Leverage Formik and Yup to make your Netlify Forms hassle free and sanitised.

Netlify Forms is yet another amazing service provided by Netlify with a generous free tier. For those who don’t know, it allows you to set up a form and take submissions without needing a backend. The form data is not only stored in your dashboard, but you can also directly get a notification on any email address! Sounds interesting right?! As we start implementing you’ll find out just how easy it is to set up if you know basics of React. Although I should mention it’s not just a React only feature, you can set it up with basic HTML as well!

Setting Up Formik Form

We’re gonna first install Formik:

yarn add formik

Then we create a Function Component called ContactForm.js, in it, we’ll begin by setting up Formik and it’s required props - initialValues, onSubmit & render).

ContactForm.js:

import React from 'react'
import { Formik, Field } from 'formik'

const ContactForm = () => {
  return (
    <Formik
      initialValues={{ name: '', email: '', message: '' }}
      onSubmit={values => console.log(values)}
      render={({
        isSubmitting,
        handleSubmit,
        handleReset,
      }) => (
        <form className='form'
          name='contact'
          onSubmit={handleSubmit}
          onReset={handleReset}
          data-netlify='true'
          data-netlify-honeypot='bot-field'
        >
          <div className='field'>
            <label htmlFor='name' className='label'>Name</label>
            <Field
              className='input'
              type='text'
              name='name'
            />
          </div>
          <div className='field'>
            <label htmlFor='email' className='label'>Email</label>
            <Field
              className='input'
              type='text'
              name='email'
            />
          </div>
          <div className='field'>
            <label htmlFor='message' className='label'>Message</label>
            <Field
              className='input-textarea'
              name='message'
              component='textarea'
              rows='6'
            />
          </div>
          <div className='buttons'>
            <input type='reset' value='Clear'
              className='button' />
            <input name='submit' type='submit' disabled={isSubmitting} value='Send Message'
              className='button' />
          </div>
        </form>
      )}
    />
  )
}

export default ContactForm

You might’ve noticed that we have also added a flag for Send Message Button to be disabled while submitting. This is to prevent unwanted behaviour.

This is a basic Contact form with fields for Name, Email & Message. Next, we set up validation using Yup.

Creating a Validation Schema for Contact Form

Yup is a form validation library and has tight integration with Formik. Yup helps us define schema like Joi and validate against it. Add it to your project:

yarn add yup

Create a file called validationSchema.js and create a schema as shown below:

validationSchema.js:

import * as Yup from 'yup'

const validationSchema = Yup.object().shape({
  name: Yup.string()
    .min(2, 'Too Short!')
    .max(50, 'Too Long!')
    .required('Name is Required!'),
  email: Yup.string()
    .email('Enter a Valid Email!')
    .required('Email is Required!'),
  message: Yup.string()
    .required('Message is Required!'),
})

export default validationSchema

Import the above file and add it to formik’s validationSchema prop.

ContactForm.js:

import React from 'react'
import { Formik, Field } from 'formik'
import validationSchema from './validationSchema'

const ContactForm = () => {
  return (
    <Formik
      initialValues={{ name: '', email: '', message: '' }}
      validationSchema={validationSchema}
      onSubmit={values => console.log(values)}
    ...

Writing form On Submit method

In on Submit function of Formik Component, we’ll replace console.log with a application/x-www-form-urlencoded fetch request. But before we do that we need to make an uri component encoder (you can use third-party library if you like).

ContactForm.js:

...
import validationSchema from './validationSchema'

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

const ContactForm = () => {
...

Now we write the onSubmit method, the fetch request has to be made to home path ie /. We also called setSubmitting method, which will be used to change the state of isSubmitting flag.

ContactForm.js:

...
onSubmit={(values, { setSubmitting }) => {
        fetch("/", {                                 
          method: 'POST',
          headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
          body: encode({
            'form-name': 'contact',
            ...values,
          }),
        })
          .then(() => {
            alert('Success!')
            setSubmitting(false)
          })
          .catch(error => {
            alert('Error: Please Try Again!')                            
            setSubmitting(false)
          })
      }}
...

If you are using Gatsby JS, especially gatsby-plugin-offline then you’ll need to add ?no-cache=1 along with / or it won’t work.

ContactForm.js:

...
fetch("/?no-cache=1", {   
...

Displaying Validation Errors to User

To display the validation errors we need to use two params from render method touched & errors. touched object tells us if the user has touched the field, and errors object tell us the errors. We are gonna display the errors if the user has touched the field and there’s an error for that field.

ContactForm.js:

...
      render={({
        touched,
        errors,
        isSubmitting,
        handleSubmit,
        handleReset,
      }) => (
        <form className='form'
          name='contact'
          onSubmit={handleSubmit}
          onReset={handleReset}
          data-netlify='true'
          data-netlify-honeypot='bot-field'
        >
          <div className='field'>
            <label htmlFor='name' className='label'>Name</label>
            <Field
              className='input'
              type='text'
              name='name'
            />
           {touched.name && errors.name && <p className='danger'>{errors.name}</p>}
          </div>
          <div className='field'>
            <label htmlFor='email' className='label'>Email</label>
            <Field
              className='input'
              type='text'
              name='email'
            />
           {touched.email && errors.email && <p className='danger'>{errors.email}</p>}
          </div>
          <div className='field'>
            <label htmlFor='message' className='label'>Message</label>
            <Field
              className='input-textarea'
              name='message'
              component='textarea'
              rows='6'
            />
           {touched.message && errors.message && <p className='danger'>{errors.message}</p>}
          </div>
          <div className='buttons'>
            <input type='reset' value='Clear'
              className='button' />
            <input name='submit' type='submit' disabled={isSubmitting} value='Send Message'
              className='button' />
          </div>
        </form>
      )}
    />
...

And with this, we are finally done. Now according to our validation Schema:

‘Name’, ‘Email’ & ‘Message’ are required fields.
‘Name’ should be minimum 2 characters and maximum 50 characters.
‘Email’ field should have a valid email.
And ‘Message’ field cannot be empty.

I hope this helps you, happy coding.