Habari\Theme::theme_header PHP Method

    public function theme_header($theme)
    {
        // Add prev and next links
        if (isset($theme->posts) && $theme->posts instanceof Posts) {
            $settings = array();
            $settings['page'] = (int) ($theme->page + 1);
            $items_per_page = isset($theme->posts->get_param_cache['limit']) ? $theme->posts->get_param_cache['limit'] : Options::get('pagination');
            $total = Utils::archive_pages($theme->posts->count_all(), $items_per_page);
            if ($settings['page'] <= $total) {
                Stack::add('template_atom', array('next', 'text/html', _t('Page %s', array($settings['page'])), URL::get(null, $settings, false)));
            }
            $settings['page'] = (int) ($theme->page - 1);
            if ($settings['page'] >= 1) {
                Stack::add('template_atom', array('prev', 'text/html', _t('Page %s', array($settings['page'])), URL::get(null, $settings, false)));
            }
        } elseif ($theme->posts instanceof Post) {
            if ($next = $theme->posts->ascend()) {
                Stack::add('template_atom', array('next', 'text/html', $next->title, $next->permalink));
            }
            if ($previous = $theme->posts->descend()) {
                Stack::add('template_atom', array('prev', 'text/html', $previous->title, $previous->permalink));
            }
        }
        // create a stack of the atom tags before the first action so they can be unset if desired
        Stack::add('template_atom', array('alternate', 'application/atom+xml', 'Atom 1.0', implode('', $this->feed_alternate_return())), 'atom');
        Stack::add('template_atom', array('service', 'application/atomsvc+xml', 'Atom Publishing Protocol', URL::get('atompub_servicedocument')), 'app');
        Stack::add('template_atom', array('EditURI', 'application/rsd+xml', 'RSD', URL::get('rsd')), 'rsd');
        Plugins::act('template_header', $theme);
        $atom = Stack::get('template_atom', '<link rel="%1$s" type="%2$s" title="%3$s" href="%4$s">');
        $styles = Stack::get('template_stylesheet', Method::create('\\Habari\\Stack', 'styles'));
        $scripts = Stack::get('template_header_javascript', Method::create('\\Habari\\Stack', 'scripts'));
        $output = implode("\n", array($atom, $styles, $scripts));
        Plugins::act('template_header_after', $theme);
        return $output;
    }