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How to build a Phone Number Validation App using Phone Validate API?

•

Fri Dec 31 2021

•

9 min read

Saad Irfan

Sometimes you get a phone number that you are unsure if it is correct. Although many services can validate your number, almost all of them are paid. If you are a developer like me, we can create our application for this.

Today, I am building a phone number validation application to validate any phone number for you. So without any further ado, let’s jump in!

Stack

We need to choose a stack first to build this application. I have decided to go with the Jamstack.

I am going to use Next.js for the frontend and TailwindCSS for the styling.

If you don’t know about Next.js, it is a JavaScript framework built on top of React and provides features like server-side rendering, static site generation, etc. Tailwind is a CSS framework that provides utility classes to speed up the development process.

Choosing The API

Let’s find an API that we can use to validate phone numbers. Go to RapidAPI Hub and create an account if you haven’t already and then search for “phone number validation” in the search section.

Loading component...

You will see different search results related to validation APIs. For this piece, I am using Phone Validate API.

It is a free API, so you do not need to subscribe to it. However, you will need your RapidAPI key. Go ahead and save the x-rapidapi-key so you can use it later.

Building The UI

You can create a Next.js boilerplate with TailwindCSS integrated by running the following command in your terminal. So let’s do that.

sh
npx create-next-app -e with-tailwindcss phone-number-validate-app

This command is going to take a minute to set everything up. After generating the boilerplate, you will see a folder with the name phone-number-validate-app has been created. Open this folder in your preferred code editor. I will use VSCode for this project.

Project Files

When you open the project in your code editor, you will see the following directories and files in the root directory:

pages directory: Inside it, you will have files index.js, _app.js, and another directory called api. You only need to know about the index.js file that is the main entry point in your project.
public directory: This directory contains icons. You place your static files here to load later in the application.
node_modules: It’s another directory that contains all the node modules you are using in your application.
package.json: This file contains the metadata of your project.
package-lock.json: This file is responsible for tracking the exact version of every installed package.
postcss.config.js: This file contains PostCSS configurations.
tailwind.config.js: It contains TailwindCSS configurations.
readme.md: It’s a markdown file for documentation.

Before we move on to writing the code, open this file, and copy all of its content, then paste it inside the tailwind.config.js file in your project. These are some TailwindCSS configurations I have done specifically for this project. I have added some colors that you do not have by default with TailwindCSS and set some screen sizes.

Now let’s start writing the code. I am going to do it in steps so you can follow along.

→ STEP #1

Open the pages/index.js file and remove all the existing code. After this, copy-paste the following code there:

js
export default function Home() {
	return (
		<div className="flex flex-col items-center relative min-h-screen">
			<h2 className="font-raleway font-bold text-5xl text-primary pt-20 pb-6 md:text-3xl">
				Phone Number <span className="text-secondary">Validation</span>{' '}
				App
			</h2>
			<h3 className="text-active text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Check if a Phone Number is valid or not
			</h3>
		</div>
	);
}

It will create two headings for you with the text “Phone Number Validation App” and “Check if a Phone Number is valid or not”. You can change it to anything you prefer.

→ STEP #2

Now let’s create an input field and a validate button. The user will be able to type the phone number in the input box and use the validate button to get the validation details.

For this, copy the following code and paste it in pages/index.js:

js
export default function Home() {
	return (
		<div className="flex flex-col items-center relative min-h-screen">
			<h2 className="font-raleway font-bold text-5xl text-primary pt-20 pb-6 md:text-3xl">
				Phone Number <span className="text-secondary">Validation</span>{' '}
				App
			</h2>
			<h3 className="text-active text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Check if a Phone Number is valid or not
			</h3>
			<div className="flex flex-col justify-between items-center w-full md:items-center">
				<form
					className="flex w-full justify-center md:flex-col md:w-5/6"
					onSubmit={e => fetchValidation(e)}
				>
					<input
						autoFocus={true}
						type="number"
						className="border-none outline-none w-2/5 bg-primary px-4 py-2 rounded-sm md:w-full"
						placeholder="Enter the phone number..."
					/>
					<button className="outline-none border border-danger font-bold font-raleway ml-4 px-12 py-2 rounded-sm bg-background text-primary transition duration-300 hover:bg-active hover:text-background md:ml-0 md:mt-4">
						Validate
					</button>
				</form>
			</div>
		</div>
	);
}

This code is going to create an input field and button. I have also styled them a little bit using TailwindCSS.

