s2member / src / includes / classes / no-cache.inc.php

no-cache.inc.php in s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions trunk, at src/includes/classes/no-cache.inc.php

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1	<?php
2	// @codingStandardsIgnoreFile
3	/**
4	* No-cache routines.
5	*
6	* Copyright: © 2009-2011
7	* {@link http://websharks-inc.com/ WebSharks, Inc.}
8	* (coded in the USA)
9	*
10	* Released under the terms of the GNU General Public License.
11	* You should have received a copy of the GNU General Public License,
12	* along with this software. In the main directory, see: /licensing/
13	* If not, see: {@link http://www.gnu.org/licenses/}.
14	*
15	* @package s2Member\No_Cache
16	* @since 3.5
17	*/
18	if(!defined('WPINC')) // MUST have WordPress.
19	exit ('Do not access this file directly.');
20
21	if(!class_exists('c_ws_plugin__s2member_no_cache'))
22	{
23	/**
24	* No-cache routines.
25	*
26	* @package s2Member\No_Cache
27	* @since 3.5
28	*/
29	class c_ws_plugin__s2member_no_cache
30	{
31	/**
32	* No-cache headers required?
33	*
34	* @package s2Member\No_Cache
35	* @since 111115
36	*
37	* @var null\|bool
38	*/
39	public static $headers;
40
41	/**
42	* Sets up no-cache header behavior mode.
43	*
44	* This runs on `init` so s2Member options are available (options are configured after hooks are included).
45	*
46	* @package s2Member\No_Cache
47	* @since 260307
48	*
49	* @attaches-to ``add_action('init');``
50	*
51	* @return void
52	*/
53	public static function setup_no_cache_headers_mode()
54	{
55	static $once; // Run only once per request.
56
57	if($once)
58	return;
59
60	$once = TRUE;
61
62	$mode = (!empty($GLOBALS['WS_PLUGIN__']['s2member']['o']['no_cache_headers_mode']))
63	? (string)$GLOBALS['WS_PLUGIN__']['s2member']['o']['no_cache_headers_mode']
64	: 'always';
65
66	if($mode === 'evaluative' \|\| !empty($GLOBALS['WS_PLUGIN__']['s2member']['o']['no_cache_headers_debug']))
67	add_filter('wp_headers', 'c_ws_plugin__s2member_no_cache::no_cache_wp_headers', 9999); //260309 Run last; also adds debug header in all modes when enabled.
68
69	if($mode === 'evaluative')
70	{
71	add_filter('ws_plugin__s2member_no_cache_headers_selective', '__return_true');
72	c_ws_plugin__s2member_no_cache::no_cache_constants(FALSE);
73
74	add_action('wp', 'c_ws_plugin__s2member_no_cache::evaluative_no_cache_scan', 3); //260308 Rename staged scan to evaluative scan.
75	}
76	else
77	{
78	if($mode === 'selective')
79	add_filter('ws_plugin__s2member_no_cache_headers_selective', '__return_true');
80
81	c_ws_plugin__s2member_no_cache::no_cache(FALSE);
82	}
83	}
84
85	/**
86	* Evaluative mode: scans queried post content for s2Member shortcodes before headers are sent.
87	*
88	* Shortcodes execute after headers (during rendering), so evaluative mode must pre-detect likely s2Member
89	* shortcodes to ensure no-cache headers are applied when needed.
90	*
91	* @package s2Member\No_Cache
92	* @since 260307
93	*
94	* @attaches-to ``add_action('wp');``
95	*
96	* @return void
97	*/
98	public static function evaluative_no_cache_scan()
99	{
100	if(!is_singular())
101	return;
102
103	$post = get_queried_object();
104	if(!is_object($post) \|\| empty($post->post_content) \|\| !is_string($post->post_content))
105	return;
106
107	//260307 Conservative pre-detection of s2Member shortcodes in post content.
108	// This intentionally errs on the safe side (prevents caching) for any `[s2...` usage.
109	if(stripos($post->post_content, '[s2') !== FALSE)
110	c_ws_plugin__s2member_no_cache::no_cache_constants(true);
111	}
112
113	/**
114	* Handles no-cache constants, and no-cache headers.
115	*
116	* @package s2Member\No_Cache
117	* @since 3.5
118	*
119	* @attaches-to ``add_action('init');``
120	* @also-called-by Other routines within s2Member.
