DMModuleManager.php

<?php
#
# dmBridge: a data access framework for CONTENTdm(R)
#
# Copyright © 2009, 2010, 2011 Board of Regents of the Nevada System of Higher
# Education, on behalf of the University of Nevada, Las Vegas
#

class DMModuleManager {

   private static $all_modules;

   private static $instance;

   private $config_xml;

   private $modules_pathname;

   public static function destroyInstance() {
      self::$instance = null;
   }

   public static function getInstance() {
      if (!self::$instance) {
         self::$instance = new DMModuleManager();
      }
      return self::$instance;
   }

   protected function __construct() {
      $this->config_xml = DMConfigXML::getInstance();
      $this->setModulesPathname(
            dirname(__FILE__) . "/../../extensions/modules");
   }

   public function __clone() {
      //trigger_error("Cannot clone a Singleton");
   }

   public function __wakeup() {
      //trigger_error("Cannot deserialize a Singleton");
   }

   public function bootstrapAllModules() {
      $this->getAllModules();
   }

   public function getAllModules() {
      if (self::$all_modules == null) {
         self::$all_modules = array();

         $it = new RecursiveDirectoryIterator($this->getModulesPathname());
         foreach (new RecursiveIteratorIterator($it) as $filename) {
            if (substr(basename($filename), -4, 4) == ".php"
                  && basename($filename, ".php") == basename(dirname($filename))) {

               $class = basename($filename, ".php");
               include_once(dirname($filename) . "/"
                     . DMAbstractDMBridgeModule::BOOTSTRAP_FILENAME);
               self::$all_modules[] = new $class;
            }
         }
      }
      return self::$all_modules;
   }

   public function setConfigXML(DMConfigXML $config_xml) {
      $this->config_xml = $config_xml;
      self::$all_modules = null;
   }

   public function getEnabledModules() {
      $modules = array();
      foreach ($this->getAllModules() as $module) {
         if ($this->isModuleEnabled($module)) {
            $modules[] = $module;
         }
      }
      return $modules;
   }

   public function getModuleByName($name) {
      foreach ($this->getAllModules() as $module) {
         if ($module->getName() == $name) {
            return $module;
         }
      }
      return null;
   }

   public function isModuleEnabled($module) {
      return $this->config_xml->isModuleEnabled($module);
   }

   public function setModuleEnabled(DMBridgeModule $module, $enabled) {
      // is the module compatible with the current system version?
      if ($module->getMinSupportedVersionSequence()
            > DMBridgeVersion::getDmBridgeVersionSequence()) {
         throw new DMModuleActivationException(
               DMLocalizedString::getString("INCOMPATIBLE_MODULE"));
      }

      // do we need to prepare the data store?
      if ($enabled && $module instanceof DMBridgeDataStoreModule) {
         $ds = DMDataStoreFactory::getDataStore();
         $stmts = array();
         // Re-run the setup just to make sure the tables are set up. This
         // will probably fail but that's OK.
         switch ($ds->getType()) {
         case DMDataStoreType::PDO_MySQL:
            $stmts = $module->getSetupSQLForMySQL();
            break;
         case DMDataStoreType::PDO_SQLite:
            $stmts = $module->getSetupSQLForSQLite();
            break;
         }

         $ds->beginTransaction();
         foreach ($stmts as $sql) {
            try {
               $ds->write($sql, array());
            } catch (DMPDOException $e) {
               // if a create command failed for some reason OTHER than
               // the tables already existing, roll back and throw an
               // exception.
               if (strpos($e->getMessage(), "already exists") === false) {
                  $ds->rollBack();
                  throw new DMModuleActivationException($e->getMessage());
               }
            }
         }
         $ds->commit();

         if (!$this->config_xml->isModuleOfSameNameAndVersionInstalled($module)) {
            $stmts = array();
            if ($this->config_xml->isModuleOfSameNameInstalled($module)) { // upgrade
               switch ($ds->getType()) {
               case DMDataStoreType::PDO_MySQL:
                  $stmts = $module->getUpgradeSQLForMySQL();
                  break;
               case DMDataStoreType::PDO_SQLite:
                  $stmts = $module->getUpgradeSQLForSQLite();
                  break;
               }
            }
            $ds->beginTransaction();
            foreach ($stmts as $sql) {
               try {
                  $ds->write($sql, array());
               } catch (DMPDOException $e) {
                  $msg = DMLocalizedString::getString(
                        sprintf("MODULE_ACTIVATION_SQL_FAILED", $sql));
                  $ds->rollBack();
                  throw new DMModuleActivationException($msg);
               }
            }
            $ds->commit();
         }
      }
      return $this->config_xml->setModuleEnabled($module, $enabled);
   }

   public function getModulesPathname() {
      return $this->modules_pathname;
   }
   
   public function setModulesPathname($pathname) {
      $this->modules_pathname = $pathname;
   }

}