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- Ref: 
- Note: this sol’n requires a server-side (PHP, or Ruby, or Node etc) script endpoint for processing the submitted form data
- Why do we even need JS here? I guess because this is a thing intended for portability and you’ve made the decision that you want error and success messaging to be “white-labelled” on the consuming website rather than user being taken to a separate website, and you don’t know the context’s stack so you’ll use JS to handle the messaging, which then means you need to use JS to orchestrate everything.
- However we don’t need a JS library for this. It’s a pretty straightforward and lightweight combo of DOM manipulation plus fetch(). 

<div class="container">
  <div role="status"></div>
  <form action="/path/to/an/endpoint.php">
    <label for="email">Enter your email</label>
    <input type="email" id="email" name="email">


                label {
  display: block;
  font-weight: bold;



                // Get the form and error message elements
let fc = document.querySelector(".container");
let status = fc.querySelector('[role="status"]');
let form = document.querySelector("form");

// Handle submit events
function submitHandler(event) {
  // Stop the form from reloading the page

  // Validate the email field
  if (! {
    status.textContent = "Please include a valid email address.";

  // Submit the form
  fetch(form.action, {
    method: "POST",
    body: JSON.stringify({ email: }),
    headers: {
      Accept: "application/json"
    .then(function (response) {
      return response.json();
    .then(function (data) {
      announce.textContent = data.msg;
    .catch(function (error) {
      announce.textContent = "Something went wrong. Please try again.";

// Listen for submit events
form.addEventListener("submit", submitHandler);