Hello Node: How to transpile ActionScript for Node.js

by Josh Tynjala

Over the years, many developers have dreamed of using ActionScript on both the client and the server. Today, transpilers make it possible.

Previously, we learned how to transpile ActionScript for the web browser using Apache FlexJS™. The transpiler also enables ActionScript developers to write code that runs in the popular server-side JavaScript environment, Node.js.

The asnodec transpiler gives you full access to all Node.js APIs, and it's even possible to require NPM modules in ActionScript. Let's get started with a simple example.

Requirements

For this tutorial, you should install Apache FlexJS 0.7 or newer. Use the Apache Flex SDK Installer to download it.

Create a new project

1. Create a new folder for your project, and name it HelloNode.

2. Inside the new project, create a new folder named src. This is where our ActionScript classes will go.

3. Inside the src folder, create a file named HelloNode.as, and add the following code:

   package
   {
       public class HelloNode
       {
           public function HelloNode()
           {
               dns.lookup("localhost", null, dnsLookupCallback);
           }
           
           private function dnsLookupCallback(error:Object, address:String):void
           {
               console.log("The address of localhost is:", address);
           }
       }
   }
   

In this class, we're using Node's built-in dns module to look up an IP address.

Compile the project on the command line

Inside Apache FlexJS, the js/bin folder contains the ActionScript to JavaScript transpilers. Use the asnodec executable from this folder to transpile the HelloNode ActionScript class that you created above for Node.js.

asnodec src/HelloNode.as

This will produce a folder named bin containing js-debug and js-release folders. The js-debug folder contains JavaScript that is easy to read, and each class is loaded at runtime from a separate file. The js-release folder contains JavaScript that has been concatenated and minified.

The project should now contain the following files and folders:

Finally, let's try running our code with Node.js.

Run the project

Inside the js-debug folder, a file named index.js will be created as the entry point for your Node.js project. You can run this script using the node executable:

node bin/js-debug/index.js

You should see the following output in your console:

The address of localhost is: 127.0.0.1

What's Next?

This is just a simple example, but it gives you a glimpse of how developers can bring ActionScript server-side using Apache FlexJS and Node.js. By using an established ecosystem like Node.js, ActionScript developers can take advantage of all of the libraries published to NPM and join a large, vibrant community.