Save search form in a Ajax modal

I got here after some googling and didn't find an usable solution. To solve this, I created the Block Button Modal module which shows a button instead of a block, which can be used as a solution for this issue.

See https://www.drupal.org/project/block_button_modal →

As you have already discovered, getting the active query in an AJAX call (which doesn’t execute the search itself) is very tricky. You’d probably need to save the most recent search query in the session, or something like that, and that, too, would seem error-prone if someone has multiple tabs open.

I think a much easier solution, if that would also be acceptable, would be to include the block/form on the page as usual, but hide it with Javascript. Then you just provide a link for displaying the form again, maybe in a modal window if you want.