Redirect after comment submit according to value of query string in comment form URL?

Question

For redirecting user to some page after comment submit my below code is working fine :

function my_module_form_alter(&$form, $form_state, $form_id) {
   if ($form_id == "comment_node_link_form") {
      $form['#submit'][] = 'my_module_submit';
  }
}


function my_module_submit($form, &$form_state) {
    $form_state['redirect'] = 'newsroom/en';
}

For Comment links I am sending some query string in comment form URL and want to redirect to user to page after comment according to query string value, How can we fetch the query string value to pass it to redirect on hook_submit

http://www.example.com/comment/reply/208943?destination=newsroom#comment-form

http://www.example.com/comment/reply/208943?destination=sections#comment-form

How can we fetch value of destination and pass it to redirect in hook_submit

Please suggest ! Thanks!

UPDATE : I have tried adding hidden field but not able to access it in hook_submit it shows null :

function my_module_form_alter(&$form, $form_state, $form_id) {
       if ($form_id == "comment_node_link_form") {

           $form['redirect_to'] = array(
             '#type' => 'hidden',
             '#value' => $_GET['destination'],
           );

          $form['#submit'][] = 'my_module_submit';
      }
    }

Answer 1

After More deep debugging I found that action of comment from is set to

comment/reply/nodeid

So with below URL's:

http://www.example.com/comment/reply/208943?destination=newsroom#comment-form

http://www.example.com/comment/reply/208943?destination=sections#comment-form

My query string variable destination is lost or either at form submit it shows null because from moves to action URL where no query string was set.

To solve this I have added query string in action URL which works very well :

function my_module_form_alter(&$form, $form_state, $form_id) {
   if ($form_id == "comment_node_link_form") {
      $form['#action'] = $form['#action'] . '?destination=' . $_GET['destination'];
  }
}

ie: All I have to do is add required query string to $form['#action']

Hope this will help any one who is trying similar solution.

Answer 2

function module_menu() {
  $items = array();

  $items['redirect_query_string'] = array(
    'page callback' => 'YourRedirectpagecallbackfunction',
    'access callback' => 'user_access',
    //'access argument' =>  array('Download CSV'),
    'type'  => MENU_CALLBACK,
  );
  return $items;
}

In your form submit write:

if(isset($_GET["redirect_query_string"])){
    return YourRedirectpagecallbackfunction();
  }

function YourRedirectpagecallbackfunction(){
......your redirect url......
}