source: trunk/www.guidonia.net/wp/wp-admin/import/rss.php@ 44

<?php
/**
 * RSS Importer
 *
 * @package WordPress
 * @subpackage Importer
 */

/**
 * RSS Importer
 *
 * Will process a RSS feed for importing posts into WordPress. This is a very
 * limited importer and should only be used as the last resort, when no other
 * importer is available.
 *
 * @since unknown
 */
class RSS_Import {

        var $posts = array ();
        var $file;

        function header() {
                echo '<div class="wrap">';
                screen_icon();
                echo '<h2>'.__('Import RSS').'</h2>';
        }

        function footer() {
                echo '</div>';
        }

        function unhtmlentities($string) { // From php.net for < 4.3 compat
                $trans_tbl = get_html_translation_table(HTML_ENTITIES);
                $trans_tbl = array_flip($trans_tbl);
                return strtr($string, $trans_tbl);
        }

        function greet() {
                echo '<div class="narrow">';
                echo '<p>'.__('Howdy! This importer allows you to extract posts from an RSS 2.0 file into your blog. This is useful if you want to import your posts from a system that is not handled by a custom import tool. Pick an RSS file to upload and click Import.').'</p>';
                wp_import_upload_form("admin.php?import=rss&amp;step=1");
                echo '</div>';
        }

        function get_posts() {
                global $wpdb;

                set_magic_quotes_runtime(0);
                $datalines = file($this->file); // Read the file into an array
                $importdata = implode('', $datalines); // squish it
                $importdata = str_replace(array ("\r\n", "\r"), "\n", $importdata);

                preg_match_all('|<item>(.*?)</item>|is', $importdata, $this->posts);
                $this->posts = $this->posts[1];
                $index = 0;
                foreach ($this->posts as $post) {
                        preg_match('|<title>(.*?)</title>|is', $post, $post_title);
                        $post_title = str_replace(array('<![CDATA[', ']]>'), '', $wpdb->escape( trim($post_title[1]) ));

                        preg_match('|<pubdate>(.*?)</pubdate>|is', $post, $post_date_gmt);

                        if ($post_date_gmt) {
                                $post_date_gmt = strtotime($post_date_gmt[1]);
                        } else {
                                // if we don't already have something from pubDate
                                preg_match('|<dc:date>(.*?)</dc:date>|is', $post, $post_date_gmt);
                                $post_date_gmt = preg_replace('|([-+])([0-9]+):([0-9]+)$|', '\1\2\3', $post_date_gmt[1]);
                                $post_date_gmt = str_replace('T', ' ', $post_date_gmt);
                                $post_date_gmt = strtotime($post_date_gmt);
                        }

                        $post_date_gmt = gmdate('Y-m-d H:i:s', $post_date_gmt);
                        $post_date = get_date_from_gmt( $post_date_gmt );

                        preg_match_all('|<category>(.*?)</category>|is', $post, $categories);
                        $categories = $categories[1];

                        if (!$categories) {
                                preg_match_all('|<dc:subject>(.*?)</dc:subject>|is', $post, $categories);
                                $categories = $categories[1];
                        }

                        $cat_index = 0;
                        foreach ($categories as $category) {
                                $categories[$cat_index] = $wpdb->escape($this->unhtmlentities($category));
                                $cat_index++;
                        }

                        preg_match('|<guid.*?>(.*?)</guid>|is', $post, $guid);
                        if ($guid)
                                $guid = $wpdb->escape(trim($guid[1]));
                        else
                                $guid = '';

                        preg_match('|<content:encoded>(.*?)</content:encoded>|is', $post, $post_content);
                        $post_content = str_replace(array ('<![CDATA[', ']]>'), '', $wpdb->escape(trim($post_content[1])));

                        if (!$post_content) {
                                // This is for feeds that put content in description
                                preg_match('|<description>(.*?)</description>|is', $post, $post_content);
                                $post_content = $wpdb->escape($this->unhtmlentities(trim($post_content[1])));
                        }

                        // Clean up content
                        $post_content = preg_replace_callback('|<(/?[A-Z]+)|', create_function('$match', 'return "<" . strtolower($match[1]);'), $post_content);
                        $post_content = str_replace('<br>', '<br />', $post_content);
                        $post_content = str_replace('<hr>', '<hr />', $post_content);

                        $post_author = 1;
                        $post_status = 'publish';
                        $this->posts[$index] = compact('post_author', 'post_date', 'post_date_gmt', 'post_content', 'post_title', 'post_status', 'guid', 'categories');
                        $index++;
                }
        }

        function import_posts() {
                echo '<ol>';

                foreach ($this->posts as $post) {
                        echo "<li>".__('Importing post...');

                        extract($post);

                        if ($post_id = post_exists($post_title, $post_content, $post_date)) {
                                _e('Post already imported');
                        } else {
                                $post_id = wp_insert_post($post);
                                if ( is_wp_error( $post_id ) )
                                        return $post_id;
                                if (!$post_id) {
                                        _e('Couldn&#8217;t get post ID');
                                        return;
                                }

                                if (0 != count($categories))
                                        wp_create_categories($categories, $post_id);
                                _e('Done !');
                        }
                        echo '</li>';
                }

                echo '</ol>';

        }

        function import() {
                $file = wp_import_handle_upload();
                if ( isset($file['error']) ) {
                        echo $file['error'];
                        return;
                }

                $this->file = $file['file'];
                $this->get_posts();
                $result = $this->import_posts();
                if ( is_wp_error( $result ) )
                        return $result;
                wp_import_cleanup($file['id']);
                do_action('import_done', 'rss');

                echo '<h3>';
                printf(__('All done. <a href="%s">Have fun!</a>'), get_option('home'));
                echo '</h3>';
        }

        function dispatch() {
                if (empty ($_GET['step']))
                        $step = 0;
                else
                        $step = (int) $_GET['step'];

                $this->header();

                switch ($step) {
                        case 0 :
                                $this->greet();
                                break;
                        case 1 :
                                check_admin_referer('import-upload');
                                $result = $this->import();
                                if ( is_wp_error( $result ) )
                                        echo $result->get_error_message();
                                break;
                }

                $this->footer();
        }

        function RSS_Import() {
                // Nothing.
        }
}

$rss_import = new RSS_Import();

register_importer('rss', __('RSS'), __('Import posts from an RSS feed.'), array ($rss_import, 'dispatch'));
?>