inc/classes/middleware/database/class_DatabaseConnection.php

   1 <?php
   2 /**
   3  * Database selector class
   4  *
   5  * @author              Roland Haeder <webmaster@ship-simu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright(c) 2007, 2008 Roland Haeder, this is free software
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.ship-simu.org
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24 class DatabaseConnection extends BaseMiddleware implements DatabaseConnector, LimitableObject {
  25         // Array for connection data
  26         private $connectData = array();
  27
  28         // The real database layer
  29         private $dbLayer = null;
  30
  31         // An instance of this class
  32         private static $thisInstance = null;
  33
  34         // Private constructor
  35         protected function __construct() {
  36                 // Call parent constructor
  37                 parent::__construct(__CLASS__);
  38
  39                 // Set description
  40                 $this->setObjectDescription("Datenbank-Mittelschicht");
  41
  42                 // Create an unique ID
  43                 $this->createUniqueID();
  44
  45                 // Clean up a little
  46                 $this->removeSystemArray();
  47         }
  48
  49         // Create new database connection layer
  50         public final static function createDatabaseConnection (DebugMiddleware $debugInstance, DatabaseFrontendInterface $dbLayer) {
  51                 // Get instance
  52                 $dbInstance = new DatabaseConnection();
  53
  54                 // Set debug output handler
  55                 $dbInstance->setDebugInstance($debugInstance);
  56
  57                 // Set database layer
  58                 $dbInstance->setDatabaseLayer($dbLayer);
  59
  60                 // Set db instance
  61                 self::$thisInstance = $dbInstance;
  62
  63                 // Return instance
  64                 return $dbInstance;
  65         }
  66
  67         // Get an instance of this class
  68         public final static function getInstance () {
  69                 return self::$thisInstance;
  70         }
  71
  72         // Public setter for database connection
  73         public final function setConnectionData ($login, $pass, $dbase, $host) {
  74                 // Transfer connection data
  75                 $this->connectData['login'] = (string) $login;
  76                 $this->connectData['pass']  = (string) $pass;
  77                 $this->connectData['dbase'] = (string) $dbase;
  78                 $this->connectData['host']  = (string) $host;
  79         }
  80
  81         /**
  82          * Save a whole object or parts of it to the database or local file
  83          *
  84          * @param               $object The object we shall save
  85          * @return      void
  86          * @throws      NullPointerException    If $limitInstance is null
  87          * @throws      NoObjectException               If $limitInstance is not an object
  88          * @throws      MissingMethodException  If the required method
  89          *                                                              saveObject() was not found
  90          */
  91         public final function saveObject ($object) {
  92                 // Some sanity checks
  93                 if (is_null($this->dbLayer)) {
  94                         // Is null
  95                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
  96                 } elseif (!is_object($this->dbLayer)) {
  97                         // Is not an object
  98                         throw new NoObjectException($this->dbLayer, self::EXCEPTION_IS_NO_OBJECT);
  99                 } elseif (!method_exists($this->dbLayer, 'saveObject')) {
 100                         // Does not have the required instance
 101                         throw new MissingMethodException(array($this->dbLayer, 'saveObject'), self::EXCEPTION_MISSING_METHOD);
 102                 }
 103
 104                 // For now just pipe it through to the database layer
 105                 $this->dbLayer->saveObject($object);
 106         }
 107
 108         /**
 109          * Set a limitation for the saving process. This shall be done before
 110          * saveObject() is called else saveObject() shall save the whole object.
