How to build a Food Nutrient App using Calorie Ninja API?

Mon Jan 17 2022

10 min read

You often need to find out what kind of nutrients a particular food contains. There any many calculators available on the internet. But you can build your own using an API from RapidAPI Hub.

Today, I am building a food nutrient app that will show the user quantity of different nutrients present in a food. 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 search for food nutrients. Go to RapidAPI Hub and create an account if you haven’t already and then search for “food nutrients” in the search section.

Deep dive
Learn more about how to use RapidAPI Hub.
Read more

You will see different search results related to food APIs. For this piece, I am using CalorieNinja 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 food-nutrient-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 food-nutrient-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:

jsx
export default function Home() {
return (
<div className="flex flex-col items-center relative min-h-screen">
<h2 className="font-raleway font-bold text-6xl text-primary pt-20 pb-6 md:text-3xl">
Food <span className="text-secondary">Nutrient</span> App
</h2>
<h3 className="text-secondary text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
Shows Different Nutrient Quantity in A Food
</h3>
</div>
);
}

It will create two headings for you with the text “Food Nutrient App” and “Shows Different Nutrient Quantity in A Food”. You can change it to anything you prefer.

→ STEP #2

Now let’s create an input field and a search button. The user will be able to type the food name in the input box and use the search button to get the nutrient details.

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

jsx
export default function Home() {
return (
<div className="flex flex-col items-center relative min-h-screen">
<h2 className="font-raleway font-bold text-6xl text-primary pt-20 pb-6 md:text-3xl">
Food <span className="text-secondary">Nutrient</span> App
</h2>
<h3 className="text-secondary text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
Shows Different Nutrient Quantity in A Food
</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 ">
<input
autoFocus={true}
type="text"
className="border-none outline-none w-2/5 bg-primary px-4 py-2 rounded-sm font-raleway md:w-full"
placeholder="Enter the name of any food..."
/>
<button className="outline-none border border-secondary text-bc font-bold font-raleway ml-4 px-12 py-2 rounded-sm bg-secondary text-primary transition duration-300 hover:bg-bc hover:text-primary md:ml-0 md:mt-4">
Search
</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 food name and the nutrient details that we will receive from the API. For this, copy-paste the following code in pages/index.js.

jsx
import {useState} from 'react';
export default function Home() {
return (
<div className="flex flex-col items-center relative min-h-screen">
<h2 className="font-raleway font-bold text-6xl text-primary pt-20 pb-6 md:text-3xl">
Food <span className="text-secondary">Nutrient</span> App
</h2>
<h3 className="text-secondary text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
Shows Different Nutrient Quantity in A Food
</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 ">
<input
autoFocus={true}
type="text"
className="border-none outline-none w-2/5 bg-primary px-4 py-2 rounded-sm font-raleway md:w-full"
placeholder="Enter the name of any food..."
onChange={e => setName(e.target.value)}
/>
<button className="outline-none border border-secondary text-bc font-bold font-raleway ml-4 px-12 py-2 rounded-sm bg-secondary text-primary transition duration-300 hover:bg-bc hover:text-primary md:ml-0 md:mt-4">
Search
</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 something in the input box.

→ 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 CalorieNinja 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.

Now create a file with the name nutrient.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/nutrient

Now copy the following code in this file:

js
import axios from 'axios';
export default function handler(req, res) {
if (req.method === 'GET') {
const options = {
method: 'GET',
url: 'https://calorieninjas.p.rapidapi.com/v1/nutrition',
params: {query: req.query.name},
headers: {
'x-rapidapi-host': 'calorieninjas.p.rapidapi.com',
'x-rapidapi-key': process.env.NEXT_PUBLIC_RAPIDAPI_KEY
}
};
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 CalorieNinja API on the server and returns the results to the user. It executes when the user makes an API call to the nutrient endpoint I mentioned above.

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

jsx
import {useState} from 'react';
import axios from 'axios';
export default function Home() {
const [name, setName] = useState('');
const [res, setRes] = useState(null);
/**
*
*
* Fetch nutrient information of a given food
*/
const fetchNutrients = async e => {
e.preventDefault();
try {
const res = await axios.get(`/api/nutrient`, {
params: {
name
}
});
setRes(res.data.items[0]);
} catch (err) {
console.log(err);
}
};
return (
<div className="flex flex-col items-center relative min-h-screen">
<h2 className="font-raleway font-bold text-6xl text-primary pt-20 pb-6 md:text-3xl">
Food <span className="text-secondary">Nutrient</span> App
</h2>
<h3 className="text-secondary text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
Shows Different Nutrient Quantity in A Food
</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 ">
<input
autoFocus={true}
type="text"
className="border-none outline-none w-2/5 bg-primary px-4 py-2 rounded-sm font-raleway md:w-full"
placeholder="Enter the name of any food..."
onChange={e => setName(e.target.value)}
/>
<button
className="outline-none border border-secondary text-bc font-bold font-raleway ml-4 px-12 py-2 rounded-sm bg-secondary text-primary transition duration-300 hover:bg-bc hover:text-primary md:ml-0 md:mt-4"
onClick={fetchNutrients}
>
Search
</button>
</form>
{res && (
<div className="flex flex-col text-primary text-sm 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 text-secondary">
<tr>
<th className="border border-x-0 text-left px-4 py-4">
Nutrient
</th>
<th className="border border-x-0 text-left px-4 py-4">
Quantity
</th>
</tr>
</thead>
<tbody className="text-primary">
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Calories
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.calories}
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Carbohydrates
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.carbohydrates_total_g} g
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Cholesterol
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.cholesterol_mg} mg
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Fat Saturated
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.fat_saturated_g} g
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Total Fat
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.fat_total_g} g
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Fiber
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.fiber_g} g
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Potassium
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.potassium_mg} mg
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Protein
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.protein_g} g
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Serving Size
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.serving_size_g} g
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Sodium
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.sodium_mg} mg
</th>
</tr>
<tr>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
Sugar
</th>
<th className="border border-x-0 border-secondary text-left px-4 py-4">
{res.sugar_g} g
</th>
</tr>
</tbody>
</table>
</div>
)}
</div>
<div className="flex flex-col mt-10 justify-end h-36 md:h-24">
<p className="block mb-10 text-center text-secondary 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, ​​fetchNutrients, 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 Food Nutrient App using CalorieNinjas API. You can find the source code of this web app here.

In the end, it will look something like this: