CNavigation

src/CNavigation.php
<?php
class CNavigation
{
    public static function GenerateMenu($menu, $class)
    {
        if(isset($menu['callback']))
        {
            $items = call_user_func($menu['callback'], $menu['items']);
        }
        $html = "<nav class='$class'>\n";
        foreach($items as $item)
        {
            $html .= "<a href='{$item['url']}' class='{$item['class']}'>{$item['text']}</a>\n";
        }
        $html .= "</nav>\n";
        return $html;
    }
}
?>

theme/functions.php
/**
* Navigation bar
*/

function modifyNavbar($items)
{
    $ref = isset($_GET['p']) && isset($items[$_GET['p']]) ? $_GET['p'] : null;
    if($ref) {
        $items[$ref]['class'] .= 'selected';
    }
    return $items;
}

$menu = array(
  'callback' => 'modifyNavbar',
  'items' => array(
    'hem'  => array('text'=>'Hem',  'url'=>'me.php', 'class'=>null),
    'redovisning'  => array('text'=>'Redovisning',  'url'=>'redovisning.php', 'class'=>null),
    'källkod' => array('text'=>'Källkod', 'url'=>'source.php', 'class'=>null),
  ), 'callback_selected' => function($url) {
    if(basename($_SERVER['SCRIPT_FILENAME']) == $url) {
      return true;
);

theme\index.tpl.php

<?php echo CNavigation::GenerateMenu($menu); ?>