Identify language from the Accept-language HTTP header we got.

File

drupal-6.x/includes/language.inc, line 71

Multiple language handling functionality.

Code

function language_from_browser() {
  // Specified by the user via the browser's Accept Language setting
  // Samples: "hu, en-us;q=0.66, en;q=0.33", "hu,en-us;q=0.5"
  $browser_langs = array();

  if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
    $browser_accept = explode(",", $_SERVER['HTTP_ACCEPT_LANGUAGE']);
    for ($i = 0; $i < count($browser_accept); $i++) {
      // The language part is either a code or a code with a quality.
      // We cannot do anything with a * code, so it is skipped.
      // If the quality is missing, it is assumed to be 1 according to the RFC.
      if (preg_match("!([a-z-]+)(;q=([0-9\\.]+))?!", trim($browser_accept[$i]), $found)) {
        $browser_langs[$found[1]] = (isset($found[3]) ? (float) $found[3] : 1.0);
      }
    }
  }

  // Order the codes by quality
  arsort($browser_langs);

  // Try to find the first preferred language we have
  $languages = language_list('enabled');
  foreach ($browser_langs as $langcode => $q) {
    if (isset($languages['1'][$langcode])) {
      return $languages['1'][$langcode];
    }
  }
}