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[squirrelmail.git] / functions / plugin.php
CommitLineData
7b086a80 1<?php
2
35586184 3/**
4 * plugin.php
5 *
35586184 6 * This file provides the framework for a plugin architecture.
7 *
8 * Documentation on how to write plugins might show up some time.
9 *
4b5049de 10 * @copyright &copy; 1999-2007 The SquirrelMail Project Team
4b4abf93 11 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
31841a9e 12 * @version $Id$
d6c32258 13 * @package squirrelmail
35586184 14 */
15
d6c32258 16/**
17 * This function adds a plugin.
18 * @param string $name Internal plugin name (ie. delete_move_next)
19 * @return void
20 */
0606ca1f 21function use_plugin ($name) {
bd9c880b 22 if (file_exists(SM_PATH . "plugins/$name/setup.php")) {
23 include_once(SM_PATH . "plugins/$name/setup.php");
8b56e282 24
25 /**
26 * As of SM 1.5.2, plugin hook registration is statically
27 * accomplished using the configuration utility (config/conf.pl).
28 * And this code is deprecated (but let's keep it until
29 * the new registration system is proven).
30 *
31 */
32 //$function = "squirrelmail_plugin_init_$name";
33 //if (function_exists($function)) {
34 // $function();
35 //}
2d367c68 36 }
0606ca1f 37}
2d367c68 38
d6c32258 39/**
d849b570 40 * This function executes a plugin hook.
41 *
42 * It includes an arbitrary return value that is managed by
43 * all plugins on the same hook and returned to the core hook
44 * location.
45 *
46 * The desired format of the return value should be defined
47 * by the context in which the hook is called.
48 *
49 * Note that the master return value for this hook is passed
50 * to each plugin after the main argument(s) value/array as a
51 * convenience only - to show what the current return value is
52 * even though it is liable to be changed by other plugins.
53 *
54 * If any plugin on this hook wants to modify the $args
55 * plugin parameter, it simply has to use call-by-reference
56 * syntax in the hook function that it has registered for the
57 * current hook. Note that this is in addition to (entirely
58 * independent of) the return value for this hook.
59 *
60 * @param string $name Name of hook being executed
61 * @param mixed $args A single value or an array of arguments
62 * that are to be passed to all plugins
63 * operating off the hook being called.
64 * Note that this argument is passed by
65 * reference thus it is liable to be
66 * changed after the hook completes.
67 *
68 * @return mixed The return value that is managed by the plugins
69 * on the current hook.
8b096f0a 70 *
8b096f0a 71 */
d849b570 72function do_hook($name, &$args) {
73
eb1f02bc 74 global $squirrelmail_plugin_hooks, $currentHookName;
eb1f02bc 75 $currentHookName = $name;
d849b570 76 $ret = NULL;
31524bcd 77
78 if (isset($squirrelmail_plugin_hooks[$name])
79 && is_array($squirrelmail_plugin_hooks[$name])) {
8b56e282 80 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
81 use_plugin($plugin_name);
31524bcd 82 if (function_exists($function)) {
0fe6826d 83 $ret = $function($args, $ret);
dd389be5 84 }
2d367c68 85 }
2d367c68 86 }
7b086a80 87
eb1f02bc 88 $currentHookName = '';
2586d588 89 return $ret;
d849b570 90
0606ca1f 91}
7b086a80 92
8b096f0a 93/**
d849b570 94 * This function executes a hook that allows for an arbitrary
95 * return value from each plugin that will be merged into one
96 * array (or one string if all return values are strings) and
97 * returned to the core hook location.
7edd8ad6 98 *
99 * Note that unlike PHP's array_merge function, matching array keys
100 * will not overwrite each other, instead, values under such keys
101 * will be concatenated if they are both strings, or merged if they
102 * are arrays (in the same (non-overwrite) manner recursively).
103 *
104 * Plugins returning non-arrays (strings, objects, etc) will have
105 * their output added to the end of the ultimate return array,
106 * unless ALL values returned are strings, in which case one string
0db60ced 107 * with all returned strings concatenated together is returned
108 * (unless $force_array is TRUE).
8b096f0a 109 *
d849b570 110 * If any plugin on this hook wants to modify the $args
111 * plugin parameter, it simply has to use call-by-reference
112 * syntax in the hook function that it has registered for the
113 * current hook. Note that this is in addition to (entirely
114 * independent of) the return value for this hook.
115 *
0db60ced 116 * @param string $name Name of hook being executed
117 * @param mixed $args A single value or an array of arguments
118 * that are to be passed to all plugins
119 * operating off the hook being called.
120 * Note that this argument is passed by
121 * reference thus it is liable to be
122 * changed after the hook completes.
123 * @param boolean $force_array When TRUE, guarantees the return
124 * value will ALWAYS be an array,
125 * (simple strings will be forced
126 * into a one-element array).
127 * When FALSE, behavior is as
128 * described above (OPTIONAL;
129 * default behavior is to return
130 * mixed - array or string).