121	*
122	* @param bool $no_cache Optional. Defaults to false. If true, force no-cache if at all possible.
123	*
124	* @return bool This function will always return `true`.
125	*/
126	public static function no_cache($no_cache = FALSE)
127	{
128	do_action('ws_plugin__s2member_before_no_cache', get_defined_vars());
129
130	c_ws_plugin__s2member_no_cache::no_cache_constants($no_cache).c_ws_plugin__s2member_no_cache::no_cache_headers($no_cache);
131
132	do_action('ws_plugin__s2member_after_no_cache', get_defined_vars());
133
134	return TRUE; // Always return true.
135	}
136
137	/**
138	* Defines no-cache constants for various WordPress plugins.
139	*
140	* This is compatible with Quick Cache, W3 Total Cache, and also with WP Super Cache.
141	* Quick Cache uses: ``QUICK_CACHE_ALLOWED``, and other plugins use: ``DONOTCACHEPAGE``.
142	* W3 Total Cache is also known to be compatible with ``DONOTCACHEOBJECT`` and ``DONOTCACHEDB``.
143	*
144	* Disallow caching if the ``$no_cache`` parameter is passed in as ``true``, by other routines.
145	* In addition, always disallow caching for logged in users, and GET requests with: `/?s2member` Systematics.
146	* For clarity on s2Member Systematics, see: {@link s2Member\Systematics\c_ws_plugin__s2member_systematics::is_s2_systematic_use_page()}.
147	*
148	* However, this routine will ALWAYS obey the `?qcAC` query string parameter.
149	* This Quick Cache parameter explicitly allows caching to occur.
150	*
151	* @package s2Member\No_Cache
152	* @since 3.5
153	*
154	* @also-called-by Other routines within s2Member.
155	*
156	* @param bool $no_cache Optional. Defaults to false. If true, force no-cache if at all possible.
157	*
158	* @return bool This function will always return `true`.
159	*/
160	public static function no_cache_constants($no_cache = FALSE)
161	{
162	static $once; // We only need to set these constants once.
163
164	foreach(array_keys(get_defined_vars()) as $__v) $__refs[$__v] =& $$__v;
165	do_action('ws_plugin__s2member_before_no_cache_constants', get_defined_vars());
166	unset($__refs, $__v); // Housekeeping.
167
168	if(!$once && (empty($_GET['qcAC']) \|\| !filter_var($_GET['qcAC'], FILTER_VALIDATE_BOOLEAN))
169	&& (
170	$no_cache === TRUE // Forces no-cache constants; if `TRUE` explicitly.
171	\|\| ($no_cache === 'restricted' && (!defined('COMET_CACHE_WHEN_LOGGED_IN') \|\| !COMET_CACHE_WHEN_LOGGED_IN) && (!defined('ZENCACHE_WHEN_LOGGED_IN') \|\| !ZENCACHE_WHEN_LOGGED_IN) && (!defined('QUICK_CACHE_WHEN_LOGGED_IN') \|\| !QUICK_CACHE_WHEN_LOGGED_IN))
172	\|\| (is_user_logged_in() && (!defined('COMET_CACHE_WHEN_LOGGED_IN') \|\| !COMET_CACHE_WHEN_LOGGED_IN) && (!defined('ZENCACHE_WHEN_LOGGED_IN') \|\| !ZENCACHE_WHEN_LOGGED_IN) && (!defined('QUICK_CACHE_WHEN_LOGGED_IN') \|\| !QUICK_CACHE_WHEN_LOGGED_IN))
173	\|\| c_ws_plugin__s2member_systematics::is_s2_systematic_use_page()
174	)
175	)
176	{
177	/**
178	* No-cache DB queries for plugins.
179	*
180	* @package s2Member\No_Cache
181	* @since 111115
182	*
183	* @var bool
184	*/
185	if(!defined('DONOTCACHEDB'))
186	define('DONOTCACHEDB', TRUE);
187
188	/**
189	* No-cache Page for plugins.
190	*
191	* @package s2Member\No_Cache
192	* @since 3.5
193	*
194	* @var bool
195	*/
196	if(!defined('DONOTCACHEPAGE'))
197	define('DONOTCACHEPAGE', TRUE);
198
199	/**
200	* No-cache Objects for plugins.
