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<?php
require_once("DB.php");
/**
* A simple preference manager, takes userid, preference name pairs and returns the value
* of that preference.
*
* CREATE TABLE `preferences` (
* `user_id` varchar( 255 ) NOT NULL default '',
* `pref_id` varchar( 32 ) NOT NULL default '',
* `pref_value` longtext NOT NULL ,
* PRIMARY KEY ( `user_id` , `pref_id` )
* )
*
* @author Jon Wood <jon@jellybob.co.uk>
* @package Auth_PrefManager
* @category Authentication
*/
class Auth_PrefManager
{
/**
* The database object.
* @var object
* @access private
*/
var $_db;
/**
* The user name to get preferences from if the user specified doesn't
* have that preference set.
* @var string
* @access private
*/
var $_defaultUser = "__default__";
/**
* Should we search for default values, or just fail when we find out that
* the specified user didn't have it set.
*
* @var bool
* @access private
*/
var $_returnDefaults = true;
/**
* The table containing the preferences.
* @var string
* @access private
*/
var $_table = "preferences";
/**
* The column containing user ids.
* @var string
* @access private
*/
var $_userColumn = "user_id";
/**
* The column containing preference names.
* @var string
* @access private
*/
var $_nameColumn = "pref_id";
/**
* The column containing preference values.
* @var string
* @access private
*/
var $_valueColumn = "pref_value";
/**
* The quoted value column.
* @var string
* @access private
*/
var $_valueColumnQuoted = "pref_value";
/**
* The session variable that the cache array is stored in.
* @var string
* @access private
*/
var $_cacheName = "prefCache";
/**
* The last error given.
* @var string
* @access private
*/
var $_lastError;
/**
* Defines whether the cache should be used or not.
* @var bool
* @access private
*/
var $_useCache = true;
/**
* Defines whether values should be serialized before saving.
* @var bool
* @access private
*/
var $_serialize = false;
/**
* Constructor
*
* Options:
* table: The table to get prefs from. [preferences]
* userColumn: The field name to search for userid's [user_id]
* nameColumn: The field name to search for preference names [pref_name]
* valueColumn: The field name to search for preference values [pref_value]
* defaultUser: The userid assigned to default values [__default__]
* cacheName: The name of cache in the session variable ($_SESSION[cacheName]) [prefsCache]
* useCache: Whether or not values should be cached.
* serialize: Should preference values be serialzed before saving?
*
* @param string $dsn The DSN of the database connection to make, or a DB object.
* @param array $properties An array of properties to set.
* @param string $defaultUser The default user to manage for.
* @return bool Success or failure.
* @access public
*/
function Auth_PrefManager($dsn, $properties = NULL)
{
// Connect to the database.
if (isset($dsn)) {
if (is_string($dsn)) {
$this->_db = DB::Connect($dsn);
if (DB::isError($this->_db)) {
$this->_lastError = "DB Error: ".$this->_db->getMessage();
}
} else if (is_subclass_of($dsn, 'db_common')) {
$this->_db = &$dsn;
} else {
$this->_lastError = "Invalid DSN specified.";
return false;
}
} else {
$this->_lastError = "No DSN specified.";
return false;
}
if (is_array($properties)) {
if (isset($properties["table"])) { $this->_table = $this->_db->quoteIdentifier($properties["table"]); }
if (isset($properties["userColumn"])) { $this->_userColumn = $this->_db->quoteIdentifier($properties["userColumn"]); }
if (isset($properties["nameColumn"])) { $this->_nameColumn = $this->_db->quoteIdentifier($properties["nameColumn"]); }
if (isset($properties["valueColumn"])) { $this->_valueColumn = $properties["valueColumn"]; }
if (isset($properties["valueColumn"])) { $this->_valueColumnQuoted = $this->_db->quoteIdentifier($properties["valueColumn"]); }
if (isset($properties["defaultUser"])) { $this->_defaultUser = $properties["defaultUser"]; }
if (isset($properties["cacheName"])) { $this->_cacheName = $properties["cacheName"]; }
if (isset($properties["useCache"])) { $this->_useCache = $properties["useCache"]; }
if (isset($properties["serialize"])) { $this->_serialize = $properties["serialize"]; }
}
return true;
}
function setReturnDefaults($returnDefaults = true)
{
if (is_bool($returnDefaults)) {
$this->_returnDefaults = $returnDefaults;
}
}
/**
* Sets whether the cache should be used.