7edd8ad6 131 *
132 * @return mixed the merged return arrays or strings of each
d849b570 133 * plugin on this hook.
7edd8ad6 134 *
8b096f0a 135 */
0db60ced 136function concat_hook_function($name, &$args, $force_array=FALSE) {
d849b570 137
eb1f02bc 138 global $squirrelmail_plugin_hooks, $currentHookName;
eb1f02bc 139 $currentHookName = $name;
d849b570 140 $ret = '';
31524bcd 141
09ac2863 142 if (isset($squirrelmail_plugin_hooks[$name])
143 && is_array($squirrelmail_plugin_hooks[$name])) {
8b56e282 144 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
145 use_plugin($plugin_name);
09ac2863 146 if (function_exists($function)) {
d849b570 147 $plugin_ret = $function($args);
5fba72db 148 if (!empty($plugin_ret)) {
149 $ret = sqm_array_merge($ret, $plugin_ret);
150 }
09ac2863 151 }
152 }
153 }
154
0db60ced 155 if ($force_array && is_string($ret)) {
156 $ret = array($ret);
157 }
158
eb1f02bc 159 $currentHookName = '';
09ac2863 160 return $ret;
d849b570 161
09ac2863 162}
cd7fc9e6 163
164/**
5576644b 165 * This function is used for hooks which are to return true or
166 * false. If $priority is > 0, any one or more trues will override
167 * any falses. If $priority < 0, then one or more falses will
168 * override any trues.
8b096f0a 169 * Priority 0 means majority rules. Ties will be broken with $tie
170 *
d849b570 171 * If any plugin on this hook wants to modify the $args
172 * plugin parameter, it simply has to use call-by-reference
173 * syntax in the hook function that it has registered for the
174 * current hook. Note that this is in addition to (entirely
175 * independent of) the return value for this hook.
176 *
177 * @param string $name The hook name
178 * @param mixed $args A single value or an array of arguments
179 * that are to be passed to all plugins
180 * operating off the hook being called.
181 * Note that this argument is passed by
182 * reference thus it is liable to be
183 * changed after the hook completes.
184 * @param int $priority See explanation above
185 * @param boolean $tie See explanation above
186 *
187 * @return boolean The result of the function
188 *
8b096f0a 189 */
d849b570 190function boolean_hook_function($name, &$args, $priority=0, $tie=false) {
191
eb1f02bc 192 global $squirrelmail_plugin_hooks, $currentHookName;
5576644b 193 $yea = 0;
194 $nay = 0;
195 $ret = $tie;
196
197 if (isset($squirrelmail_plugin_hooks[$name]) &&
198 is_array($squirrelmail_plugin_hooks[$name])) {
199
200 /* Loop over the plugins that registered the hook */
eb1f02bc 201 $currentHookName = $name;
8b56e282 202 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
203 use_plugin($plugin_name);
5576644b 204 if (function_exists($function)) {
d849b570 205 $ret = $function($args);
5576644b 206 if ($ret) {
207 $yea++;
208 } else {
209 $nay++;
210 }
211 }
212 }
eb1f02bc 213 $currentHookName = '';
5576644b 214
215 /* Examine the aftermath and assign the return value appropriately */
216 if (($priority > 0) && ($yea)) {
217 $ret = true;
218 } elseif (($priority < 0) && ($nay)) {
219 $ret = false;
220 } elseif ($yea > $nay) {
221 $ret = true;
222 } elseif ($nay > $yea) {
223 $ret = false;
224 } else {
225 // There's a tie, no action needed.
226 }
227 return $ret;
228 }
229 // If the code gets here, there was a problem - no hooks, etc.
230 return NULL;
d849b570 231
5576644b 232}
233
234/**
141105fc 235 * Do not use, use checkForJavascript() instead.
236 *
cd7fc9e6 237 * This function checks whether the user's USER_AGENT is known to
238 * be broken. If so, returns true and the plugin is invisible to the
239 * offending browser.
7349fa12 240 * *** THIS IS A TEST FOR JAVASCRIPT SUPPORT ***
8b096f0a 241 *
242 * @return bool whether this browser properly supports JavaScript
ccacde36 243 * @deprecated use checkForJavascript() since 1.5.1
cd7fc9e6 244 */
245function soupNazi(){
7349fa12 246 return !checkForJavascript();
cd7fc9e6 247}
fe0aa536 248
249/**
250 * Check if plugin is enabled
251 * @param string $plugin_name plugin name
252 * @since 1.5.1
253 * @return boolean
254 */
255function is_plugin_enabled($plugin_name) {
256 global $plugins;
257
e83cfcef 258 /**
202bcbcc 259 * check if variable is empty. if var is not set, php empty
e495bd68 260 * returns true without error notice.
261 *
262 * then check if it is an array
e83cfcef 263 */
e495bd68 264 if (empty($plugins) || ! is_array($plugins))
fe0aa536 265 return false;
266
267 if ( in_array($plugin_name,$plugins) ) {
268 return true;
269 } else {
270 return false;
271 }
272}
d99b6c56 273
274/**
d95b10b3 275 * Get a plugin's version.
