wikimedia/mediawiki-extensions-Wikibase

<?php

namespace Wikibase\Client\Hooks;

use MediaWiki\Parser\Parser;
use MediaWiki\Parser\ParserOutput;
use Wikibase\Client\NamespaceChecker;
use Wikibase\Client\WikibaseClient;

/**
 * Handles the NOEXTERNALLANGLINKS parser function.
 *
 * @license GPL-2.0-or-later
 * @author Nikola Smolenski <smolensk@eunet.rs>
 * @author Katie Filbert < aude.wiki@gmail.com >
 * @author Daniel Kinzler
 */
class NoLangLinkHandler {
    /**
     * Key used to store data in ParserOutput.  Exported for use by unit tests.
     * @var string
     */
    public const EXTENSION_DATA_KEY = 'wikibase-noexternallanglinks';

    /**
     * @var NamespaceChecker
     */
    private $namespaceChecker;

    /**
     * Parser function
     *
     * @param Parser $parser
     * @param string ...$langs Language codes or '*'
     */
    public static function handle( Parser $parser, ...$langs ) {
        $handler = self::factory();
        $handler->doHandle( $parser, $langs );
    }

    private static function factory(): self {
        return new self( WikibaseClient::getNamespaceChecker() );
    }

    public function __construct( NamespaceChecker $namespaceChecker ) {
        $this->namespaceChecker = $namespaceChecker;
    }

    /**
     * Get the noexternallanglinks data from the ParserOutput,
     * which is set by the {{#noexternallanglinks}} parser function.
     *
     * @param ParserOutput $parserOutput
     *
     * @return string[] A list of language codes, identifying which repository links to ignore.
     *         Empty if {{#noexternallanglinks}} was not used on the page.
     */
    public static function getNoExternalLangLinks( ParserOutput $parserOutput ) {
        $property = $parserOutput->getExtensionData(
            self::EXTENSION_DATA_KEY
        );
        if ( $property === null ) {
            // BACKWARD COMPATIBILITY: remove after the ParserCache expires
            // This property used to be stored as a page property, so check
            // there as well.
            $old = $parserOutput->getPageProperty( 'noexternallanglinks' );
            if ( is_string( $old ) ) {
                return unserialize( $old );
            }
        }

        return array_keys( $property ?? [] );
    }

    /**
     * Append new languages to the noexternallanglinks data in the ParserOutput,
     * which is set by the {{#noexternallanglinks}} parser function.
     *
     * @param ParserOutput $parserOutput
     * @param string[] $noexternallanglinks a list of languages to suppress
     */
    public static function appendNoExternalLangLinks( ParserOutput $parserOutput, array $noexternallanglinks ) {
        foreach ( $noexternallanglinks as $lang ) {
            $parserOutput->appendExtensionData(
                self::EXTENSION_DATA_KEY, $lang
            );
        }
    }

    /**
     * Parser function
     *
     * @param Parser $parser
     * @param string[] $langs
     *
     * @return string
     */
    public function doHandle( Parser $parser, array $langs ) {
        if ( !$this->namespaceChecker->isWikibaseEnabled( $parser->getTitle()->getNamespace() ) ) {
            // shorten out
            return '';
        }

        $parserOutput = $parser->getOutput();
        self::appendNoExternalLangLinks( $parserOutput, $langs );

        return '';
    }

}