must pass $args by ref to to plugin function too, if we want the plugin
[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 *
47ccfad4 10 * @copyright &copy; 1999-2006 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)) {
141105fc 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
107 * with all returned strings concatenated together is returned.
8b096f0a 108 *
d849b570 109 * If any plugin on this hook wants to modify the $args
110 * plugin parameter, it simply has to use call-by-reference
111 * syntax in the hook function that it has registered for the
112 * current hook. Note that this is in addition to (entirely
113 * independent of) the return value for this hook.
114 *
115 * @param string $name Name of hook being executed
116 * @param mixed $args A single value or an array of arguments
117 * that are to be passed to all plugins
118 * operating off the hook being called.
119 * Note that this argument is passed by
120 * reference thus it is liable to be
121 * changed after the hook completes.
7edd8ad6 122 *
123 * @return mixed the merged return arrays or strings of each
d849b570 124 * plugin on this hook.
7edd8ad6 125 *
8b096f0a 126 */
d849b570 127function concat_hook_function($name, &$args) {
128
eb1f02bc 129 global $squirrelmail_plugin_hooks, $currentHookName;
eb1f02bc 130 $currentHookName = $name;
d849b570 131 $ret = '';
31524bcd 132
09ac2863 133 if (isset($squirrelmail_plugin_hooks[$name])
134 && is_array($squirrelmail_plugin_hooks[$name])) {
8b56e282 135 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
136 use_plugin($plugin_name);
09ac2863 137 if (function_exists($function)) {
d849b570 138 $plugin_ret = $function($args);
5fba72db 139 if (!empty($plugin_ret)) {
140 $ret = sqm_array_merge($ret, $plugin_ret);
141 }
09ac2863 142 }
143 }
144 }
145
eb1f02bc 146 $currentHookName = '';
09ac2863 147 return $ret;
d849b570 148
09ac2863 149}
cd7fc9e6 150
151/**
5576644b 152 * This function is used for hooks which are to return true or
153 * false. If $priority is > 0, any one or more trues will override
154 * any falses. If $priority < 0, then one or more falses will
155 * override any trues.
8b096f0a 156 * Priority 0 means majority rules. Ties will be broken with $tie
157 *
d849b570 158 * If any plugin on this hook wants to modify the $args
159 * plugin parameter, it simply has to use call-by-reference
160 * syntax in the hook function that it has registered for the
161 * current hook. Note that this is in addition to (entirely
162 * independent of) the return value for this hook.
163 *
164 * @param string $name The hook name
165 * @param mixed $args A single value or an array of arguments
166 * that are to be passed to all plugins
167 * operating off the hook being called.
168 * Note that this argument is passed by
169 * reference thus it is liable to be
170 * changed after the hook completes.
171 * @param int $priority See explanation above
172 * @param boolean $tie See explanation above
173 *
174 * @return boolean The result of the function
175 *
8b096f0a 176 */
d849b570 177function boolean_hook_function($name, &$args, $priority=0, $tie=false) {
178
eb1f02bc 179 global $squirrelmail_plugin_hooks, $currentHookName;
5576644b 180 $yea = 0;
181 $nay = 0;
182 $ret = $tie;
183
184 if (isset($squirrelmail_plugin_hooks[$name]) &&
185 is_array($squirrelmail_plugin_hooks[$name])) {
186
187 /* Loop over the plugins that registered the hook */
eb1f02bc 188 $currentHookName = $name;
8b56e282 189 foreach ($squirrelmail_plugin_hooks[$name] as $plugin_name => $function) {
190 use_plugin($plugin_name);
5576644b 191 if (function_exists($function)) {
d849b570 192 $ret = $function($args);
5576644b 193 if ($ret) {
194 $yea++;
195 } else {
196 $nay++;
197 }
198 }
199 }
eb1f02bc 200 $currentHookName = '';
5576644b 201
202 /* Examine the aftermath and assign the return value appropriately */
203 if (($priority > 0) && ($yea)) {
204 $ret = true;
205 } elseif (($priority < 0) && ($nay)) {
206 $ret = false;
207 } elseif ($yea > $nay) {
208 $ret = true;
209 } elseif ($nay > $yea) {
210 $ret = false;
211 } else {
212 // There's a tie, no action needed.
213 }
214 return $ret;
215 }
216 // If the code gets here, there was a problem - no hooks, etc.
217 return NULL;
d849b570 218
5576644b 219}
220
221/**
141105fc 222 * Do not use, use checkForJavascript() instead.
223 *
cd7fc9e6 224 * This function checks whether the user's USER_AGENT is known to
225 * be broken. If so, returns true and the plugin is invisible to the
226 * offending browser.
