Contact form

React Contact form component

A typical subscription form used when subscribing to a newsletter, asking a question in a FAQ section, or leaving a testimonial / review for a product.

To learn more read Docs.

Prerequisites

Before starting the project make sure to install the following utilities:

Node LTS environment (12.x.x recommended)
Express- setting the server
Express-validator - for validating the form
Nodemailer - for sending mails
Multer - for handling multiparts request (reading FormData)
Dotenv - for loading environment variables
Cors - for enabling CORS (Cross-origin resource sharing)

Within this tutorial we are using the Material Design for Bootstrap library, you can download it for free from here. Without the library, the form will still work — however it may look and behave differently. It's recommended to use this library along with the tutorial.

Form HTML

First, create basic contact form which will be our base for validating and sending data.

Copy and paste the following HTML and JavaScript code into your file (e.g. index.html):

JSX

        
            
            import React from 'react';
            import { MDBInput, MDBCheckbox, MDBBtn } from 'mdb-react-ui-kit';
    
            export default function App() {
              return (
                <form id='form' className='text-center' style={{ width: '100%', maxWidth: '300px' }}>
                  <h2>Contact us</h2>
    
                  <MDBInput label='Name' v-model='name' wrapperClass='mb-4' />
    
                  <MDBInput type='email' label='Email address' v-model='email' wrapperClass='mb-4' />
    
                  <MDBInput label='Subject' v-model='subject' wrapperClass='mb-4' />
    
                  <MDBTextArea wrapperClass='mb-4' label='Message' />
    
                  <MDBCheckbox wrapperClass='d-flex justify-content-center' label='Send me copy' />
    
                  <MDBBtn color='primary' block className='my-4'>
                    Send
                  </MDBBtn>
                </form>
              );
            }

Frontend validation

Our form now works fine. However currently if the user makes a mistake by clicking send without filling in the form first, this will result in sending an empty email. The other potential problem is that user might make a mistake in his email address so he would never get a response from us.

MDB Validation

MDBootstrap form components provide built-in validation which can be used to validate user data before sending email via PHP script. Read more about MDBootstrap form validation here.

In the example below all inputs were marked as required, and JavaScript code enabling custom MDB Form Validation was added.

JSX

        
            
            import React from 'react';
            import { MDBInput, MDBCheckbox, MDBBtn, MDBValidation, MDBValidationItem } from 'mdb-react-ui-kit';
    
            export default function App() {
              return (
                <MDBValidation noValidate id='form' className='text-center' style={{ width: '100%', maxWidth: '300px' }}>
                  <h2>Contact us</h2>
    
                  <MDBValidationItem invalid feedback='Please provide your name.'>
                    <MDBInput label='Name' v-model='name' wrapperClass='mb-4' required />
                  </MDBValidationItem>
    
                  <MDBValidationItem invalid feedback='Please provide your email.'>
                    <MDBInput type='email' label='Email address' v-model='email' wrapperClass='mb-4' required />
                  </MDBValidationItem>
    
                  <MDBValidationItem invalid feedback='Please provide mail subject.'>
                    <MDBInput label='Subject' v-model='subject' wrapperClass='mb-4' required />
                  </MDBValidationItem>
    
                  <MDBValidationItem invalid feedback='Please provide a message text.'>
                    <MDBTextArea wrapperClass='mb-4' label='Message' required />
                  </MDBValidationItem>
    
                  <MDBValidationItem feedback=''>
                    <MDBCheckbox wrapperClass='d-flex justify-content-center' label='Send me copy' />
                  </MDBValidationItem>
    
                  <MDBBtn type='submit' color='primary' block className='my-4'>
                    Send
                  </MDBBtn>
                </MDBValidation>
              );
            }

Create NodeJS server file

Create a new file called server.js inside your application's root directory.

