Hide Members Directory Search Form If Input is Empty

yzc_hide_search_button.php

<?php

/**
 * Hide Members Directory Search Form If Input is Empty.
 */
function yzc_hide_search_button() { ?>
    <style type="text/css">#yz-directory-search-box form input#members_search_submit{display: none;}</style>
    <script type="text/javascript">
    ( function( $ ) {

        'use strict';

        $( document ).ready( function() {
            $( document ).on( 'keypress keyup paste', '#members_search', function() {
                if ( $ ( this ).val() == '' ) {
                    $( '#members_search_submit' ).fadeOut();
                } else {
                    $( '#members_search_submit' ).fadeIn();
                }
            });
        });

    })( jQuery );
    </script>

    <?php

}

add_action( 'wp_head' , 'yzc_hide_search_button', 999 );