language : add the languageSubTag function to the HTML tag

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@2264 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

language.php

@@ -340,4 +340,12 @@ class language
         throw new Exception ("No language available for '$languageCode'", 500);
     }
   }
+
+  /** Return the language subtag for the language
+      http://www.iana.org/assignments/language-subtag-registry/
+      language-subtag-registry*/
+  public function languageSubTag ($languageCode)
+  {
+    return str_replace ("_", "-", $languageCode);
+  }
 }