How to trigger AJAX when the search input is cleared in jstree

[zwehtetaung-sg]

I want to rely entirely on jsTree’s built-in AJAX search function, ensuring that clearing the search box still makes an AJAX request without manually calling another AJAX function.

[zedee]

Why? IMHO that would break freedom of action.
Just attach a listener to clear_search event, and handle it the way it suits your needs. For some use cases, clearing the search box may or may not trigger another request, it's up to your implementation to do so.