Stately, a Javascript State Machine

State machines are awesome, and are handy for modeling many real-world problems. If you're not sure what they do, then let me direct you to the lamson's project awesome introduction to state machines. Once you've read that, come back here to see how to apply that knowledge to Stately.

I've attempted to write the library in an engine-neutral style. vows tests are included, which require node.js to execute, but stately.js should be runnable in the browser as well.

Usage

Call Stately.machine with an object whose keys are the names of the different states modeled by the state machine. ALL CAPS is the convention that I use, and it ensures that the state names don't clash with the event names.

State machines start in the NEW state. Stately.machine does modify the object passed in, but it's safe to call multiple times to generate multiple state machines.

Here's the raw syntax for setting up the machine:

var machine = Stately.machine({
    NEW: {
        confirm: function () {
            // TODO: add your logic here
            return this.WATCHING;
        }
    },
    WATCHING: {
        check: function () {
            // TODO: add your logic here
            return this.CHECKING;
        },
        deactivate: function () {
            // TODO: add your logic here
            return this.SLEEPING;
        },
    },
    CHECKING: {
        response_ok: function () {
            // TODO: add your logic here
            return this.WATCHING;
        },
        response_error: function () {
            // TODO: add your logic here
            return this.WATCHING;
        },
        response_timeout: function () {
            // TODO: add your logic here
            return this.WATCHING;
        },
        response_too_many_errors: function () {
            // TODO: add your logic here
            return this.SLEEPING;
        },
    },
    SLEEPING: {
    });

Once it's running, use it as follows:

   machine.confirm()  // Transitions from NEW to WATCHING
   machine.check() // Transitions from WATCHING to CHECKING
   machine.response_ok() // Transitions from CHECKING to WATCHING
   machine.deactivate() // Transitions from WATCHING to SLEEPING