(Almost) finished DB-Models / abstraction layer.

1 files changed, 2071 insertions, 0 deletions

diff --git a/ratatoeskr/sys/models.php b/ratatoeskr/sys/models.php
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+<?php
+/*
+ * File: models.php
+ * Data models to make database accesses more comfortable.
+ *
+ * This file is part of Ratatöskr.
+ * Ratatöskr is licensed unter the MIT / X11 License.
+ * See "ratatoeskr/licenses/ratatoeskr" for more information.
+ */
+
+require_once(dirname(__FILE__) . "/db.php");
+require_once(dirname(__FILE__) . "/utils.php");
+
+db_connect();
+
+/*
+ * Class: DoesNotExistError
+ * This Exception is thrown by an ::by_*-constructor or any array-like object if the desired object is not present in the database.
+ */
+class DoesNotExistError extends Exception { }
+
+/*
+ * Class: AlreadyExistsError
+ * This Exception is thrown by an ::create-constructor if the creation of the object would result in duplicates.
+ */
+class AlreadyExistsError extends Exception { }
+
+/*
+ * Class: NotAllowedError
+ */
+class NotAllowedError extends Exception { }
+
+/*
+ * Class: User
+ * Data model for Users
+ */
+class User
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class properties
+	 * 
+	 * $username - The username
+	 * $pwhash   - SHA1-Hash of the password
+	 * $mail     - E-Mail-address
+	 * $fullname - The full name of the user.
+	 * $language - Users language
+	 */
+	public $username;
+	public $pwhash;
+	public $mail;
+	public $fullname;
+	public $language;
+	
+	/* Should not be constructed directly. */
+	private function __construct() {  }
+	
+	/*
+	 * Constructor: create
+	 * Creates a new user.
+	 * 
+	 * Parameters:
+	 * 	$username - The username
+	 * 	$pwhash   - SHA1-Hash of the password
+	 * 	$mail     - E-Mail-address
+	 * 	$fullname - The full name.
+	 * 
+	 * Returns:
+	 * 	An User object
+	 */
+	public static function create($username, $pwhash, $mail, $fullname)
+	{
+		try
+		{
+			$obj = self::by_name($name);
+		}
+		catch(DoesNotExistError $e)
+		{
+			global $ratatoeskr_settings;
+			qdb("INSERT INTO `PREFIX_users` (`username`, `pwhash`, `mail`, `username`, `language`) VALUES ('%s', '%s', '%s', '%s', '%s')",
+				$username, $pwhash, $mail, $fullname, $ratatoeskr_settings["default_language"]);
+			$obj = new self;
+			
+			$obj->id       = mysql_insert_id();
+			$obj->username = $username;
+			$obj->pwhash   = $pwhash;
+			$obj->mail     = $mail;
+			$obj->fullname = $fullname;
+			$obj->language = $ratatoeskr_settings["default_language"];
+			
+			return $obj;
+		}
+		throw new AlreadyExistsError("\"$name\" is already in database.");
+	}
+	
+	/* DANGER: $result must be valid! The calling function has to check this! */
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow == False)
+			throw new DoesNotExistError();
+		
+		$this->id       = $sqlrow["id"];
+		$this->username = $sqlrow["username"];
+		$this->pwhash   = $sqlrow["pwhash"];
+		$this->mail     = $sqlrow["mail"];
+		$this->fullname = $sqlrow["fullname"];
+		$this->language = $sqlrow["language"];
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Get a User object by ID
+	 * 
+	 * Parameters:
+	 * 	$id - The ID.
+	 * 
+	 * Returns:
+	 * 	An User object.
+	 */
+	public static function by_id($id)
+	{
+		$result = qdb("SELECT `id`, `username`, `pwhash`, `mail`, `fullname`, `language` FROM `PREFIX_users` WHERE `id` = %d", $id);
+		
+		$obj = new self;
+		$obj->populate_by_sqlresult($result);
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_username
+	 * Get a User object by username
+	 * 
+	 * Parameters:
+	 * 	$username - The username.
+	 * 
+	 * Returns:
+	 * 	An User object.
+	 */
+	public static function by_name($username)
+	{
+		$result = qdb("SELECT `id`, `username`, `pwhash`, `mail`, `fullname`, `language` FROM `PREFIX_users` WHERE `name` = '%s'", $username);
+		
+		$obj = new self;
+		$obj->populate_by_sqlresult($result);
+		return $obj;
+	}
+	
+	/*
+	 * Function: all_users
+	 * Returns array of all available users.
+	 */
+	public static function all_users()
+	{
+		$rv = array();
+		
+		$result = qdb("SELECT `id` FROM `PREFIX_users` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($sqlrow["id"]);
+		
+		return $rv;
+	}
+	
+	/*
+	 * Function: get_id
+	 * Returns:
+	 * 	The user ID.
+	 */
+	public function get_id()
+	{
+		return $this->id;
+	}
+	
+	/*
+	 * Function: save
+	 * Saves the object to database
+	 */
+	public function save()
+	{
+		qdb("UPDATE `PREFIX_users` SET `username` = '%s', `pwhash` = '%s', `mail` = '%s', `fullname` = '%s', `language` = '%s' WHERE `id` = %d",
+			$this->username, $this->pwhash, $this->mail, $this->id, $this->fullname, $this->language);
+	}
+	
+	/*
+	 * Function: delete
+	 * Deletes the user from the database.
+	 * WARNING: Do NOT use this object any longer after you called this function!
+	 */
+	public function delete()
+	{
+		qdb("DELETE FROM `PREFIX_group_members` WHERE `user` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_users` WHERE `id` = %d", $this->id);
+	}
+	
+	/*
+	 * Function: get_groups
+	 * Returns:
+	 * 	List of all groups where this user is a member (array of <Group> objects).
+	 */
+	public function get_groups()
+	{
+		$rv = array();
+		$result = qdb("SELECT `group` FROM `PREFIX_group_members` WHERE `user` = %d", $this->id);
+		while($sqlrow = mysql_fetch_assoc($result))
+		{
+			try
+			{
+				$rv[] = Group::by_id($sqlrow["group"]);
+			}
+			catch(DoesNotExistError $e)
+			{
+				/* WTF?!? This should be fixed! */
+				qdb("DELETE FROM `PREFIX_group_members` WHERE `user` = %d AND `group` = %d", $this->id, $sqlrow["group"]);
+			}
+		}
+		return $rv;
+	}
+	
+	/*
+	 * Function: member_of
+	 * Checks, if the user is a member of a group.
+	 * 
+	 * Parameters:
+	 * 	$group - A Group object
+	 * 
+	 * Returns:
+	 * 	True, if the user is a member of $group. False, if not.
+	 */
+	public function member_of($group)
+	{
+		$result = qdb("SELECT COUNT(*) AS `num` FROM `PREFIX_group_members` WHERE `user` = %d AND `group` = %d", $this->id, $group->get_id());
+		$sqlrow = mysql_fetch_assoc($result);
+		return ($sqlrow["num"] > 0);
+	}
+}
+
+/*
+ * Class: Group
+ * Data model for groups
+ */
+class Group
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class properties
+	 * 
+	 * $name - Name of the group.
+	 */
+	public $name;
+	
+	/* Should not be constructed directly. */
+	private function __construct() {  }
+	
+	/*
+	 * Constructor: create
+	 * Creates a new group.
