Make your own API under 30 lines of code

Make your own API under 30 lines of code:

What is an API :

API stands for Application Programming Interface, which is a way for computer to talk to each other. APIs are just like website, except the UI part, it sends a request to a server and in return the server send a response .

Most APIs which we use are RESTFUL APIs, which means they follow a set of protocols/rules .

You all already know what URLs are, but APIs use URIs which stands for Uniform Resource Identifiers and they help to differentiate between data on a server.

There can me many more end points, like here in the above image the end point is /names.

There are many requests we can make to the server but most common ones are :

• GET: Reading the data.
• POST: Creating new data.
• PATCH: Updating new data.
• DELETE: Delete new data.

We have talked a lot about requesting, let’s talk about responses.

There is a thing called status code, which tells you about the response you got from the server. The responses can be divided into 3 levels.

• 2** Level (200-300) : Everything was fine, the response is fetched.
• 4** Level (400-500): There was something with our request, and the data is not fetched.
• 5** Level (500+): Server has failed to send the data.

Tech used to make an API:

I have used :

• JavaScript
• Node.JS
  • Express JS
• Replit (for deployment)

How to code an API:

This is going to be the most important part of the blog.

In this blog, I am going to make an API which returns the details of devices available at an electronic shop.

const products = [
    {
      name: 'iPhone 13',
      color: 'White',
      company: 'Apple'
    },
    {
      name: 'OnePlus 9',
      color: 'Blue',
      company: 'Oneplus'
    },
    {
      name: 'iPhone 12',
      color: 'Purple',
      company: 'Apple'
    }
]

Above is an object which we want the API to return.

By this point I am assuming that you all have initialized npm and installed express

npm init -y (Initializes NPM)

npm i express (Install Express)

Steps :

• Step 1: We have to import express in our project.
  • const express = require('express');
• Step 2 : Initialize a variable to call the main express() method.
  • const app = express();
• Step 3: Setup a port.
  • const PORT = 8080;
• Step 4: Use a middleware to parse the data into json.
  • app.use(express.json());
• Step 5: Add the Product Object to the file.

Till now the code looks like :

const express = require('express');
const app = express();
const PORT = 8080;
app.use(express.json());

const products = [
    {
      name: 'iPhone 13',
      color: 'White',
      company: 'Apple'
    },
    {
      name: 'OnePlus 9',
      color: 'Blue',
      company: 'Oneplus'
    },
    {
      name: 'iPhone 12',
      color: 'Purple',
      company: 'Apple'
    }
]

• Step 6: Make the server listen to our port / Start the server.
  • app.listen(PORT, () => console.log('server is 🟢'))
  • .listen() is a function, which starts the server and listens at the port assigned.

The code is 👇🏻

const express = require('express');
const app = express();
const PORT = 8080;
app.use(express.json());

const products = [
    {
      name: 'iPhone 13',
      color: 'White',
      company: 'Apple'
    },
    {
      name: 'OnePlus 9',
      color: 'Blue',
      company: 'Oneplus'
    },
    {
      name: 'iPhone 12',
      color: 'Purple',
      company: 'Apple'
    }
]

app.listen(PORT, () => console.log(`API 🟢`))

• Step 7: Make a function which handles GET Requests.

  • For this we have an in-built function called as .get(resource-link, callBack-Function)

    app.get('/products', (req, res) =>{
      res.status(200).send(products)
    })

• Here we are setting the resource-link as /products which means the user can get the data when he heads to www.xyz.com/products.

  • In the callback function, we have 2 parameters one is for request and another is for response.
  • Now as a server, when a user sends get request we have to respond to that and send data.
  • In agreement to the above point, we are sending the data using res (response parameter).
  • To send the data we use .send() method, and additionally we are also sending the status code using .status().

That’s It!! Your API is ready 🎉 and right now you can start your localhost server and head on to http://localhost:3000/products and you will be able to see the data.

How to deploy your API for FREE :

If we do not deploy our API, then what is the use of it?

Deployment in simple terms is making your API go live for 27×7, you can use it whenever you like.

By this point I am assuming that you all have a Replit Account

The steps are really simple :

• Step 1: Make a new project in replit account under the section of Node.JS
• Copy Paste the code you just wrote in your text editor / IDE.
• On the right hand side, you’ll see a package section.
  • Go inside it and download express.
• Run the code.
• You’ll see a URI on the right hand side of the screen like this 👇🏻

Now head on to the link and write /products or the any endpoint which you created and you’ll be able to see the data in json format.

from Tumblr https://generouspiratequeen.tumblr.com/post/663269550189576192