 111          *
 112          * @param               $limitInstance  An instance of ObjectLimits which contains
 113          *                                              elements we shall exclusivly include in
 114          *                                              saving process
 115          * @return      void
 116          * @throws      NullPointerException    If $limitInstance is null
 117          * @throws      NoObjectException               If $limitInstance is not an object
 118          * @throws      MissingMethodException  If the required method
 119          *                                                              limitObject() was not found
 120          */
 121         public final function limitObject (ObjectLimits $limitInstance) {
 122                 // Get real database connection
 123                 $this->dbLayer = $this->getDatabaseInstance();
 124
 125                 // Some sanity checks
 126                 if (is_null($this->dbLayer)) {
 127                         // Is null
 128                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 129                 } elseif (!is_object($this->dbLayer)) {
 130                         // Is not an object
 131                         throw new NoObjectException($object, self::EXCEPTION_IS_NO_OBJECT);
 132                 } elseif (!method_exists($this->dbLayer, 'limitObject')) {
 133                         // Does not have the required instance
 134                         throw new MissingMethodException(array($this->dbLayer, 'limitObject'), self::EXCEPTION_MISSING_METHOD);
 135                 }
 136
 137                 // For now we pipe this through to the real database instance
 138                 $this->dbLayer->limitObject($limitInstance);
 139         }
 140
 141         /**
 142          * Analyses if a unique ID has already been used or not. This method does
 143          * only pass the given ID through to the "real" database layer.
 144          *
 145          * @param               $uniqueID               A unique ID number which shall be checked
 146          *                                              before it will be used
 147          * @param               $inConstructor  If called from a constructor or from
 148          *                                              somewhere else
 149          * @return      $isUnused               true    = The unique ID was not found in the database,
 150          *                                              false = It is already in use by an other object
 151          * @throws      NullPointerException    If $this->dbLayer is null
 152          * @throws      NoObjectException               If $this->dbLayer is not an object
 153          * @throws      MissingMethodException  If the required method
 154          *                                                              isUniqueIdUsed() was not found
 155          */
 156         public final function isUniqueIdUsed ($uniqueID, $inConstructor = false) {
 157                 // Some sanity checks
 158                 if (is_null($this->dbLayer)) {
 159                         // Is null
 160                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 161                 } elseif (!is_object($this->dbLayer)) {
 162                         // Is not an object
 163                         throw new NoObjectException($object, self::EXCEPTION_IS_NO_OBJECT);
 164                 } elseif (!method_exists($this->dbLayer, 'isUniqueIdUsed')) {
 165                         // Does not have the required instance
 166                         throw new MissingMethodException(array($this->dbLayer, 'isUniqueIdUsed'), self::EXCEPTION_MISSING_METHOD);
 167                 }
 168
 169                 // Pass the returning result through
 170                 return $this->dbLayer->isUniqueIdUsed($uniqueID, $inConstructor);
 171         }
 172
 173         /**
 174          * Gets cached data from the database layer and if not found fetch it from
 175          * the database again. This method does not return the header stuff because
 176          * The underlaying database class will return only the requested content.
 177          *
 178          * @param               $idNumber               The ID number which we need for looking up
 179          *                                              the requested data
 180          * @return      $cachedArray    The maybe cached data from the database
 181          * @throws      NullPointerException    If $this->dbLayer is null
 182          * @throws      NoObjectException               If $this->dbLayer is not an object
 183          * @throws      MissingMethodException  If the required method
 184          *                                                              isUniqueIdUsed() was not found
 185          */
 186         public final function getObjectFromCachedData ($idNumber) {
 187                 // Some sanity checks
 188                 if (is_null($this->dbLayer)) {
 189                         // Is null
 190                         throw new NullPointerException($this, self::EXCEPTION_IS_NULL_POINTER);
 191                 } elseif (!is_object($this->dbLayer)) {
 192                         // Is not an object
 193                         throw new NoObjectException($object, self::EXCEPTION_IS_NO_OBJECT);
 194                 } elseif (!method_exists($this->dbLayer, 'getObjectFromCachedData')) {
 195                         // Does not have the required instance
 196                         throw new MissingMethodException(array($this->dbLayer, 'getObjectFromCachedData'), self::EXCEPTION_MISSING_METHOD);
 197                 }
 198
 199                 // Pass the returning result through
 200                 return $this->dbLayer->getObjectFromCachedData($idNumber);
 201         }
 202
 203         /**
 204          * Setter for the real database layer
 205          * @param               $dbLayer                An instance of the real database layer
 206          * @return      void
 207          */
 208         public final function setDatabaseLayer (DatabaseFrontendInterface $dbLayer) {
 209                 $this->dbLayer = $dbLayer;
 210         }
 211 }
 212
 213 // [EOF]
 214 ?>