class.PersistenceFacade.php

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<?php
/**
 * wCMF - wemove Content Management Framework
 * Copyright (C) 2005-2014 wemove digital solutions GmbH
 *
 * Licensed under the terms of any of the following licenses
 * at your choice:
 *
 * - GNU Lesser General Public License (LGPL)
 *   http://www.gnu.org/licenses/lgpl.html
 * - Eclipse Public License (EPL)
 *   http://www.eclipse.org/org/documents/epl-v10.php
 *
 * See the license.txt file distributed with this work for
 * additional information.
 *
 * $Id: class.PersistenceFacade.php 1462 2014-02-04 23:52:27Z iherwig $
 */
require_once(BASE."wcmf/lib/persistence/class.RemoteCapablePersistenceFacadeImpl.php");
require_once(BASE."wcmf/lib/persistence/class.PersistenceFacadeImpl.php");

/**
 * Some constants describing the build process
 */
define("BUILDDEPTH_INFINITE", -1); // build complete tree from given root on
define("BUILDDEPTH_SINGLE",   -2); // build only given object
define("BUILDDEPTH_REQUIRED", -4); // build tree from given root on respecting the required property defined in element relations
define("BUILDDEPTH_MAX", 10);      // maximum possible creation depth in one call

/**
 * @class PersistenceFacade
 * @ingroup Persistence
 * @brief PersistenceFacade instantiates the PersistenceFacade implementation.
 *
 * @author ingo herwig <ingo@wemove.com>
 */
class PersistenceFacade
{
  private static $knownTypes = null;
  private static $numPkKeys = array();
  private static $dummyIdPattern = 'wcmf[A-Za-z0-9]{32}';

  /**
   * Returns an instance of the PersistenceFacade implementation.
   * @return A reference to the only instance of the Singleton object
   */
  function &getInstance()
  {
    static $instance = null;

    if (!isset($instance))
      $instance = new RemoteCapablePersistenceFacadeImpl();

    return $instance;
  }
  /**
   * Get a list of types defined in the application.
   * @return The list of types
   */
  function getKnownTypes()
  {
    if (self::$knownTypes == null)
    {
      $parser = &InifileParser::getInstance();
      self::$knownTypes = $parser->getSection('typemapping');
    }
    return array_keys(self::$knownTypes);
  }
  /**
   * Check if a type is defined in the application.
   * @param type The type to check
   * @return True/False wether the type is defined or not
   */
  function isKnownType($type)
  {
    if (self::$knownTypes == null) {
      self::getKnownTypes();
    }
    return (isset(self::$knownTypes[$type]) || isset(self::$knownTypes['*']));
  }
  /**
   * Create an object query.
   * @param type The object type to search for
   * @return An ObjectQuery instance
   */
  function createObjectQuery($type)
  {
    return new ObjectQuery($type);
  }
  /**
   * Create a string query.
   * @return An StringQuery instance
   */
  function createStringQuery()
  {
    return new StringQuery();
  }
  /**
   * Compose an OID from several parameters.
   * @param params An assoziative array with the keys 'prefix', 'type' and 'id' where the value of id
   * maybe a single value or an array (for compound primary keys). If id is an array, the order
   * of the values must match the order of the primary key names given by PersistenceMapper::getPkNames().
   * If only type is given in params, the primary key columns will be set with initial values.
   * @return An OID
   */
  function composeOID($params)
  {
    if (!is_array($params) || !isset($params['type']))
      WCMFException::throwEx("Parameter 'type' is missing.", __FILE__, __LINE__);

    $type = $params['type'];

    // get given primary keys
    $pks = array();
    if (array_key_exists('id', $params))
    {
      $givenPKs = $params['id'];
      if (!is_array($givenPKs))
        array_push($pks, $givenPKs);
      else
        $pks = $givenPKs;
    }

    // add dummy ids for missing primary key values
    $numPKs = self::getNumberOfPKs($type);
    while (sizeof($pks) < $numPKs)
      array_push($pks, self::getDummyId());

    // compose the oid
    $oid = $type.':'.join(':', $pks);
    if (isset($params['prefix']) && strlen(trim($params['prefix'])) > 0) {
      $oid = $params['prefix'].':'.$oid;
    }
    return $oid;
  }
  /**
   * Get the base oid for a given oid (@see PersistentObject::getBaseOID()).
   * @param oid The object id
   * @param validate True/False if an exception should be thrown if the OID is invalid (default: true)
   * @return An OID
   */
  function getBaseOID($oid, $validate=true)
  {
    $oidParts = PersistenceFacade::decomposeOID($oid, $validate);
    if (self::isKnownType($oidParts['type']))
    {
      $persistenceFacade = &PersistenceFacade::getInstance();
      $tpl = $persistenceFacade->create($oidParts['type'], BUILDDEPTH_SINGLE);

