1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
<?php
/*
* StatusNet - the distributed open-source microblogging tool
* Copyright (C) 2009, StatusNet, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @package FeedSubPlugin
* @maintainer Brion Vibber <brion@status.net>
*/
if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
class FeedSubBadURLException extends FeedSubException
{
}
class FeedSubBadResponseException extends FeedSubException
{
}
class FeedSubEmptyException extends FeedSubException
{
}
class FeedSubBadHTMLException extends FeedSubException
{
}
class FeedSubUnrecognizedTypeException extends FeedSubException
{
}
class FeedSubNoFeedException extends FeedSubException
{
}
/**
* Given a web page or feed URL, discover the final location of the feed
* and return its current contents.
*
* @example
* $feed = new FeedDiscovery();
* if ($feed->discoverFromURL($url)) {
* print $feed->uri;
* print $feed->type;
* processFeed($feed->body);
* }
*/
class FeedDiscovery
{
public $uri;
public $type;
public $body;
public function feedMunger()
{
require_once 'XML/Feed/Parser.php';
$feed = new XML_Feed_Parser($this->body, false, false, true); // @fixme
return new FeedMunger($feed, $this->uri);
}
/**
* @param string $url
* @param bool $htmlOk pass false here if you don't want to follow web pages.
* @return string with validated URL
* @throws FeedSubBadURLException
* @throws FeedSubBadHtmlException
* @throws FeedSubNoFeedException
* @throws FeedSubEmptyException
* @throws FeedSubUnrecognizedTypeException
*/
function discoverFromURL($url, $htmlOk=true)
{
try {
$client = new HTTPClient();
$response = $client->get($url);
} catch (HTTP_Request2_Exception $e) {
throw new FeedSubBadURLException($e);
}
if ($htmlOk) {
$type = $response->getHeader('Content-Type');
$isHtml = preg_match('!^(text/html|application/xhtml\+xml)!i', $type);
if ($isHtml) {
$target = $this->discoverFromHTML($response->getUrl(), $response->getBody());
if (!$target) {
throw new FeedSubNoFeedException($url);
}
return $this->discoverFromURL($target, false);
}
}
return $this->initFromResponse($response);
}
function initFromResponse($response)
{
if (!$response->isOk()) {
throw new FeedSubBadResponseException($response->getCode());
}
$sourceurl = $response->getUrl();
$body = $response->getBody();
if (!$body) {
throw new FeedSubEmptyException($sourceurl);
}
$type = $response->getHeader('Content-Type');
if (preg_match('!^(text/xml|application/xml|application/(rss|atom)\+xml)!i', $type)) {
$this->uri = $sourceurl;
$this->type = $type;
$this->body = $body;
return true;
} else {
common_log(LOG_WARNING, "Unrecognized feed type $type for $sourceurl");
throw new FeedSubUnrecognizedTypeException($type);
}
}
/**
* @param string $url source URL, used to resolve relative links
* @param string $body HTML body text
* @return mixed string with URL or false if no target found
*/
function discoverFromHTML($url, $body)
{
// DOMDocument::loadHTML may throw warnings on unrecognized elements.
$old = error_reporting(error_reporting() & ~E_WARNING);
$dom = new DOMDocument();
$ok = $dom->loadHTML($body);
error_reporting($old);
if (!$ok) {
throw new FeedSubBadHtmlException();
}
// Autodiscovery links may be relative to the page's URL or <base href>
$base = false;
$nodes = $dom->getElementsByTagName('base');
for ($i = 0; $i < $nodes->length; $i++) {
$node = $nodes->item($i);
if ($node->hasAttributes()) {
$href = $node->attributes->getNamedItem('href');
if ($href) {
$base = trim($href->value);
}
}
}
if ($base) {
$base = $this->resolveURI($base, $url);
} else {
$base = $url;
}
// Ok... now on to the links!
// Types listed in order of priority -- we'll prefer Atom if available.
// @fixme merge with the munger link checks
$feeds = array(
'application/atom+xml' => false,
'application/rss+xml' => false,
);
$nodes = $dom->getElementsByTagName('link');
for ($i = 0; $i < $nodes->length; $i++) {
$node = $nodes->item($i);
if ($node->hasAttributes()) {
$rel = $node->attributes->getNamedItem('rel');
$type = $node->attributes->getNamedItem('type');
$href = $node->attributes->getNamedItem('href');
if ($rel && $type && $href) {
$rel = trim($rel->value);
$type = trim($type->value);
$href = trim($href->value);
if (trim($rel) == 'alternate' && array_key_exists($type, $feeds) && empty($feeds[$type])) {
// Save the first feed found of each type...
$feeds[$type] = $this->resolveURI($href, $base);
}
}
}
}
// Return the highest-priority feed found
foreach ($feeds as $type => $url) {
if ($url) {
return $url;
}
}
return false;
}
/**
* Resolve a possibly relative URL against some absolute base URL
* @param string $rel relative or absolute URL
* @param string $base absolute URL
* @return string absolute URL, or original URL if could not be resolved.
*/
function resolveURI($rel, $base)
{
require_once "Net/URL2.php";
try {
$relUrl = new Net_URL2($rel);
if ($relUrl->isAbsolute()) {
return $rel;
}
$baseUrl = new Net_URL2($base);
$absUrl = $baseUrl->resolve($relUrl);
return $absUrl->getURL();
} catch (Exception $e) {
common_log(LOG_WARNING, 'Unable to resolve relative link "' .
$rel . '" against base "' . $base . '": ' . $e->getMessage());
return $rel;
}
}
}
|