→ STEP #3

Let’s create some states to store the phone number and the validation details we will receive from the API. For this, copy-paste the following code in pages/index.js.

js
import {useState} from 'react';
export default function Home() {
	const [number, setNumber] = useState('');
	const [res, setRes] = useState(null);
	return (
		<div className="flex flex-col items-center relative min-h-screen">
			<h2 className="font-raleway font-bold text-5xl text-primary pt-20 pb-6 md:text-3xl">
				Phone Number <span className="text-secondary">Validation</span>{' '}
				App
			</h2>
			<h3 className="text-active text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Check if a Phone Number is valid or not
			</h3>
			<div className="flex flex-col justify-between items-center w-full md:items-center">
				<form
					className="flex w-full justify-center md:flex-col md:w-5/6"
					onSubmit={e => fetchValidation(e)}
				>
					<input
						autoFocus={true}
						type="number"
						className="border-none outline-none w-2/5 bg-primary px-4 py-2 rounded-sm md:w-full"
						placeholder="Enter the phone number..."
						onChange={e => setNumber(e.target.value)}
					/>
					<button className="outline-none border border-danger font-bold font-raleway ml-4 px-12 py-2 rounded-sm bg-background text-primary transition duration-300 hover:bg-active hover:text-background md:ml-0 md:mt-4">
						Validate
					</button>
				</form>
			</div>
		</div>
	);
}

You can see that I have added an onChange event handler to set the state value as soon as the user types the number.

→ STEP #4

Let’s integrate the API now. For this, first, create a .env.local file and paste the following in it:

sh
NEXT_PUBLIC_RAPIDAPI_KEY=YOUR-RAPIDAPI-KEY

You need to replace YOUR-RAPIDAPI-KEY here with the API key you got when you subscribed to the Phone Validate API. It is the value of x-rapidapi-key that you saved earlier.

Now download and add axios in your project. For this, run the following command in the terminal:

sh
npm install axios

Now import axios at the top of the pages/index.js.

js
import axios from 'axios';

→ STEP #5

RapidAPI Hub provides you with code snippets in different languages for integrating the API. I am going to use the (JavaScript) Axios one.

Fetching data using (JavaScript) Axios

Now create a file with the name validate.js inside the pages/api directory. It is going to create a REST API endpoint for you. The endpoint point will look like this:

sh
http://localhost:3000/api/validate

Now copy the following code in this file:

js
import axios from 'axios';
export default async function handler(req, res) {
	if (req.method === 'POST') {
		const options = {
			method: 'POST',
			url: 'https://neutrinoapi-phone-validate.p.rapidapi.com/phone-validate',
			headers: {
				'x-rapidapi-host': 'neutrinoapi-phone-validate.p.rapidapi.com',
				'x-rapidapi-key': process.env.NEXT_PUBLIC_RAPIDAPI_KEY
			},
			data: {number: req.body.number}
		};
		axios
			.request(options)
			.then(function (response) {
				res.status(200).json(response.data);
			})
			.catch(function (error) {
				console.error(error);
			});
	} else {
		res.status(400);
	}
}

This code makes an API call to the Phone Validate API on the server and returns the results to the user. It executes when the user makes an API call to the validate endpoint I mentioned above.

