Kotlin Playground

Component that creates Kotlin-aware editors capable of running code from HTML block elements.

Examples

Installation

Use our CDN

Insert a <script> element into your page and specify what elements should be converted in its data-selector attribute.

<script src="https://unpkg.com/kotlin-playground@1" data-selector="code"></script>

Or, if you need to separate process of loading/conversion, omit the data-selector attribute and use a second <script> element like this:

<script src="https://unpkg.com/kotlin-playground@1"></script>

<script>
document.addEventListener('DOMContentLoaded', function() {
  KotlinPlayground('.code-blocks-selector');
});
</script>

You can also overwrite the server where the code will be sent to be compiled and analyzed (for example if you host a server instance that includes your own Kotlin libraries). For that you can set the data-server attibute, like this:

<script src="https://unpkg.com/kotlin-playground@1"
        data-selector="code" 
        data-server="https://my-kotlin-playground-server">
</script>

Fork & clone server repository.

Host your own instance

Install Kotlin-playground as dependency via NPM.

npm install kotlin-playground -S

And then just use it in your code.

// ES5
var playground = require('kotlin-playground');

document.addEventListener('DOMContentLoaded', function() {
  playground('code'); // attach to all <code> elements
});


// ES6
import playground from 'kotlin-playground';

document.addEventListener('DOMContentLoaded', () => {
  playground('code'); // attach to all <code> elements
});

Use from plugins

1. Kotlin Playground WordPress plugin — WordPress plugin which allows to embed interactive Kotlin playground to any post.
2. Kotlin Playground Coursera plugin — Allows embedding interactive Kotlin playground for coursera lessons.

Options

Kotlin Playground supports several events, and also server URL overwriting passing an additional options parameter on initialisation.

For example:

function onChange(code) {
  console.log("Editor code was changed:\n" + code);
}

function onTestPassed() {
   console.log("Tests passed!");
}

const options = {
  server: 'https://my-kotlin-playground-server',
  onChange: onChange(code),
  onTestPassed: onTestPassed,
  callback: callback(targetNode, mountNode)
};

playground('.selector', options)

Options description:

• server — string, server where the code will be sent to be compiled and analyzed
• offline — boolean, if true don't send any requests to server

Events description:

• onChange(code) — Fires every time the content of the editor is changed. Debounce time: 0.5s. code — current playground code.

• onTestPassed — Is called after all tests passed. Use for target platform junit.

• onTestFailed — Is called after all tests failed. Use for target platform junit.

• onCloseConsole — Is called after the console's closed.

• onOpenConsole — Is called after the console's opened.

• getJsCode(code) — Is called after compilation Kotlin to JS. Use for target platform js. code — converted JS code from Kotlin.

• callback(targetNode, mountNode) — Is called after playground's united. targetNode — node with plain text before component initialization. mountNode — new node with runnable editor.

• getInstance(instance) - Getting playground state API.

  instance.state      // playground attributes, dependencies and etc.
  instance.nodes      // playground NodeElement.
  instance.codemirror // editor specification.
  instance.execute()  // function for executing code snippet.
  instance.getCode()  // function for getting code from snippet.

Customizing editors

Use the following attributes on elements that are converted to editors to adjust their behavior.

• data-version: Target Kotlin compiler version:

   <code data-version="1.0.7">
   /*
   Your code here
   */
   </code>

• args: Command line arguments.

  <code args="1 2 3">
  /*
  Your code here
  */
  </code>

• data-target-platform: target platform: junit, canvas, js or java (default).

   <code data-target-platform="js">
    /*
    Your code here
    */
   </code>

• data-highlight-only: Read-only mode, with only highlighting. data-highlight-only="nocursor" - no focus on editor.

  <code data-highlight-only>
    /*
    Your code here
    */
  </code>

  Or, you can make only a part of code read-only by placing it between //sampleStart and //sampleEnd markers. If you don't need this just use attribute none-markers. For adding hidden files: put files between <textarea> tag with class hidden-dependency.

  <code>
  import cat.Cat
  
  fun main(args: Array<String>) {
  //sampleStart
      val cat = Cat("Kitty")
      println(cat.name)  
  //sampleEnd                 
  }
    <textarea class="hidden-dependency">
      package cat
      class Cat(val name: String)
    </textarea>
  </code>

  Also if you want to hide code snippet just set the attribute folded-button to false value.

• data-js-libs: By default component loads jQuery and makes it available to the code running in the editor. If you need any additional JS libraries, specify them as comma-separated list in this attribute.

  <code data-js-libs="https://my-awesome-js-lib/lib.min.js">
    /*
    Your code here
    */
   </code>

• auto-indent="true|false": Whether to use the context-sensitive indentation. Defaults to false.

• theme="idea|darcula|default": Editor IntelliJ IDEA themes.

• mode="kotlin|js|java|groovy|xml|c|shell|swift|obj-c": Different languages styles. Runnable snippets only with kotlin. Default to kotlin.

• data-min-compiler-version="1.0.7": Minimum target Kotlin compiler version

• data-autocomplete="true|false": Get completion on every key press. If false => Press ctrl-space to activate autocompletion. Defaults to false.

• highlight-on-fly="true|false": Errors and warnings check for each change in the editor. Defaults to false.

• indent="4": How many spaces a block should be indented. Defaults to 4.

• lines="true|false": Whether to show line numbers to the left of the editor. Defaults to false.

• from="5" to="10: Create a part of code. Example from line 5 to line 10.

• data-output-height="200": Set the iframe height in px in output. Use for target platform canvas.

• match-brackets="true|false"": Determines whether brackets are matched whenever the cursor is moved next to a bracket. Defaults to false.

Supported keyboard shortcuts

• Ctrl+Space — code completion
• Ctrl+F9/Cmd+R — execute snippet
• Ctrl+/ — comment code
• Ctrl+Alt+L/Cmd+Alt+L — format code
• Shift+Tab — decrease indent

Develop and contribute

1. Fork & clone our repository.
2. Install required dependencies yarn install.
3. yarn start to start local development server at http://localhost:9000.
4. yarn run build to create production bundles.