ACF Frontend Form AJAX Override

### In my page template ###

<?php

acf_form_head();

print '<div id="acf-messages"></div>';

acf_form(
  array(
    'post_id' => 'new_post',
    'form_attributes' => array(
      'id' => 'checklist-new',
    ),
    'post_title' => true,
    'post_content' => false,
    'new_post' => array(
      'post_type' => $type,
      'post_status' => 'publish'
    ),
    'submit_value' => 'Add the Checklist',
  )
);

checklists_add_initialisation_js('checklist-new');

?>

### In functions.php ###

<?php

function checklists_add_initialisation_js($form_id) {

  $camelcase = 'Checklist' . str_replace(" ", '', ucwords(str_replace("-", ' ', $form_id)));

?>
<script type="text/javascript">
(function($) {
  jQuery('#<?php print $form_id; ?> .acf-form-submit input[type=submit]').attr('data-saving-text', 'Saving ...');
  jQuery('#<?php print $form_id; ?> .acf-form-submit input[type=submit]').attr('data-saved-text', jQuery('#<?php print $form_id; ?> .acf-form-submit input[type=submit]').prop('value'));

  jQuery('#<?php print $form_id; ?> .acf-form-submit input[type=submit]').on('click', function(e) {
    e.preventDefault();
    console.log(typeof jQuery.<?php print $camelcase; ?>);
    var proceed = true;
    if (typeof jQuery.<?php print $camelcase; ?> != 'undefined') {
      proceed = jQuery.<?php print $camelcase; ?>('presubmit');
    }
    if (proceed) {
      var acfForm = jQuery('#<?php print $form_id; ?>');
      var submitBtn = jQuery(this);
      var messageBox = jQuery('#acf-messages');
      submitBtn.prop('disabled', true);
      submitBtn.button('saving');
      acfForm.block({
        message: '<p>Processing ...</p>',
        overlayCSS: {
          backgroundColor: '#fff'
        }
      });
      var post_data = jQuery('#<?php print $form_id; ?>').serialize() + '&checklists_return=json';
      post_data['action'] = 'acf/validate_save_post';
      post_data['lsb_return'] = 'json';

      jQuery.post('/wp-admin/admin-ajax.php?action=checklist_submit&json=true', post_data, null, 'json').done(function(data) {
        acfForm.unblock();
        if (data.success == false || typeof data.success == 'undefined') {

          messageBox.addClass('alert alert-warning');

          var html = '<p><strong>There were some problems when saving:</strong></p><ul>';

          for (i in data.errors) {
            html = html + '<li>' + data.errors[i].message + '</li>';
          }

          html = html + '</ul>';

          messageBox.html(html);

          $('html, body').animate({
            scrollTop: jQuery('.entry-header').offset().top
          }, 1000);
          submitBtn.button('reset');
          submitBtn.prop('disabled', false);
        }
        else {

          messageBox.removeClass('alert-warning');
          messageBox.addClass('alert alert-success');

          var html = '<p>Saved</p>';

          messageBox.html(html);

          submitBtn.button('saved');
          $('html, body').animate({
            scrollTop: jQuery('.entry-header').offset().top
          }, 1000);
          submitBtn.prop('disabled', false);
        }
      });
    }
  });

})(jQuery);
</script>
<?php
}

add_action('wp_ajax_nopriv_checklist_submit',  'acf_form_head');
add_action('wp_ajax_checklist_submit','acf_form_head');

add_action( 'wp_ajax_nopriv_checklists_load_edit_form',  'checklists_load_edit_form' );
add_action( 'wp_ajax_checklists_load_edit_form','checklists_load_edit_form' );

if (isset($_POST['checklists_return']) && $_POST['checklists_return'] == 'json') {
  add_action('acf/validate_save_post', 'checklists_validation_json', 99);
  add_action('acf/save_post', 'checklists_save_json', 99);
}

function checklists_validation_json() {
  $errors = acf_get_validation_errors();
  if ($errors) {

    $response = new \stdClass;
    $response->success = false;
    $response->errors = $errors;

    wp_send_json($response);
    exit;
  }
  return true;
}

function checklists_save_json() {

  $response = new \stdClass;
  $response->success = true;

  wp_send_json($response);
  exit;
}

?>