By Irene Morente in Guides & Tutorials

How to Integrate Netlify’s Form Handling in a React App

Netlify comes with some handy, built-in features to process form submissions without having to write any server-side code. Form handling was historically a paid feature but, with the new super-powered free tier, it is now available for all sites for free. 🎉

If your site includes an HTML form, you can add a netlify (or data-netlify="true") attribute to the form tag and start receiving submissions right away (learn more in the form handling docs).

In a React app, however, just adding a netlify attribute to a JSX form won’t work [sad trombone]. Note: If you are using a static site generator like Gatsby or React-Static, it will work but requires a form-name field, so skip to the Static Site Generator section below for examples.

The post-processing bots that look for the netlify attributes when a site is deployed only know how to parse HTML. Until they evolve enough to detect forms rendered with JavaScript, we need to give them a little extra help.

Form Handling with a Stateless React Form

For simplicity’s sake, we’ll use React’s single file example as starting point for our very basic React contact form.

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Contact</title>
    <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
  </head>
  <body>
    <div id="root"></div>
    <script type="text/babel">

      ReactDOM.render(
        <form name="contact" method="post">
          <p>
            <label>Your Name: <input type="text" name="name"/></label>
          </p>
          <p>
            <label>Your Email: <input type="email" name="email"/></label>
          </p>
          <p>
            <label>Message: <textarea name="message"></textarea></label>
          </p>
          <p>
            <button type="submit">Send</button>
          </p>
        </form>,
        document.getElementById("root")
      );

    </script>
  </body>
</html>

You will not want to use this setup for your production app, but the steps for integrating form handling are the same for any React app you host on Netlify.

1. Add a static HTML version of the form to your site

In any HTML file in your site folder, include an HTML form with the netlify attribute and the input fields you want Netlify to process.

For this example, we’ll just add it right after the opening <body> tag in our index HTML file.

<!-- A little help for the Netlify post-processing bots -->
<form name="contact" netlify netlify-honeypot="bot-field" hidden>
  <input type="text" name="name" />
  <input type="email" name="email" />
  <textarea name="message"></textarea>
</form>

Besides the netlify attribute, we’ve also added a netlify-honeypot attribute to avoid showing a captcha when a user submits the form.

Note that form labels are optional here since the HTML form is hidden and our site visitors won’t interact with it directly.

2. Add a hidden form-name field to your JSX form

In the JSX form, include an <input type="hidden" name="form-name" value="the-name-of-the-html-form" />.

Our example HTML form name is contact, so we’ll add:

<input type="hidden" name="form-name" value="contact" />

Our final example now looks as follows:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>Contact</title>
    <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
  </head>
  <body>

    <!-- A little help for the Netlify bots if you're not using a SSG -->
    <form name="contact" netlify netlify-honeypot="bot-field" hidden>
      <input type="text" name="name" />
      <input type="email" name="email" />
      <textarea name="message"></textarea>
    </form>

    <div id="root"></div>
    <script type="text/babel">

      ReactDOM.render(
        <form name="contact" method="post">
          <input type="hidden" name="form-name" value="contact" />
          <p>
            <label>Your Name: <input type="text" name="name"/></label>
          </p>
          <p>
            <label>Your Email: <input type="email" name="email"/></label>
          </p>
          <p>
            <label>Message: <textarea name="message"></textarea></label>
          </p>
          <p>
            <button type="submit">Send</button>
          </p>
        </form>,
        document.getElementById("root")
      );

    </script>
  </body>
</html>

To see it in action, you can download the example zip file and drag & drop it onto your Netlify dashboard to deploy it.

Form Handling With Static Site Generators

If you’re using a static site generator like Gatsby or React-Static, or tools like react-snapshot that generate a static snapshot of your site, the build tool will generate the static HTML form automatically for you. That means you can skip step 1 and add the netlify attributes to your JSX form instead.

Gatsby strips out input fields that are not included in the JSX form, so you will still need to add the form-name hidden input field as described in step 2.

<form name="contact" method="post" data-netlify="true" data-netlify-honeypot="bot-field">
  {/* You still need to add the hidden input with the form name to your JSX form */}
  <input type="hidden" name="form-name" value="contact" />
  ...
</form>

To see an example of a basic contact page using Gatsby, you can check out the code on GitHub, or use the quick deploy to Netlify option to get your own copy.

Form Handling with a Stateful React Form

Let’s replace the JSX form in the previous example with a stateful React component.

The juicy bit is the handleSubmit function in the ContactForm component.

<script type="text/babel">

  const encode = (data) => {
    return Object.keys(data)
        .map(key => encodeURIComponent(key) + "=" + encodeURIComponent(data[key]))
        .join("&");
  }

  class ContactForm extends React.Component {
    constructor(props) {
      super(props);
      this.state = { name: "", email: "", message: "" };
    }

    /* Here’s the juicy bit for posting the form submission */

    handleSubmit = e => {
      fetch("/", {
        method: "POST",
        headers: { "Content-Type": "application/x-www-form-urlencoded" },
        body: encode({ "form-name": "contact", ...this.state })
      })
        .then(() => alert("Success!"))
        .catch(error => alert(error));

      e.preventDefault();
    };

    handleChange = e => this.setState({ [e.target.name]: e.target.value });

    render() {
      const { name, email, message } = this.state;
      return (
        <form onSubmit={this.handleSubmit}>
          <p>
            <label>
              Your Name: <input type="text" name="name" value={name} onChange={this.handleChange} />
            </label>
          </p>
          <p>
            <label>
              Your Email: <input type="email" name="email" value={email} onChange={this.handleChange} />
            </label>
          </p>
          <p>
            <label>
              Message: <textarea name="message" value={message} onChange={this.handleChange} />
            </label>
          </p>
          <p>
            <button type="submit">Send</button>
          </p>
        </form>
      );
    }
  }

  ReactDOM.render(<ContactForm />, document.getElementById("root"));

</script>

Like before, you can download the zip file with this example and drop it onto your Netlify dashboard to deploy it.

Troubleshooting tips

  1. The form isn’t listed in the Forms section of the Netlify dashboard. The most likely cause is that the Netlify bots haven’t found a static HTML version of the form. Make sure somewhere in your site folder there’s an HTML form with the right name, and a netlify or data-netlify attribute. If you’re using Gatsby, or any other static site generator, try browsing your site with JavaScript disabled – if you can’t see the form in the source code, the Netlify bots probably won’t either.

  2. The form is listed in the Forms section but there are no submissions. Make sure the POST request includes the form-name parameter with the correct name of the form.

  3. There are submissions but they are blank. Make sure the input fields in the HTML version of the form have a name attribute, and the parameters sent in the POST request have the same names as the input fields in the HTML form.

Key take-aways

  1. In any HTML file in your site folder, add an HTML form with the netlify attribute and the input fields you want Netlify to process.
  2. In the JavaScript form, add a hidden field called form-name with the name of the HTML form. Alternatively, if you’re using AJAX to submit the form, send a POST request to any path on your site. The request should include the header "Content-Type": "application/x-www-form-urlencoded", and the form-name attribute in the body. Make sure the attributes in the request body are URL-encoded to match the content-type.
  3. Happy form handling!