PHP：在类外定义的回调函数中的访问类方法

Question

I have a class like

class Foo
{
  public function runWithCallback($custom_callback) {
    ...
    return call_user_func_array($custom_callback, [$arg_a, $arg_b]);
  }
  public function aHelperMethod($arg_a) {
    ...
  }
}

And when I use the class like

$foo = new Foo();
$foo->runWithCallback(function($arg_a, $arg_b) {
  ...
  // now I need to use helper method "aHelperMethod"
  $this->aHelperMethod($arg_c); // wrong code
  ...
});

Of course the above code does not work as $this makes no sense in that anonymous function.

Is it possible to do what I intended to? Thx.

Answer 1

Ok thanks to @BilalAhmed 's comment, I found a "dirty" way of doing this:

$foo = new Foo();
$foo->runWithCallback(function($arg_a, $arg_b) use ($foo) {
  ...
  // now I need to use helper method "aHelperMethod"
  $foo->aHelperMethod($arg_c); // wrong code
  ...
});