7349fa12 227 * *** THIS IS A TEST FOR JAVASCRIPT SUPPORT ***
8b096f0a 228 *
229 * @return bool whether this browser properly supports JavaScript
ccacde36 230 * @deprecated use checkForJavascript() since 1.5.1
cd7fc9e6 231 */
232function soupNazi(){
7349fa12 233 return !checkForJavascript();
cd7fc9e6 234}
fe0aa536 235
236/**
237 * Check if plugin is enabled
238 * @param string $plugin_name plugin name
239 * @since 1.5.1
240 * @return boolean
241 */
242function is_plugin_enabled($plugin_name) {
243 global $plugins;
244
e83cfcef 245 /**
202bcbcc 246 * check if variable is empty. if var is not set, php empty
e495bd68 247 * returns true without error notice.
248 *
249 * then check if it is an array
e83cfcef 250 */
e495bd68 251 if (empty($plugins) || ! is_array($plugins))
fe0aa536 252 return false;
253
254 if ( in_array($plugin_name,$plugins) ) {
255 return true;
256 } else {
257 return false;
258 }
259}
d99b6c56 260
261/**
262 * Check a plugin's version.
263 *
264 * Returns TRUE if the given plugin is installed,
265 * activated and is at minimum version $a.$b.$c.
266 * If any one of those conditions fails, FALSE
267 * will be returned (careful of plugins that are
268 * sufficiently versioned but are not activated).
269 *
270 * By overriding the default value of $force_inclusion,
271 * this function will attempt to grab versioning
272 * information from the given plugin even if it
273 * is not activated (plugin still has to be
274 * unpackaged and set in place in the plugins
275 * directory). Use with care - some plugins
276 * might break SquirrelMail when this is used.
277 *
278 * Note that this function assumes plugin
279 * versioning is consistently applied in the same
280 * fashion that SquirrelMail versions are, with the
281 * exception that an applicable SquirrelMail
282 * version may be appended to the version number
283 * (which will be ignored herein). That is, plugin
284 * version number schemes are expected in the following
285 * format: 1.2.3, or 1.2.3-1.4.0.
286 *
287 * Any characters after the third number are discarded,
288 * so formats such as the following will also work,
289 * although extra information about beta versions can
290 * possibly confuse the desired results of the version
291 * check: 1.2.3-beta4, 1.2.3.RC2, and so forth.
292 *
b2a6a14c 293 * @since 1.5.2
d99b6c56 294 *
295 * @param string plugin_name name of the plugin to
296 * check; must precisely
297 * match the plugin
298 * directory name
299 * @param int a major version number
300 * @param int b minor version number
301 * @param int c release number
302 * @param bool force_inclusion try to get version info
303 * for plugins not activated?
304 * (default FALSE)
305 *
306 * @return bool
307 *
308 */
309function check_plugin_version($plugin_name,
310 $a = 0, $b = 0, $c = 0,
311 $force_inclusion = FALSE)
312{
313
6b6bcf00 314 $info_function = $plugin_name . '_info';
d99b6c56 315 $version_function = $plugin_name . '_version';
6b6bcf00 316 $plugin_info = array();
d99b6c56 317 $plugin_version = FALSE;
318
319
6b6bcf00 320 // first attempt to find the plugin info function, wherein
321 // the plugin version should be available
d99b6c56 322 //
6b6bcf00 323 if (function_exists($info_function))
324 $plugin_info = $info_function();
d99b6c56 325 else if ($force_inclusion
326 && file_exists(SM_PATH . 'plugins/' . $plugin_name . '/setup.php'))
327 {
328 include_once(SM_PATH . 'plugins/' . $plugin_name . '/setup.php');
6b6bcf00 329 if (function_exists($info_function))
330 $plugin_info = $info_function();
d99b6c56 331 }
6b6bcf00 332 if (!empty($plugin_info['version']))
333 $plugin_version = $plugin_info['version'];
334
335
336 // otherwise, look for older version function
337 //
338 if (!$plugin_version && function_exists($version_function))
339 $plugin_version = $version_function();
340
d99b6c56 341
342 if (!$plugin_version) return FALSE;
343
344
345 // now massage version number into something we understand
346 //
347 $plugin_version = trim(preg_replace(array('/[^0-9.]+.*$/', '/[^0-9.]/'),
348 '', $plugin_version),
349 '.');
350 $plugin_version = explode('.', $plugin_version);
351 if (!isset($plugin_version[0])) $plugin_version[0] = 0;
352 if (!isset($plugin_version[1])) $plugin_version[1] = 0;
353 if (!isset($plugin_version[2])) $plugin_version[2] = 0;
354// sm_print_r($plugin_version);
355
356
357 // now test the version number
358 //
359 if ($plugin_version[0] < $a ||
360 ($plugin_version[0] == $a && $plugin_version[1] < $b) ||
361 ($plugin_version[0] == $a && $plugin_version[1] == $b && $plugin_version[2] < $c))
362 return FALSE;
363
364
365 return TRUE;
366
367}
368