If you haven't installed the express, nodemailer, body-parser and other necessary packages from the npm repository so far, do so immediately using the following command in your application terminal:

JS

        
            
            // terminal
            npm install express nodemailer express-validator multer dotenv cors

Having all set up, let's create our server. Paste following code into your file:

JS

        
            
            // JS

            const express = require("express");
            const multer = require("multer");
            const cors = require("cors");

            const app = express();
            const upload = multer();

            const port = process.env.PORT || 3000;

            app.use(cors());
            app.use(upload.none());

            app.listen(port, () => {
              console.log('Express started on port: ', port);
            });

This will import all necessary dependencies, initialize application as express instance, allows Cross-Origin Resource Sharing (CORS) for sending information between frontend and backend development servers and finally start the server. const upload = multer() and app.use(upload.none()) creates middlewarae for handling multiparts requests, which will allow to send contact form data using FormData object.

In this example we use app.use(upload.none()) to show how multipart request can be handled (with file upload turned off), however it is not recommended to use it global scope. In your production app use e.g. upload.any() for specific endpoints in which you expect to handle multipart requests.

Create file structure for mail sending server

Having the server set up you are ready to create a file structure for mail sending route and middleware. For the purposes of our course, it is not necessary, but in case you want to expand the functionality of our example, it is worth knowing what the file structure could looks like in applications using the NodeJS environment and Express server.

Create and read environment variables file

Firstly, create .env file inside your root directory. This file will contain all your private data used inside your NodeJS project. It's content for our purposes would look like this:

JS

        
            
          // JS

          NODE_ENV=development
          PORT=3000
          MAIL_USERNAME=your_smtp_email_address
          MAIL_PASSWORD=your_smtp_email_password
          MAIL_HOST=your_smtp_host
          MAIL_PORT=your_smtp_port
          MAIL_TO=email_address_to_which_you_want_mails_to_be_sent

Example .env file for Gmail SMTP

JS

        
            
          // JS

          NODE_ENV=development
          PORT=3000
          MAIL_USERNAME=your_email_address_here
          MAIL_PASSWORD=your_email_password
          MAIL_HOST=smtp.gmail.com
          MAIL_PORT=465
          MAIL_TO=email_address_to_which_you_want_mails_to_be_sent

Please note that we are using SMTP for Gmail here. If you would like to use another provider your HOST, PORT and PROVIDER would be different. Also if you would like to send test mails in development mode you may want to be interested in fake SMTP servers, e.g. Mailtrap. Also for production purposes it is recommended to use one of many SMTP providers.

Never publish your environment variable files. Include all your .env files inside .gitignore file when you publish your code.

Now add /config/index. file that will read all your environment variables.

JS

        
            
        // JS

          require('dotenv').config();

          module.exports = {
            PORT: process.env.PORT || 3000,
            NODE_ENV,
            MAIL_HOST: process.env.MAIL_HOST,
            MAIL_PORT: process.env.MAIL_PORT,
            MAIL_USERNAME: process.env.MAIL_USERNAME,
            MAIL_PASSWORD: process.env.MAIL_PASSWORD,
            MAIL_TO: process.env.MAIL_TO
          };

... and change your server.js file so the config can expose your variables to the server:

JS

        
            
          // JS

          const express = require("express");
          const multer = require("multer");
          const cors = require("cors");
          const config = require("./config");
          const routes = require("./routes");

          const upload = multer();
          const app = express();

          app.use(cors());
          app.use(upload.none());

          app.use("/api", routes);

          app.listen(config.PORT, () => {
            console.log(`Server is running on port ${config.PORT}.`);
          });

Also notice that we added app.use("/api", routes); which will use our router from the next section.

Create router and contact form routes

Create /routes folder and inside it create two files. First index.js that will control all your project routes:

JS

        
            
          // JS

          const router = require("express").Router({ mergeParams: true });
          const contactRoutes = require("./contact.routes");

          router.use("/contact", contactRoutes);

          module.exports = router;

... and contact.routes.js file that will contain all your contact form related routes.

JS

        
            
        // JS

        // express server specific imports
        const router = require("express").Router({ mergeParams: true });

        // import for contact form routes controller
        const { ContactController } = require("../controllers/contact.controller");

        router.post("/", (req, res) => {
          const controller = new ContactController(req, res);
          controller.sendContactForm();
        });

        module.exports = router;

Thanks to express.Router({ mergeParams: true }) we can access the params from the parent router inside the child router. In our case creating router.post('/', ...) is equal to router.post('/contact', ...). This structure is very helpful in deep nested routes structure.