*
* @param bool $use Should the cache be used.
* @access public
*/
function useCache($use = true)
{
$this->_useCache = $use;
}
/**
* Cleans out the cache.
*
* @access public
*/
function clearCache()
{
unset($_SESSION[$this->_cacheName]);
}
/**
* Get a preference for the specified user, or, if returning default values
* is enabled, the default.
*
* @param string $user_id The user to get the preference for.
* @param string $pref_id The preference to get.
* @param bool $showDefaults Should default values be searched (overrides the global setting).
* @return mixed The value if it's found, or NULL if it isn't.
* @access public
*/
function getPref($user_id, $pref_id, $showDefaults = true)
{
if (isset($_SESSION[$this->_cacheName][$user_id][$pref_id]) && $this->_useCache) {
// Value is cached for the specified user, so give them the cached copy.
return $_SESSION[$this->_cacheName][$user_id][$pref_id];
} else {
// Not cached, search the database for this user's preference.
$query = sprintf("SELECT * FROM %s WHERE %s=%s AND %s=%s", $this->_table,
$this->_userColumn,
$this->_db->quote($user_id),
$this->_nameColumn,
$this->_db->quote($pref_id));
$result = $this->_db->query($query);
if (DB::isError($result)) {
// Ouch! The query failed!
$this->_lastError = "DB Error: ".$result->getMessage();
return NULL;
} else if ($result->numRows()) {
// The query found a value, so we can cache that, and then return it.
$row = $result->fetchRow(DB_FETCHMODE_ASSOC);
$_SESSION[$this->_cacheName][$user_id][$pref_id] = $this->_unpack($row[$this->_valueColumn]);
return $_SESSION[$this->_cacheName][$user_id][$pref_id];
} else if ($this->_returnDefaults && $showDefaults) {
// I was doing this with a call to getPref again, but it threw things into an
// infinite loop if the default value didn't exist. If you can fix that, it would
// be great ;)
if (isset($_SESSION[$this->_cacheName][$this->_defaultUser][$pref_id]) && $this->_useCache) {
$_SESSION[$this->_cacheName][$user_id][$pref_id] = $_SESSION[$this->_cacheName][$this->_defaultUser][$pref_id];
return $_SESSION[$this->_cacheName][$this->_defaultUser][$pref_id];
} else {
$query = sprintf("SELECT * FROM %s WHERE %s=%s AND %s=%s", $this->_table,
$this->_userColumn,
$this->_db->quote($this->_defaultUser),
$this->_nameColumn,
$this->_db->quote($pref_id));
$result = $this->_db->query($query);
if (DB::isError($result)) {
$this->_lastError = "DB Error: ".$result->getMessage();
return NULL;
} else {
if ($result->numRows()) {
$row = $result->fetchRow(DB_FETCHMODE_ASSOC);
$_SESSION[$this->_cacheName][$this->_defaultUser][$pref_id] = $this->_unpack($row[$this->_valueColumn]);
$_SESSION[$this->_cacheName][$user_id][$pref_id] = $_SESSION[$this->_cacheName][$this->_defaultUser][$pref_id];
return $_SESSION[$this->_cacheName][$user_id][$pref_id];
} else {
return NULL;
}
}
}
} else {
// We've used up all the resources we're allowed to search, so return a NULL.
return NULL;
}
}
}
/**
* A shortcut function for getPref($this->_defaultUser, $pref_id, $value),
* useful if you have a logged in user, but want to get defaults anyway.
*
* @param string $pref_id The name of the preference to get.
* @return mixed The value if it's found, or NULL if it isn't.
* @access public
*/
function getDefaultPref($pref_id)
{
return $this->getPref($this->_defaultUser, $pref_id);
}
/**
* Set a preference for the specified user.
*
* @param string $user_id The user to set for.