      $oidParams = array('type' => $tpl->getBaseType(), 'id' => $oidParts['id']);
      if (strlen($oidParts['prefix']) > 0) {
        $oidParams['prefix'] = $oidParts['prefix'];
      }
      $oid = PersistenceFacade::composeOID($oidParams);
    }
    return $oid;
  }
  /**
   * Decompose an OID into several parameters.
   * @param oid The OID of the object.
   * @param validate True/False if an exception should be thrown if the OID is invalid (default: true)
   * @return An assoziative array with the keys 'prefix', 'type' and 'id' where the value of id is an array
   * holding the primary key values.
   */
  function decomposeOID($oid, $validate=true)
  {
    // do simple test first
    $oidParts = self::extractOIDParts($oid);
    if (!$oidParts['valid'] && $validate) {
      WCMFException::throwEx('Illegal OID found: '.$oid, __FILE__, __LINE__);
    }
    return $oidParts;
  }
  /**
   * Get a part of an object id (e.g. the 'type' parameter).
   * @param oid The OID of the object.
   * @param param The name of the parameter.
   * @param validate True/False if an exception should be thrown if the OID is invalid (default: true)
   * @return The value of the parameter.
   */
  function getOIDParameter($oid, $param, $validate=true)
  {
    if ($oid == null)
      return null;
    $oidParts = self::decomposeOID($oid, $validate);
    return $oidParts[$param];
  }
  /**
   * Set a part of an object id (e.g. the 'type' parameter).
   * @param oid The OID of the object.
   * @param param The name of the parameter.
   * @param value The value of the parameter.
   * @return The modified object id.
   */
  function setOIDParameter($oid, $param, $value)
  {
    if ($oid == null)
      return null;
    $oidParts = self::decomposeOID($oid);
    $oidParts[$param] = $value;
    return self::composeOID($oidParts);
  }
  /**
   * Validate a given OID.
   * @param oid The OID of the object.
   * @return An True/False whether the OID is valid
   */
  function isValidOID($oid)
  {
    $oidParts = self::extractOIDParts($oid);
    if (!$oidParts['valid']) {
      return false;
    }
    return true;
  }
  /**
   * Get the number of primary keys a type has.
   * @param type The type to check.
   * @return The number of primary keys [defaults to 1]
   */
  function getNumberOfPKs($type)
  {
    if (!isset(self::$numPkKeys[$type]))
    {
      $numPKs = 1;
      if (self::isKnownType($type))
      {
        $persistenceFacade = &self::getInstance();
        $mapper = &$persistenceFacade->getMapper($type);
        $numPKs = sizeof(array_keys($mapper->getPKNames()));
      }
      self::$numPkKeys[$type] = $numPKs;
    }
    return self::$numPkKeys[$type];
  }
  /**
   * Get a dummy id ("wcmf" + unique 32 character string).
   * @return A dummy id
   */
  function getDummyId()
  {
    return "wcmf".md5(uniqid(ip2long($_SERVER['REMOTE_ADDR']) ^ (int)$_SERVER['REMOTE_PORT'] ^ @getmypid() ^ @disk_free_space('/tmp'), 1));
  }
  /**
   * Check if a given id is a dummy id.
   * @param id The id to check
   * @return True/False
   */
  function isDummyId($id)
  {
    static $pattern = null;
    if ($pattern == null) {
      $pattern = '/^'.self::$dummyIdPattern.'$/';
    }
    return preg_match($pattern, $id) > 0;
  }
  /**
   * Extract all parts of an object id.
   * @param oid The object id
   * @return An associative array with keys 'prefix', 'type', 'id', 'valid'
   */
  private function extractOIDParts($oid)
  {
    $valid = true;

    // fast checks first
    if (strlen($oid) == 0) {
      $valid = false;
    }
    else
    {
      $oidParts = split(':', $oid);
      if (!is_array($oidParts)) {
        $valid = false;
      }
      else
      {
        static $idPattern = null;
        if ($idPattern == null) {
          $idPattern = '/^[0-9]*$|^'.self::$dummyIdPattern.'$/';
        }

        // get the ids from the oid
        $ids = array();
        $nextPart = array_pop($oidParts);
        while($nextPart !== null && preg_match($idPattern, $nextPart) == 1)
        {
          $ids[] = $nextPart;
          $nextPart = array_pop($oidParts);
        }
        $ids = array_reverse($ids);

        // get the type
        $type = $nextPart;
        if (!self::isKnownType($type)) {
          $valid = false;
        }
        else
        {
          // check if number of ids match the type
          $numPks = self::getNumberOfPKs($type);
          if ($numPks == null || $numPks != sizeof($ids)) {
            $valid = false;
          }
        }
        // get the prefix
        $prefix = join(':', $oidParts);
      }
    }
    return array('prefix' => $prefix, 'type' => $type, 'id' => $ids, 'valid' => $valid);
  }
}
?>