+	 * 
+	 * Parameters:
+	 * 	$name - The name of the group.
+	 * 
+	 * Returns:
+	 * 	An Group object
+	 */
+	public static function create($name)
+	{
+		try
+		{
+			$obj = self::by_username($name);
+		}
+		catch(DoesNotExistError $e)
+		{
+			qdb("INSERT INTO `PREFIX_groups` (`name`) VALUES ('%s')", $name);
+			$obj = new self;
+			
+			$obj->id   = mysql_insert_id();
+			$obj->name = $name;
+			
+			return $obj;
+		}
+		throw new AlreadyExistsError("\"$name\" is already in database.");
+	}
+	
+	/* DANGER: $result must be valid! The calling function has to check this! */
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow == False)
+			throw new DoesNotExistError();
+		
+		$this->id   = $sqlrow["id"];
+		$this->name = $sqlrow["name"];
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Get a Group object by ID
+	 * 
+	 * Parameters:
+	 * 	$id - The ID.
+	 * 
+	 * Returns:
+	 * 	A Group object.
+	 */
+	public static function by_id($id)
+	{
+		$result = qdb("SELECT `id`, `name` FROM `PREFIX_groups` WHERE `id` = %d", $id);
+		
+		$obj = new self;
+		$obj->populate_by_sqlresult($result);
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_name
+	 * Get a Group object by name
+	 * 
+	 * Parameters:
+	 * 	$name - The group name.
+	 * 
+	 * Returns:
+	 * 	A Group object.
+	 */
+	public static function by_name($name)
+	{
+		$result = qdb("SELECT `id`, `name` FROM `PREFIX_groups` WHERE `name` = '%s'", $name);
+		
+		$obj = new self;
+		$obj->populate_by_sqlresult($result);
+		return $obj;
+	}
+	
+	/*
+	 * Function: all_groups
+	 * Returns array of all groups
+	 */
+	public static function all_groups()
+	{
+		$rv = array();
+		
+		$result = qdb("SELECT `id` FROM `PREFIX_groups` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($sqlrow["id"]);
+		
+		return $rv;
+	}
+	
+	/*
+	 * Function: get_id
+	 * Returns:
+	 * 	The group ID.
+	 */
+	public function get_id()
+	{
+		return $this->id;
+	}
+	
+	/*
+	 * Function: delete
+	 * Deletes the group from the database.
+	 * WARNING: Do NOT use this object any longer after you called this function!
+	 */
+	public function delete()
+	{
+		qdb("DELETE FROM `PREFIX_group_members` WHERE `group` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_groups` WHERE `id` = %d", $this->id);
+	}
+	
+	/*
+	 * Function: get_members
+	 * Get all members of the group.
+	 *
+	 * Returns:
+	 * 	Array of <User> objects.
+	 */
+	public function get_members()
+	{
+		$rv = array();
+		$result = qdb("SELECT `user` FROM `PREFIX_group_members` WHERE `group` = %d", $this->id);
+		while($sqlrow = mysql_fetch_assoc($result))
+		{
+			try
+			{
+				$rv[] = User::by_id($sqlrow["user"]);
+			}
+			catch(DoesNotExistError $e)
+			{
+				/* WTF?!? This should be fixed!*/
+				qdb("DELETE FROM `PREFIX_group_members` WHERE `user` = %d AND `group` = %d", $sqlrow["user"], $this->id);
+			}
+		}
+		return $rv;
+	}
+	
+	/*
+	 * Function: exclude_user
+	 * Excludes user from group.
+	 * 
+	 * Parameters:
+	 * 	$user - <User> object.
+	 */
+	public function exclude_user($user)
+	{
+		qdb("DELETE FROM `PREFIX_group_members` WHERE `user` = %d AND `group` = %d", $user->get_id(), $this->id);
+	}
+	
+	/*
+	 * Function: include_user
+	 * Includes user to group.
+	 * 
+	 * Parameters:
+	 * 	$user - <User> object.
+	 */
+	public function include_user($user)
+	{
+		if(!$user->member_of($this))
+			qdb("INSERT INTO `PREFIX_group_members` (`user`, `group`) VALUES (%d, %d)", $user->get_id(), $this->id);
+	}
+}
+
+/*
+ * Class: ACL
+ * Data model for AccessControlLists
+ */
+class ACL
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class properties. *_rights are arrays, which can have this elements: "read", "write", "delete".
+	 * 
+	 * $users         - Array of <User> objects
+	 * $user_rights   - User rights
+	 * $groups        - Array of <Group> objects
+	 * $group_rights  - Group rights
+	 * $others_rights - The rights of everyone
+	 */
+	public $users;
+	public $user_rights;
+	public $groups;
+	public $group_rights;
+	public $others_rights;
+	
+	/* Should not be constructed directly. */
+	private function __construct()
+	{
+		$this->users         = array();
+		$this->user_rights   = array();
+		$this->groups        = array();
+		$this->group_rights  = array();
+		$this->others_rights = array();
+	}
+	
+	/*
+	 * Function: get_id
+	 * Returns:
+	 * 	The ACL ID.
+	 */
+	public function get_id()
+	{
+		return $this->id;
+	}
+	
+	private static function filter_invalid_rights($rights)
+	{
+		return array_filter($rights, function($x) { return in_array($x, array("read", "write", "delete")); });
+	}
+	
+	/*
+	 * Constructor: by_json
+	 * Creates an ACL object from an JSON string.
+	 * 
+	 * Parameters:
+	 * 	json - The JSON string
+	 *
+	 * Returns:
+	 * 	An ACL object
+	 */
+	public static function by_json($json)
+	{
+		$obj = new self;
+		$obj->id = 0;
+		
+		$pre = json_decode($json, True);
+		if($pre === NULL)
+			return $obj;
+		
+		$obj->users = array_filter(
+			array_map(
+				function($x){ try{ return User::by_id($x); } catch(DoesNotExistError $e) { return NULL; } },
+				$pre["users"]),
+			function($x) { return $x!==NULL; });
+		$obj->groups = array_filter(
+			array_map(
+				function($x){ try{ return Group::by_id($x); } catch(DoesNotExistError $e) { return NULL; } },
+				$pre["groups"]),
+			function($x) { return $x!==NULL; });
+		$obj->user_rights = self::filter_invalid_rights($pre["rights"]["users"]);
+		$obj->group_rights = self::filter_invalid_rights($pre["rights"]["groups"]);
+		$obj->others_rights = self::filter_invalid_rights($pre["rights"]["others"]);
+		
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: create
+	 * Creates a new ACL object.
+	 *
+	 * Params:
+	 * 	$in_db - Should this ACL be stored in the database? (Defaults to True)
+	 * 
+	 * Returns:
+	 * 	ACL object.
+	 */
+	public static function create($in_db = True)
+	{
+		$obj = new self;
+		
+		if($in_db)
+		{
+			qdb("INSERT INTO `PREFIX_acl` (`acl_json`) VALUES ('%s')", $obj->to_json());
+			$obj->id = mysql_insert_id();
+		}
+		
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Gets ACL object by id.
+	 *
+	 * Parameters:
+	 * 	$id - The ID.
+	 *
+	 * Returns:
+	 * 	An ACL object.
