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;

/**
 * A parser that translates page titles on a foreign wiki into ForeignTitle
 * objects, using information about the namespace setup on the foreign site.
 */
class NamespaceAwareForeignTitleFactory implements ForeignTitleFactory {
    /**
     * @var array
     */
    protected $foreignNamespaces;
    /**
     * @var array
     */
    private $foreignNamespacesFlipped;

    /**
     * Normalizes an array name for $foreignNamespacesFlipped.
     * @param string $name
     * @return string
     */
    private function normalizeNamespaceName( $name ) {
        return strtolower( str_replace( ' ', '_', $name ) );
    }

    /**
     * @param array|null $foreignNamespaces An array 'id' => 'name' which contains
     * the complete namespace setup of the foreign wiki. Such data could be
     * obtained from siteinfo/namespaces in an XML dump file, or by an action API
     * query such as api.php?action=query&meta=siteinfo&siprop=namespaces. If
     * this data is unavailable, use NaiveForeignTitleFactory instead.
     */
    public function __construct( $foreignNamespaces ) {
        $this->foreignNamespaces = $foreignNamespaces;
        if ( $foreignNamespaces !== null ) {
            $this->foreignNamespacesFlipped = [];
            foreach ( $foreignNamespaces as $id => $name ) {
                $newKey = self::normalizeNamespaceName( $name );
                $this->foreignNamespacesFlipped[$newKey] = $id;
            }
        }
    }

    /**
     * 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.
     *
     * @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 ) {
        // 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 ( $ns === null ) {
            return self::parseTitleNoNs( $title );
        } else {
            return self::parseTitleWithNs( $title, $ns );
        }
    }

    /**
     * Helper function to parse the title when the namespace ID is not specified.
     *
     * @param string $title
     * @return ForeignTitle
     */
    protected function parseTitleNoNs( $title ) {
        $pieces = explode( ':', $title, 2 );
        $key = self::normalizeNamespaceName( $pieces[0] );

        // Does the part before the colon match a known namespace? Check the
        // foreign namespaces
        $isNamespacePartValid = isset( $this->foreignNamespacesFlipped[$key] );

        if ( count( $pieces ) === 2 && $isNamespacePartValid ) {
            [ $namespaceName, $pageName ] = $pieces;
            $ns = $this->foreignNamespacesFlipped[$key];
        } else {
            $namespaceName = '';
            $pageName = $title;
            $ns = 0;
        }

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

    /**
     * Helper function to parse the title when the namespace value is known.
     *
     * @param string $title
     * @param int $ns
     * @return ForeignTitle
     */
    protected function parseTitleWithNs( $title, $ns ) {
        $pieces = explode( ':', $title, 2 );

        // Is $title of the form Namespace:Title (true), or just Title (false)?
        $titleIncludesNamespace = ( $ns != '0' && count( $pieces ) === 2 );

        if ( isset( $this->foreignNamespaces[$ns] ) ) {
            $namespaceName = $this->foreignNamespaces[$ns];
        } else {
            // If the foreign wiki is misconfigured, XML dumps can contain a page with
            // a non-zero namespace ID, but whose title doesn't contain a colon
            // (T114115). In those cases, output a made-up namespace name to avoid
            // collisions. The ImportTitleFactory might replace this with something
            // more appropriate.
            $namespaceName = $titleIncludesNamespace ? $pieces[0] : "Ns$ns";
        }

        // We assume that the portion of the page title before the colon is the
        // namespace name, except in the case of namespace 0.
        if ( $titleIncludesNamespace ) {
            $pageName = $pieces[1];
        } else {
            $pageName = $title;
        }

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

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