/**
* Etabli la connection à la bases de données si ce n'est pas déjà fait et
* retourne l'objet connection.
*
* @static
* @access public
* @param string $dsn (optionnel, sinon récupéré dans la constante DB_DSN)
* @return ressource
*/
public static function connection($dsn = false)
{
if (false === $dsn) {
if (false !== self::$activeDSN) {
$dsn = self::$activeDSN;
} else {
if (defined('DB_DSN')) {
$dsn = DB_DSN;
} else {
// exit with a FATAL ERROR
trigger_error('No database DSN provided. You must pass a dsn string to ' . 'Database::connection() or define a DB_DSN constant.', E_USER_ERROR);
}
}
}
if (!isset(self::$connectionArray[$dsn])) {
// register connection
self::$connectionArray[$dsn] = NewADOConnection($dsn);
}
if (self::$activeDSN !== false && self::$activeDSN != $dsn) {
// we must "re-connect" explicitely if another connection was
// opened before
if (!self::$connectionArray[$dsn]->connect()) {
trigger_error('Unable to connect to database.', E_USER_ERROR);
}
}
self::$activeDSN = $dsn;
return self::$connectionArray[$dsn];
}