+	 */
+	public static function by_id($id)
+	{
+		$result = qdb("SELECT `acl_json` FROM `PREFIX_acl` WHERE `id` = %d", $id);
+		
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow == False)
+			throw new DoesNotExistError("ACL with ID = \"$id\" does not exist.");
+		$obj = self::by_json($sqlrow["acl_json"]);
+		$obj->id = $id;
+		
+		return $obj;
+	}
+	
+	/*
+	 * Function: to_json
+	 * Genearets JSON string
+	 *
+	 * Returns:
+	 * 	JSON string.
+	 */
+	public function to_json()
+	{
+		return json_encode(array(
+			"users"  => array_map(function($x) { return $x->get_id(); }, $this->users),
+			"groups" => array_map(function($x) { return $x->get_id(); }, $this->groups),
+			"rights" => array(
+				"users"  => self::filter_invalid_rights($this->user_rights),
+				"groups" => self::filter_invalid_rights($this->group_rights),
+				"others" => self::filter_invalid_rights($this->others_rights)
+			)
+		));
+	}
+	
+	/*
+	 * Function: save
+	 * If ACL comes from database, save it. Do nothing otherwise.
+	 */
+	public function save()
+	{
+		if($this->id > 0)
+			qdb("UPDATE `PREFIX_acl` SET `acl_json` = '%s'", $this->to_json);
+	}
+	
+	/*
+	 * Function: delete
+	 * If ACL comes from database, delete it. Do nothing otherwise.
+	 */
+	public function delete()
+	{
+		if($this->id > 0)
+		{
+			qdb("DELETE FROM `PREFIX_acl` WHERE `id` = %d", $this->id);
+			$this->id = 0;
+		}
+	}
+	
+	/*
+	 * Function: user_rights
+	 * Get the rights of $user.
+	 *
+	 * Parameters:
+	 * 	$user - A <User> object.
+	 *
+	 * Returns:
+	 * 	An Array of rights.
+	 */
+	public function user_rights($user)
+	{
+		$get_id_func = function($x) { return $x->get_id(); };
+		$rights = $this->others_rights;
+		if(in_array($user->get_id(), array_map($get_id_func, $this->users)))
+			$rights = array_merge($rights, $this->user_rights);
+		$temp = array_intersect(array_map($get_id_func, $user->get_groups()), $this->groups);
+		if(!empty($temp))
+			$rights = array_merge($rights, $this->group_rights);
+		return self::filter_invalid_rights(array_unique($rights));
+	}
+}
+
+/*
+ * Class: Translation
+ * A translation. Can only be stored using an <Multilingual> object.
+ */
+class Translation
+{
+	/*
+	 * Varialbes: Public class variables.
+	 * 
+	 * $text - The translated text.
+	 * $texttype - The type of the text. Has only a meaning in a context.
+	 */
+	public $text;
+	public $texttype;
+	
+	/*
+	 * Constructor: __construct
+	 * Creates a new Translation object.
+	 * IT WILL NOT BE STORED TO DATABASE!
+	 *
+	 * Parameters:
+	 * 	$text - The translated text.
+	 * 	$texttype - The type of the text. Has only a meaning in a context.
+	 * 
+	 * See also:
+	 * 	<Multilingual>
+	 */
+	public function __construct($text, $texttype)
+	{
+		$this->text     = $text;
+		$this->texttype = $texttype;
+	}
+}
+
+/*
+ * Class: Multilingual
+ * Container for <Translation> objects.
+ * Translations can be accessed array-like. So, if you want the german translation: $translation = $my_multilingual["de"];
+ * 
+ * See also:
+ * 	<languages.php>
+ */
+class Multilingual implements Countable, ArrayAccess, IteratorAggregate
+{
+	private $translations;
+	private $id;
+	private $to_be_deleted;
+	private $to_be_created;
+	
+	private function __construct()
+	{
+		$this->translations  = array();
+		$this->to_be_deleted = array();
+		$this->to_be_created = array();
+	}
+	
+	/*
+	 * Function: get_id
+	 * Retuurns the ID of the object.
+	 */
+	public function get_id()
+	{
+		return $this->id;
+	}
+	
+	/*
+	 * Constructor: create
+	 * Creates a new Multilingual object
+	 * 
+	 * Returns:
+	 * 	An Multilingual object.
+	 */
+	public static function create()
+	{
+		$obj = new self;
+		qdb("INSERT INTO `PREFIX_multilingual` () VALUES ()");
+		$obj->id = mysql_insert_id();
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Gets an Multilingual object by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The ID.
+	 * 
+	 * Returns:
+	 * 	An Multilingual object.
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		$result = qdb("SELECT `id` FROM `PREFIX_multilingual` WHERE `id` = %d", $id);
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow == False)
+			throw new DoesNotExistError();
+		$obj->id = $id;
+		
+		$result = qdb("SELECT `language`, `text`, `texttype` FROM `PREFIX_translations` WHERE `multilingual` = %d", $id);
+		while($sqlrow = mysql_fetch_assoc($result))
+			$obj->translations[$sqlrow["language"]] = new Translation($sqlrow["text"], $sqlrow["texttype"]);
+		
+		return $obj;
+	}
+	
+	/*
+	 * Function: save
+	 * Saves the translations to database.
+	 */
+	public function save()
+	{
+		foreach($this->to_be_deleted as $deletelang)
+			qdb("DELETE FROM `PREFIX_translations` WHERE `multilingual` = %d AND `language` = '%s'", $this->id, $deletelang);
+		$this->to_be_deleted = array();
+		
+		foreach($this->to_be_created as $lang)
+			qdb("INSERT INTO `PREFIX_translations` (`multilingual`, `language`, `text`, `texttype`) VALUES (%d, '%s', '%s', '%s')",
+				$this->id, $lang, $this->translations[$lang]->text, $this->translations[$lang]->texttype);
+		
+		foreach($this->translations as $lang => $translation)
+		{
+			if(!in_array($lang, $this->to_be_created))
+				qdb("UPDATE `PREFIX_translations` SET `text` = '%s', `texttype` = '%s' WHERE `multilingual` = %d AND `language` = '%s'",
+					$translation->text, $translation->texttype, $this->id, $lang);
+		}
+		
+		$this->to_be_created = array();
+	}
+	
+	/*
+	 * Function: delete
+	 * Deletes the data from database.
+	 */
+	public function delete()
+	{
+		qdb("DELETE FROM `PREFIX_translations` WHERE `multilingual` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_multilingual` WHERE `id` = %d", $this->id);
+	}
+	
+	/* Countable interface implementation */
+	public function count() { return count($this->languages); }
+	
+	/* ArrayAccess interface implementation */
+	public function offsetExists($offset) { return isset($this->translations[$offset]); }
+	public function offsetGet($offset)
+	{
+		if(isset($this->translations[$offset]))
+			return $this->translations[$offset];
+		else
+			throw new DoesNotExistError();
+	}
+	public function offsetUnset($offset)
+	{
+		unset($this->translations[$offset]);
+		if(in_array($offset, $this->to_be_created))
+			unset($this->to_be_created[array_search($offset, $this->to_be_created)]);
+		else
+			$this->to_be_deleted[] = $offset;
+	}
+	public function offsetSet($offset, $value)
+	{
+		if(!isset($this->translations[$offset]))
+		{
+			if(in_array($offset, $this->to_be_deleted))
+				unset($this->to_be_deleted[array_search($offset, $this->to_be_deleted)]);
+			else
+				$this->to_be_created[] = $offset;
+		}
+		$this->translations[$offset] = $value;
+	}
+	
+	/* IteratorAggregate interface implementation */
+	public function getIterator() { return new ArrayIterator($this->translations); }
+}
+
+/*
+ * Variable: $global_settings_keys_buffer
+ * Buffer for settings key.
