squirrelmail/functions/plugin.php

<?php

/**
 ** plugin.php
 **
 ** This file provides the framework for a plugin architecture.
 **
 ** Plugins will eventually be a way to provide added functionality
 ** without having to patch the SquirrelMail source code. Have some
 ** patience, though, as the these funtions might change in the near
 ** future.
 **
 ** Documentation on how to write plugins might show up some time.
 **
 ** $Id$
 **/


   if (defined('plugin_php'))
      return;
   define('plugin_php', true);

   global $plugin_general_debug, $squirrelmail_plugin_hooks;
   $plugin_general_debug = false;
   
   $squirrelmail_plugin_hooks = array();

   // This function adds a plugin
   function use_plugin ($name) {
      global $plugin_general_debug;
      
      if (file_exists('../plugins/'.$name.'/setup.php')) {
         if ($plugin_general_debug)
	    echo "plugin:  --  Loading $name/setup.php<br>\n";
         include ('../plugins/'.$name.'/setup.php');
         $function = 'squirrelmail_plugin_init_'.$name;
         if (function_exists($function))
	 {
	    if ($plugin_general_debug)
	       echo "plugin:  ---- Executing $function to init plugin<br>\n";
            $function($plugin_general_debug);
	 }
	 elseif ($plugin_general_debug)
	    echo "plugin:  -- Init function $function doesn't exist.<br>\n";
      }
      elseif ($plugin_general_debug)
         echo "plugin:  Couldn't find $name/setup.php<br>\n";
   }

   // This function executes a hook
   function do_hook ($name) {
      global $squirrelmail_plugin_hooks;
      $Data = func_get_args();
      if (isset($squirrelmail_plugin_hooks[$name]) && 
          is_array($squirrelmail_plugin_hooks[$name])) {
         foreach ($squirrelmail_plugin_hooks[$name] as $id => $function) {
            // Add something to set correct gettext domain for plugin
            if (function_exists($function)) {
                $function($Data);
            }
         }
      }
      
      // Variable-length argument lists have a slight problem when
      // passing values by reference.  Pity.  This is a workaround.
      return $Data;
  }

   // On startup, register all plugins configured for use
   if (isset($plugins) && is_array($plugins))
      foreach ($plugins as $id => $name)
      {
         if ($plugin_general_debug)
	    echo "plugin:  Attempting load of plugin $name<br>\n";
         use_plugin($name);
      }

   if ($plugin_general_debug)
   {
      echo "plugin:  Hook list<br>\n";
      foreach ($squirrelmail_plugin_hooks as $Hook => $Plugins)
      {
          foreach ($Plugins as $Name => $Func)
	  {
	      echo "[$Hook][$Name] = $Func<br>\n";
	  }
      }
   }

?>