lib/pkp/classes/plugins/PluginRegistry.inc.php

   1 <?php
   2
   3 /**
   4  * @file classes/plugins/PluginRegistry.inc.php
   5  *
   6  * Copyright (c) 2000-2009 John Willinsky
   7  * Distributed under the GNU GPL v2. For full terms see the file docs/COPYING.
   8  *
   9  * @class PluginRegistry
  10  * @ingroup plugins
  11  * @see Plugin
  12  *
  13  * @brief Registry class for managing plugins.
  14  */
  15
  16 // $Id: PluginRegistry.inc.php,v 1.8 2009/08/31 16:29:56 asmecher Exp $
  17
  18
  19 define('PLUGINS_PREFIX', 'plugins/');
  20
  21 class PluginRegistry {
  22         /**
  23          * Return all plugins in the given category as an array, or, if the
  24          * category is not specified, all plugins in an associative array of
  25          * arrays by category.
  26          * @param $category String the name of the category to retrieve
  27          */
  28         function &getPlugins($category = null) {
  29                 $plugins =& Registry::get('plugins');
  30                 if ($category !== null) return $plugins[$category];
  31                 return $plugins;
  32         }
  33
  34         /**
  35          * Get all plugins in a single array.
  36          */
  37         function &getAllPlugins() {
  38                 $plugins =& PluginRegistry::getPlugins();
  39                 $allPlugins = array();
  40                 if (is_array($plugins)) foreach ($plugins as $category => $list) {
  41                         if (is_array($list)) $allPlugins += $list;
  42                 }
  43                 return $allPlugins;
  44         }
  45
  46         /**
  47          * Register a plugin with the registry in the given category.
  48          * @param $category String the name of the category to extend
  49          * @param $plugin The instantiated plugin to add
  50          * @param $path The path the plugin was found in
  51          * @return boolean True IFF the plugin was registered successfully
  52          */
  53         function register($category, &$plugin, $path) {
  54                 $pluginName = $plugin->getName();
  55                 $plugins =& PluginRegistry::getPlugins();
  56                 if (!$plugins) $plugins = array();
  57
  58                 // If the plugin was already loaded, do not load it again.
  59                 if (isset($plugins[$category][$pluginName])) return false;
  60
  61                 // Allow the plugin to register.
  62                 if (!$plugin->register($category, $path)) return false;
  63
  64                 if (isset($plugins[$category])) $plugins[$category][$plugin->getName()] =& $plugin;
  65                 else $plugins[$category] = array($plugin->getName() => &$plugin);
  66                 Registry::set('plugins', $plugins);
  67                 return true;
  68         }
  69
  70         /**
  71          * Get a plugin by name.
  72          * @param $category String category name
  73          * @param $name String plugin name
  74          */
  75         function &getPlugin ($category, $name) {
  76                 $plugins =& PluginRegistry::getPlugins();
  77                 $plugin = @$plugins[$category][$name];
  78                 return $plugin;
  79         }
  80
  81         /**
  82          * Load all plugins for a given category.
  83          * @param $category String The name of the category to load
  84          * @param $forceLoad boolean Whether or not to force loading of the
  85          * category (since if e.g. a single plugin is already registered, the
  86          * current set will be returned rather than attempting to load others)
  87          */
  88         function &loadCategory ($category, $forceLoad = false) {
  89                 $plugins = array();
  90                 $categoryDir = PLUGINS_PREFIX . $category;
  91                 if (!is_dir($categoryDir)) return $plugins;
  92
  93                 $handle = opendir($categoryDir);
  94                 while (($file = readdir($handle)) !== false) {
  95                         if ($file == '.' || $file == '..') continue;
  96                         $pluginPath = "$categoryDir/$file";
  97                         $pluginWrapper = "$pluginPath/index.php";
  98
  99                         if (!file_exists($pluginWrapper)) continue;
 100                         $plugin = include($pluginWrapper);
 101                         if ($plugin && is_object($plugin)) {
 102                                 $plugins[$plugin->getSeq()][$pluginPath] =& $plugin;
 103                                 unset($plugin);
 104                         }
 105                 }
 106                 closedir($handle);
 107
 108                 // If anyone else wants to jump category, here is the chance.
 109                 HookRegistry::call('PluginRegistry::loadCategory', array(&$category, &$plugins));
 110
 111                 // Register the plugins in sequence.
 112                 ksort($plugins);
 113                 foreach ($plugins as $seq => $junk1) {
 114                         foreach ($plugins[$seq] as $pluginPath => $junk2) {
 115                                 PluginRegistry::register($category, $plugins[$seq][$pluginPath], $pluginPath);
 116                         }
 117                 }
 118                 unset($plugins);
 119
 120                 // Return the list of successfully-registered plugins.
 121                 $plugins =& PluginRegistry::getPlugins($category);
 122                 return $plugins;
 123         }
 124
 125         /**
 126          * Load a specific plugin from a category by path name.
 127          * Similar to loadCategory, except that it only loads a single plugin
 128          * within a category rather than loading all.
 129          * @param $category string
 130          * @param $pathName string
 131          * @return object
 132          */
 133         function &loadPlugin($category, $pathName) {
 134                 $pluginPath = PLUGINS_PREFIX . $category . '/' . $pathName;
 135                 $plugin = null;
 136                 if (!file_exists($pluginPath . '/index.php')) return $plugin;
 137
 138                 $plugin = @include("$pluginPath/index.php");
 139                 if ($plugin && is_object($plugin)) {
 140                         PluginRegistry::register($category, $plugin, $pluginPath);
 141                 }
 142                 return $plugin;
 143         }
 144
 145         /**
 146          * Get a list of the various plugin categories available.
 147          */
 148         function getCategories() {
 149                 $application =& PKPApplication::getApplication();
 150                 $categories = $application->getPluginCategories();
 151                 HookRegistry::call('PluginRegistry::getCategories', array(&$categories));
 152                 return $categories;
 153         }
 154
 155         /**
 156          * Load all plugins in the system and return them in a single array.
 157          */
 158         function &loadAllPlugins() {
 159                 foreach (PluginRegistry::getCategories() as $category) {
 160                         PluginRegistry::loadCategory($category);
 161                 }
 162                 $allPlugins =& PluginRegistry::getAllPlugins();
 163                 return $allPlugins;
 164         }
 165 }
 166
 167 ?>