6 * This file provides the framework for a plugin architecture.
8 * Documentation on how to write plugins might show up some time.
10 * @copyright © 1999-2007 The SquirrelMail Project Team
11 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
13 * @package squirrelmail
17 * This function adds a plugin.
18 * @param string $name Internal plugin name (ie. delete_move_next)
21 function use_plugin ($name) {
22 if (file_exists(SM_PATH
. "plugins/$name/setup.php")) {
23 include_once(SM_PATH
. "plugins/$name/setup.php");
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).
32 //$function = "squirrelmail_plugin_init_$name";
33 //if (function_exists($function)) {
40 * This function executes a plugin hook.
42 * It includes an arbitrary return value that is managed by
43 * all plugins on the same hook and returned to the core hook
46 * The desired format of the return value should be defined
47 * by the context in which the hook is called.
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.
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.
60 * @param string $name Name of hook being executed
61 * @param mixed $args A single value or an array of arguments
62 * that are to be passed to all plugins
63 * operating off the hook being called.
64 * Note that this argument is passed by
65 * reference thus it is liable to be
66 * changed after the hook completes.
68 * @return mixed The return value that is managed by the plugins
69 * on the current hook.
72 function do_hook($name, &$args) {
74 global $squirrelmail_plugin_hooks, $currentHookName;
75 $currentHookName = $name;
78 if (isset($squirrelmail_plugin_hooks[$name])
79 && is_array($squirrelmail_plugin_hooks[$name])) {
80 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
81 use_plugin($plugin_name);
82 if (function_exists($function)) {
83 $ret = $function($args, $ret);
85 // each plugin can call additional hooks, so need
86 // to make sure the current hook name is accurate
87 // again after each plugin has finished
89 $currentHookName = $name;
94 $currentHookName = '';
100 * This function executes a hook that allows for an arbitrary
101 * return value from each plugin that will be merged into one
102 * array (or one string if all return values are strings) and
103 * returned to the core hook location.
105 * Note that unlike PHP's array_merge function, matching array keys
106 * will not overwrite each other, instead, values under such keys
107 * will be concatenated if they are both strings, or merged if they
108 * are arrays (in the same (non-overwrite) manner recursively).
110 * Plugins returning non-arrays (strings, objects, etc) will have
111 * their output added to the end of the ultimate return array,
112 * unless ALL values returned are strings, in which case one string
113 * with all returned strings concatenated together is returned
114 * (unless $force_array is TRUE).
116 * If any plugin on this hook wants to modify the $args
117 * plugin parameter, it simply has to use call-by-reference
118 * syntax in the hook function that it has registered for the
119 * current hook. Note that this is in addition to (entirely
120 * independent of) the return value for this hook.
122 * @param string $name Name of hook being executed
123 * @param mixed $args A single value or an array of arguments
124 * that are to be passed to all plugins
125 * operating off the hook being called.
126 * Note that this argument is passed by
127 * reference thus it is liable to be
128 * changed after the hook completes.
129 * @param boolean $force_array When TRUE, guarantees the return
130 * value will ALWAYS be an array,
131 * (simple strings will be forced
132 * into a one-element array).
133 * When FALSE, behavior is as
134 * described above (OPTIONAL;
135 * default behavior is to return
136 * mixed - array or string).
138 * @return mixed the merged return arrays or strings of each
139 * plugin on this hook.
142 function concat_hook_function($name, &$args, $force_array=FALSE) {
144 global $squirrelmail_plugin_hooks, $currentHookName;
145 $currentHookName = $name;
148 if (isset($squirrelmail_plugin_hooks[$name])
149 && is_array($squirrelmail_plugin_hooks[$name])) {
150 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
151 use_plugin($plugin_name);
152 if (function_exists($function)) {
153 $plugin_ret = $function($args);
154 if (!empty($plugin_ret)) {
155 $ret = sqm_array_merge($ret, $plugin_ret);
158 // each plugin can call additional hooks, so need
159 // to make sure the current hook name is accurate
160 // again after each plugin has finished
162 $currentHookName = $name;
167 if ($force_array && is_string($ret)) {
171 $currentHookName = '';
177 * This function is used for hooks which are to return true or
178 * false. If $priority is > 0, any one or more trues will override
179 * any falses. If $priority < 0, then one or more falses will
180 * override any trues.