+ * NEVER(!) MODIFY DIRECTLY!
+ */
+$global_settings_keys_buffer = NULL;
+
+/* DO NOT CONSTRUCT THIS YOURSELF! */
+class SettingsIterator implements Iterator
+{
+	private $iter_keys_buffer;
+	private $settings_obj;
+	private $position = 0;
+	
+	public function __construct($settings_obj)
+	{
+		global $global_settings_keys_buffer;
+		$this->settings_obj = $settings_obj;
+		$this->iter_keys_buffer = array_slice($global_settings_keys_buffer, 0); /* a.k.a. copying */
+	}
+	
+	function rewind()  { return $this->position = 0; }
+	function current() { return $this->settings_obj->offsetGet($this->iter_keys_buffer[$this->position]); }
+	function key()     { return $this->iter_keys_buffer[$this->position]; }
+	function next()    { ++$this->position; }
+	function valid()   { return isset($this->iter_keys_buffer[$this->position]); }
+}
+
+/*
+ * Class: Settings
+ * Representing the settings.
+ * You can access them like an array.
+ */
+class Settings implements Countable, ArrayAccess, IteratorAggregate
+{
+	private $rw;
+	
+	/*
+	 * Constructor: __construct
+	 * Creates a new Settings object.
+	 *
+	 * Parameters:
+	 * 	$mode - "rw" for read-write access, "r" for read-only access (default)
+	 */
+	public function __construct($mode="r")
+	{
+		global $global_settings_keys_buffer;
+		if($global_settings_keys_buffer === NULL)
+		{
+			$global_settings_keys_buffer = array();
+			$result = qdb("SELECT `key` FROM `PREFIX_settings_kvstorage` WHERE 1");
+			while($sqlrow = mysql_fetch_assoc($result))
+				$global_settings_keys_buffer[] = $sqlrow["key"];
+		}
+		$this->rw = ($mode == "rw");
+	}
+	
+	/* Countable interface implementation */
+	public function count() { global $global_settings_keys_buffer; return count($global_settings_keys_buffer); }
+	
+	/* ArrayAccess interface implementation */
+	public function offsetExists($offset) { global $global_settings_keys_buffer; return in_array($offset, $global_settings_keys_buffer); }
+	public function offsetGet($offset)
+	{
+		global $global_settings_keys_buffer;
+		if($this->offsetExists($offset))
+		{
+			$result = qdb("SELECT `value` FROM `PREFIX_settings_kvstorage` WHERE `key` = '%s'", $offset);
+			$sqlrow = mysql_fetch_assoc($result);
+			return unserialize(base64_decode($sqlrow["value"]));
+		}
+		else
+			throw new DoesNotExistError();
+	}
+	public function offsetUnset($offset)
+	{
+		global $global_settings_keys_buffer;
+		if(!$this->rw)
+			throw new NotAllowedError();
+		unset($global_settings_keys_buffer[array_search($offset, $global_settings_keys_buffer)]);
+		qdb("DELETE FROM `PREFIX_settings_kvstorage` WHERE `key` = '%s'", $offset);
+	}
+	public function offsetSet($offset, $value)
+	{
+		global $global_settings_keys_buffer;
+		if(!$this->rw)
+			throw new NotAllowedError();
+		if(in_array($offset, $global_settings_keys_buffer))
+			qdb("UPDATE `PREFIX_settings_kvstorage` SET `value` = '%s' WHERE `key` = '%s'",  base64_encode(serialize($value)), $offset);
+		else
+		{
+			$global_settings_keys_buffer[] = $offset;
+			qdb("INSERT INTO `PREFIX_settings_kvstorage` (`key`, `value`) VALUES ('%s', '%s')", $offset, base64_encode(serialize($value)));
+		}
+	}
+	
+	/* IteratorAggregate interface implementation */
+	public function getIterator() { return new SettingsIterator($this); }
+}
+
+/*
+ * Variable: $ratatoeskr_settings
+ * The global <Settings> object. For internal use.
+ */
+$ratatoeskr_settings = new Settings("rw");
+
+/*
+ * Class: PluginKVStorage
+ * A Key-Value-Storage for Plugins
+ * Can be accessed like an array.
+ * Keys are strings and Values can be everything serialize() can process.
+ */
+class PluginKVStorage implements Countable, ArrayAccess, Iterator
+{
+	private $plugin_id;
+	private $keybuffer;
+	private $counter;
+	
+	/*
+	 * Constructor: __construct
+	 * 
+	 * Parameters:
+	 * 	$plugin_id - The ID of the Plugin.
+	 */
+	public function __construct($plugin_id)
+	{
+		$this->keybuffer = array();
+		$this->plugin_id = $plugin_id;
+		
+		$result = qdb("SELECT `key` FROM `PREFIX_plugin_kvstorage` WHERE `plugin` = %d", $plugin_id);
+		while($sqlrow = mysql_fetch_assoc($result))
+			$this->keybuffer[] = $sqlrow["key"];
+		
+		$this->counter = 0;
+	}
+	
+	/* Countable interface implementation */
+	public function count() { return count($this->keybuffer); }
+	
+	/* ArrayAccess interface implementation */
+	public function offsetExists($offset) { return in_array($offset, $this->keybuffer); }
+	public function offsetGet($offset)
+	{
+		if($this->offsetExists($offset))
+		{
+			$result = qdb("SELECT `value` FROM `PREFIX_plugin_kvstorage` WHERE `key` = '%s' AND `plugin` = %d", $offset, $this->plugin_id);
+			$sqlrow = mysql_fetch_assoc($result);
+			return unserialize(base64_decode($sqlrow["value"]));
+		}
+		else
+			throw new DoesNotExistError();
+	}
+	public function offsetUnset($offset)
+	{
+		if($this->offsetExists($offset))
+		{
+			unset($this->keybuffer[array_search($offset, $this->keybuffer)]);
+			$this->keybuffer = array_merge($this->keybuffer);
+			qdb("DELETE FROM `PREFIX_plugin_kvstorage` WHERE `key` = '%s' AND `plugin` = %d", $offset, $this->plugin_id);
+		}
+	}
+	public function offsetSet($offset, $value)
+	{
+		if($this->offsetExists($offset))
+			qdb("UPDATE `PREFIX_plugin_kvstorage` SET `value` = '%s' WHERE `key` = '%s' AND `plugin` = %d",
+				base64_encode(serialize($value)), $offset, $this->plugin_id);
+		else
+		{
+			qdb("INSERT INTO `PREFIX_plugin_kvstorage` (`plugin`, `key`, `value`) VALUES (%d, '%s', '%s')",
+				$this->plugin_id, $offset, base64_encode(serialize($value)));
+			$this->keybuffer[] = $offset;
+		}
+	}
+	
+	/* Iterator interface implementation */
+	function rewind()  { return $this->position = 0; }
+	function current() { return $this->offsetGet($this->keybuffer[$this->position]); }
+	function key()     { return $this->keybuffer[$this->position]; }
+	function next()    { ++$this->position; }
+	function valid()   { return isset($this->keybuffer[$this->position]); }
+}
+
+/*
+ * Class: Comment
+ * Representing a user comment
+ */
+class Comment
+{
+	private $id;
+	private $article;
+	private $language;
+	private $timestamp;
+	
+	/*
+	 * Variables: Public class variables.
