What your are looking for is call_user_func_array()
EDIT, to reply to comment : You have two options: rewrite all your function so that they accept only one array() as argument and you parse that array for values. A bit fastidious but it can be useful in some cases. Or you can request for the required argument of a function:
// This will create an object that is the definition of your object
$f = new ReflectionMethod($instance_of_object, $method_name);
$args = array();
// Loop trough params
foreach ($f->getParameters() as $param) {
// Check if parameters is sent through POST and if it is optional or not
if (!isset($_POST[$param->name]) && !$param->isOptional()) {
throw new Exception("You did not provide a value for all parameters");
}
if (isset($_POST[$param->name])) {
$args[] = $_POST[$param->name];
}
if ($param->name == 'args') {
$args[] = $_POST;
}
}
$result = call_user_func_array(array($instance_of_object, $method_name), $args);
That way your array will be properly constructed. You can also add some specific treatment whether a parameter is optional or not (I guess you can understand how to do it from the code I gave you ;)