忽略未使用的类型参数并移至下一步

Question

I've been searching alot, but I could not find any solution. I also don't exactly know if this is possible.

So here I have 2 cases somebody could do:

Case 1:

$callback = function(Object $obj, $var) {
    // Do stuff
}

Case 2:

$callback = function($var) {
    // Do stuff
}

Now I will call the function like this:

call_user_func_array($callback, [new Object, 'some text'])

But now there is a problem. In case 2 the $var will be seen as the object parameter. How do I send only the string parameter to the call when the object isn't used? And I don't want the order to change, the Object must be first.

P.S. I noticed that this is possible in the Symfony framework. I will continue researching how Symfony does this, any tips are appreciated!

Thanks for reading!

Answer 1

You can use reflection.

Example:

function call(callable $callback, $var, object $obj = null)
{
    $callbackArguments = array();
    $parameters = (new ReflectionFunction($callback))->getParameters();
    foreach ($parameters as $parameter) {
        if ($parameter->getType() == 'object') {
            $callbackArguments[] = $obj;
        } else {
            $callbackArguments[] = $var;
        }
    }
    return call_user_func_array($callback, $callbackArguments);
}