Convert example theme to directory-based theme.
[squirrelmail.git] / functions / plugin.php
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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");
0606ca1f 24 $function = "squirrelmail_plugin_init_$name";
25 if (function_exists($function)) {
26 $function();
2d367c68 27 }
2d367c68 28 }
0606ca1f 29}
2d367c68 30
d6c32258 31/**
32 * This function executes a hook.
33 * @param string $name Name of hook to fire
34 * @return mixed $data
35 */
31524bcd 36function do_hook ($name) {
eb1f02bc 37 global $squirrelmail_plugin_hooks, $currentHookName;
0606ca1f 38 $data = func_get_args();
eb1f02bc 39 $currentHookName = $name;
a3439b27 40
0606ca1f 41 if (isset($squirrelmail_plugin_hooks[$name])
42 && is_array($squirrelmail_plugin_hooks[$name])) {
43 foreach ($squirrelmail_plugin_hooks[$name] as $function) {
44 /* Add something to set correct gettext domain for plugin. */
45 if (function_exists($function)) {
31524bcd 46 $function($data);
47 }
48 }
49 }
50
eb1f02bc 51 $currentHookName = '';
52
31524bcd 53 /* Variable-length argument lists have a slight problem when */
54 /* passing values by reference. Pity. This is a workaround. */
55 return $data;
56}
57
8b096f0a 58/**
e900d242 59 * This function executes a hook and allows for parameters to be
60 * passed, wherein each plugin can modify the parameters before
61 * they are passed to the next funciton. Whether or not the
62 * parameters are modified, plugins on this hook should always
63 * return the given parameters.
64 *
65 * @param string name the name of the hook
66 * @param mixed param the parameters to pass to the hook function
67 * @return mixed the possibly modified hook parameters
68 */
69function filter_hook_function($name,$parm=NULL) {
70 global $squirrelmail_plugin_hooks, $currentHookName;
71 $ret = '';
72 $currentHookName = $name;
73
74 if (isset($squirrelmail_plugin_hooks[$name])
75 && is_array($squirrelmail_plugin_hooks[$name])) {
76 foreach ($squirrelmail_plugin_hooks[$name] as $function) {
77 /* Add something to set correct gettext domain for plugin. */
78 if (function_exists($function)) {
79 $parm = $function($parm);
80 }
81 }
82 }
83
84 $currentHookName = '';
85
86 /* Variable-length argument lists have a slight problem when */
87 /* passing values by reference. Pity. This is a workaround. */
88 return $parm;
89}
90
91/**
8b096f0a 92 * This function executes a hook and allows for parameters to be passed.
93 *
94 * @param string name the name of the hook
95 * @param mixed param the parameters to pass to the hook function
96 * @return mixed the return value of the hook function
97 */
31524bcd 98function do_hook_function($name,$parm=NULL) {
eb1f02bc 99 global $squirrelmail_plugin_hooks, $currentHookName;
31524bcd 100 $ret = '';
eb1f02bc 101 $currentHookName = $name;
31524bcd 102
103 if (isset($squirrelmail_plugin_hooks[$name])
104 && is_array($squirrelmail_plugin_hooks[$name])) {
105 foreach ($squirrelmail_plugin_hooks[$name] as $function) {
106 /* Add something to set correct gettext domain for plugin. */
107 if (function_exists($function)) {
108 $ret = $function($parm);
dd389be5 109 }
2d367c68 110 }
2d367c68 111 }
7b086a80 112
eb1f02bc 113 $currentHookName = '';
114
0606ca1f 115 /* Variable-length argument lists have a slight problem when */
116 /* passing values by reference. Pity. This is a workaround. */
2586d588 117 return $ret;
0606ca1f 118}
7b086a80 119
8b096f0a 120/**
7edd8ad6 121 * This function executes a hook, allows for parameters to be passed,
122 * and looks for an array returned from each plugin: each array is
123 * then merged into one and returned to the core hook location.
124 *
125 * Note that unlike PHP's array_merge function, matching array keys
126 * will not overwrite each other, instead, values under such keys
127 * will be concatenated if they are both strings, or merged if they
128 * are arrays (in the same (non-overwrite) manner recursively).
129 *
130 * Plugins returning non-arrays (strings, objects, etc) will have
131 * their output added to the end of the ultimate return array,
132 * unless ALL values returned are strings, in which case one string
133 * with all returned strings concatenated together is returned.
