Tip: The remix buttons like the one above, allow you to try out the samples in this guide and make changes to them. Playing around with the code is probably the best way to get to grips with the framework.

Nact has only been tested to work on Node 8 and above. You can install nact in your project by invoking the following:

    npm install --save nact

Once installed, you need to import the start function, which starts and then returns the actor system.

const { start, dispatch, stop, spawnStateless } = require('nact');
const system = start();

Once you have a reference to the system, it is now possible to create our first actor. To create an actor you have to spawn it. As is traditional, let us create an actor which says hello when a message is sent to it. Since this actor doesn't require any state, we can use the simpler spawnStateless function.

const greeter = spawnStateless(
  system, // parent
  (msg, ctx) => console.log(`Hello ${msg.name}`), // function
  'greeter' // name
);

The first argument to spawnStateless is the parent, which is in this case the actor system. The hierarchy section will go into more detail about this.

The second argument to spawnStateless is a function which is invoked when a message is received.

The third argument to spawnStateless is the name of the actor, which in this case is 'greeter'. The name field is optional, and if omitted, the actor is automatically assigned a name by the system.

To communicate with the greeter, we need to dispatch a message to it informing it who we are:

dispatch(greeter, { name: 'Erlich Bachman' });

This should print Hello Erlich Bachman to the console.

To complete this example, we need to shutdown our system. We can do this by calling stop(system) The stop function also can be used to terminate an actor.

Note: Stateless actors can service multiple requests at the same time. Statelessness means that such actors do not have to cater for concurrency issues.