PHP mysqli wrapper: passing by reference with __call() and call_user_func_array()
- by Dave
Hi everyone. I'm a long running fan of stackoverflow, first time poster. I'd love to see if someone can help me with this. Let me dig in with a little code, then I'll explain my problem. I have the following wrapper classes:
class mysqli_wrapper
{
private static $mysqli_obj;
function __construct() // Recycles the mysqli object
{
if (!isset(self::$mysqli_obj))
{
self::$mysqli_obj = new mysqli(MYSQL_SERVER, MYSQL_USER, MYSQL_PASS, MYSQL_DBNAME);
}
}
function __call($method, $args)
{
return call_user_func_array(array(self::$mysqli_obj, $method), $args);
}
function __get($para)
{
return self::$mysqli_obj->$para;
}
function prepare($query) // Overloaded, returns statement wrapper
{
return new mysqli_stmt_wrapper(self::$mysqli_obj, $query);
}
}
class mysqli_stmt_wrapper
{
private $stmt_obj;
function __construct($link, $query)
{
$this->stmt_obj = mysqli_prepare($link, $query);
}
function __call($method, $args)
{
return call_user_func_array(array($this->stmt_obj, $method), $args);
}
function __get($para)
{
return $this->stmt_obj->$para;
}
// Other methods will be added here
}
My problem is that when I call bind_result() on the mysqli_stmt_wrapper class, my variables don't seem to be passed by reference and nothing gets returned. To illustrate, if I run this section of code, I only get NULL's:
$mysqli = new mysqli_wrapper;
$stmt = $mysqli->prepare("SELECT cfg_key, cfg_value FROM config");
$stmt->execute();
$stmt->bind_result($cfg_key, $cfg_value);
while ($stmt->fetch())
{
var_dump($cfg_key);
var_dump($cfg_value);
}
$stmt->close();
I also get a nice error from PHP which tells me: PHP Warning: Parameter 1 to mysqli_stmt::bind_result() expected to be a reference, value given in test.php on line 48
I've tried to overload the bind_param() function, but I can't figure out how to get a variable number of arguments by reference. func_get_args() doesn't seem to be able to help either.
If I pass the variables by reference as in $stmt->bind_result(&$cfg_key, &$cfg_value) it should work, but this is deprecated behaviour and throws more errors.
Does anyone have some ideas around this? Thanks so much for your time.
