How to inspect a closure in php?

Question

I have a function that is being passed a Closure. I want to find out the name of the method that closure is derived from. When I call print_r, it outputs this:

Closure Object
(
  [static] => Array
    (
      [listener] => Event_Subscriber_Calq@vendor_product_created
      [container] => Illuminate\Foundation\Application Object
...

How do I acess that listener value? I tried ->static, ::$static, getStatic(), I can't think of any way to get the value.

Currently, my plan is to use output buffering to capture the output from a var_dump. I can't use print_r for this, because the closure contains a reference to and object that references itself, and print_r takes ages to handle the recursion. I also can't use var_export, because it does not include the value I want in the output. So, this is my solution:

ob_start();
var_dump($closure);
$data = ob_get_clean();
$data = preg_replace('#^([^\n]*\n){4}#', '', $data);
$data = preg_replace('#\n.*#', '', $data);
$data = preg_replace('#.*string.[0-9]+. "(.*)".*#', '\1', $data);
list($class, $method) = explode('@', $data);

Which is horrible. Is there another way to do this? Maybe using reflection?

Answer 1

I know this post is old, but in case someone is looking for info, you need to use ReflectionFunction:

$r = new ReflectionFunction($closure);
var_dump($r, $r->getStaticVariables(), $r->getParameters());

Regards, Alex