How to build a Topic Keyword Generator App using Topic Tagging API?

So in this piece, I will build a topic generator app where you can paste your article and generate topics and keywords for it. 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 generate topics and keywords. Go to RapidAPI Hub and create an account if you haven’t already and then search for “topics generator api” in the search section.

You will see different search results related to topics and keywords API. For this piece, I am using Topic Tagging API.

To use this API, you need to subscribe to it first. You can do this by clicking on Subscribe to Test button.

Subscribe to Topic Tagging API

Once you click the button, you will be redirected to another page where different available subscription packages will be shown. Let’s go with the free one for now.

After all this, you will be redirected back to the original page. Here you will have a key x-rapidapi-key. Save it. It will be used later in the application.

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
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npx create-next-app -e with-tailwindcss topic-generator-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 topic-generator-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
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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">
				Topic <span className="text-secondary">Generator</span> App
			</h2>
			<h3 className="text-danger text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Automatically generate topics and keywords for articles and
				blogs
			</h3>
		</div>
	);
}

It will create two headings for you with the text “Topic Generator App” and “Automatically generate topics and keywords for articles and blogs”. You can change it to anything you prefer.

→ STEP #2

Now let’s create two text areas, one for user content and the other to display topics and keywords, and the generate button. For this, copy the following code and paste it in pages/index.js:

jsx
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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">
				Topic <span className="text-secondary">Generator</span> App
			</h2>
			<h3 className="text-danger text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Automatically generate topics and keywords for articles and
				blogs
			</h3>
			<div className="flex justify-between w-5/6 h-96 mt-8 md:flex-col md:items-center md:justify-start">
				<textarea
					type="text"
					className="border border-primary outline-none w-2/5 px-4 py-2 rounded-sm font-raleway md:w-full"
					placeholder="Write/paste any content..."
				/>
				<div className="flex items-center">
					<button className="h-1/6 outline-none border border-secondary font-bold font-raleway mx-12 px-12 rounded-sm bg-secondary text-primary transition duration-300 hover:bg-bc hover:text-black md:h-16 md:my-12">
						Generate
					</button>
				</div>
				<textarea
					type="text"
					className="border border-primary outline-none w-2/5  px-4 py-2 rounded-sm font-raleway md:w-full"
					placeholder="Topics and keywords will appear here..."
				/>
			</div>
		</div>
	);
}

This code is going to create two text areas and a button. I have also styled them a little bit using TailwindCSS.

→ STEP #3

Let’s create some states to store the user content and the topics that we will receive from the API. For this, copy-paste the following code in pages/index.js.

jsx
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import {useState} from 'react';
export default function Home() {
	const [content, setContent] = useState(
		`Computer science is the scientific and practical approach to computation and its applications. It is the systematic study of the feasibility, structure, expression, and mechanization of the methodical procedures (or algorithms) that underlie the acquisition, representation, processing, storage, communication of, and access to information, whether such information is encoded as bits in a computer memory or transcribed in genes and protein structures in a biological cell. An alternate, more succinct definition of computer science is the study of automating algorithmic processes that scale. A computer scientist specializes in the theory of computation and the design of computational systems.`
	);
	const [res, setRes] = useState('');
	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">
				Topic <span className="text-secondary">Generator</span> App
			</h2>
			<h3 className="text-danger text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Automatically generate topics and keywords for articles and
				blogs
			</h3>
			<div className="flex justify-between w-5/6 h-96 mt-8 md:flex-col md:items-center md:justify-start">
				<textarea
					type="text"
					className="border border-primary outline-none w-2/5 px-4 py-2 rounded-sm font-raleway md:w-full"
					placeholder="Write/paste any content..."
					value={content}
					onChange={e => setContent(e.target.value)}
				/>
				<div className="flex items-center">
					<button className="h-1/6 outline-none border border-secondary font-bold font-raleway mx-12 px-12 rounded-sm bg-secondary text-primary transition duration-300 hover:bg-bc hover:text-black md:h-16 md:my-12">
						Generate
					</button>
				</div>
				<textarea
					type="text"
					className="border border-primary outline-none w-2/5  px-4 py-2 rounded-sm font-raleway md:w-full"
					placeholder="Topics and keywords will appear here..."
					value={res}
				/>
			</div>
		</div>
	);
}

You can see that I have added an onChange event handler to set the state value as soon as the user writes something in the text area field. I am also setting the value of the content text area to content state variable to render the default value of content state there.