Once you are done, copy the following code in the pages/index.js file:

js
import {useState} from 'react';
import axios from 'axios';
export default function Home() {
	const [number, setNumber] = useState('');
	const [res, setRes] = useState(null);
	/**
	 *
	 *
	 * Check if phone number is valid or not
	 */
	const fetchValidation = async e => {
		e.preventDefault();
		try {
			const res = await axios.post(`/api/validate`, {number});
			const {data} = res;
			setRes(data);
		} catch (err) {
			console.log(err);
		}
	};
	return (
		<div className="flex flex-col items-center relative min-h-screen">
			<h2 className="font-raleway font-bold text-5xl text-primary pt-20 pb-6 md:text-3xl">
				Phone Number <span className="text-secondary">Validation</span>{' '}
				App
			</h2>
			<h3 className="text-active text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Check if a Phone Number is valid or not
			</h3>
			<div className="flex flex-col justify-between items-center w-full md:items-center">
				<form
					className="flex w-full justify-center md:flex-col md:w-5/6"
					onSubmit={e => fetchValidation(e)}
				>
					<input
						autoFocus={true}
						type="number"
						className="border-none outline-none w-2/5 bg-primary px-4 py-2 rounded-sm md:w-full"
						placeholder="Enter the phone number..."
						onChange={e => setNumber(e.target.value)}
					/>
					<button
						className="outline-none border border-danger font-bold font-raleway ml-4 px-12 py-2 rounded-sm bg-background text-primary transition duration-300 hover:bg-active hover:text-background md:ml-0 md:mt-4"
						onClick={fetchValidation}
					>
						Validate
					</button>
				</form>
				{res && (
					<div className="flex flex-col text-primary text-raleway mt-12 w-3/6 h-4/5  md:flex-col md:w-4/6 md:h-full md:mb-12">
						<table className="bg-white w-full text-primary mb-8 md:text-sm md:mx-2">
							<thead className="font-raleway uppercase tracking-wide">
								<tr>
									<th className="border text-left px-4 py-4">
										<span className="text-secondary">
											Information
										</span>
									</th>
									<th className="border text-left px-4 py-4">
										<span className="text-secondary">
											Result
										</span>
									</th>
								</tr>
							</thead>
							<tbody>
								<tr>
									<td className="border px-4 py-4">Valid</td>
									<td className="border px-4 py-4 capitalize">
										{JSON.stringify(res.valid)}
									</td>
								</tr>
								<tr>
									<td className="border px-4 py-4">
										Country
									</td>
									<td className="border px-4 py-4 capitalize">
										{res.country}
									</td>
								</tr>
								<tr>
									<td className="border px-4 py-4">
										Country Code
									</td>
									<td className="border px-4 py-4">
										{res['country-code3']}
									</td>
								</tr>
								{res['prefix-network'] && (
									<tr>
										<td className="border px-4 py-4">
											Prefix Network
										</td>
										<td className="border px-4 py-4">
											{res['prefix-network']}
										</td>
									</tr>
								)}
								<tr>
									<td className="border px-4 py-4">
										International Number
									</td>
									<td className="border px-4 py-4">
										{res['international-number']}
									</td>
								</tr>
								<tr>
									<td className="border px-4 py-4">
										Local Number
									</td>
									<td className="border px-4 py-4">
										{res['local-number']}
									</td>
								</tr>
								<tr>
									<td className="border px-4 py-4">
										International Calling Code
									</td>
									<td className="border px-4 py-4">
										{res['international-calling-code']}
									</td>
								</tr>
								<tr>
									<td className="border px-4 py-4">Type</td>
									<td className="border px-4 py-4">
										{res.type}
									</td>
								</tr>
							</tbody>
						</table>
					</div>
				)}
			</div>
			{res && (
				<div className="flex flex-col mt-4 justify-center">
					<p className="block mb-10 text-center text-primary text-xs">
						Made by RapidAPI DevRel Team -{' '}
						<a
							className="hover:text-active"
							href="https://github.com/RapidAPI/DevRel-Examples-External"
						>
							See more examples like this
						</a>
					</p>
				</div>
			)}
		</div>
	);
}

You can see that I have created a function, fetchValidation, to request the API. I have also created a piece of UI that is conditionally rendering on the screen based on the res state variable’ value.

Wrap Up

That’s it. We have successfully built an Phone Number Validation App using Phone Validate API. You can find the source code of this web app here.

In the end, it will look something like this:

Phone Number Validation Application built with Next.js and Phone Validate API

# app # phone-number # RapidAPI # validation

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