xref: /dokuwiki/inc/Subscriptions/SubscriberRegexBuilder.php (revision 479c05b1f975e52558d9ff3234097c0c5c405d27) 
1<?php
2
3
4namespace dokuwiki\Subscriptions;
5
6
7use Exception;
8
9class SubscriberRegexBuilder
10{
11
12    /**
13     * Construct a regular expression for parsing a subscription definition line
14     *
15     * @author Andreas Gohr <andi@splitbrain.org>
16     *
17     * @param string|array $user
18     * @param string|array $style
19     * @param string|array $data
20     * @return string complete regexp including delimiters
21     * @throws Exception when no data is passed
22     */
23    public function buildRegex($user = null, $style = null, $data = null) {
24        // always work with arrays
25        $user = (array) $user;
26        $style = (array) $style;
27        $data = (array) $data;
28
29        // clean
30        $user = array_filter(array_map('trim', $user));
31        $style = array_filter(array_map('trim', $style));
32        $data = array_filter(array_map('trim', $data));
33
34        // user names are encoded
35        $user = array_map('auth_nameencode', $user);
36
37        // quote
38        $user = array_map('preg_quote_cb', $user);
39        $style = array_map('preg_quote_cb', $style);
40        $data = array_map('preg_quote_cb', $data);
41
42        // join
43        $user = join('|', $user);
44        $style = join('|', $style);
45        $data = join('|', $data);
46
47        // any data at all?
48        if($user.$style.$data === '') throw new Exception('no data passed');
49
50        // replace empty values, set which ones are optional
51        $sopt = '';
52        $dopt = '';
53        if($user === '') {
54            $user = '\S+';
55        }
56        if($style === '') {
57            $style = '\S+';
58            $sopt = '?';
59        }
60        if($data === '') {
61            $data = '\S+';
62            $dopt = '?';
63        }
64
65        // assemble
66        return "/^($user)(?:\\s+($style))$sopt(?:\\s+($data))$dopt$/";
67    }
68}
69