PHP magic constants - automatically passed to function?

Question

I wrote a simple access control system which reads an array of access strings, and return true or false depending on the result.

I would call it as follows (for example in a method list_user_data of class User): `

if (current_user_can(__CLASS__, __METHOD__)) { 
    ... 
}

and inside there, it checks if the current user has permission to access method list_user_data in class User.

It works, but I find it annoying that I always have to specify __CLASS__ and __METHOD__ in the call. Is there a way to get those values from within the current_user_can function for the calling function so that I can simply call current_user_can() without having to pass the magic constants?

My code works as is, but I am thinking it could be improved.

Is this possible?

Worth looking into [debug_backtrace](https://www.php.net/manual/en/function.debug-backtrace.php) perhaps. — ccKep, Aug 03 '19 at 23:44
Ah, that works, thank you. Please post as an answer for me to accept. — Kobus Myburgh, Aug 03 '19 at 23:58

ccKep · Accepted Answer · 2019-08-05T23:11:32.453

The return value from debug_backtrace should return the calling function in the 2nd entry (index 1), for example:

<?php

function current_user_can()
{
    $backtrace = debug_backtrace(false, 2);
    // ToDo: Check if $backtrace[1] (and especially the class-key of that) actually exist...
    //       It should always (although the class key might not if this function isn't called from within a class), since this function is being called
    //       but it's still a good habbit to check array keys before accessing the array
    $callerClass = $backtrace[1]["class"];
    $callerMethod = $backtrace[1]["function"];

    // ToDo: implementation of check, in this example $callerClass would be "User" and $callerMethod would be "list_user_data"

    return true;
}

class User {
    public function list_user_data() {
        if (current_user_can())
        {

        }
    }
}

$user = new User();
$user->list_user_data();

PHP magic constants - automatically passed to function?

1 Answers1