Moreover, I am setting the value of the text area that will show the topics and keywords to the state variable res.

→ STEP #4

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

sh
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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 Topic Tagging API. It is the value of x-rapidapi-key that you saved earlier.

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

sh
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npm install axios

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

js
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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 generate.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
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http://localhost:3000/api/generate

Now copy the following code in this file:

js
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import axios from 'axios';
export default async function handler(req, res) {
	if (req.method === 'GET') {
		var options = {
			method: 'GET',
			url: 'https://twinword-topic-tagging.p.rapidapi.com/generate/',
			params: {
				text: req.query.content
			},
			headers: {
				'x-rapidapi-host': 'twinword-topic-tagging.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);
				res.status(response.status);
			});
	} else {
		res.status(400);
	}
}

This code makes an API call to the Topic Tagging API on the server and returns the results to the user. It executes when the user makes an API call to the generate endpoint I mentioned above.

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

jsx
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import {useState} from 'react';
import axios from 'axios';
export default function Home() {
	const [content, setContent] = useState(
		`Computer science is the scientific and practical approach to computation and its applications. It is the systematic study of the feasibility, structure, expression, and mechanization of the methodical procedures (or algorithms) that underlie the acquisition, representation, processing, storage, communication of, and access to information, whether such information is encoded as bits in a computer memory or transcribed in genes and protein structures in a biological cell. An alternate, more succinct definition of computer science is the study of automating algorithmic processes that scale. A computer scientist specializes in the theory of computation and the design of computational systems.`
	);
	const [res, setRes] = useState('');
	const [btnText, setBtnText] = useState('Generate');
	/**
	 *
	 *
	 * Generate topics and keywords
	 */
	const generateTopicKeyword = async () => {
		try {
			setBtnText('Generating...');
			const response = await axios.get('/api/generate', {
				params: {content}
			});
			const {data} = response;
			const keywords = Object.keys(data.keyword).join(', ');
			const topics = Object.keys(data.topic).join(', ');
			const resString = `Keywords: ${keywords}. \n\nTopics: ${topics}.`;
			setRes(resString);
		} catch (err) {
			console.log(err);
		}
		setBtnText('Generate');
	};
	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">
				Topic <span className="text-secondary">Generator</span> App
			</h2>
			<h3 className="text-danger text-2xl font-raleway font-bold uppercase tracking-wide mb-12 md:text-base md:px-4 md:text-center">
				Automatically generate topics and keywords for articles and
				blogs
			</h3>
			<div className="flex justify-between w-5/6 h-96 mt-8 md:flex-col md:items-center md:justify-start">
				<textarea
					type="text"
					className="border border-primary outline-none w-2/5 px-4 py-2 rounded-sm font-raleway md:w-full"
					placeholder="Write/paste any content..."
					value={content}
					onChange={e => setContent(e.target.value)}
				/>
				<div className="flex items-center">
					<button
						className="h-1/6 outline-none border border-secondary font-bold font-raleway mx-12 px-12 rounded-sm bg-secondary text-primary transition duration-300 hover:bg-bc hover:text-black md:h-16 md:my-12"
						onClick={generateTopicKeyword}
					>
						{btnText}
					</button>
				</div>
				<textarea
					type="text"
					className="border border-primary outline-none w-2/5  px-4 py-2 rounded-sm font-raleway md:w-full"
					placeholder="Topics and keywords will appear here..."
					value={res}
				/>
			</div>
			<div className="flex flex-col mt-10 justify-end h-36 md:h-24">
				<p className="block mb-10 text-center text-primary text-xs">
					Made by RapidAPI DevRel Team -{' '}
					<a
						className="hover:text-secondary"
						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, generateTopicKeyword, for calling the API. It will get the topics and keywords from the API, manipulate them and then show it to the user.

Wrap Up

That’s it. We have successfully built a Topic Generator App using Topic Tagging API. You can find the source code here of this web app.

In the end, it will look something like this:

Topic Generator App built using Next.js and Topic Tagging API