1<?php
2/**
3 * Shortcuts to construct a special page alias.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
19 *
20 * @file
21 * @ingroup SpecialPage
22 */
23
24/**
25 * Superclass for any RedirectSpecialPage which redirects the user
26 * to a particular article (as opposed to user contributions, logs, etc.).
27 *
28 * For security reasons these special pages are restricted to pass on
29 * the following subset of GET parameters to the target page while
30 * removing all others:
31 *
32 * - useskin, uselang, printable: to alter the appearance of the resulting page
33 *
34 * - redirect: allows viewing one's user page or talk page even if it is a
35 * redirect.
36 *
37 * - rdfrom: allows redirecting to one's user page or talk page from an
38 * external wiki with the "Redirect from..." notice.
39 *
40 * - limit, offset: Useful for linking to history of one's own user page or
41 * user talk page. For example, this would be a link to "the last edit to your
42 * user talk page in the year 2010":
43 * https://en.wikipedia.org/wiki/Special:MyPage?offset=20110000000000&limit=1&action=history
44 *
45 * - feed: would allow linking to the current user's RSS feed for their user
46 * talk page:
47 * https://en.wikipedia.org/w/index.php?title=Special:MyTalk&action=history&feed=rss
48 *
49 * - preloadtitle: Can be used to provide a default section title for a
50 * preloaded new comment on one's own talk page.
51 *
52 * - summary : Can be used to provide a default edit summary for a preloaded
53 * edit to one's own user page or talk page.
54 *
55 * - preview: Allows showing/hiding preview on first edit regardless of user
56 * preference, useful for preloaded edits where you know preview wouldn't be
57 * useful.
58 *
59 * - redlink: Affects the message the user sees if their talk page/user talk
60 * page does not currently exist. Avoids confusion for newbies with no user
61 * pages over why they got a "permission error" following this link:
62 * https://en.wikipedia.org/w/index.php?title=Special:MyPage&redlink=1
63 *
64 * - debug: determines whether the debug parameter is passed to load.php,
65 * which disables reformatting and allows scripts to be debugged. Useful
66 * when debugging scripts that manipulate one's own user page or talk page.
67 *
68 * @par Hook extension:
69 * Extensions can add to the redirect parameters list by using the hook
70 * RedirectSpecialArticleRedirectParams
71 *
72 * This hook allows extensions which add GET parameters like FlaggedRevs to
73 * retain those parameters when redirecting using special pages.
74 *
75 * @par Hook extension example:
76 * @code
77 *    $wgHooks['RedirectSpecialArticleRedirectParams'][] =
78 *        'MyExtensionHooks::onRedirectSpecialArticleRedirectParams';
79 *    public static function onRedirectSpecialArticleRedirectParams( &$redirectParams ) {
80 *        $redirectParams[] = 'stable';
81 *        return true;
82 *    }
83 * @endcode
84 *
85 * @stable to extend
86 *
87 * @ingroup SpecialPage
88 */
89abstract class RedirectSpecialArticle extends RedirectSpecialPage {
90
91	/**
92	 * @stable to call
93	 *
94	 * @param string $name
95	 */
96	public function __construct( $name ) {
97		parent::__construct( $name );
98		$redirectParams = [
99			'action',
100			'redirect', 'rdfrom',
101			# Options for preloaded edits
102			'preload', 'preloadparams', 'editintro', 'preloadtitle', 'summary', 'nosummary',
103			# Options for overriding user settings
104			'preview', 'minor', 'watchthis',
105			# Options for history/diffs
106			'section', 'oldid', 'diff', 'dir',
107			'limit', 'offset', 'feed',
108			# Misc options
109			'redlink',
110			# Options for action=raw; missing ctype can break JS or CSS in some browsers
111			'ctype', 'maxage', 'smaxage',
112		];
113
114		$this->getHookRunner()->onRedirectSpecialArticleRedirectParams( $redirectParams );
115		$this->mAllowedRedirectParams = $redirectParams;
116	}
117
118	/**
119	 * @inheritDoc
120	 */
121	public function getRedirectQuery( $subpage ) {
122		$query = parent::getRedirectQuery( $subpage );
123		$title = $this->getRedirect( $subpage );
124		// Avoid double redirect for action=edit&redlink=1 for existing pages
125		// (compare to the check in EditPage::edit)
126		if (
127			$query && isset( $query['action'] ) && isset( $query['redlink'] ) &&
128			( $query['action'] === 'edit' || $query['action'] === 'submit' ) &&
129			(bool)$query['redlink'] &&
130			$title instanceof Title &&
131			$title->exists()
132		) {
133			return false;
134		}
135		return $query;
136	}
137
138}
139