201	*
202	* @package s2Member\No_Cache
203	* @since 111115
204	*
205	* @var bool
206	*/
207	if(!defined('DONOTCACHEOBJECT'))
208	define('DONOTCACHEOBJECT', TRUE);
209
210	/**
211	* No-cache anything for Comet Cache plugin.
212	*
213	* @package s2Member\No_Cache
214	* @since 160222
215	*
216	* @var bool
217	*/
218	if(!defined('COMET_CACHE_ALLOWED'))
219	define('COMET_CACHE_ALLOWED', FALSE);
220
221	/**
222	* No-cache anything for ZenCache plugin.
223	*
224	* @package s2Member\No_Cache
225	* @since 3.5
226	*
227	* @var bool
228	*/
229	if(!defined('ZENCACHE_ALLOWED'))
230	define('ZENCACHE_ALLOWED', FALSE);
231
232	/**
233	* No-cache anything for Quick Cache plugin.
234	*
235	* @package s2Member\No_Cache
236	* @since 3.5
237	*
238	* @var bool
239	*/
240	if(!defined('QUICK_CACHE_ALLOWED'))
241	define('QUICK_CACHE_ALLOWED', FALSE);
242
243	$once = TRUE; // Set these one time only.
244
245	c_ws_plugin__s2member_no_cache::$headers = TRUE;
246
247	do_action('ws_plugin__s2member_during_no_cache_constants', get_defined_vars());
248	}
249	do_action('ws_plugin__s2member_after_no_cache_constants', get_defined_vars());
250
251	return TRUE; // Always return true.
252	}
253
254	/**
255	* Filters HTTP headers (wp_headers) to apply no-cache headers when needed.
256	*
257	* This is used by the `evaluative` no-cache headers mode. It allows s2Member runtime checks/shortcodes
258	* (e.g., `[s2If]`) to set no-cache constants/flags during rendering, while still applying no-cache
259	* headers during WordPress's standard header-sending stage (wp_headers/send_headers).
260	*
261	* Obeys `?qcABC`, `?zcABC`, and `?ccABC` query string parameters, which explicitly allow caching.
262	*
263	* @package s2Member\No_Cache
264	* @since 260307
265	*
266	* @param array $headers An associative array of HTTP headers.
267	*
268	* @return array Possibly modified headers.
269	*/
270	public static function no_cache_wp_headers($headers = array())
271	{
272	static $once; // We only need to filter these headers one time.
273
274	foreach(array_keys(get_defined_vars()) as $__v) $__refs[$__v] =& $$__v;
275	do_action('ws_plugin__s2member_before_no_cache_headers', get_defined_vars());
276	unset($__refs, $__v); // Housekeeping.
277
278	$mode = (!empty($GLOBALS['WS_PLUGIN__']['s2member']['o']['no_cache_headers_mode']))
279	? (string)$GLOBALS['WS_PLUGIN__']['s2member']['o']['no_cache_headers_mode']
280	: 'always';
281	$no_cache = (bool)apply_filters('ws_plugin__s2member_no_cache', FALSE, get_defined_vars());
282	$using_selective_behavior = (bool)apply_filters('ws_plugin__s2member_no_cache_headers_selective', FALSE, get_defined_vars());
283
284	if($mode === 'evaluative' && !$no_cache && $using_selective_behavior && !c_ws_plugin__s2member_no_cache::$headers) //260309 Evaluative mode: pre-detect s2 shortcodes in queried content.
285	{
286	global $wp_query;
287
288	if(!empty($wp_query) && !empty($wp_query->post) && is_object($wp_query->post) && !empty($wp_query->post->post_content))
289	if(stripos((string)$wp_query->post->post_content, '[s2') !== FALSE)
290	c_ws_plugin__s2member_no_cache::$headers = TRUE;
291	}
292
293	//260308 Debug header (support use only).
294	if(!empty($GLOBALS['WS_PLUGIN__']['s2member']['o']['no_cache_headers_debug']))
295	{
296	$_st = 's2member;desc="mode='.$mode.';no_cache='.(int)$no_cache.';selective='.(int)$using_selective_behavior.';headers='.(int)c_ws_plugin__s2member_no_cache::$headers.'"';
297
298	if(!empty($headers['Server-Timing']))
299	$headers['Server-Timing'] .= ', '.$_st;
300	else
301	$headers['Server-Timing'] = $_st;
302
303	unset($_st); // Housekeeping.