+	 * 
+	 * $author_name - Name of comment author.
+	 * $author_mail - E-Mail of comment author.
+	 * $text        - Comment text.
+	 * $visible     - Should the comment be visible?
+	 */
+	public $author_name;
+	public $author_mail;
+	public $text;
+	public $visible;
+	
+	/* Should not be constructed manually. */
+	private function __construct() { }
+	
+	/*
+	 * Functions: Getters
+	 * 
+	 * get_id        - Gets the comment ID.
+	 * get_article   - Gets the article.
+	 * get_language  - Gets the language.
+	 * get_timestamp - Gets the timestamp.
+	 */
+	public function get_id()        { return $this->id;        }
+	public function get_article()   { return $this->article;   }
+	public function get_language()  { return $this->language;  }
+	public function get_timestamp() { return $this->timestamp; }
+	
+	/*
+	 * Constructor: create
+	 * Creates a new comment.
+	 * Automatically sets the $timestamp and $visible (default form setting "comment_visible_default").
+	 * 
+	 * Parameters:
+	 * 	$article  - An <Article> Object.
+	 * 	$language - Which language? (see <languages.php>)
+	 */
+	public static function create($article, $language)
+	{
+		global $ratatoeskr_settings;
+		$obj = new self;
+		
+		qdb("INSERT INTO `PREFIX_comments` (`article`, `language`, `author_name`, `author_mail`, `text`, `timestamp`, `visible`) VALUES (%d, '%s', '', '', '', UNIX_TIMESTAMP(NOW()), %d)",
+			$article->id, $language, $ratatoeskr_settings["comment_visible_default"] ? 1 : 0);
+		
+		$obj->id          = mysql_insert_id();
+		$obj->article     = $article;
+		$obj->language    = $language;
+		$obj->author_name = "";
+		$obj->author_mail = "";
+		$obj->text        = "";
+		$obj->timestamp   = time();
+		$obj->visible     = $ratatoeskr_settings["comment_visible_default"];
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Gets a Comment by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The comments ID.
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		
+		$result = qdb("SELECT `id`, `article`, `language`, `author_name`, `author_mail`, `text`, `timestamp`, visible` FROM `PREFIX_comments` WHERE `id` = %d",
+			$id);
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$obj->id          = $sqlrow["id"];
+		$obj->article     = Article::by_id($sqlrow["article"]);
+		$obj->language    = $sqlrow["language"];
+		$obj->author_name = $sqlrow["author_name"];
+		$obj->author_mail = $sqlrow["author_mail"];
+		$obj->text        = $sqlrow["text"];
+		$obj->timestamp   = $sqlrow["timestamp"];
+		$obj->visible     = $sqlrow["visible"] == 1;
+		
+		return $obj;
+	}
+	
+	/*
+	 * Function: save
+	 * Save changes to database.
+	 */
+	public function save()
+	{
+		qdb("UPDATE `PREFIX_comments` SET `author_name` = '%s', `author_mail` = '%s', `text` = '%s', `visible` = %d` WHERE `id` = %d`",
+			$this->author_name, $this->author_mail, $this->text, ($this->visible ? 1 : 0), $this->id);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		qdb("DELETE FROM `PREFIX_comments` WHERE `id` = %d", $this->id);
+	}
+}
+
+/*
+ * Class: Style
+ * Represents a Style
+ */
+class Style
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class variables.
+	 * 
+	 * $name - The name of the style.
+	 * $code - The CSS code.
+	 * $acl  - An <ACL> object.
+	 */
+	public $name;
+	public $code;
+	public $acl;
+	
+	/* Should not be constructed manually */
+	private function __construct() { }
+	
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$this->id   = $sqlrow["id"];
+		$this->name = $sqlrow["name"];
+		$this->code = $sqlrow["code"];
+		$this->acl  = ACL::by_id($sqlrow["acl"]);
+	}
+	
+	/*
+	 * Function: get_id
+	 */
+	public function get_id() { return $this->id; }
+	
+	/*
+	 * Constructor: create
+	 * Create a new style.
+	 * 
+	 * Parameters:
+	 * 	$name - A name for the new style.
+	 */
+	public static function create($name)
+	{
+		$obj = new self;
+		$obj->acl  = ACL::create(True);
+		$obj->name = $name;
+		$obj->code = "";
+		
+		qdb("INSERT INTO `PREFIX_styles` (`name`, `code`, `acl`) VALUES ('%s', '', %d)",
+			$name, $this->acl->get_id());
+		
+		$obj->id = mysql_insert_id();
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Gets a style object by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The ID
+	 */
+	public static function by_id($id)
+	{
+		$obj = new seld;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `acl`, `name`, `code` FROM `PREFIX_styles` WHERE `id` = %d", $id));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_name
+	 * Gets a style object by name.
+	 * 
+	 * Parameters:
+	 * 	$name - The name.
+	 */
+	public static function by_name($id)
+	{
+		$obj = new seld;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `acl`, `name`, `code` FROM `PREFIX_styles` WHERE `name` = '%s'", $name));
+		return $obj;
+	}
+	
+	/*
+	 * Function: save
+	 * Save changes to database.
+	 */
+	public function save()
+	{
+		$this->acl->save();
+		qdb("UPDATE `PREFIX_styles` SET `name` = '%s', `code` = '%s', `acl` = %d WHERE `id` = %d",
+			$this->name, $this->code, $this->acl, $this->id);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		$this->acl->delete();
+		qdb("DELETE FROM `PREFIX_styles` WHERE `id` = %d", $this->id);
+	}
+}
+
+/*
+ * Class: PluginDB
+ * The representation of a plugin in the database.
+ * See <plugin.php> for loader functions and higher-level plugin access.
+ */
+class PluginDB
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class variables.
+	 *
+	 * $name        - Plugin name
+	 * $class       - Main class of the plugin
+	 * $version     - Plugin version
+	 * $author      - Plugin author
+	 * $author_url  - Website of author
+	 * $description - Description of plugin
+	 * $help        - Help page (HTML)
+	 * $phpcode     - The plugin code
+	 * $active      - Is the plugin active?
