Write better Android apps faster with Kotlin.
10 best kotlin web frameworks
Kotlin is a modern statically typed programming language that will boost your productivity and increase your developer happiness. Many apps are already built with Kotlin—from the hottest startups to Fortune companies. Learn how Kotlin has helped their teams become more productive and write higher quality apps.
Kotlin helped Zomato reduce the number of lines of code in their app significantly, and it has also helped them find important defects in their app at compile time. Watch Zomato's Rahul, Vice President, Product Management, and Prateek Sharma, Android developer, talk about how Zomato started adopting Kotlin and about how they now use it for all new feature releases.
Kotlin is a free and open source project under the Apache 2. The code for the project is developed openly on GitHub primarily by the team employed at JetBrains, with contributions from Google and others. Our choice of Kotlin reaffirms our commitment to an open developer ecosystem as we evolve and grow the Android platform, and we are excited to see the language evolve. Overview Get Started Developer Stories. Google is committed to advancing racial equity for Black communities.
See how. Android Developers. Get started. Expressive and concise Kotlin's modern language features allow you to focus on expressing your ideas and write less boilerplate code. Learn more. Safer code Improve your app quality. Structured concurrency Kotlin coroutines streamline asynchronous programming, making common tasks like network calls and database updates simple and performant. Kotlin for Android Java developers If you already know Java, our interop guides and documentation can help you get started.
Start course. After taking the Bootcamp, this course will show you Android Kotlin programming concepts and how to build a variety of apps. Go beyond the basics.Write the business logic for your iOS and Android apps with less time and effort — using nothing but Kotlin. Kotlin's philosophy is that you don't have to migrate the entire application. Start with a single module or feature, see how it goes, and then gradually move other parts as you see fit. Use the Kotlin code you have already written, and modify it to be compatible with iOS.
Its appearance, behavior, and performance all remain native. Go cross-platform without introducing any new languages to your codebase. Quizlet is a product that helps people practice and master whatever they're trying to learn. Using Kotlin Multiplatform lets us focus on innovating in learning, instead of spending time rewriting the same code for each platform.
MPP works much better for us than our previous attempts at sharing code, because it treats each platform as a first-class target, rather than relying on brittle workarounds or bridge layers. A set of modern Kotlin Common libraries for full-stack development.
State utility library to facilitate state management in Kotlin Multiplatform. Collection of small Kotlin Multiplatform libraries. Library for saving simple key-value data. Open-source library providing encrypted key-value storage. Bluetooth library for iOS and Android. Share your feedback on Twitter or let us know when you build something cool! Seamless integration with existing codebases 1 An SDK, not a framework Kotlin's philosophy is that you don't have to migrate the entire application.
Common expect fun String.TornadoFX - Build JavaFX UI's with Kotlin Programming Language
Android actual fun String. Teams that use Kotlin Mobile Multiplatform in production. Quizlet Quizlet is a product that helps people practice and master whatever they're trying to learn. Ankush Gupta, Senior Software Engineer. All pieces of the application are implemented in Kotlin. Droidcon Kotlin Multiplatform app for Droidcon Events.
Korlibs A set of modern Kotlin Common libraries for full-stack development Source. Stately State utility library to facilitate state management in Kotlin Multiplatform Source. Splitties Collection of small Kotlin Multiplatform libraries Source. Multiplatform settings Library for saving simple key-value data Source.
Kissme Open-source library providing encrypted key-value storage Source. Try this Kotlin flavor. Interactive hands-on.What this means, is that we don't have to reinvent the wheel or spend ages rewriting existing code from scratch, rather we can continue building things on top of what we already have and improve our efficiency at the same time.
When it comes to UI development, Kotlin suggests the same principle, e.
The feasible use-cases of Kotlin are growing, so the question arises: how should you implement UI on each platform? On mobile it's easy, both Android and iOS have a rich ecosystem of design guidelines and widget systems to implement them. Today we are going to take a look at another platform that we are interacting with quite often: desktop.
As we are transitioning to a "web first" and "mobile first" world, many desktop applications basically got implemented as a webpage, pre-packaged with a browser engine which approach has its own issues. Getting started with TornadoFX is very simple.
All you have to do is defining a dependency on no. For now, TornadoFX only supports Java8, so you should explicitly tell the Kotlin compiler to target 1. Using Gradle it would look like this:. Coming from e.
Connected Applications with Kotlin
There are Views, there is an Application, and if you have ever used the Anko Layout DSLyou'll find a resemblance to how we defined the root variable. By extending class TornadoApp : App MainView::classTornadoFX takes care of a lot of things for us, but it is also providing ways to customize our application. We can access its properties by overriding the start method in our App.
The scene takes care of placing and rendering your widgets on the screen. The list of built-in JavaFX controls is extensive, so I'm not going to cover all of them. But you will find all kinds of basic controls like labels, text fields, buttons, progress bars, etc. To give you a taste how they look like, here is a screenshot of some of them:.
One of the grunt works of UI development is placing the controls of our application on screen in various layouts, pixel perfect. It is basically syntactic sugar for making UI programming more ergonomic.
We have already seen this DSL in action in the Hello World example when we defined the root variable. The basic concept is to wrap definition of UI controls inside a layout DSL, so the end result will be concise and very easy to read. This concept scales really well, especially when you are combining it with one more abstraction provided by TornadoFX: View or Fragment they are basically the same abstraction, it's just Views are singletons and Fragments may have multiple instances.
The code above could be encapsulated into e. The default look and feel of the controls is a good baseline on each OS macOS, Linux, Windowsbut it's reasonable to expect that you want to apply your own brand identity to your application. In JavaFX there are two fundamental ways of achieving that:.