8b096f0a 134 *
135 * @param string name the name of the hook
7edd8ad6 136 * @param mixed param the parameters to pass to the hook function
137 *
138 * @return mixed the merged return arrays or strings of each
139 * plugin on this hook
140 *
8b096f0a 141 */
09ac2863 142function concat_hook_function($name,$parm=NULL) {
eb1f02bc 143 global $squirrelmail_plugin_hooks, $currentHookName;
bbac5629 144 $ret = '';
eb1f02bc 145 $currentHookName = $name;
31524bcd 146
09ac2863 147 if (isset($squirrelmail_plugin_hooks[$name])
148 && is_array($squirrelmail_plugin_hooks[$name])) {
149 foreach ($squirrelmail_plugin_hooks[$name] as $function) {
7edd8ad6 150 /* Add something to set correct gettext domain for plugin. */
09ac2863 151 if (function_exists($function)) {
5fba72db 152 $plugin_ret = $function($parm);
153 if (!empty($plugin_ret)) {
154 $ret = sqm_array_merge($ret, $plugin_ret);
155 }
09ac2863 156 }
157 }
158 }
159
eb1f02bc 160 $currentHookName = '';
161
09ac2863 162 /* Variable-length argument lists have a slight problem when */
163 /* passing values by reference. Pity. This is a workaround. */
164 return $ret;
165}
cd7fc9e6 166
167/**
5576644b 168 * This function is used for hooks which are to return true or
169 * false. If $priority is > 0, any one or more trues will override
170 * any falses. If $priority < 0, then one or more falses will
171 * override any trues.
8b096f0a 172 * Priority 0 means majority rules. Ties will be broken with $tie
173 *
174 * @param string name the hook name
175 * @param mixed parm the parameters for the hook function
176 * @param int priority
177 * @param bool tie
178 * @return bool the result of the function
179 */
5576644b 180function boolean_hook_function($name,$parm=NULL,$priority=0,$tie=false) {
eb1f02bc 181 global $squirrelmail_plugin_hooks, $currentHookName;
5576644b 182 $yea = 0;
183 $nay = 0;
184 $ret = $tie;
185
186 if (isset($squirrelmail_plugin_hooks[$name]) &&
187 is_array($squirrelmail_plugin_hooks[$name])) {
188
189 /* Loop over the plugins that registered the hook */
eb1f02bc 190 $currentHookName = $name;
5576644b 191 foreach ($squirrelmail_plugin_hooks[$name] as $function) {
192 if (function_exists($function)) {
193 $ret = $function($parm);
194 if ($ret) {
195 $yea++;
196 } else {
197 $nay++;
198 }
199 }
200 }
eb1f02bc 201 $currentHookName = '';
5576644b 202
203 /* Examine the aftermath and assign the return value appropriately */
204 if (($priority > 0) && ($yea)) {
205 $ret = true;
206 } elseif (($priority < 0) && ($nay)) {
207 $ret = false;
208 } elseif ($yea > $nay) {
209 $ret = true;
210 } elseif ($nay > $yea) {
211 $ret = false;
212 } else {
213 // There's a tie, no action needed.
214 }
215 return $ret;
216 }
217 // If the code gets here, there was a problem - no hooks, etc.
218 return NULL;
219}
220
221/**
cd7fc9e6 222 * This function checks whether the user's USER_AGENT is known to
223 * be broken. If so, returns true and the plugin is invisible to the
224 * offending browser.
7349fa12 225 * *** THIS IS A TEST FOR JAVASCRIPT SUPPORT ***
94ba79ce 226 * FIXME: This function needs to have its name changed!
8b096f0a 227 *
228 * @return bool whether this browser properly supports JavaScript
ccacde36 229 * @deprecated use checkForJavascript() since 1.5.1
cd7fc9e6 230 */
231function soupNazi(){
7349fa12 232 return !checkForJavascript();
cd7fc9e6 233}
fe0aa536 234
235/**
236 * Check if plugin is enabled
237 * @param string $plugin_name plugin name
238 * @since 1.5.1
239 * @return boolean
240 */
241function is_plugin_enabled($plugin_name) {
242 global $plugins;
243
e83cfcef 244 /**
202bcbcc 245 * check if variable is empty. if var is not set, php empty
e495bd68 246 * returns true without error notice.
