When I use some characters like / in the textbox I get returned an empty string in response. I can easily make a check for empty string in my html but my question is how can I avoid having that empty string from being sent over in my php code?

$("#search").keyup(function(){
    var newVal = $(this).val();
    if(!newVal==""){
         $.ajax({
              type : 'get',
              dataType: 'html',
              url : '/searchpost/' + newVal , 
              success : function(response) {
                   console.log(response);
              }
         });
    }
});

public function searchpost() {

        $q = $this->uri->segment(3);
        if(!$q) die();

        $string = trim(strip_tags($q));
        $db_string = urldecode($string);

        $this->db->select("postID, post_title, post_url, post_status");
        $this->db->like("post_title", $db_string);
        $this->db->or_like("post_url", $db_string);

        $posts = $this->db->get('posts', 10);

        if(!count($posts->result())) {
            die('Nothing to display');
        }

        ?>

        

        result() as $m) : 
            if($m->post_status != 'active' OR empty($m->post_title)) continue;
        ?>
        

            post_url; ?>