jGrowl

jGrowl: jQuery plugin for toasts. It shipped with AjaxForm in the past.

The library requires jQuery.

CDN setup

Load jQuery first, then jGrowl. Define themes in CSS for success/error types:

<!-- jQuery -->
<script src="https://cdn.jsdelivr.net/npm/jquery@3/dist/jquery.min.js" defer></script>

<!-- JavaScript -->
<script src="https://cdn.jsdelivr.net/npm/jgrowl@1/jquery.jgrowl.min.js" defer></script>

<!-- CSS -->
<link href="https://cdn.jsdelivr.net/npm/jgrowl@1/jquery.jgrowl.min.css" rel="stylesheet">
<style>
  .custom-success { background: green; }
  .custom-error { background: red; }
</style>

Set FetchIt.Message:

document.addEventListener('DOMContentLoaded', () => {
  FetchIt.Message = {
    success(message) {
      $.jGrowl(message, { theme: 'custom-success' })
    },
    error(message) {
      $.jGrowl(message, { theme: 'custom-error' })
    },
  }
})

In a separate file with defer (after the FetchIt script), skip the DOMContentLoaded wrapper:

FetchIt.Message = {
  success(message) {
    $.jGrowl(message, { theme: 'custom-success' })
  },
  error(message) {
    $.jGrowl(message, { theme: 'custom-error' })
  },
}

Skip jGrowl if jQuery is not on the site: load it only when jQuery is already in use. Form blocks [data-success] and [data-validation-error] work alongside toasts. Skip Message if you only need those blocks. Selectors: documentation.