Update: Issue resolved! The AJAX works but I had the function debug_to_console for testing which echo to the console log. Here is the function:
/* This is a function to print data to web browser console **
** Use debug_to_console( $data ); to print */
function debug_to_console( $data ) {
  $output = $data;
  if ( is_array( $output ) )
  $output = implode( ',', $output);
  echo "<script>console.log( 'Debug Objects: " . $output . "' );</script>";
}
on WooCommerce's admin order page (WooCommerce > Orders > Edit) I added custom fields to add a custom fee to the order. I'm following this article to add AJAX but it's not working. I successfully registered and enqueued my jQuery script add-custom-fee.js and for the most part it works, but I do not receive a response at all.
On the admin order page, I added the following link below my custom fields to trigger the AJAX:
$nonce = wp_create_nonce('add_custom_fee_nonce');
$link = admin_url('admin_ajax.php?action=add_custom_fee&post_id=' . $order->id . '&nonce=' . $nonce );
echo '<a class="add-custom-fee" data-nonce="' . $nonce . '" data-post_id="' . $order->id . '" href="' . $link . '">Add fee?</a>';
Here is how I registered and enqueued my script:
add_action('admin_enqueue_scripts', 'load_add_custom_fee_ajax_js');
function load_add_custom_fee_ajax_js( $hook ) {
  // Deprecated; append datetime as version number of script
  //$my_js_ver = date("ymd-Gis", filemtime( plugin_dir_path( __FILE__ ) . 'js/add-custom-fee.js' ));
  // Only register and enqueue on order edit page
  if ( 'post.php' == $hook || 'edit.php' == $hook ) {
    global $post;
    if ('shop_order' === $post->post_type) {
      wp_register_script( 'add-custom-fee', get_stylesheet_directory_uri() . '/js/add-custom-fee.js', array('jquery'), 1.0, true );
      // enqueue the JavaScript file
      wp_enqueue_script( 'jquery' );
      wp_enqueue_script( 'add-custom-fee');
      // localize the script to reference admin-ajax URL
      wp_localize_script( 'add-custom-fee', 'myAjax', array( 'ajaxurl' => admin_url('admin-ajax.php') ) );
    }
  }
}
And here is my jQuery script:
jQuery(document).ready(function () {
  console.log("Hello world! Add custom fee JS script enqueued!");
});
/* START of code to add a custom fee to the order in admin and recalculate */
jQuery(document).ready(function ($) {
  $('.add-custom-fee').click( function(e) {
    e.preventDefault();
    console.log("Add fee toggle change detected! Grabbing values...");
    // var ajaxurl = 'https://staging1.orderpantry.com/wp-admin/admin-ajax.php';
    var add_fee_toggle = $("input[name='add_fee_toggle']:checked").val();
    var add_fee_name = $("input[name='add_fee_name']").val();
    var add_fee_percentage = $("input[name='add_fee_percentage']").val();
    console.log("Toggle? " + add_fee_toggle + ". Fee name: " + add_fee_name + ". Fee percentage: " + add_fee_percentage + "%");
    // Remove cookie and do not apply fee
    if (add_fee_toggle == '') {
      // Clear the fee fields
      $("input[name='add_fee_toggle'][value='']").prop('checked', true);
      $("#add_fee_name").val('');
      $("#add_fee_percentage").val('');
      console.log('Fee not added!');
      $('button.calculate-action').trigger('click'); // <-- trigger recalculate order
      //$('button.save-action').trigger('click');       <-- trigger saving order
    } else {
      order_id = $(this).attr('data-post_id');
      nonce = $(this).attr('data-nonce');
      console.log("This order's ID is " + order_id + " and its nonce is " + nonce);
      // Push fee values to AJAX function
      $.ajax({
        type: 'post',
        dataType: 'json',
        url: myAjax.ajaxurl,
        data: {
          action: 'create_fee_object',
          order_id: order_id,
          nonce: nonce,
          add_fee_toggle: add_fee_toggle,
          add_fee_name: add_fee_name,
          add_fee_percentage: add_fee_percentage
        },
        success: function(response) {
          if ( response.type == 'success' ) {
            console.log('Success! AJAX request received!');
            // Trigger the order to recalculate on success
            $('button.calculate-action').trigger('click');
          } else {
            alert('An error has occurred while adding your fee.');
            $('button.calculate-action').trigger('click');
          }
        }
      });
    }
  });
});
I do not receive any response, success or failure. The code seem to just stopped working here.
And here is my PHP code:
add_action('wp_ajax_create_fee_object', 'create_fee_object');
add_action('wp_ajax_nopriv_create_fee_object', 'please_login');
function create_fee_object() {
  if ( !wp_verify_nonce( $_REQUEST['nonce'], 'add_custom_fee_nonce' ) ) {
    exit("Unsecured access detected!");
  }
  debug_to_console( "Add fee data reached AJAX function!" );
  // Check if action was fired via Ajax call. If yes, JS code will be triggered, else the user is redirected to the post page
  if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
    $result['type'] = 'success';
    $result = json_encode($result);
    echo $result;
  } else {
    header("Location: ".$_SERVER["HTTP_REFERER"]);
  }
  die();
}
function please_login() {
  alert("You must log in to do this.");
  die();
}
I don't think the function create_fee_object works or AJAX POST is not reaching it.
Any idea what is causing it to not work? Thank you!
 
    