276 *
277 * Determines and returns a plugin's version.
278 *
279 * By default, the desired plugin must be currently
280 * activated, and if it is not, this function will
281 * return FALSE. By overriding the default value
282 * of $force_inclusion, this function will attempt
283 * to grab versioning information from the given
284 * plugin even if it is not activated (plugin still
285 * has to be unpackaged and set in place in the
286 * plugins directory). Use with care - some plugins
287 * might break SquirrelMail when this is used.
288 *
289 * @since 1.5.2
290 *
291 * @param string plugin_name name of the plugin to
292 * check; must precisely
293 * match the plugin
294 * directory name
295 * @param bool force_inclusion try to get version info
296 * for plugins not activated?
297 * (default FALSE)
298 *
299 * @return mixed The plugin version string if found, otherwise,
300 * boolean FALSE is returned indicating that no
301 * version information could be found for the plugin.
302 *
303 */
304function get_plugin_version($plugin_name, $force_inclusion = FALSE)
305{
306
307 $info_function = $plugin_name . '_info';
308 $version_function = $plugin_name . '_version';
309 $plugin_info = array();
310 $plugin_version = FALSE;
311
312
313 // first attempt to find the plugin info function, wherein
314 // the plugin version should be available
315 //
316 if (function_exists($info_function))
317 $plugin_info = $info_function();
318 else if ($force_inclusion
319 && file_exists(SM_PATH . 'plugins/' . $plugin_name . '/setup.php'))
320 {
321 include_once(SM_PATH . 'plugins/' . $plugin_name . '/setup.php');
322 if (function_exists($info_function))
323 $plugin_info = $info_function();
324 }
325 if (!empty($plugin_info['version']))
326 $plugin_version = $plugin_info['version'];
327
328
329 // otherwise, look for older version function
330 //
331 if (!$plugin_version && function_exists($version_function))
332 $plugin_version = $version_function();
333
334
335 return $plugin_version;
336
337}
338
339/**
d99b6c56 340 * Check a plugin's version.
341 *
342 * Returns TRUE if the given plugin is installed,
343 * activated and is at minimum version $a.$b.$c.
344 * If any one of those conditions fails, FALSE
345 * will be returned (careful of plugins that are
346 * sufficiently versioned but are not activated).
347 *
348 * By overriding the default value of $force_inclusion,
349 * this function will attempt to grab versioning
350 * information from the given plugin even if it
351 * is not activated (plugin still has to be
352 * unpackaged and set in place in the plugins
353 * directory). Use with care - some plugins
354 * might break SquirrelMail when this is used.
355 *
356 * Note that this function assumes plugin
357 * versioning is consistently applied in the same
358 * fashion that SquirrelMail versions are, with the
359 * exception that an applicable SquirrelMail
360 * version may be appended to the version number
361 * (which will be ignored herein). That is, plugin
362 * version number schemes are expected in the following
363 * format: 1.2.3, or 1.2.3-1.4.0.
364 *
365 * Any characters after the third number are discarded,
366 * so formats such as the following will also work,
367 * although extra information about beta versions can
368 * possibly confuse the desired results of the version
369 * check: 1.2.3-beta4, 1.2.3.RC2, and so forth.
370 *
b2a6a14c 371 * @since 1.5.2
d99b6c56 372 *
373 * @param string plugin_name name of the plugin to
374 * check; must precisely
375 * match the plugin
376 * directory name
377 * @param int a major version number
378 * @param int b minor version number
379 * @param int c release number
380 * @param bool force_inclusion try to get version info
381 * for plugins not activated?
382 * (default FALSE)
383 *
384 * @return bool
385 *
386 */
387function check_plugin_version($plugin_name,
388 $a = 0, $b = 0, $c = 0,
389 $force_inclusion = FALSE)
390{
391
d95b10b3 392 $plugin_version = get_plugin_version($plugin_name, $force_inclusion);
d99b6c56 393 if (!$plugin_version) return FALSE;
394
395
396 // now massage version number into something we understand
397 //
398 $plugin_version = trim(preg_replace(array('/[^0-9.]+.*$/', '/[^0-9.]/'),
399 '', $plugin_version),
400 '.');
401 $plugin_version = explode('.', $plugin_version);
402 if (!isset($plugin_version[0])) $plugin_version[0] = 0;
403 if (!isset($plugin_version[1])) $plugin_version[1] = 0;
404 if (!isset($plugin_version[2])) $plugin_version[2] = 0;
405// sm_print_r($plugin_version);
406
407
408 // now test the version number
409 //
410 if ($plugin_version[0] < $a ||
411 ($plugin_version[0] == $a && $plugin_version[1] < $b) ||
412 ($plugin_version[0] == $a && $plugin_version[1] == $b && $plugin_version[2] < $c))
413 return FALSE;
414
415
416 return TRUE;
417
418}
419