Let's see some examples.
This is how would you make the labels bold in the login form, by changing its font property. Of course, you don't have to inline the CSS rules inside your layout code, rather you can write them in type-safe Kotlin and apply them by calling addClass on your controls. So far so good, now we have the basic building blocks to make user interfaces for desktop applications. When we are working on real-world applications though, there are a couple of questions that we usually have to answer:.
Well, TornadoFX comes with "batteries included" opinionated ways of implementing things but doesn't force you to use any of them. Later on, I'll show you some of these features.In the wonderful world of Kotlinlibraries and frameworks are often released that are adapted on top of existing java frameworks.
In this blog post, I will be going through a very basic application that demonstrates the usefulness of TornadoFX and event-driven UIs using a traffic light system. Setting up a TornadoFX application is pretty straight forward. And, although I will not be going through that in this blog, by following the guide created by Edvin Syseit can be done easily. In my application, I have arranged the structure of the application into a typical MVC pattern as seen below.
The vbox is a vertical box container that positions new elements below previous elements. Below I have demonstrated the in-line styling that can be used such as spacing or alignment and also the external styling by adding a class on an element.
This behaves exactly like most HTML based frameworks by allowing the inline style to override the external class. In the TrafficLight class, we listen for TrafficLightEvent s, fired when the user presses one of the buttons.
Then we call the TrafficLightController to get the updated information used to set the text and background properties of the view by setting the state equal to the colour from the TrafficLightEvent event.
So, while the TrafficLight view listens for the events, we need something to fire the events, this is where the EventButton comes in:.
The coloured event buttons just inherit this class and fire their respective colours to the UI when clicked:. As you can see this is a very basic application, but it does demonstrate the usefulness of using an event-driven UI.
A New JavaFX App Framework for Kotlin — TornadoFX
For each of the first 12 days of December we will be giving away a free Kotlin insight. Discover something new about Kotlin by seeing what's behind each door. User Interface First, we need to get an overview of the application. Kotlin Advent Calendar.Unlike other Java and Kotlin web frameworks, Javalin has very few concepts that you need to learn. You never extend classes and you rarely implement interfaces. Javalin is just a few thousand lines of code on top of Jetty, and its performance is equivalent to raw Jetty code.
Due to its size, it's very easy to reason about the source code. Other Java and Kotlin web frameworks usually offer separate version for each language. Javalin is being developed with interoperability in mind, so apps are built the same way in both Java and Kotlin.
Javalin is designed to be simple and blocking, as this is the easiest programming model to reason about. However, if you set a Future as a result, Javalin switches into asynchronous mode. Visit our educators page if you're teaching web programming and looking for a web framework which will get out of your way and let you focus on the core concepts of your curriculum.
Javalin takes the best concepts from these two frameworks. Are you using Javalin? Let us know! Check out our current survey results Spring to learn more about how people use Javalin. A simple web framework for Java and Kotlin Java Kotlin import io. Show me the docs Show me tutorials. Why Javalin? Simple Unlike other Java and Kotlin web frameworks, Javalin has very few concepts that you need to learn. Lightweight Javalin is just a few thousand lines of code on top of Jetty, and its performance is equivalent to raw Jetty code.Utilizes language features like coroutinestype-safe builders and operator overloading to ease game development.
Extends a robust multi-platform game framework with highly modular and minimally opinionated Kotlin utilities. Supports other platforms through third-party libraries. Our main goals are usability and stability. Comprehensive test suites are written for every KTX feature. Each module is documented by a guide with a list of its features and extensions, as well as API usage examples. We are open to contributions.
Web Firm Framework
Toggle navigation. Kotlin meets LibGDX. Written in Kotlin Utilizes language features like coroutinestype-safe builders and operator overloading to ease game development.
Based on LibGDX Extends a robust multi-platform game framework with highly modular and minimally opinionated Kotlin utilities. Safe Our main goals are usability and stability. Well documented Each module is documented by a guide with a list of its features and extensions, as well as API usage examples.
KTX modules. Gradle Maven Module ktx-actors ktx-app ktx-ashley ktx-assets ktx-assets-async ktx-async ktx-box2d ktx-collections ktx-freetype ktx-freetype-async ktx-graphics ktx-i18n ktx-inject ktx-json ktx-log ktx-math ktx-preferences ktx-scene2d ktx-style ktx-tiled ktx-vis ktx-vis-style. Sources Releases Issues. Desktop Sources Made in under 40 hours.
Won the BialJam competition. Can you outlast the horde? Clear the neighbourhood out of filthy wrongdoers! Won the third price on the East Games United game jam. Eat smaller fish, grow bigger, repeat.Comment 6. A View contains the root node of the UI as well as the view logic. Controllers contain the business logic.
Elegant async support ensures that long running tasks run in a background thread and that the result is applied on the UI thread. TornadoFX does not have any visual components. While such frameworks are great for some types of applications, they often make you carry baggage you don't need.
They also add to the learning curve.
You can learn TornadoFX in an afternoon and be instantly productive because you are using your existing JavaFX knowledge on top of a very light framework that doesn't force you into a lot of new patterns. The principal design goal is to provide just what you need, without getting in the way.
You can clone the example application repository on GitHub to get a basic skeleton up and running quickly. Head over to the Wiki for complete Documentation and more usage examples.
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Here are some code samples to give you a feel for the framework. Enjoy JavaFX and Kotlin. Like This Article? DZone Article. Free DZone Refcard. Opinions expressed by DZone contributors are their own. Java Partner Resources.