* @param string $pref_id The preference to set.
* @param mixed $value The value it should be set to.
* @return bool Sucess or failure.
* @access public
*/
function setPref($user_id, $pref_id, $value)
{
// Start off by checking if the preference is already set (if it is we need to do
// an UPDATE, if not, it's an INSERT.
if ($this->_exists($user_id, $pref_id, false)) {
$query = sprintf("UPDATE %s SET %s=%s WHERE %s=%s AND %s=%s", $this->_table,
$this->_valueColumnQuoted,
$this->_db->quote($this->_pack($value)),
$this->_userColumn,
$this->_db->quote($user_id),
$this->_nameColumn,
$this->_db->quote($pref_id));
} else {
$query = sprintf("INSERT INTO %s (%s, %s, %s) VALUES(%s, %s, %s)", $this->_table,
$this->_userColumn,
$this->_nameColumn,
$this->_valueColumnQuoted,
$this->_db->quote($user_id),
$this->_db->quote($pref_id),
$this->_db->quote($this->_pack($value)));
}
$result = $this->_db->query($query);
if (DB::isError($result)) {
$this->_lastError = "DB Error: ".$result->getMessage();
return false;
} else {
if ($this->_useCache) {
$_SESSION[$this->_cacheName][$user_id][$pref_id] = $value;
}
return true;
}
}
/**
* A shortcut function for setPref($this->_defaultUser, $pref_id, $value)
*
* @param string $pref_id The name of the preference to set.
* @param mixed $value The value to set it to.
* @return bool Sucess or failure.
* @access public
*/
function setDefaultPref($pref_id, $value)
{
return $this->setPref($this->_defaultUser, $pref_id, $value);
}
/**
* Deletes a preference for the specified user.
*
* @param string $user_id The userid of the user to delete from.
* @param string $pref_id The preference to delete.
* @return bool Success/Failure
* @access public
*/
function deletePref($user_id, $pref_id)
{
if ($this->getPref($user_id, $pref_id) == NULL) {
// The user doesn't have this variable anyway ;)
return true;
} else {
$query = sprintf("DELETE FROM %s WHERE %s=%s AND %s=%s", $this->_table,
$this->_userColumn,
$this->_db->quote($user_id),
$this->_nameColumn,
$this->_db->quote($pref_id));
$result = $this->_db->query($query);
if (DB::isError($result)) {
$this->_lastError = "DB Error: ".$result->getMessage();
return false;
} else {
if ($this->_useCache) {
unset($_SESSION[$this->_cacheName][$user_id][$pref_id]);
}
return true;
}
}
}
/**
* Deletes a preference for the default user.
*
* @param string $pref_id The preference to delete.
* @return bool Success/Failure
* @access public
*/
function deleteDefaultPref($pref_id)
{
return $this->deletePref($this->_defaultUser, $pref_id);
}
/**
* Checks if a preference exists in the database.
*
* @param string $user_id The userid of the preference owner.
* @param string $pref_id The preference to check for.
* @return bool True if the preference exists.
* @access private
*/
function _exists($user_id, $pref_id)
{
$query = sprintf("SELECT COUNT(%s) FROM %s WHERE %s=%s AND %s=%s", $this->_nameColumn,
$this->_table,
$this->_userColumn,
$this->_db->quoteSmart($user_id),
$this->_nameColumn,
$this->_db->quote($pref_id));
$result = $this->_db->getOne($query);
if (DB::isError($result)) {
$this->_lastError = "DB Error: ".$result->getMessage();
return false;
} else {
return (bool)$result;
}
}
/**
* Does anything needed to prepare a value for saving in the database.
*
* @param mixed $value The value to be saved.
* @return string The value in a format valid for saving to the database.
* @access private
*/
function _pack($value)
{
if ($this->_serialize) {
return serialize($value);
} else {
return $value;
}
}
/**
* Does anything needed to create a value of the preference, such as unserializing.
*
* @param string $value The value of the preference.
* @return mixed The unpacked version of the preference.
* @access private
*/
function _unpack($value)
{
if ($this->_serialize) {
return unserialize($value);
} else {
return $value;
}
}
}
?>
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