functions/plugin.php

   1 <?php
   2
   3 /**
   4  * plugin.php
   5  *
   6  * Copyright (c) 1999-2003 The SquirrelMail Project Team
   7  * Licensed under the GNU GPL. For full terms see the file COPYING.
   8  *
   9  * This file provides the framework for a plugin architecture.
  10  *
  11  * Documentation on how to write plugins might show up some time.
  12  *
  13  * $Id$
  14  */
  15
  16 require_once(SM_PATH . 'functions/global.php');
  17
  18 global $squirrelmail_plugin_hooks;
  19 $squirrelmail_plugin_hooks = array();
  20
  21 /* This function adds a plugin. */
  22 function use_plugin ($name) {
  23     if (file_exists(SM_PATH . "plugins/$name/setup.php")) {
  24         include_once(SM_PATH . "plugins/$name/setup.php");
  25         $function = "squirrelmail_plugin_init_$name";
  26         if (function_exists($function)) {
  27             $function();
  28         }
  29     }
  30 }
  31
  32 /* This function executes a hook. */
  33 function do_hook ($name) {
  34     global $squirrelmail_plugin_hooks;
  35     $data = func_get_args();
  36     $ret = '';
  37
  38     if (isset($squirrelmail_plugin_hooks[$name])
  39           && is_array($squirrelmail_plugin_hooks[$name])) {
  40         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
  41             /* Add something to set correct gettext domain for plugin. */
  42             if (function_exists($function)) {
  43                 $function($data);
  44             }
  45         }
  46     }
  47
  48     /* Variable-length argument lists have a slight problem when */
  49     /* passing values by reference. Pity. This is a workaround.  */
  50     return $data;
  51 }
  52
  53 /* This function executes a hook. */
  54 function do_hook_function($name,$parm=NULL) {
  55     global $squirrelmail_plugin_hooks;
  56     $ret = '';
  57
  58     if (isset($squirrelmail_plugin_hooks[$name])
  59           && is_array($squirrelmail_plugin_hooks[$name])) {
  60         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
  61             /* Add something to set correct gettext domain for plugin. */
  62             if (function_exists($function)) {
  63                 $ret = $function($parm);
  64             }
  65         }
  66     }
  67
  68     /* Variable-length argument lists have a slight problem when */
  69     /* passing values by reference. Pity. This is a workaround.  */
  70     return $ret;
  71 }
  72
  73 /* This function executes a hook. */
  74 function concat_hook_function($name,$parm=NULL) {
  75     global $squirrelmail_plugin_hooks;
  76     $ret = '';
  77
  78     if (isset($squirrelmail_plugin_hooks[$name])
  79           && is_array($squirrelmail_plugin_hooks[$name])) {
  80         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
  81             /* Concatenate results from hook. */
  82             if (function_exists($function)) {
  83                 $ret .= $function($parm);
  84             }
  85         }
  86     }
  87
  88     /* Variable-length argument lists have a slight problem when */
  89     /* passing values by reference. Pity. This is a workaround.  */
  90     return $ret;
  91 }
  92
  93 /**
  94  * This function is used for hooks which are to return true or
  95  * false. If $priority is > 0, any one or more trues will override
  96  * any falses. If $priority < 0, then one or more falses will
  97  * override any trues.
  98  * Priority 0 means majority rules.  Ties will be broken with $tie */
  99 function boolean_hook_function($name,$parm=NULL,$priority=0,$tie=false) {
 100     global $squirrelmail_plugin_hooks;
 101     $yea = 0;
 102     $nay = 0;
 103     $ret = $tie;
 104
 105     if (isset($squirrelmail_plugin_hooks[$name]) &&
 106         is_array($squirrelmail_plugin_hooks[$name])) {
 107
 108         /* Loop over the plugins that registered the hook */
 109         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
 110             if (function_exists($function)) {
 111                 $ret = $function($parm);
 112                 if ($ret) {
 113                     $yea++;
 114                 } else {
 115                     $nay++;
 116                 }
 117             }
 118         }
 119
 120         /* Examine the aftermath and assign the return value appropriately */
 121         if (($priority > 0) && ($yea)) {
 122             $ret = true;
 123         } elseif (($priority < 0) && ($nay)) {
 124             $ret = false;
 125         } elseif ($yea > $nay) {
 126             $ret = true;
 127         } elseif ($nay > $yea) {
 128             $ret = false;
 129         } else {
 130             // There's a tie, no action needed.
 131         }
 132         return $ret;
 133     }
 134     // If the code gets here, there was a problem - no hooks, etc.
 135     return NULL;
 136 }
 137
 138 /**
 139  * This function checks whether the user's USER_AGENT is known to
 140  * be broken. If so, returns true and the plugin is invisible to the
 141  * offending browser.
 142  */
 143 function soupNazi(){
 144
 145     $soup_menu = array('Mozilla/3','Mozilla/2','Mozilla/1', 'Opera 4',
 146                        'Opera/4', 'OmniWeb', 'Lynx');
 147     sqgetGlobalVar('HTTP_USER_AGENT', $user_agent, SQ_SERVER);
 148     foreach($soup_menu as $browser) {
 149         if(stristr($user_agent, $browser)) {
 150             return 1;
 151         }
 152     }
 153     return 0;
 154 }
 155 /*************************************/
 156 /*** MAIN PLUGIN LOADING CODE HERE ***/
 157 /*************************************/
 158
 159 /* On startup, register all plugins configured for use. */
 160 if (isset($plugins) && is_array($plugins)) {
 161     foreach ($plugins as $name) {
 162         use_plugin($name);
 163     }
 164 }
 165
 166 ?>