PHP equivalence: getFunctionCalledName()

G'day:
I touched on this in the last article: "Looking at PHP's OOP from a CFMLer's perspective: overloading (which is not what you'd assume it is)". PHP has a magic constant __FUNCTION__ which returns the name of the function being called. I claimed it's kinda like getFunctionCalledName() in CFML. But not quite. Let's have a look.

(This will be a pretty short article, I think).

CFML: getFunctionCalledName()

As a recap, here's some CFML code demonstrating getFunctionCalledName():

// getFunctionCalledName.cfm

function f(){
    echo("#getFunctionCalledName()#() called<br>");
}

f();
echo("<hr>");

g = f;
g();

This outputs:

F() called

---

G() called

Note that despite the function being declared as f(), getFunctionCalledName() "knows" the latter call to it was via the reference g. OK. That's the baseline expectation set.

PHP equivalent: __function__?

(Betteridge alert!)

Here's the equivalent PHP code using __function__:

<?php
// testFunction.php

function f()
{
    echo sprintf("Using __FUNCTION__: %s() called<br>", __FUNCTION__);
}

f();
echo "<hr>";

$g = "f";
$g();

And this outputs:

Using __FUNCTION__: f() called

---

Using __FUNCTION__: f() called

Hmmm. So __FUNCTION__ always returns the function with its defined name.

On a whim, let's see what happens with a function expression:

<?php
// testFunctionExpression.php

$f = function () {
    echo sprintf("Using __FUNCTION__: %s() called<br>", __FUNCTION__);
};

$f();
echo "<hr>";

$g = $f;
$g();

Result:

Using __FUNCTION__: {closure}() called

---

Using __FUNCTION__: {closure}() called

"closure". Harrumph. But anyway, that's along the lines of what I expected. Pleasingly, the syntax for a function expression is the same as CFML, so I was able to correctly guess that. Win.

debug_backtrace()?

So how do we find the actual name the function was called with?

Googling about I found a lot of references to debug_backtrace(), which is worth looking at:

<?php
// debugBackTraceDump.php

require "../../debug/dBug.php";

function f()
{
    new dBug(debug_backtrace());
}

f();
echo "<hr>";

$g = "f";
$g();

Result:

debug_backtrace() (array)
0	array file D:\Websites\www.scribble.local\shared\scratch\php\www\experiment\constants\debugBackTraceDump.php line 11 function f args array

---

debug_backtrace() (array)
0	array file D:\Websites\www.scribble.local\shared\scratch\php\www\experiment\constants\debugBackTraceDump.php line 15 function f args array

Well it's handy to know about debug_backtrace(), but it's no help to us here.

Nope

More googling... and I've drawn a blank.

Maybe I have to pop my head above the parapet on Stack Overflow and ask a question? Shudder. Done: "PHP: Get the name a function was called as, equivalent to CFML's getFunctionCalledName()".

--
Adam