181 * Priority 0 means majority rules. Ties will be broken with $tie
183 * If any plugin on this hook wants to modify the $args
184 * plugin parameter, it simply has to use call-by-reference
185 * syntax in the hook function that it has registered for the
186 * current hook. Note that this is in addition to (entirely
187 * independent of) the return value for this hook.
189 * @param string $name The hook name
190 * @param mixed $args A single value or an array of arguments
191 * that are to be passed to all plugins
192 * operating off the hook being called.
193 * Note that this argument is passed by
194 * reference thus it is liable to be
195 * changed after the hook completes.
196 * @param int $priority See explanation above
197 * @param boolean $tie See explanation above
199 * @return boolean The result of the function
202 function boolean_hook_function($name, &$args, $priority=0, $tie=false) {
204 global $squirrelmail_plugin_hooks, $currentHookName;
209 if (isset($squirrelmail_plugin_hooks[$name]) &&
210 is_array($squirrelmail_plugin_hooks[$name])) {
212 /* Loop over the plugins that registered the hook */
213 $currentHookName = $name;
214 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
215 use_plugin($plugin_name);
216 if (function_exists($function)) {
217 $ret = $function($args);
224 // each plugin can call additional hooks, so need
225 // to make sure the current hook name is accurate
226 // again after each plugin has finished
228 $currentHookName = $name;
231 $currentHookName = '';
233 /* Examine the aftermath and assign the return value appropriately */
234 if (($priority > 0) && ($yea)) {
236 } elseif (($priority < 0) && ($nay)) {
238 } elseif ($yea > $nay) {
240 } elseif ($nay > $yea) {
243 // There's a tie, no action needed.
247 // If the code gets here, there was a problem - no hooks, etc.
253 * Do not use, use checkForJavascript() instead.
255 * This function checks whether the user's USER_AGENT is known to
256 * be broken. If so, returns true and the plugin is invisible to the
258 * *** THIS IS A TEST FOR JAVASCRIPT SUPPORT ***
260 * @return bool whether this browser properly supports JavaScript
261 * @deprecated use checkForJavascript() since 1.5.1
264 return !checkForJavascript();
268 * Check if plugin is enabled
269 * @param string $plugin_name plugin name
273 function is_plugin_enabled($plugin_name) {
277 * check if variable is empty. if var is not set, php empty
278 * returns true without error notice.
280 * then check if it is an array
282 if (empty($plugins) ||
! is_array($plugins))
285 if ( in_array($plugin_name,$plugins) ) {
293 * Get a plugin's version.
295 * Determines and returns a plugin's version.
297 * By default, the desired plugin must be currently
298 * activated, and if it is not, this function will
299 * return FALSE. By overriding the default value
300 * of $force_inclusion, this function will attempt
301 * to grab versioning information from the given
302 * plugin even if it is not activated (plugin still
303 * has to be unpackaged and set in place in the
304 * plugins directory). Use with care - some plugins
305 * might break SquirrelMail when this is used.
307 * By turning on the $do_parse argument, the version
308 * string will be parsed by SquirrelMail into a
309 * SquirrelMail-compatible version string (such as
310 * "1.2.3") if it is not already.
312 * Note that this assumes plugin versioning is
313 * consistently applied in the same fashion that
314 * SquirrelMail versions are, with the exception that
315 * an applicable SquirrelMail version may be appended
316 * to the version number (which will be ignored herein).
317 * That is, plugin version number schemes are expected
318 * in the following format: 1.2.3, or 1.2.3-1.4.0.
320 * Any characters after the third version number
321 * indicating things such as beta or release candidate
322 * versions are discarded, so formats such as the
323 * following will also work, although extra information
324 * about beta versions can possibly confuse the desired
325 * results of the version check: 1.2.3-beta4, 1.2.3.RC2,
330 * @param string plugin_name name of the plugin to
331 * check; must precisely
334 * @param bool force_inclusion try to get version info
335 * for plugins not activated?
337 * @param bool do_parse return the plugin version
338 * in SquirrelMail-compatible
339 * format (default FALSE)
341 * @return mixed The plugin version string if found, otherwise,
342 * boolean FALSE is returned indicating that no
343 * version information could be found for the plugin.
