source: trunk/www.guidonia.net/wp/wp-content/plugins/feedwordpress/feedfinder.class.php@ 44

Last change on this file since 44 was 44, checked in by luciano, 14 years ago
File size: 5.2 KB
Line 
1<?php
2################################################################################
3## class FeedFinder: find likely feeds using autodetection and/or guesswork ####
4################################################################################
5
6class FeedFinder {
7 var $uri = NULL;
8 var $_cache_uri = NULL;
9
10 var $verify = FALSE;
11
12 var $_response = NULL;
13 var $_data = NULL;
14 var $_error = NULL;
15 var $_head = NULL;
16
17 # -- Recognition patterns
18 var $_feed_types = array(
19 'application/rss+xml',
20 'text/xml',
21 'application/atom+xml',
22 'application/x.atom+xml',
23 'application/x-atom+xml'
24 );
25 var $_feed_markers = array('\\<feed', '\\<rss', 'xmlns="http://purl.org/rss/1.0');
26 var $_html_markers = array('\\<html');
27 var $_obvious_feed_url = array('[./]rss', '[./]rdf', '[./]atom', '[./]feed', '\.xml');
28 var $_maybe_feed_url = array ('rss', 'rdf', 'atom', 'feed', 'xml');
29
30 function FeedFinder ($uri = NULL, $verify = TRUE) {
31 $this->uri = $uri; $this->verify = $verify;
32 } /* FeedFinder::FeedFinder () */
33
34 function find ($uri = NULL) {
35 $ret = array ();
36 if (!is_null($this->data($uri))) {
37 if ($this->is_feed($uri)) {
38 $ret = array($this->uri);
39 } else {
40 // Assume that we have HTML or XHTML (even if we don't, who's it gonna hurt?)
41 // Autodiscovery is the preferred method
42 $href = $this->_link_rel_feeds();
43
44 // ... but we'll also take the little orange buttons
45 $href = array_merge($href, $this->_a_href_feeds(TRUE));
46
47 // If all that failed, look harder
48 if (count($href) == 0) $href = $this->_a_href_feeds(FALSE);
49
50 // Our search may turn up duplicate URIs. We only need to do any given URI once.
51 // Props to Camilo <http://projects.radgeek.com/2008/12/14/feedwordpress-20081214/#comment-20090122160414>
52 $href = array_unique($href);
53
54 // Verify feeds and resolve relative URIs
55 foreach ($href as $u) {
56 $the_uri = Relative_URI::resolve($u, $this->uri);
57 if ($this->verify) {
58 $feed =& new FeedFinder($the_uri);
59 if ($feed->is_feed()) $ret[] = $the_uri;
60 $feed = NULL;
61 } else {
62 $ret[] = $the_uri;
63 }
64 } /* foreach */
65 } /* if */
66 } /* if */
67 return array_unique($ret);
68 } /* FeedFinder::find () */
69
70 function data ($uri = NULL) {
71 $this->_get($uri);
72 return $this->_data;
73 }
74
75 function status ($uri = NULL) {
76 $this->_get($uri);
77
78 if (isset($this->_response->status)) :
79 $ret = $this->_response->status;
80 else :
81 $ret = NULL;
82 endif;
83 return $ret;
84 }
85
86 function error () {
87 return $this->_error;
88 }
89
90 function is_feed ($uri = NULL) {
91 $data = $this->data($uri);
92
93 return (
94 preg_match (
95 "\007(".implode('|',$this->_feed_markers).")\007i",
96 $data
97 ) and !preg_match (
98 "\007(".implode('|',$this->_html_markers).")\007i",
99 $data
100 )
101 );
102 } /* FeedFinder::is_feed () */
103
104 # --- Private methods ---
105 function _get ($uri = NULL) {
106 if ($uri) $this->uri = $uri;
107
108 // Is the result not yet cached?
109 if ($this->_cache_uri !== $this->uri) :
110 $headers['Connection'] = 'close';
111 $headers['Accept'] = 'application/atom+xml application/rdf+xml application/rss+xml application/xml text/html */*';
112 $headers['User-Agent'] = 'feedfinder/1.2 (compatible; PHP FeedFinder) +http://projects.radgeek.com/feedwordpress';
113
114 // Use function provided by MagpieRSS package
115 $client = _fetch_remote_file($this->uri, $headers);
116 if (isset($client->error)) :
117 $this->_error = $client->error;
118 else :
119 $this->_error = NULL;
120 endif;
121 $this->_response = $client;
122 $this->_data = $client->results;
123
124 // Kilroy was here
125 $this->_cache_uri = $this->uri;
126 endif;
127 } /* FeedFinder::_get () */
128
129 function _link_rel_feeds () {
130 $links = $this->_tags('link');
131 $link_count = count($links);
132
133 // now figure out which one points to the RSS file
134 $href = array ();
135 for ($n=0; $n<$link_count; $n++) {
136 if (strtolower($links[$n]['rel']) == 'alternate') {
137 if (in_array(strtolower($links[$n]['type']), $this->_feed_types)) {
138 $href[] = $links[$n]['href'];
139 } /* if */
140 } /* if */
141 } /* for */
142 return $href;
143 }
144
145 function _a_href_feeds ($obvious = TRUE) {
146 $pattern = ($obvious ? $this->_obvious_feed_url : $this->_maybe_feed_url);
147
148 $links = $this->_tags('a');
149 $link_count = count($links);
150
151 // now figure out which one points to the RSS file
152 $href = array ();
153 for ($n=0; $n<$link_count; $n++) {
154 if (preg_match("\007(".implode('|',$pattern).")\007i", $links[$n]['href'])) {
155 $href[] = $links[$n]['href'];
156 } /* if */
157 } /* for */
158 return $href;
159 }
160
161 function _tags ($tag) {
162 $html = $this->data();
163
164 // search through the HTML, save all <link> tags
165 // and store each link's attributes in an associative array
166 preg_match_all('/<'.$tag.'\s+(.*?)\s*\/?>/si', $html, $matches);
167 $links = $matches[1];
168 $ret = array();
169 $link_count = count($links);
170 for ($n=0; $n<$link_count; $n++) {
171 $attributes = preg_split('/\s+/s', $links[$n]);
172 foreach($attributes as $attribute) {
173 $att = preg_split('/\s*=\s*/s', $attribute, 2);
174 if (isset($att[1])) {
175 $att[1] = preg_replace('/([\'"]?)(.*)\1/', '$2', $att[1]);
176 $final_link[strtolower($att[0])] = $att[1];
177 } /* if */
178 } /* foreach */
179 $ret[$n] = $final_link;
180 } /* for */
181 return $ret;
182 }
183} /* class FeedFinder */
184
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