247 *
248 * then check if it is an array
e83cfcef 249 */
e495bd68 250 if (empty($plugins) || ! is_array($plugins))
fe0aa536 251 return false;
252
253 if ( in_array($plugin_name,$plugins) ) {
254 return true;
255 } else {
256 return false;
257 }
258}
d99b6c56 259
260/**
261 * Check a plugin's version.
262 *
263 * Returns TRUE if the given plugin is installed,
264 * activated and is at minimum version $a.$b.$c.
265 * If any one of those conditions fails, FALSE
266 * will be returned (careful of plugins that are
267 * sufficiently versioned but are not activated).
268 *
269 * By overriding the default value of $force_inclusion,
270 * this function will attempt to grab versioning
271 * information from the given plugin even if it
272 * is not activated (plugin still has to be
273 * unpackaged and set in place in the plugins
274 * directory). Use with care - some plugins
275 * might break SquirrelMail when this is used.
276 *
277 * Note that this function assumes plugin
278 * versioning is consistently applied in the same
279 * fashion that SquirrelMail versions are, with the
280 * exception that an applicable SquirrelMail
281 * version may be appended to the version number
282 * (which will be ignored herein). That is, plugin
283 * version number schemes are expected in the following
284 * format: 1.2.3, or 1.2.3-1.4.0.
285 *
286 * Any characters after the third number are discarded,
287 * so formats such as the following will also work,
288 * although extra information about beta versions can
289 * possibly confuse the desired results of the version
290 * check: 1.2.3-beta4, 1.2.3.RC2, and so forth.
291 *
b2a6a14c 292 * @since 1.5.2
d99b6c56 293 *
294 * @param string plugin_name name of the plugin to
295 * check; must precisely
296 * match the plugin
297 * directory name
298 * @param int a major version number
299 * @param int b minor version number
300 * @param int c release number
301 * @param bool force_inclusion try to get version info
302 * for plugins not activated?
303 * (default FALSE)
304 *
305 * @return bool
306 *
307 */
308function check_plugin_version($plugin_name,
309 $a = 0, $b = 0, $c = 0,
310 $force_inclusion = FALSE)
311{
312
6b6bcf00 313 $info_function = $plugin_name . '_info';
d99b6c56 314 $version_function = $plugin_name . '_version';
6b6bcf00 315 $plugin_info = array();
d99b6c56 316 $plugin_version = FALSE;
317
318
6b6bcf00 319 // first attempt to find the plugin info function, wherein
320 // the plugin version should be available
d99b6c56 321 //
6b6bcf00 322 if (function_exists($info_function))
323 $plugin_info = $info_function();
d99b6c56 324 else if ($force_inclusion
325 && file_exists(SM_PATH . 'plugins/' . $plugin_name . '/setup.php'))
326 {
327 include_once(SM_PATH . 'plugins/' . $plugin_name . '/setup.php');
6b6bcf00 328 if (function_exists($info_function))
329 $plugin_info = $info_function();
d99b6c56 330 }
6b6bcf00 331 if (!empty($plugin_info['version']))
332 $plugin_version = $plugin_info['version'];
333
334
335 // otherwise, look for older version function
336 //
337 if (!$plugin_version && function_exists($version_function))
338 $plugin_version = $version_function();
339
d99b6c56 340
341 if (!$plugin_version) return FALSE;
342
343
344 // now massage version number into something we understand
345 //
346 $plugin_version = trim(preg_replace(array('/[^0-9.]+.*$/', '/[^0-9.]/'),
347 '', $plugin_version),
348 '.');
349 $plugin_version = explode('.', $plugin_version);
350 if (!isset($plugin_version[0])) $plugin_version[0] = 0;
351 if (!isset($plugin_version[1])) $plugin_version[1] = 0;
352 if (!isset($plugin_version[2])) $plugin_version[2] = 0;
353// sm_print_r($plugin_version);
354
355
356 // now test the version number
357 //
358 if ($plugin_version[0] < $a ||
359 ($plugin_version[0] == $a && $plugin_version[1] < $b) ||
360 ($plugin_version[0] == $a && $plugin_version[1] == $b && $plugin_version[2] < $c))
361 return FALSE;
362
363
364 return TRUE;
365
366}
367