Improved locale detection

app.php

@@ -8,21 +8,10 @@ require 'DatabaseAuthenticator.php';
  * Set locale based on browser language specification, and set up gettext
  */
 
-$supported_locales = array('nl_NL');  // English is default, Dutch is optional
-
-if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
-    $locale = explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE'])[0];
-
-    // nl -> nl_NL
-    if (preg_match('/^[a-z]{2}$/', $locale))
-        $locale .= '_' . strtoupper($locale);
-
-    if (in_array($locale, $supported_locales)) {
-        putenv("LANG=$locale");
-        putenv("LC_ALL=$locale");
-        putenv("LC_MESSAGES=$locale");
-        setlocale(LC_ALL, $locale);
-    }
+if ($locale = set_accept_locale(array('nl'))) {
+    putenv("LANG=$locale");
+    putenv("LC_ALL=$locale");
+    putenv("LC_MESSAGES=$locale");
 }
 
 $domain = 'archery';

util.php

@@ -15,3 +15,30 @@ function load_config($filename, $optional=false) {
 
     return $config;
 }
+
+function set_accept_locale($supported_languages=null) {
+    if (!isset($_SERVER['HTTP_ACCEPT_LANGUAGE']))
+        return null;
+
+    foreach (explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE']) as $locale) {
+        if (!preg_match('/^(\w\w)(?:[-_](\w\w))?(\.\w+)?$/', $locale, $m))
+            continue;
+
+        $lang = $m[1];
+        $region = isset($m[2]) ? '_'.$m[2] : '';
+        $ext = isset($m[3]) ? $m[3] : '';
+
+        if ($supported_languages === null || in_array($lang, $supported_languages)) {
+            $locale = setlocale(LC_ALL,
+                $lang.$region.$ext,
+                $lang.$region.'.utf8',
+                $lang.$region,
+                $lang.$ext,
+                $lang.'.utf8',
+                $lang);
+            return $locale;
+        }
+    }
+
+    return null;
+}