... and contact.routes.js file that will contain all your contact form related routes.

Contact controller

Controllers are callbacks passed to the router methods which process request to the route and generate the response.

Create /controllers folder inside which you will create contact.controllers.js file. Controller for /contact route will look as follows:

JS

        
            
          // JS

          const nodemailer = require("nodemailer");

          const { MAIL_HOST, MAIL_PORT, MAIL_PROVIDER, MAIL_USERNAME, MAIL_PASSWORD, MAIL_TO } =
          require('../config');

          const transporter = nodemailer.createTransport({
            host: MAIL_HOST,
            port: MAIL_PORT,
            auth: {
              user: MAIL_USERNAME,
              pass: MAIL_PASSWORD,
            },
          });

          class ContactController {
            constructor(request, response) {
              this.request = request;
              this.response = response;
            }

            sendContactForm() {

            const { name, email, subject, message, mailCopy } = this.request.body;

            const mailOptions = {
              to: [MAIL_TO], // Enter here the email address on which you want to send emails from your
              customers
              from: name,
              subject,
              text: message,
            };

            if (mailCopy) {
              mailOptions.to.push(email);
            }

            transporter
              .sendMail(mailOptions)
              .then(() => {
                return this.response
                .status(200)
                .json({ msg: "Email sent successfully" });
              })
              .catch((error) => {
                return this.response
                .status(400)
                .json({ errors: [{ msg: `Something went wrong: ${error}` }] });
                });
            }
          }

          module.exports = ContactController;

Controller is based on a class instance for better scalability of the application. You could also use function based controller as well.

Line 5 - const transporter = nodemailer.createTransport({ }) is used to create a function that takes the object containing the configuration of the transporter as a parameter. It is in this configuration that you define the host from which emails are sent port, authorization, and many other settings that are to be sent.

Line 14 - create class instance of the controller that, in this example will take request and response from the server as its constructor arguments.

Line 20 - declares sendContactForm method for handling POST method on /contact route.

Lines 22-33 - defines the mailOptions object that is sent to the sendMail() method of transporter. It is in this object that we define, to who the email is to be sent, from who, what is its subject, text, and to who the response in the email is to be addressed. In this object are many more options that you can use. You will find them here.

Lines 35-48 - Code responsible for sending the mail with the parameters defined inside mailOptions. Will send either success or failure response message to the frontend.

Create validating middleware

Middlewares are functions that have access to the server request and response objects. In our example we will create middleware function that will validate contact form data.

Create /middleware folder and inside it create validate.js file.

JS

        
            
        // JS
        const { body, validationResult } = require("express-validator");

        module.exports = [
          body("name").notEmpty().withMessage("You must supply a name"),
          body("email").isEmail().normalizeEmail().withMessage("Email is not valid"),
          body("subject").notEmpty().withMessage("You must supply a subject"),
          body("message").notEmpty().withMessage("You must supply a message"),
          body("mailCopy").toBoolean(),
          function (req, res, next) {
            const errors = validationResult(req);

            if (!errors.isEmpty()) {
              return res.status(400).json({ errors: errors.array() });
            }

            next();
          },
        ];

We are using here express-validator package that will help us validate request.body and if something is wrong provide server response with proper error message. If everything in the request is ok, next() function that will allow server to call next function (controller) is called.

Now update contact.routes.js file with our validator. Note that middleware function is added between the route and controller callback.

JS

        
            
          // JS

          // express server specific imports
          const router = require("express").Router({ mergeParams: true });

          // import validation middleware
          const validate = require("../middleware/validate");

          // import for contact form routes controller
          const { ContactController } = require("../controllers/contact.controller");

          // add validator to the route callback
          router.post("/", validate, (req, res) => {
            const controller = new ContactController(req, res);
            controller.sendContactForm();
          });

          module.exports = router;

Run server

In your package.json file add script that will run your server:

JS

        
            
          // package.json

          "start": "node server.js",
          "start:dev" : "nodemon server.js"

You can also add start:dev script for development purposes that will restart your server anytime you make a change to the code. For that add nodemon package to your application.

JS

        
            
          // Terminal

          npm install nodemon --save-dev