PHP language detection

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

Answer 1

You can use: Locale::acceptFromHttp().

Tries to find locale that can satisfy the language list that is requested by the HTTP "Accept-Language" header.

Answer 2

Your code looks just fine. You might want to add a final else default choice if the visitor asks for a language you aren't providing. Also, if the visitor himself selects a language you should save that choice in a persistent cookie and check its value, giving it precedence over HTTP_ACCEPT_LANGUAGE.

As far as I can tell Youtube does use HTTP_ACCEPT_LANGUAGE, but at the same time uses IP geolocation to suggest a change in language if the langauge of the visitor's country doesn't match that. Definitely annoying.

Just nitpicking: if you're gonna add languages to the list a switch() statement might be more readable.

Answer 3

Here's a function for selecting the best out of a group of supported languages. It extracts languages from Accept-Language, then sorts the given array of languages according to their priority.

function select_best_language($languages) {
    if (!$_SERVER['HTTP_ACCEPT_LANGUAGE']) return $languages[0];
    $default_q=100;
    foreach (explode(",",$_SERVER['HTTP_ACCEPT_LANGUAGE']) as $lqpair) {
        $lq=explode(";q=",$lqpair);
        if ($lq[1]) $lq[1]=floatval($lq[1]); else $lq[1]=$default_q--;
        $larr[$lq[0]]=$lq[1];
    }
    usort($languages,function($a,$b) use ($larr) { return $larr[$b]<=>$larr[$a]; });
    return $languages[0];
}

$lang = select_best_language(['en','fr','it']);

Answer 4

This is also possible. It will use english as default if .php is not available.

$lang = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
(@include_once 'languages/'.$lang.'.php') or (@include_once 'languages/en.php'); 

Answer 5

if(isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])){
    $parts=explode(';',$_SERVER['HTTP_ACCEPT_LANGUAGE']);
    $langs=explode(',',$parts[0]);
    var_dump($langs);
}

Answer 6

I know there already many good solutions, but have found my own way to solve this problem.

<?php
  $prefLocales = array_reduce(
    explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE']), 
      function ($res, $el) { 
        list($l, $q) = array_merge(explode(';q=', $el), [1]); 
        $res[$l] = (float) $q; 
        return $res; 
      }, []);
    arsort($prefLocales);
    /*
    This get you from headers like this
      string 'en-US,en;q=0.8,uk;q=0.6,ru;q=0.4' (length=32)
    array like this
    array (size=4)
      'en-US' => float 1
      'en' => float 0.8
      'uk' => float 0.6
      'ru' => float 0.4
    */

Code will convert HTTP_ACCEPT_LANGUAGE string to array with locales as keys and weight as values, sorted from high value to low. So you can just get one by one with array_shift to get the best match with your site locales.