wikimedia/mediawiki-core

<?php
/**
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

namespace MediaWiki\Title;

use Language;

/**
 * A parser that translates page titles on a foreign wiki into ForeignTitle
 * objects, with no knowledge of the namespace setup on the foreign site.
 */
class NaiveForeignTitleFactory implements ForeignTitleFactory {

    /** @var Language */
    private $contentLanguage;

    /**
     * @param Language $contentLanguage
     */
    public function __construct( Language $contentLanguage ) {
        $this->contentLanguage = $contentLanguage;
    }

    /**
     * Create a ForeignTitle object.
     *
     * Based on the page title and optionally the namespace ID, of a page on a foreign wiki.
     * These values could be, for example, the `<title>` and `<ns>` attributes found in an
     * XML dump.
     *
     * Although exported XML dumps have contained a map of namespace IDs to names
     * since MW 1.5, the importer used to completely ignore the `<siteinfo>` tag
     * before MW 1.25.  It is therefore possible that custom XML dumps (i.e. not
     * generated by Special:Export) have been created without this metadata.
     * As a result, this code falls back to using namespace data for the local
     * wiki (similar to buggy pre-1.25 behaviour) if $ns is not supplied.
     *
     * @param string $title The page title
     * @param int|null $ns The namespace ID, or null if this data is not available
     * @return ForeignTitle
     */
    public function createForeignTitle( $title, $ns = null ) {
        $pieces = explode( ':', $title, 2 );

        /**
         * Can we assume that the part of the page title before the colon is a
         * namespace name?
         *
         * XML export schema version 0.5 and earlier (MW 1.18 and earlier) does not
         * contain a <ns> tag, so we need to be able to handle that case.
         *
         * If we know the namespace ID, we assume a non-zero namespace ID means
         * the ':' sets off a valid namespace name. If we don't know the namespace
         * ID, we fall back to using the local wiki's namespace names to resolve
         * this -- better than nothing, and mimics the old crappy behavior
         */
        $isNamespacePartValid = $ns === null
            ? $this->contentLanguage->getNsIndex( $pieces[0] ) !== false
            : $ns != 0;

        if ( count( $pieces ) === 2 && $isNamespacePartValid ) {
            [ $namespaceName, $pageName ] = $pieces;
        } else {
            $namespaceName = '';
            $pageName = $title;
        }

        return new ForeignTitle( $ns, $namespaceName, $pageName );
    }
}

/** @deprecated class alias since 1.41 */
class_alias( NaiveForeignTitleFactory::class, 'NaiveForeignTitleFactory' );