346 function get_plugin_version($plugin_name, $force_inclusion = FALSE, $do_parse = FALSE)
349 $info_function = $plugin_name . '_info';
350 $version_function = $plugin_name . '_version';
351 $plugin_info = array();
352 $plugin_version = FALSE;
355 // first attempt to find the plugin info function, wherein
356 // the plugin version should be available
358 if (function_exists($info_function))
359 $plugin_info = $info_function();
360 else if ($force_inclusion
361 && file_exists(SM_PATH
. 'plugins/' . $plugin_name . '/setup.php'))
363 include_once(SM_PATH
. 'plugins/' . $plugin_name . '/setup.php');
364 if (function_exists($info_function))
365 $plugin_info = $info_function();
367 if (!empty($plugin_info['version']))
368 $plugin_version = $plugin_info['version'];
371 // otherwise, look for older version function
373 if (!$plugin_version && function_exists($version_function))
374 $plugin_version = $version_function();
377 if ($plugin_version && $do_parse)
380 // massage version number into something we understand
382 // the first regexp strips everything and anything that follows
383 // the first occurance of a non-digit (or non decimal point), so
384 // beware that putting letters in the middle of a version string
385 // will effectively truncate the version string right there (but
386 // this also just helps remove the SquirrelMail version part off
387 // of versions such as "1.2.3-1.4.4")
389 // the second regexp just strips out non-digits/non-decimal points
390 // (and might be redundant(?))
392 // the regexps are wrapped in a trim that makes sure the version
393 // does not start or end with a decimal point
395 $plugin_version = trim(preg_replace(array('/[^0-9.]+.*$/', '/[^0-9.]/'),
396 '', $plugin_version),
401 return $plugin_version;
406 * Check a plugin's version.
408 * Returns TRUE if the given plugin is installed,
409 * activated and is at minimum version $a.$b.$c.
410 * If any one of those conditions fails, FALSE
411 * will be returned (careful of plugins that are
412 * sufficiently versioned but are not activated).
414 * By overriding the default value of $force_inclusion,
415 * this function will attempt to grab versioning
416 * information from the given plugin even if it
417 * is not activated (the plugin still has to be
418 * unpackaged and set in place in the plugins
419 * directory). Use with care - some plugins
420 * might break SquirrelMail when this is used.
422 * Note that this function assumes plugin
423 * versioning is consistently applied in the same
424 * fashion that SquirrelMail versions are, with the
425 * exception that an applicable SquirrelMail
426 * version may be appended to the version number
427 * (which will be ignored herein). That is, plugin
428 * version number schemes are expected in the following
429 * format: 1.2.3, or 1.2.3-1.4.0.
431 * Any characters after the third number indicating
432 * things such as beta or release candidate versions
433 * are discarded, so formats such as the following
434 * will also work, although extra information about
435 * beta versions can possibly confuse the desired results
436 * of the version check: 1.2.3-beta4, 1.2.3.RC2, and so forth.
440 * @param string plugin_name name of the plugin to
441 * check; must precisely
444 * @param int a major version number
445 * @param int b minor version number
446 * @param int c release number
447 * @param bool force_inclusion try to get version info
448 * for plugins not activated?
454 function check_plugin_version($plugin_name,
455 $a = 0, $b = 0, $c = 0,
456 $force_inclusion = FALSE)
459 $plugin_version = get_plugin_version($plugin_name, $force_inclusion, TRUE);
460 if (!$plugin_version) return FALSE;
463 // split the version string into sections delimited by
464 // decimal points, and make sure we have three sections
466 $plugin_version = explode('.', $plugin_version);
467 if (!isset($plugin_version[0])) $plugin_version[0] = 0;
468 if (!isset($plugin_version[1])) $plugin_version[1] = 0;
469 if (!isset($plugin_version[2])) $plugin_version[2] = 0;
470 // sm_print_r($plugin_version);
473 // now test the version number
475 if ($plugin_version[0] < $a ||
476 ($plugin_version[0] == $a && $plugin_version[1] < $b) ||
477 ($plugin_version[0] == $a && $plugin_version[1] == $b && $plugin_version[2] < $c))