304	}
305
306	if($mode === 'evaluative' && !$once
307	&& (empty($_GET['ccABC']) \|\| !filter_var($_GET['ccABC'], FILTER_VALIDATE_BOOLEAN))
308	&& (empty($_GET['zcABC']) \|\| !filter_var($_GET['zcABC'], FILTER_VALIDATE_BOOLEAN))
309	&& (empty($_GET['qcABC']) \|\| !filter_var($_GET['qcABC'], FILTER_VALIDATE_BOOLEAN))
310	&& ($no_cache \|\| !$using_selective_behavior \|\| c_ws_plugin__s2member_no_cache::$headers)
311	)
312	if(!apply_filters('ws_plugin__s2member_disable_no_cache_headers', FALSE, get_defined_vars()))
313	{
314	$nocache_headers = wp_get_nocache_headers();
315
316	foreach(array('Expires', 'Cache-Control', 'Pragma') as $_k)
317	if(isset($headers[$_k])) unset($headers[$_k]);
318
319	foreach((array)$nocache_headers as $_k => $_v)
320	$headers[$_k] = $_v;
321
322	unset($_k, $_v); // Housekeeping.
323
324	$once = TRUE; // This is static var. Only apply once.
325
326	do_action('ws_plugin__s2member_during_no_cache_headers', get_defined_vars());
327	}
328	do_action('ws_plugin__s2member_after_no_cache_headers', get_defined_vars());
329
330	return $headers;
331	}
332
333	/**
334	* Sends Cache-Control (no-cache) headers.
335	*
336	* Disallow browser caching if the ``$no_cache`` parameter is passed in as ``true``, by other routines.
337	* Disallow browser caching when/if no-cache Constants are set by {@link s2Member\No_Cache\c_ws_plugin__s2member_no_cache::no_cache_constants()},
338	* via static variable boolean value for: ``c_ws_plugin__s2member_no_cache::$headers``.
339	*
340	* However, this routine will ALWAYS obey the `?qcABC` query string parameter.
341	* This Quick Cache parameter explicitly allows browser caching to occur.
342	*
343	* @package s2Member\No_Cache
344	* @since 3.5
345	*
346	* @also-called-by Other routines within s2Member.
347	*
348	* @param bool $no_cache Optional. Defaults to false. If true, force no-cache if at all possible.
349	*
350	* @return bool This function will always return `true`.
351	*/
352	public static function no_cache_headers($no_cache = FALSE)
353	{
354	static $once; // We only need to set these headers one time.
355
356	foreach(array_keys(get_defined_vars()) as $__v) $__refs[$__v] =& $$__v;
357	do_action('ws_plugin__s2member_before_no_cache_headers', get_defined_vars());
358	unset($__refs, $__v); // Housekeeping.
359
360	$using_selective_behavior = apply_filters('ws_plugin__s2member_no_cache_headers_selective', FALSE, get_defined_vars());
361
362	if(!$once && !headers_sent() // Only once, and only if possible.
363	&& (empty($_GET['ccABC']) \|\| !filter_var($_GET['ccABC'], FILTER_VALIDATE_BOOLEAN))
364	&& (empty($_GET['zcABC']) \|\| !filter_var($_GET['zcABC'], FILTER_VALIDATE_BOOLEAN))
365	&& (empty($_GET['qcABC']) \|\| !filter_var($_GET['qcABC'], FILTER_VALIDATE_BOOLEAN))
366	&& ($no_cache \|\| !$using_selective_behavior \|\| c_ws_plugin__s2member_no_cache::$headers)
367	)
368	if(!apply_filters('ws_plugin__s2member_disable_no_cache_headers', FALSE, get_defined_vars()))
369	{
370	foreach(headers_list() as $header) // No-cache headers already sent? We need to check here.
371	if(stripos($header, 'no-cache') !== FALSE) // No-cache headers already sent?
372	{
373	$no_cache_headers_already_sent = TRUE; // Yep, sent.
374	break; // Break now, no need to continue further.
375	}
376	if(!isset ($no_cache_headers_already_sent)) // Not yet?
377	nocache_headers(); // Only if NOT already sent.
378
379	$once = TRUE; // This is static var. Only send headers once.
380
381	do_action('ws_plugin__s2member_during_no_cache_headers', get_defined_vars());
382	}
383	do_action('ws_plugin__s2member_after_no_cache_headers', get_defined_vars());
384
385	return TRUE; // Always return true.
386	}
387	}
388	}
389