Question

I’m trying to build multilangual site.

I use this piece of code to detect users language. If you havent chosen a language, it will include your language file based on HTTP_ACCEPT_LANGUAGE.

I don’t know where it gets it from though:

session_start();

if (!isset($_SESSION['lang'])) {
   $_SESSION['lang'] = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
}

elseif (isset($_GET['setLang']) && $_GET['setLang'] == 'en') $_SESSION['lang'] = "en";
elseif (isset($_GET['setLang']) && $_GET['setLang'] == 'sv') $_SESSION['lang'] = "sv";
elseif (isset($_GET['setLang']) && $_GET['setLang'] == 'pl') $_SESSION['lang'] = "pl";
elseif (isset($_GET['setLang']) && $_GET['setLang'] == 'fr') $_SESSION['lang'] = "fr";

include('languages/'.$_SESSION['lang'].'.php');

It works for me and includes the polish lang file. But is this code accurate? Or is there another way?

Answer 1

The browser generally sends a HTTP header, name Accept-Language, that indicates which languages the user is willing to get.

For instance, this header can be :

Accept-Language: en-us,en;q=0.5

There is notion of priority in it, btw 😉

In PHP, you can get this in the $_SERVER super global :

var_dump($_SERVER['HTTP_ACCEPT_LANGUAGE']);

will get me :

string 'en-us,en;q=0.5' (length=14)

Now, you have to parse that 😉

If I edit my preferences in the browser’s option to say “I want french, and if you can’t serve me french, get me english from the US ; and if you can’t get me that either, just get me english), the header will be :

Accept-Language: fr-fr,en-us;q=0.7,en;q=0.3

And, from PHP :

string 'fr-fr,en-us;q=0.7,en;q=0.3' (length=26)

For more informations, you can take a look at [section 14.4 of the HTTP RFC][1].

And you probably can find lots of code example in PHP to parse that header ; for instance : Parse Accept-Language to detect a user’s language

Have fun !