3 * Laconica, the distributed open-source microblogging tool
5 * Plugin to do linkbacks for notices containing links
9 * LICENCE: This program is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU Affero General Public License as published by
11 * the Free Software Foundation, either version 3 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Affero General Public License for more details.
19 * You should have received a copy of the GNU Affero General Public License
20 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 * @author Evan Prodromou <evan@controlyourself.ca>
25 * @copyright 2009 Control Yourself, Inc.
26 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
27 * @link http://laconi.ca/
30 if (!defined('LACONICA')) {
34 require_once('Auth/Yadis/Yadis.php');
36 define('LINKBACKPLUGIN_VERSION', '0.1');
39 * Plugin to do linkbacks for notices containing URLs
41 * After new notices are saved, we check their text for URLs. If there
42 * are URLs, we test each URL to see if it supports any
46 * @author Evan Prodromou <evan@controlyourself.ca>
47 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
48 * @link http://laconi.ca/
53 class LinkbackPlugin extends Plugin
57 function __construct()
59 parent::__construct();
62 function onEndNoticeSave($notice)
64 if ($notice->is_local == 1) {
65 // Try to avoid actually mucking with the
67 $c = $notice->content;
68 $this->notice = $notice;
70 common_replace_urls_callback($c,
71 array($this, 'linkbackUrl'));
76 function linkbackUrl($url)
79 $url = htmlspecialchars_decode($orig);
80 $scheme = parse_url($url, PHP_URL_SCHEME);
81 if (!in_array($scheme, array('http', 'https'))) {
85 // XXX: Do a HEAD first to save some time/bandwidth
87 $fetcher = Auth_Yadis_Yadis::getHTTPFetcher();
89 $result = $fetcher->get($url,
90 array('User-Agent: ' . $this->userAgent(),
91 'Accept: application/html+xml,text/html'));
93 if (!in_array($result->status, array('200', '206'))) {
100 if (array_key_exists('X-Pingback', $result->headers)) {
101 $pb = $result->headers['X-Pingback'];
102 } else if (preg_match('/<link rel="pingback" href="([^"]+)" ?/?>/',
109 $this->pingback($result->final_url, $pb);
111 $tb = $this->getTrackback($result->body, $result->final_url);
113 $this->trackback($result->final_url, $tb);
120 function pingback($url, $endpoint)
122 $args = array($this->notice->uri, $url);
124 $request = xmlrpc_encode_request('pingback.ping', $args);
125 $context = stream_context_create(array('http' => array('method' => "POST",
127 "Content-Type: text/xml\r\n".
128 "User-Agent: " . $this->userAgent(),
129 'content' => $request)));
130 $file = file_get_contents($endpoint, false, $context);
131 $response = xmlrpc_decode($file);
132 if (xmlrpc_is_fault($response)) {
133 common_log(LOG_WARNING,
134 "Pingback error for '$url' ($endpoint): ".
135 "$response[faultString] ($response[faultCode])");
138 "Pingback success for '$url' ($endpoint): ".
143 // Largely cadged from trackback_cls.php by
144 // Ran Aroussi <ran@blogish.org>, GPL2
145 // http://phptrackback.sourceforge.net/
147 function getTrackback($text, $url)
149 if (preg_match_all('/(<rdf:RDF.*?<\/rdf:RDF>)/sm', $text, $match, PREG_SET_ORDER)) {
150 for ($i = 0; $i < count($match); $i++) {
151 if (preg_match('|dc:identifier="' . preg_quote($url) . '"|ms', $match[$i][1])) {
152 $rdf_array[] = trim($match[$i][1]);
156 // Loop through the RDFs array and extract trackback URIs
158 $tb_array = array(); // <- holds list of trackback URIs
160 if (!empty($rdf_array)) {
162 for ($i = 0; $i < count($rdf_array); $i++) {
163 if (preg_match('/trackback:ping="([^"]+)"/', $rdf_array[$i], $array)) {
164 $tb_array[] = trim($array[1]);
172 if (empty($tb_array)) {
179 if (preg_match_all('/(<a[^>]*?rel=[\'"]trackback[\'"][^>]*?>)/', $text, $match)) {
180 foreach ($match[1] as $atag) {
181 if (preg_match('/href=[\'"]([^\'"]*?)[\'"]/', $atag, $url)) {
191 function trackback($url, $endpoint)
193 $profile = $this->notice->getProfile();
195 $args = array('title' => sprintf(_('%1$s\'s status on %2$s'),
197 common_exact_date($this->notice->created)),
198 'excerpt' => $this->notice->content,
199 'url' => $this->notice->uri,
200 'blog_name' => $profile->nickname);
202 $fetcher = Auth_Yadis_Yadis::getHTTPFetcher();
204 $result = $fetcher->post($endpoint,
205 http_build_query($args),
206 array('User-Agent: ' . $this->userAgent()));
208 if ($result->status != '200') {
209 common_log(LOG_WARNING,
210 "Trackback error for '$url' ($endpoint): ".
214 "Trackback success for '$url' ($endpoint): ".
221 return 'LinkbackPlugin/'.LINKBACKPLUGIN_VERSION .
222 ' Laconica/' . LACONICA_VERSION;