Introduction to Koa.js

Koa.js is an open-source node.js framework that can be used to develop web applications and APIs which is designed by the same community behind Express.

Koa is a very minimalistic modern server-side framework that runs on node.js which is lightweight and has more cool features compared to the other Node.js frameworks. Let’s just try to get a better understanding of all these features in Koa.js to become more aware of this modern framework.

Features of Koa.js

Like every other framework, Koa.js also has its own set of unique features which differentiate it from other available server-side frameworks.

• Koa is very lightweight and extensible.

koa provides a minimal interface for developing apps and APIs. You can always extend the framework by adding modules as per your requirements. Therefore, the Koa itself is a lightweight framework compared to other Node.js frameworks which causes to increase the performance and speed.

• Simplifies asynchronous programming & error handling.

As Koa supports generators and asynchronous functions like async-await, developers can get rid of callbacks which is something that we have to deal with in other Node.js frameworks like Express. Also, we can do error handling in Koa by using middleware effectively. Above all, Koa has a very refined set of methods that simplifies server-side programming.

• Enhanced HTTP request and response.

Unlike in other Node.js frameworks, Koa uses a single object which is called as ‘ctx’ (context object) which is an encapsulation of request and response objects.

• Developer-friendly

As Koa build is based on ES6 and supports modern JS syntax, it helps developers to create highly maintainable applications that can retain over a long period of time. Also if you already know a node.js framework like Express, then it’s very easy to grasp Koa very quickly. Overall Koa.js has been created to be better than Express.

• More robust and flexible.

Since Koa comes with a minimal set of features and yet extendible by added plugins and promotes modern JS syntax obviously ES6(ECMAScript 6), Koa can be identified as a robust, flexible, and high-performing framework which could be used when building web applications and APIs.

However, the inner workings of koa are a bit different than the other server-side frameworks.

Express is kind of a very complete framework that almost has everything built into it. (Because, when you're installing express, many dependencies get installed into your node-modules directory which you have no idea whereas, in koa, it’s up to you to decide which dependencies need to be installed. hence it's more lightweight than express.

Some common AddOn modules useful in Koa are;

• Koa Router — As Koa is a very minimalistic framework, it doesn’t come with an in-built router. Therefore, Koar-router which is a simple, yet robust router module can be used.
• Koa Body Parser — This module is needed when handling HTTP POST to pass the incoming data which comes in different formats like JSON, and text.

Alright, folks. I just gave you a little introduction or more of an overview understanding of Koa.js. It’s time for you to explore the Koa.js framework more and start building web applications and APIs using Koa to get a hands-on experience on what we’ve discussed above. Also, go check the official Koa documentation to explore commands and start trying out using Koa straightforward. Will see you again soon with another blog post. Until then, Happy coding! :)