Cannot access cookies in Chrome, works properly in Firefox - php

Question

Basic situation and basic relevant info:
I have a php code that executes before the opening <doctype> tag. The hope was to (if necessary) send a redirect based on user's browser's language preferences before anything else loads.
The script attempts to do two things based on highest supported language preference:
Use php: setcookie() to create a cookie with the two-letter language code.
Example cookie name = value: x_language = es
Use php: header("Location: " . $requestedSite); to redirect to a subdomain,
Example domain: es.domain.com
Example:
if (isset($_COOKIE['x_language'])) {
-Determine correct subdomain based on cookie value-
-If not currently on that subdomain, redirect to it-
} else {
setcookie('x_language','es',time() + 31536000 ,'/','.domain.com' );
header("Location: " . $requestedSite);
}
The problem:
Firefox works perfectly. Chrome (and other browsers) fail to recognize the cookies at all.
I've boiled it down to this:
print_r($_COOKIE) works properly in Firefox, and returns a lovely, populated array.
print_r($_COOKIE) fails in Chrome, and returns an empty array.
This is the core of the problem, my function doesn't recognize the existence of a cookie because Chrome doesn't.
I've made sure every browser accepts cookies.
I've checked dev tools to make sure the cookie is in place on all browsers, (it is).
I realize a cookie's value isn't available until the next page load, but that isn't an issue here. Even after it is set, it won't read.
There is no output above the initial setcookie();
So how do I get Chrome (and other browsers) to recognize its own cookies?! Does anyone know why this would all work flawlessly on Firefox but fail elsewhere?
On a lark I decided to try this. I created a file that only contains:
<?php
print_r($_COOKIE);
?>
Again, I see the cookie array in Firefox. Meanwhile, in Chrome, IE, Opera, Safari, I get an empty array. Could this be a server issue?

Answer 1

OP returns with answer:
Alright, I'm adding this as an 'Answer' in case anyone else comes across this (totally bizarre) behavior and lands here:
It turns out my hosting provider was doing some seriously aggressive caching with my WordPress site that I was unaware of.
At the time I posted my question, I didn't think being on WordPress was relevant, but apparently it was.
Basically it was doing this:
With a clean Cache:
Visitor 1 visits the site.
The php processes and produces output as expected.
Visitor 1 is served php output (based on his browser's parameters and such).
Visitor 2 visits the site. Visitor 2 sees *Visitor 1's version of the site.
The php is processed once and only once per Cache-clear.
This caching behavior meant that accessing cookies through php was simply not going to work right, but accessing them with Javascript WOULD work.
(Important note: It turns out the above-stated caching behavior is disabled for any user viewing the site while logged into wordpress, and this is common behavior for WordPress Cache plugins. That is why I was seeing different behavior in Firefox than I saw in other browsers, because I was actively logged in with Firefox. This could be a helpful piece of information for someone out there.)
My solution:
Use Javascript to run an AJAX query to a .php file which would process the language preferences of the visitor and return the output as a 2-character code, (i.e. 'en' 'es' 'pt' 'de', etc).
Using AJAX to call php allowed me to use php's server-side access to a browser's language preferences while circumventing the super-agro caching of my host.
I hope this helps someone! And thanks to everyone who tried to help me out with this.

Answer 2

I was not having this problem with the code below. I was able to go to example.com and be redirected immediately to en.example.com and see the cookie in $_COOKIES. If I used en.example.com?set=fr I would be redirected to fr.example.com every time I tried example.com. Hopes this is what you were looking for!
<?php
print_r($_COOKIE);
if(isset($_GET['nuke'])) {
setcookie('x_language','',time()-1000,'/','.example.com');
echo 'It has been nuked!';
exit;
} else if(isset($_GET['set'])) {
setcookie('x_language',$_GET['set'],time() + 31536000, '/','.example.com');
$_COOKIE['x_language'] = $_GET['set'];
}
if (isset($_COOKIE['x_language'])) {
$redirect = $_COOKIE['x_language'].'.example.com';
if($_SERVER['HTTP_HOST'] != $redirect)
header('Location: http://'.$redirect);
} else {
setcookie('x_language','en',time() + 31536000,'/','.example.com');
$redirect = 'http://en.example.com';
header('Location: '.$redirect);
}
echo '<br />Cookie: '.$_COOKIE['x_language'].' Domain: '.$_SERVER["HTTP_HOST"];
?>