+	 */
+	
+	public $name        = "";
+	public $class       = "";
+	public $version     = "";
+	public $author      = "";
+	public $author_url  = "";
+	public $description = "";
+	public $help        = "";
+	public $phpcode     = "";
+	public $active      = False;
+	
+	private function __construct() { }
+	
+	/*
+	 * Function: get_id
+	 */
+	public function get_id() { return $this->id; }
+	
+	/*
+	 * Constructor: create
+	 * Creates a new, empty plugin database entry
+	 */
+	public static function create()
+	{
+		$obj = new self;
+		qdb("INSERT INTO `PREFIX_plugins` () VALUES ()");
+		$obj->id = mysql_insert_id();
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Gets plugin by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The ID
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		
+		$result = qdb("SELECT `name`, `class`, `version`, `author`, `author_url`, `description`, `help`, `phpcode`, `active` FROM `PREFIX_plugins` WHERE `id` = %d", $id);
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$obj->id          = $id;
+		$obj->name        = $sqlrow["name"];
+		$obj->class       = $sqlrow["class"];
+		$obj->version     = $sqlrow["version"];
+		$obj->author      = $sqlrow["author"];
+		$obj->author_url  = $sqlrow["author_url"];
+		$obj->description = $sqlrow["description"];
+		$obj->help        = $sqlrow["help"];
+		$obj->phpcode     = $sqlrow["phpcode"];
+		$obj->active      = ($sqlrow["active"] == 1);
+		
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: all
+	 * Gets all Plugins
+	 * 
+	 * Returns:
+	 * 	List of <PluginDB> objects.
+	 */
+	public static function all()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_plugins` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($sqlrow["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: save
+	 */
+	public function save()
+	{
+		qdb("UPDATE `PREFIX_plugins` SET `name` = '%s', `class` = '%s', `version` = '%s', `author` = '%s', `author_url` = '%s', `description` = '%s', `help` = '%s', `phpcode` = '%s', `active` = %d WHERE `id` = %d`",
+			$this->name, $this->class, $this->version, $this->author, $this->author_url, $this->description, $this->help, $this->phpcode, $this->active ? 1 : 0, $this->id);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		qdb("DELETE FROM `PREFIX_plugins` WHERE `id` = %d", $this->id);
+	}
+	
+	/*
+	 * Function get_kvstorage
+	 * Get the KeyValue Storage for the plugin.
+	 * 
+	 * Returns:
+	 * 	An <PluginKVStorage> object.
+	 */
+	public function get_kvstorage()
+	{
+		return new PluginKVStorage($this->id);
+	}
+}
+
+/*
+ * Class: Section
+ * Representing a section
+ */
+class Section
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class variables
+	 * 
+	 * $name     - The name of the section.
+	 * $title    - The title of the section (a <Multilingual> object).
+	 * $template - Name of the template.
+	 * $styles   - List of <Style> objects.
+	 */
+	public $name;
+	public $title;
+	public $template;
+	public $styles;
+	
+	private function __construct() {}
+	
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$this->id       = $sqlrow["id"];
+		$this->name     = $sqlrow["name"];
+		$this->title    = Multilingual::by_id($sqlrow["title"]);
+		$this->template = $sqlrow["template"];
+		$this->styles   = array_filter_empty(array_map(
+			function($id) { try{return Style::by_id($id);}catch(DoesNotExistError $e){ return "";} },
+			array_filter_empty(explode("+", $sqlrow["styles"]))));
+	}
+	
+	/*
+	 * Function: get_id
+	 */
+	public function get_id() { return $this->id; }
+	
+	/*
+	 * Constructor: create
+	 * Creates a new section.
+	 * 
+	 * Parameters:
+	 * 	$name - The name of the new section.
+	 */
+	public static function create($name)
+	{
+		try
+		{
+			$obj = self::by_name($name);
+		}
+		catch(DoesNotExistError $e)
+		{
+			$obj           = new self;
+			$obj->name     = $name;
+			$obj->title    = Multilingual::create();
+			$obj->template = "";
+			$obj->styles   = array();
+			
+			$result = qdb("INSERT INTO `PREFIX_sections` (`name`, `title`, `template`, `styles`) VALUES ('%s', %d, '', '')",
+				$name, $obj->title->get_id());
+			
+			$obj->id = mysql_insert_id();
+			
+			return $obj;
+		}
+		
+		throw new AlreadyExistsError();
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Gets section by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The ID.
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `name`, `title`, `template`, `styles` FROM `PREFIX_sections` WHERE `id` = %d", $id));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_name
+	 * Gets section by name.
+	 * 
+	 * Parameters:
+	 * 	$name - The name.
+	 */
+	public static function by_name($name)
+	{
+		$obj = new self;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `name`, `title`, `template`, `styles` FROM `PREFIX_sections` WHERE `name` = '%s'", $name));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: all
+	 * Gets all sections.
+	 * 
+	 * Returns:
+	 * 	Array of Section objects.
+	 */
+	public static function all()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_sections` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($sqlrow["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: save
+	 */
+	public function save()
+	{
+		$styles = "+";
+		foreach($this->styles as $style)
+		{
+			$style->save();
+			$styles .= $style->get_id() . "+";
+		}
+		if($styles == "+")
+			$styles = "";
+		
+		$this->title->save();
+		qdb("UPDATE `PREFIX_sections` SET `name` = '%s', `title` = %d, `template` = '%s', `styles` = '%s' WHERE `id` = %d",
+			$this->name, $this->title->get_id(), $this->template, $styles);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		$this->title->delete();
+		qdb("DELETE FROM `PREFIX_sections` WHERE `id` = %d", $this->id);
+	}
+	
+	/*
+	 * Function: get_articles
+	 * Get all articles in this section.
+	 * 
+	 * Returns:
+	 * 	Array of <Article> objects
+	 */
+	public function get_articles()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_articles` WHERE `section` = %d", $this->id);
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = Article::by_id($sqlrow["id"]);
+		return $rv;
+	}
+}
+
+/*
+ * Class: Tag
+ * Representation of a tag
+ */
+class Tag
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class variables
+	 * 
+	 * $name - The name of the tag
+	 * $title - The title (an <Multilingual> object)
+	 */
+	public $name;
+	public $title;
+	
+	/*
+	 * Function: get_id
+	 */
+	public function get_id() { return $this->id; }
+	
+	private function __construct() {}
+	
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$this->id    = $sqlrow["id"];
+		$this->name  = $sqlrow["name"];
+		$this->title = Multilingual::by_id($sqlrow["title"]);
+	}
+	
+	/*
+	 * Constructor: create
+	 * Create a new tag.
+	 * 
+	 * Parameters:
+	 * 	$name - The name
+	 */
+	public static function create($name)
+	{
+		try
+		{
+			$obj = self::by_name($name);
+		}
+		catch(DoesNotExistError $e)
+		{
+			$obj = new self;
+			
+			$obj->name  = $name;
+			$obj->title = Multilingual::create();
+			
+			qdb("INSERT INTO `PREFIX_tags` (`name`, `title`) VALUES ('%s', %d)",
+				$name, $obj->title->get_id());
+			$obj->id = mysql_insert_id();
+			
+			return $obj;
+		}
+		throw new AlreadyExistsError();
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Get tag by ID
+	 * 
+	 * Parameters:
+	 * 	$id - The ID
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `name`, `title` FROM `PREFIX_tags` WHERE `id` = %d", $id));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_name
+	 * Get tag by name
+	 * 
+	 * Parameters:
+	 * 	$name - The name
+	 */
+	public static function by_name($name)
+	{
+		$obj = new self;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `name`, `title` FROM `PREFIX_tags` WHERE `name` = '%s'", $name));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: all
+	 * Get all tags
+	 * 
+	 * Returns:
+	 * 	Array of Tag objects.
