1<?php
2
3use dokuwiki\Extension\ActionPlugin;
4use dokuwiki\Extension\Event;
5use dokuwiki\Extension\EventHandler;
6use dokuwiki\File\PageFile;
7
8/**
9 * DokuWiki Plugin renderrevisions (Action Component)
10 *
11 * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
12 * @author Andreas Gohr <dokuwiki@cosmocode.de>
13 */
14class action_plugin_renderrevisions extends ActionPlugin
15{
16    /** @var array list of pages that are processed by the plugin */
17    protected $pages = [];
18
19    /** @var string|null  the current page being saved, used to overwrite the contentchanged check */
20    protected $current = null;
21
22    /** @inheritDoc */
23    public function register(EventHandler $controller)
24    {
25        $controller->register_hook('PARSER_CACHE_USE', 'AFTER', $this, 'handleParserCacheUse');
26
27        $controller->register_hook(
28            'RENDERER_CONTENT_POSTPROCESS',
29            'AFTER',
30            $this,
31            'handleRenderContent',
32            null,
33            PHP_INT_MAX // other plugins might want to change the content before we see it
34        );
35
36        $controller->register_hook('COMMON_WIKIPAGE_SAVE', 'BEFORE', $this, 'handleCommonWikipageSave');
37    }
38
39    /**
40     * Event handler for PARSER_CACHE_USE
41     *
42     * @see https://www.dokuwiki.org/devel:event:PARSER_CACHE_USE
43     * @param Event $event Event object
44     * @param mixed $param optional parameter passed when event was registered
45     * @return void
46     */
47    public function handleParserCacheUse(Event $event, $param)
48    {
49        $cacheObject = $event->data;
50
51        if (!$cacheObject->page) return;
52        if ($cacheObject->mode !== 'xhtml') return;
53
54        // only process pages that match both the skip and match regex
55
56        $page = $cacheObject->page;
57        try {
58            [$skipRE, $matchRE] = $this->getRegexps();
59        } catch (\Exception $e) {
60            msg(hsc($e->getMessage()), -1);
61            return;
62        }
63        if (
64            ($skipRE && preg_match($skipRE, ":$page")) ||
65            ($matchRE && !preg_match($matchRE, ":$page"))
66        ) {
67            return;
68        }
69
70        // remember that this page was processed
71        // This is a somewhat ugly workaround for when text snippets are rendered within the same page.
72        // Those snippets will not have a page context set during cache use event and thus not be processed
73        // later on in the RENDERER_CONTENT_POSTPROCESS event
74        $this->pages[$page] = true;
75    }
76
77
78
79    /**
80     * Event handler for RENDERER_CONTENT_POSTPROCESS
81     *
82     * @see https://www.dokuwiki.org/devel:event:RENDERER_CONTENT_POSTPROCESS
83     * @param Event $event Event object
84     * @param mixed $param optional parameter passed when event was registered
85     * @return void
86     */
87    public function handleRenderContent(Event $event, $param)
88    {
89        [$format, $xhtml] = $event->data;
90        if ($format !== 'xhtml') return;
91
92        // thanks to the $this->pages property we might be able to skip some of those checks, but they don't hurt
93        global $ACT;
94        global $REV;
95        global $DATE_AT;
96        global $ID;
97        global $INFO;
98        if ($ACT !== 'show') return;
99        if ($REV) return;
100        if ($DATE_AT) return;
101        if (!$INFO['exists']) return;
102        if (!$ID) return;
103        if (!isset($this->pages[$ID])) return;
104
105        // all the above still does not ensure we skip sub renderings, so this is our last resort
106        if(count(array_filter(debug_backtrace(), fn($t) => $t['function'] === 'p_render')) > 1) return;
107
108        $md5cache = getCacheName($ID, '.renderrevision');
109
110        // no or outdated MD5 cache, create new one
111        // this means a new revision of the page has been created naturally
112        // we store the new render result and are done
113        if (!file_exists($md5cache) || filemtime(wikiFN($ID)) > filemtime($md5cache)) {
114            file_put_contents($md5cache, md5($xhtml));
115            return;
116        }
117
118        // only act on pages that have not been changed very recently
119        if (time() - filemtime(wikiFN($ID)) < $this->getConf('maxfrequency')) {
120            return;
121        }
122
123        // get the render result as it were when the page was last changed
124        $oldMd5 = file_get_contents($md5cache);
125
126        // did the rendered content change?
127        if ($oldMd5 === md5($xhtml)) {
128            return;
129        }
130
131        // time to create a new revision
132        $this->current = $ID;
133        (new PageFile($ID))->saveWikiText(rawWiki($ID), $this->getLang('summary'));
134        $this->current = null;
135    }
136
137    /**
138     * Event handler for COMMON_WIKIPAGE_SAVE
139     *
140     * Overwrite the contentChanged flag to force a new revision even though the content did not change
141     *
142     * @see https://www.dokuwiki.org/devel:event:COMMON_WIKIPAGE_SAVE
143     * @param Event $event Event object
144     * @param mixed $param optional parameter passed when event was registered
145     * @return void
146     */
147    public function handleCommonWikipageSave(Event $event, $param)
148    {
149        if ($this->current !== $event->data['id']) return;
150        $event->data['contentChanged'] = true;
151    }
152
153
154    /**
155     * Read the skip and match regex from the config
156     *
157     * Ensures the regular expressions are valid
158     *
159     * @return string[] [$skipRE, $matchRE]
160     * @throws \Exception if the regular expressions are invalid
161     */
162    public function getRegexps()
163    {
164        $skip = $this->getConf('skipRegex');
165        $skipRE = '';
166        $match = $this->getConf('matchRegex');
167        $matchRE = '';
168
169        if ($skip) {
170            $skipRE = '/' . $skip . '/';
171            if (@preg_match($skipRE, '') === false) {
172                throw new \Exception('Invalid regular expression in $conf[\'skipRegex\']. ' . preg_last_error_msg());
173            }
174        }
175
176        if ($match) {
177            $matchRE = '/' . $match . '/';
178            if (@preg_match($matchRE, '') === false) {
179                throw new \Exception('Invalid regular expression in $conf[\'matchRegex\']. ' . preg_last_error_msg());
180            }
181        }
182        return [$skipRE, $matchRE];
183    }
184}
185