PHP cookies issue, not including language file - php

Question

I have a piece of code that should redirect user if there's no cookies in the session..
if (isset($_GET['lang'])) {
if (in_array($_GET['lang'], $jezici)) {
$lang = $_GET['lang'];
// register the session and set the cookie
$_SESSION['lang'] = $lang;
setcookie("lang", $lang, time() + (3600 * 24 * 30));
} else {
$lang = 'hr';
$_SESSION['lang'] = $lang;
setcookie("lang", $lang, time() + (3600 * 24 * 30));
}
} else if (isset($_SESSION['lang'])) {
$lang = $_SESSION['lang'];
} else if (isset($_COOKIE['lang'])) {
$lang = $_COOKIE['lang'];
} else if (empty($_GET['lang']) || !isset($_GET['lang'])) {
$trenutni_file = basename($_SERVER['PHP_SELF']);
?>
<META http-equiv="refresh" content="0;URL=http://<?php echo $domena; ?>/<?php echo $trenutni_file; ?>?lang=hr">
<?php
exit();
}
?>
This is how I include it in index.php
$langArray = include 'lang/'.$lang.'.php';
But sometimes I get this error failed to include lang/.php ... This code is obviously not doing everything right.. If no cookie is set in the session I would redirect user to index.php?lang=hr... Any help?

Answer 1

Your last condition (empty($_GET['lang']) || !isset($_GET['lang'])) is redundant itself, since empty already checks if the function is set, as you can read here. Also, it is redundant with the first condition.
Moreover, you are lacking a condition to determine if in the case the var is set in session or cookie, it actually is not empty (it could be set as an empty string, for example)
I would change all your isset calls for an empty call, and add a final, standalone condition, to chek if $lang is set, no matter how, and if it has a valid value
if (!empty($_GET['lang'])) {
if (in_array($_GET['lang'], $jezici)) {
$lang = $_GET['lang'];
// register the session and set the cookie
$_SESSION['lang'] = $lang;
setcookie("lang", $lang, time() + (3600 * 24 * 30));
} else {
$lang = 'hr';
$_SESSION['lang'] = $lang;
setcookie("lang", $lang, time() + (3600 * 24 * 30));
}
} else if (!empty($_SESSION['lang'])) {
$lang = $_SESSION['lang'];
} else if (!empty($_COOKIE['lang'])) {
$lang = $_COOKIE['lang'];
}
if (empty($lang) || (!in_array($_GET['lang'], $jezici))) {
$trenutni_file = basename($_SERVER['PHP_SELF']);
?>
<META http-equiv="refresh" content="0;URL=http://<?php echo $domena; ?>/<?php echo $trenutni_file; ?>?lang=hr">
<?php
exit();
}