+	 */
+	public static function all()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_tags` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($result["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: get_articles
+	 * Get all articles that are tagged with this tag
+	 * 
+	 * Returns:
+	 * 	Array of <Article> objects
+	 */
+	public function get_articles()
+	{
+		$rv = array();
+		$result = qdb("SELECT `article` FROM `PREFIX_article_tag_relations` WHERE `tag` = %d", $this->id);
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = Article::by_id($sqlrow["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: count_articles
+	 * 
+	 * Retutrns:
+	 * 	The number of articles that are tagged with this tag.
+	 */
+	public function count_articles()
+	{
+		$result = qdb("SELECT COUNT(*) AS `num` FROM `PREFIX_article_tag_relations` WHERE `tag` = %d", $this->id);
+		$sqlrow = mysql_fetch_assoc($result);
+		return $sqlrow["num"];
+	}
+	
+	/*
+	 * Function: save
+	 */
+	public function save()
+	{
+		$this->title->save();
+		qdb("UPDATE `PREFIX_tags` SET `name` = '%s', `title` = %d` WHERE `id` = %d",
+			$this->name, $this->title->get_id(), $this->id);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		$this->title->delete();
+		qdb("DELETE FROM `PREFIX_article_tag_relations` WHERE `tag` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_tags` WHERE `id` = %d", $this->id);
+	}
+}
+
+/*
+ * Class: UnknownFileFormat
+ * Exception that will be thrown, if a input file has an unsupported file format.
+ */
+class UnknownFileFormat extends Exception { }
+
+/*
+ * Class: IOError
+ * This Exception is thrown, if a IO-Error occurs (file not available, no read/write acccess...).
+ */
+class IOError extends Exception { }
+
+/*
+ * Array: $imagetype_file_extensions
+ * Array of default file extensions for most IMAGETYPE_* constants
+ */
+$imagetype_file_extensions = array(
+	IMAGETYPE_GIF     => "gif",
+	IMAGETYPE_JPEG    => "jpg",
+	IMAGETYPE_PNG     => "png",
+	IMAGETYPE_BMP     => "bmp",
+	IMAGETYPE_TIFF_II => "tif",
+	IMAGETYPE_TIFF_MM => "tif",
+);
+
+/*
+ * Class: Image
+ * Representation of an image entry.
+ */
+class Image
+{
+	private $id;
+	private $filename;
+	
+	/*
+	 * Variables: Public class variables
+	 * 
+	 * $name - The image name
+	 * $alt - The alternative text (a <Multilingual> object)
+	 * $acl - An <ACL> object
+	 */
+	public $name;
+	public $alt;
+	public $acl;
+	
+	private function __construct() { }
+	
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$this->name = $sqlrow["name"];
+		$this->alt  = Multilingual::by_id($sqlrow["alt"]);
+		$this->file = $sqlrow["file"];
+		$this->acl  = ACL::by_id($sqlrow["acl"]);
+	}
+	
+	/*
+	 * Functions: Getters
+	 * 
+	 * get_id - Get the ID
+	 * get_filename - Get the filename
+	 */
+	public function get_id()       { return $this->id;   }
+	public function get_filename() { return $this->file; }
+	
+	/*
+	 * Constructor: create
+	 * Create a new image
+	 * 
+	 * Parameters:
+	 * 	$name - The name for the image
+	 * 	$file - A uploaded image file (move_uploaded_file must be able to move the file!).
+	 */
+	public static function create($name, $file)
+	{
+		$obj = new self;
+		$obj->name = $name;
+		$obj->alt  = Multilingual::create();
+		$obj->acl  = ACL::create();
+		$obj->file = "0";
+		
+		qdb("INSERT INTO `PREFIX_images` (`name`, `alt`, `file`, `acl`) VALUES ('%s', %d, '0', %d)",
+			$name, $obj->alt->get_id(), $obj->acl->get_id());
+		
+		$obj->id = mysql_insert_id();
+		try
+		{
+			$obj->exchange_image($file);
+		}
+		catch(Exception $e)
+		{
+			$obj->delete();
+			throw $e;
+		}
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Get iimage by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The ID
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		$obj->populate_by_sqlresult(qdb("SELECT `id`, `name`, `alt`, `file`, `acl` FROM `PREFIX_images` WHERE `id` = %d", $id));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: all
+	 * Gets all images.
+	 * 
+	 * Returns:
+	 * 	Array of <Image> objects.
+	 */
+	public function all()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_images` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($sqlrow["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: exchange_image
+	 * Exchanges image file. Also saves object to database.
+	 * 
+	 * Parameters:
+	 * 	$file - Location of new image.(move_uploaded_file must be able to move the file!)
+	 */
+	public function exchange_image($file)
+	{
+		global $imagetype_file_extensions;
+		if(!is_file($file))
+			throw new IOError("\"$file\" is not available");
+		$imageinfo = getimagesize($file);
+		if($imageinfo === False)
+			throw new UnknownFileFormat();
+		if(!isset($imagetype_file_extensions[$imageinfo[2]]))
+			throw new UnknownFileFormat();
+		if(is_file(SITE_BASE_PATH . "/images/" . $this->file))
+			unlink(SITE_BASE_PATH . "/images/" . $this->file);
+		$new_fn = $this->id . $imagetype_file_extensions[$imageinfo[2]];
+		move_uploaded_file($file, SITE_BASE_PATH . "/images/" . $new_fn);
+		$this->file = $new_fn;
+		$this->save();
+	}
+	
+	/*
+	 * Function: save
+	 */
+	public function save()
+	{
+		$this->acl->save();
+		$this->alt->save();
+		qdb("UPDATE `PREFIX_images` SET `name` = '%s', `alt` = %d, `file` = '%s', `acl` = %d WHERE `id` = %d",
+			$this->name, $this->alt->get_id(), $this->file, $this->acl->get_id(), $this->id);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		$this->acl->delete();
+		$this->alt->delete();
+		if(is_file(SITE_BASE_PATH . "/images/" . $this->file))
+			unlink(SITE_BASE_PATH . "/images/" . $this->file);
+		qdb("DELETE FROM `PREFIX_images` WHERE `id` = %d", $this->id);
+	}
+}
+
+/*
+ * Constants: Possible <Article>::$status values.
+ * 
+ * ARTICLE_STATUS_HIDDEN - Article is hidden
+ * ARTICLE_STATUS_LIVE   - Article is visible / live
+ * ARTICLE_STATUS_STICKY - Article is sticky
+ */
+define("ARTICLE_STATUS_HIDDEN", 0);
+define("ARTICLE_STATUS_LIVE",   1);
+define("ARTICLE_STATUS_STICKY", 2);
+
+/*
+ * Class: Article
+ * Representation of an article
+ */
+class Article
+{
+	private $id;
+	
+	/*
+	 * Variables: Public class variables
+	 * 
+	 * $urltitle - URL title
+	 * $title - Title (an <Multilingual> object)
+	 * $text - The text (an <Multilingual> object)
+	 * $excerpt - Excerpt (an <Multilingual> object)
+	 * $meta - Keywords, comma seperated
+	 * $custom - Custom fields, is an array
+	 * $acl - an <ACL> object
+	 * $article_image - The article <Image>. If none: NULL
+	 * $status - One of the ARTICLE_STATUS_* constants
+	 * $section - <Section>
+	 * $timestamp - Timestamp
+	 * $allow_comments - Are comments allowed?
