3 * Handle Trackbacks and Pingbacks Sent to WordPress
8 * @subpackage Trackbacks
12 require_once( dirname( __FILE__ ) . '/wp-load.php' );
13 wp( array( 'tb' => '1' ) );
17 * Response to a trackback.
19 * Responds with an error or success XML message.
23 * @param mixed $error Whether there was an error.
24 * Default '0'. Accepts '0' or '1', true or false.
25 * @param string $error_message Error message if an error occurred.
27 function trackback_response($error = 0, $error_message = '') {
28 header('Content-Type: text/xml; charset=' . get_option('blog_charset') );
30 echo '<?xml version="1.0" encoding="utf-8"?'.">\n";
32 echo "<error>1</error>\n";
33 echo "<message>$error_message</message>\n";
37 echo '<?xml version="1.0" encoding="utf-8"?'.">\n";
39 echo "<error>0</error>\n";
44 // Trackback is done by a POST.
45 $request_array = 'HTTP_POST_VARS';
47 if ( !isset($_GET['tb_id']) || !$_GET['tb_id'] ) {
48 $tb_id = explode('/', $_SERVER['REQUEST_URI']);
49 $tb_id = intval( $tb_id[ count($tb_id) - 1 ] );
52 $tb_url = isset($_POST['url']) ? $_POST['url'] : '';
53 $charset = isset($_POST['charset']) ? $_POST['charset'] : '';
55 // These three are stripslashed here so they can be properly escaped after mb_convert_encoding().
56 $title = isset($_POST['title']) ? wp_unslash($_POST['title']) : '';
57 $excerpt = isset($_POST['excerpt']) ? wp_unslash($_POST['excerpt']) : '';
58 $blog_name = isset($_POST['blog_name']) ? wp_unslash($_POST['blog_name']) : '';
61 $charset = str_replace( array(',', ' '), '', strtoupper( trim($charset) ) );
63 $charset = 'ASCII, UTF-8, ISO-8859-1, JIS, EUC-JP, SJIS';
65 // No valid uses for UTF-7.
66 if ( false !== strpos($charset, 'UTF-7') )
69 // For international trackbacks.
70 if ( function_exists('mb_convert_encoding') ) {
71 $title = mb_convert_encoding($title, get_option('blog_charset'), $charset);
72 $excerpt = mb_convert_encoding($excerpt, get_option('blog_charset'), $charset);
73 $blog_name = mb_convert_encoding($blog_name, get_option('blog_charset'), $charset);
76 // Now that mb_convert_encoding() has been given a swing, we need to escape these three.
77 $title = wp_slash($title);
78 $excerpt = wp_slash($excerpt);
79 $blog_name = wp_slash($blog_name);
81 if ( is_single() || is_page() )
82 $tb_id = $posts[0]->ID;
84 if ( !isset($tb_id) || !intval( $tb_id ) )
85 trackback_response( 1, __( 'I really need an ID for this to work.' ) );
87 if (empty($title) && empty($tb_url) && empty($blog_name)) {
88 // If it doesn't look like a trackback at all.
89 wp_redirect(get_permalink($tb_id));
93 if ( !empty($tb_url) && !empty($title) ) {
95 * Fires before the trackback is added to a post.
99 * @param int $tb_id Post ID related to the trackback.
100 * @param string $tb_url Trackback URL.
101 * @param string $charset Character Set.
102 * @param string $title Trackback Title.
103 * @param string $excerpt Trackback Excerpt.
104 * @param string $blog_name Blog Name.
106 do_action( 'pre_trackback_post', $tb_id, $tb_url, $charset, $title, $excerpt, $blog_name );
108 header('Content-Type: text/xml; charset=' . get_option('blog_charset') );
110 if ( !pings_open($tb_id) )
111 trackback_response( 1, __( 'Sorry, trackbacks are closed for this item.' ) );
113 $title = wp_html_excerpt( $title, 250, '…' );
114 $excerpt = wp_html_excerpt( $excerpt, 252, '…' );
116 $comment_post_ID = (int) $tb_id;
117 $comment_author = $blog_name;
118 $comment_author_email = '';
119 $comment_author_url = $tb_url;
120 $comment_content = "<strong>$title</strong>\n\n$excerpt";
121 $comment_type = 'trackback';
123 $dupe = $wpdb->get_results( $wpdb->prepare("SELECT * FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_author_url = %s", $comment_post_ID, $comment_author_url) );
125 trackback_response( 1, __( 'We already have a ping from that URL for this post.' ) );
127 $commentdata = compact('comment_post_ID', 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_content', 'comment_type');
129 wp_new_comment($commentdata);
130 $trackback_id = $wpdb->insert_id;
133 * Fires after a trackback is added to a post.
137 * @param int $trackback_id Trackback ID.
139 do_action( 'trackback_post', $trackback_id );
140 trackback_response( 0 );