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  * @package squirrelmail
  15  */
  16
  17 /** Everything needs global.. */
  18 require_once(SM_PATH . 'functions/global.php');
  19
  20 global $squirrelmail_plugin_hooks;
  21 $squirrelmail_plugin_hooks = array();
  22
  23 /**
  24  * This function adds a plugin.
  25  * @param string $name Internal plugin name (ie. delete_move_next)
  26  * @return void
  27  */
  28 function use_plugin ($name) {
  29     if (file_exists(SM_PATH . "plugins/$name/setup.php")) {
  30         include_once(SM_PATH . "plugins/$name/setup.php");
  31         $function = "squirrelmail_plugin_init_$name";
  32         if (function_exists($function)) {
  33             $function();
  34         }
  35     }
  36 }
  37
  38 /**
  39  * This function executes a hook.
  40  * @param string $name Name of hook to fire
  41  * @return mixed $data
  42  */
  43 function do_hook ($name) {
  44     global $squirrelmail_plugin_hooks;
  45     $data = func_get_args();
  46     $ret = '';
  47
  48     if (isset($squirrelmail_plugin_hooks[$name])
  49           && is_array($squirrelmail_plugin_hooks[$name])) {
  50         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
  51             /* Add something to set correct gettext domain for plugin. */
  52             if (function_exists($function)) {
  53                 $function($data);
  54             }
  55         }
  56     }
  57
  58     /* Variable-length argument lists have a slight problem when */
  59     /* passing values by reference. Pity. This is a workaround.  */
  60     return $data;
  61 }
  62
  63 /**
  64  * This function executes a hook and allows for parameters to be passed.
  65  *
  66  * @param string name the name of the hook
  67  * @param mixed param the parameters to pass to the hook function
  68  * @return mixed the return value of the hook function
  69  */
  70 function do_hook_function($name,$parm=NULL) {
  71     global $squirrelmail_plugin_hooks;
  72     $ret = '';
  73
  74     if (isset($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                 $ret = $function($parm);
  80             }
  81         }
  82     }
  83
  84     /* Variable-length argument lists have a slight problem when */
  85     /* passing values by reference. Pity. This is a workaround.  */
  86     return $ret;
  87 }
  88
  89 /**
  90  * This function executes a hook, concatenating the results of each
  91  * plugin that has the hook defined.
  92  *
  93  * @param string name the name of the hook
  94  * @param mixed parm optional hook function parameters
  95  * @return string a concatenation of the results of each plugin function
  96  */
  97 function concat_hook_function($name,$parm=NULL) {
  98     global $squirrelmail_plugin_hooks;
  99     $ret = '';
 100
 101     if (isset($squirrelmail_plugin_hooks[$name])
 102           && is_array($squirrelmail_plugin_hooks[$name])) {
 103         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
 104             /* Concatenate results from hook. */
 105             if (function_exists($function)) {
 106                 $ret .= $function($parm);
 107             }
 108         }
 109     }
 110
 111     /* Variable-length argument lists have a slight problem when */
 112     /* passing values by reference. Pity. This is a workaround.  */
 113     return $ret;
 114 }
 115
 116 /**
 117  * This function is used for hooks which are to return true or
 118  * false. If $priority is > 0, any one or more trues will override
 119  * any falses. If $priority < 0, then one or more falses will
 120  * override any trues.
 121  * Priority 0 means majority rules.  Ties will be broken with $tie
 122  *
 123  * @param string name the hook name
 124  * @param mixed parm the parameters for the hook function
 125  * @param int priority
 126  * @param bool tie
 127  * @return bool the result of the function
 128  */
 129 function boolean_hook_function($name,$parm=NULL,$priority=0,$tie=false) {
 130     global $squirrelmail_plugin_hooks;
 131     $yea = 0;
 132     $nay = 0;
 133     $ret = $tie;
 134
 135     if (isset($squirrelmail_plugin_hooks[$name]) &&
 136         is_array($squirrelmail_plugin_hooks[$name])) {
 137
 138         /* Loop over the plugins that registered the hook */
 139         foreach ($squirrelmail_plugin_hooks[$name] as $function) {
 140             if (function_exists($function)) {
 141                 $ret = $function($parm);
 142                 if ($ret) {
 143                     $yea++;
 144                 } else {
 145                     $nay++;
 146                 }
 147             }
 148         }
 149
 150         /* Examine the aftermath and assign the return value appropriately */
 151         if (($priority > 0) && ($yea)) {
 152             $ret = true;
 153         } elseif (($priority < 0) && ($nay)) {
 154             $ret = false;
 155         } elseif ($yea > $nay) {
 156             $ret = true;
 157         } elseif ($nay > $yea) {
 158             $ret = false;
 159         } else {
 160             // There's a tie, no action needed.
 161         }
 162         return $ret;
 163     }
 164     // If the code gets here, there was a problem - no hooks, etc.
 165     return NULL;
 166 }
 167
 168 /**
 169  * This function checks whether the user's USER_AGENT is known to
 170  * be broken. If so, returns true and the plugin is invisible to the
 171  * offending browser.
 172  * This function needs to have its name changed!
 173  *
 174  * @return bool whether this browser properly supports JavaScript
 175  */
 176 function soupNazi(){
 177
 178     $soup_menu = array('Mozilla/3','Mozilla/2','Mozilla/1', 'Opera 4',
 179                        'Opera/4', 'OmniWeb', 'Lynx');
 180     sqgetGlobalVar('HTTP_USER_AGENT', $user_agent, SQ_SERVER);
 181     foreach($soup_menu as $browser) {
 182         if(stristr($user_agent, $browser)) {
 183             return 1;
 184         }
 185     }
 186     return 0;
 187 }
 188 /*************************************/
 189 /*** MAIN PLUGIN LOADING CODE HERE ***/
 190 /*************************************/
 191
 192 /* On startup, register all plugins configured for use. */
 193 if (isset($plugins) && is_array($plugins)) {
 194     foreach ($plugins as $name) {
 195         use_plugin($name);
 196     }
 197 }
 198
 199 ?>