+	 * $tags - Arrray of <Tag> objects
+	 */
+	public $urltitle;
+	public $title;
+	public $text;
+	public $excerpt;
+	public $meta;
+	public $custom;
+	public $acl;
+	public $article_image;
+	public $status;
+	public $section;
+	public $timestamp;
+	public $allow_comments;
+	public $tags;
+	
+	private function __construct()
+	{
+		$this->tags = array();
+	}
+	
+	private function populate_by_sqlresult($result)
+	{
+		$sqlrow = mysql_fetch_assoc($result);
+		if($sqlrow === False)
+			throw new DoesNotExistError();
+		
+		$this->id             = $sqlrow["id"];
+		$this->urltitle       = $sqlrow["urltitle"];
+		$this->title          = Multilingual::by_id($sqlrow["title"]);
+		$this->text           = Multilingual::by_id($sqlrow["text"]);
+		$this->excerpt        = Multilingual::by_id($sqlrow["excerpt"]);
+		$this->meta           = $sqlrow["meta"];
+		$this->custom         = unserialize(base64_decode($sqlrow["custom"]));
+		$this->acl            = ACL::by_id($sqlrow["acl"]);
+		$this->article_image  = $sqlrow["article_image"] == 0 ? NULL : Image::by_id($sqlrow["article_image"]);
+		$this->status         = $sqlrow["status"];
+		$this->section        = Section::by_id($sqlrow["section"]);
+		$this->timestamp      = $sqlrow["timestamp"];
+		$this->allow_comments = $sqlrow["allow_comments"] == 1;
+		
+		$result = qdb("SELECT `tag` FROM `PREFIX_article_tag_relations` WHERE `article` = %d", $this->id);
+		while($sqlrow = mysql_fetch_assoc($result))
+			$this->tags[] = Tag::by_id($sqlrow["tag"]);
+	}
+	
+	/*
+	 * Function: get_id
+	 */
+	public function get_id() { return $this->id; }
+	
+	/*
+	 * Constructor: create
+	 * Create a new Article object
+	 */
+	public static function create()
+	{
+		global $ratatoeskr_settings;
+		$obj = new self;
+		$obj->urltitle       = "";
+		$obj->title          = Multilingual::create();
+		$obj->text           = Multilingual::create();
+		$obj->excerpt        = Multilingual::create();
+		$obj->meta           = "";
+		$obj->custom         = array();
+		$obj->acl            = ACL::create();
+		$obj->article_image  = NULL;
+		$obj->status         = ARTICLE_STATUS_HIDDEN;
+		$obj->section        = Section::by_id($ratatoeskr_settings["default_section"]);
+		$obj->timestamp      = time();
+		$obj->allow_comments = $ratatoeskr_settings["allow_comments_default"];
+		
+		qdb("INSERT INTO `PREFIX_articles` (`urltitle`, `title`, `text`, `excerpt`, `meta`, `custom`, `acl`, `article_image`, `status`, `section`, `timestamp`, `allow_comments`) VALUES ('', %d, %d, %d, '', '%s', %d, 0, %d, %d, %d, %d)",
+			$obj->title->get_id(),
+			$obj->text->get_id(),
+			$obj->excerpt->get_id(),
+			base64_encode(serialize($obj->custom)),
+			$obj->acl->get_id(),
+			$obj->status,
+			$obj->section->get_id(),
+			$obj->timestamp,
+			$obj->allow_comments ? 1 : 0);
+		$obj->id = mysql_insert_id();
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_id
+	 * Get by ID.
+	 * 
+	 * Parameters:
+	 * 	$id - The ID.
+	 */
+	public static function by_id($id)
+	{
+		$obj = new self;
+		$obj ->populate_by_sqlresult(qdb(
+			"SELECT `id`, `urltitle`, `title`, `text`, `excerpt`, `meta`, `acl`, `custom`, `article_image`, `status`, `section`, `timestamp`, `allow_comments` FROM `PREFIX_articles` WHERE `id` = %d", $id
+		));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: by_urlname
+	 * Get by urlname
+	 * 
+	 * Parameters:
+	 * 	$urlname - The urlname
+	 */
+	public static function by_urlname($id)
+	{
+		$obj = new self;
+		$obj ->populate_by_sqlresult(qdb(
+			"SELECT `id`, `urltitle`, `title`, `text`, `excerpt`, `meta`, `custom`, `acl`, `article_image`, `status`, `section`, `timestamp`, `allow_comments` FROM `PREFIX_articles` WHERE `urlname` = '%s'", $urlname
+		));
+		return $obj;
+	}
+	
+	/*
+	 * Constructor: all
+	 * Get all articles
+	 * 
+	 * Returns:
+	 * 	Array of Article objects
+	 */
+	public static function all()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_articles` WHERE 1");
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = self::by_id($sqlrow["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: get_comments
+	 * Getting comments for this article.
+	 * 
+	 * Returns:
+	 * 	Array of <Comment> objects.
+	 */
+	public function get_comments()
+	{
+		$rv = array();
+		$result = qdb("SELECT `id` FROM `PREFIX_comments` WHERE `article` = %d", $this->id);
+		while($sqlrow = mysql_fetch_assoc($result))
+			$rv[] = Comment::by_id($sqlrow["id"]);
+		return $rv;
+	}
+	
+	/*
+	 * Function: save
+	 */
+	public function save()
+	{
+		$this->title->save();
+		$this->text->save();
+		$this->excerpt->save();
+		$this->acl->save();
+		
+		qdb("DELETE FROM `PREFIX_article_tag_relations` WHERE `article`= %d", $this->id);
+		
+		$articleid = $this->id;
+		/* So we just need to fire one query instead of count($this->tags) queries. */
+		if(!empty($this->tags))
+			qdb(
+				"INSERT INTO `PREFIX_article_tag_relations` (`article`, `tag`) VALUES " .
+				implode(",",
+					array_map(function($tag) use ($articleid){ return qdb_fmt("(%d, %d)", $articleid, $tag->get_id()); },
+					$this->tags)
+				)
+			);
+		
+		qdb("UPDATE `PREFIX_articles` SET `urltitle` = '%s', `title` = %d, `text` = %d, `excerpt` = %d, `meta` = '%s', `custom` = '%s', `acl` = %d, `article_image` = %d, `status` = %d, `section` = %d, `timestamp` = %d, `allow_comments` = %d WHERE `id` = %d",
+			$this->urltitle,
+			$this->title->get_id(),
+			$this->text->get_id(),
+			$this->excerpt->get_id(),
+			$this->meta,
+			base64_encode(serialize($this->custom)),
+			$this->acl->get_id(),
+			$this->article_image === NULL ? 0 : $this->article_image->get_id(),
+			$this->status,
+			$this->section->get_id(),
+			$this->timestamp,
+			$this->allow_comments ? 1 : 0,
+			$this->id
+		);
+	}
+	
+	/*
+	 * Function: delete
+	 */
+	public function delete()
+	{
+		$this->title->delete();
+		$this->text->delete();
+		$this->excerpt->delete();
+		$this->acl->delete();
+		
+		foreach($this->get_comments() as $comment)
+			$comment->delete();
+		
+		qdb("DELETE FROM `PREFIX_article_tag_relations` WHERE `article` = %d", $this->id);
+		qdb("DELETE FROM `PREFIX_articles` WHERE `id` = %d", $this->id);
+	}
+}
+
+?>