-later
 * @author Daniel Kinzler
 */
class WikitextExternalIdentifierFormatter implements SnakFormatter {

    /**
     * @var SnakUrlExpander
     */
    private $urlExpander;

    public function __construct( SnakUrlExpander $urlExpander ) {
        $this->urlExpander = $urlExpander;
    }

    private function escapeWikitextInUrl( $url ) {
        return str_replace( [
            '[', ']', '<', '>', '\'', ' ', "\r", "\n", "\t",
        ], [
            '%5B', '%5D', '%3C', '%3E', '%27', '%20', '%0D', '%0A', '%09',
        ], $url );
    }

    /**
     * @see SnakFormatter::format
     *
     * Formats the given Snak as an wikitext link to an authoritative resource.
     * The URL of that link is determined using a SnakUrlExpander.
     * If the snak could not be expanded into a URL, the identifier is returned as simple text.
     *
     * @param Snak $snak
     *
     * @throws ParameterTypeException if $snak is not a PropertyValueSnak, or if $snak->getDataValue()
     * does not return a StringValue.
     * @return string Wikitext
     */
    public function formatSnak( Snak $snak ) {
        Assert::parameterType( PropertyValueSnak::class, $snak, '$snak' );
        /** @var PropertyValueSnak $snak */
        '@phan-var PropertyValueSnak $snak';

        $id = $snak->getDataValue()->getValue();
        $url = $this->urlExpander->expandUrl( $snak );

        if ( $url === null ) {
            return wfEscapeWikiText( $id );
        } else {
            return '[' . $this->escapeWikitextInUrl( $url ) . ' ' . wfEscapeWikiText( $id ) . ']';
        }
    }

    /**
     * @see SnakFormatter::getFormat
     *
     * @return string SnakFormatter::FORMAT_WIKI
     */
    public function getFormat() {
        return SnakFormatter::FORMAT_WIKI;
    }

}