PHP __FILE__ inheritence - php

Question

I am trying to write a method that I can use in extended classes that uses the file's full path. However, when I use __FILE__ I only get back the path for the class the inherited method is defined in. Here is an example:
foo.php
class foo
{
public function getFullFile()
{
return __FILE__;
}
}
bar.php
class bar extends foo
{
public function getFile()
{
return __FILE__;
}
}
example.php
$foo = new foo();
echo $foo->getFullFile() . PHP_EOL;
$bar = new bar();
echo $bar->getFullFile() . PHP_EOL;
echo $bar->getFile() . PHP_EOL;
The output of running example.php:
/my/full/path/foo.php
/my/full/path/foo.php
/my/full/path/bar.php
Is this expected behavior? Is there a better way to accomplish this? Am I doing something insanely stupid?

Answer 1

You can not refer to __FILE__ (for said reasons), but you can refer to the file the current object's class has been defined in:
class foo
{
public function getFullFile()
{
$c = new ReflectionClass($this);
return $c->getFileName();
}
}

Answer 2

__FILE__ is always the file where the constant is referred to. It's for debugging purposes to you can easily refer back to the exact file where the code that uses __FILE__ is located. It would be useless to say that it was in 'bar.php', when the definition resides in 'foo.php'.

Answer 3

Some code says more than thousand words...
B.php
<?
class B {
public function bar() {
return __FILE__;
}
}
A.php
<?
require "B.php";
class A extends B {
public function foo() {
echo parent::bar();
}
}
$a = new A();
$a->foo();
joe#joe-desktop:~$ php A.php
/home/joe/B.php

Answer 4

See http://php.net/manual/en/language.constants.predefined.php for more information on these 'magical constants'. If I am not mistaken these magical constants are a sort of macros and are determined at compile time, not runtime.

Answer 5

This is the expected behaviour __FILE__ will always evaluate to the filename of file in which interpreter finds it. Same with other magic constants (__METHOD__, __CLASS__, __LINE__ etc)
As far as I can tell, it is impossible to do waht you're trying to do.

Answer 6

I think if you want $bar->getFullFile() to return bar.php, you'll have to add the function to bar.php.
public function getFullFile() {
return parent::getFullFile();
}

Answer 7

Just use debug_backtrace() PHP function. Example of use (my library function my_die is placed in some included php file, but reports the callers location!):
function my_die($msg)
{
$bt = debug_backtrace();
$file = $bt[0]["file"];
$line = $bt[0]["line"];
$func = $bt[1]["function"];
# session info also!!!
$user = $_SESSION['user'];
error_log('Died in ' . $file . ': ' . $line . ': function ' . $func .
"(): user='{$user}': ip='{$_SERVER['REMOTE_ADDR']}': " . $msg .
" (browser: '{$_SERVER['HTTP_USER_AGENT']})'");
die($msg);
}