Book Image

Kotlin Blueprints

By : Ashish Belagali, Akshay Chordiya, Hardik Trivedi
Book Image

Kotlin Blueprints

By: Ashish Belagali, Akshay Chordiya, Hardik Trivedi

Overview of this book

Kotlin is a powerful language that has applications in a wide variety of fields. It is a concise, safe, interoperable, and tool-friendly language. The Android team has also announced first-class support for Kotlin, which is an added boost to the language. Kotlin’s growth is fueled through carefully designed business and technology benefits. The collection of projects demonstrates the versatility of the language and enables you to build standalone applications on your own. You’ll build comprehensive applications using the various features of Kotlin. Scale, performance, and high availability lie at the heart of the projects, and the lessons learned throughout this book. You’ll learn how to build a social media aggregator app that will help you efficiently track various feeds, develop a geospatial webservice with Kotlin and Spring Boot, build responsive web applications with Kotlin, build a REST API for a news feed reader, and build a server-side chat application with Kotlin. It also covers the various libraries and frameworks used in the projects. Through the course of building applications, you’ll not only get to grips with the various features of Kotlin, but you’ll also discover how to design and prototype professional-grade applications.
Table of Contents (16 chapters)
Title Page
About the Authors
About the Reviewer
Customer Feedback

Interoperability with JavaScript

After all the hard work we did to develop Kotlin code, what if we have a very crucial code well written, well tested, but written in JavaScript. Are we going to convert it into Kotlin? No. The way Kotlin code can interoperate with Java, Kotlin for JavaScript is interoperable with JavaScript. This means JavaScript can call Kotlin code and Kotlin can call JavaScript code.

We have covered this as well. Kotlin does not have a Date class that can accept a date in UTC format, but JavaScript has. We will format our dates in JavaScript and Kotlin will call those functions.

We wrote three functions in our index.html file just inside a <script> tag and preceding the Kotlin <script> tags. The sequence does matter here! Consider the following code snippet:

      window.getShortDate = function(longDate) {
        var options={month:'long', day:'numeric'};
        return new Date(longDate*1000).toLocaleDateString('en-