functions/plugin.php

   1 <?php
   2
   3 /**
   4  ** plugin.php
   5  **
   6  ** This file provides the framework for a plugin architecture.
   7  **
   8  ** Plugins will eventually be a way to provide added functionality
   9  ** without having to patch the SquirrelMail source code. Have some
  10  ** patience, though, as the these funtions might change in the near
  11  ** future.
  12  **
  13  ** Documentation on how to write plugins might show up some time.
  14  **
  15  ** $Id$
  16  **/
  17
  18
  19    if (defined('plugin_php'))
  20       return;
  21    define('plugin_php', true);
  22
  23    global $plugin_general_debug, $squirrelmail_plugin_hooks;
  24    $plugin_general_debug = false;
  25
  26    $squirrelmail_plugin_hooks = array();
  27
  28    // This function adds a plugin
  29    function use_plugin ($name) {
  30       global $plugin_general_debug;
  31
  32       if (file_exists('../plugins/'.$name.'/setup.php')) {
  33          if ($plugin_general_debug)
  34             echo "plugin:  --  Loading $name/setup.php<br>\n";
  35          include_once('../plugins/'.$name.'/setup.php');
  36          $function = 'squirrelmail_plugin_init_'.$name;
  37          if (function_exists($function))
  38          {
  39             if ($plugin_general_debug)
  40                echo "plugin:  ---- Executing $function to init plugin<br>\n";
  41             $function($plugin_general_debug);
  42          }
  43          elseif ($plugin_general_debug)
  44             echo "plugin:  -- Init function $function doesn't exist.<br>\n";
  45       }
  46       elseif ($plugin_general_debug)
  47          echo "plugin:  Couldn't find $name/setup.php<br>\n";
  48    }
  49
  50    // This function executes a hook
  51    function do_hook ($name) {
  52       global $squirrelmail_plugin_hooks;
  53       $Data = func_get_args();
  54       if (isset($squirrelmail_plugin_hooks[$name]) &&
  55           is_array($squirrelmail_plugin_hooks[$name])) {
  56          foreach ($squirrelmail_plugin_hooks[$name] as $id => $function) {
  57             // Add something to set correct gettext domain for plugin
  58             if (function_exists($function)) {
  59                 $function($Data);
  60             }
  61          }
  62       }
  63
  64       // Variable-length argument lists have a slight problem when
  65       // passing values by reference.  Pity.  This is a workaround.
  66       return $Data;
  67   }
  68
  69    // On startup, register all plugins configured for use
  70    if (isset($plugins) && is_array($plugins))
  71       foreach ($plugins as $id => $name)
  72       {
  73          if ($plugin_general_debug)
  74             echo "plugin:  Attempting load of plugin $name<br>\n";
  75          use_plugin($name);
  76       }
  77
  78    if ($plugin_general_debug)
  79    {
  80       echo "plugin:  Hook list<br>\n";
  81       foreach ($squirrelmail_plugin_hooks as $Hook => $Plugins)
  82       {
  83           foreach ($Plugins as $Name => $Func)
  84           {
  85               echo "[$Hook][$Name] = $Func<br>\n";
  86           }
  87       }
  88    }
  89
  90 ?>