synchronous-fsm

Synchronous finite state machine
=============

A synchronous FSM that also triggers events when entering or leaving a state.

Installation
============

``bash
npm install synchronous-fsm
`

How to use
==========

Require synchronous-fsm:

`js
var FSM = require("synchronous-fsm");
`

To initialize the statemachine we need to define states and transitions first:

`js
var states = {
// It has an 'opened' state
"opened": [
// That accepts a 'pass' event that will execute the 'pass' action
["pass", function onPass(event) {
passCalled = event;
// And when done, it will transit to the 'closed' state
}, "closed"],

// It also has a 'action' event that doesn't trigger a transition
["coin", function onCoin(event) {
console.log("thanks");
}]
],

// It also has a 'closed' state
"closed": [
// That accepts a 'coin' event that will execute the 'coin' action
["coin", function coin(event) {
coinCalled = event;
// And when done, it will transit back to the 'opened' state
}, "opened"]
]
};
`

Then we can initialize the state machine in the desired state:

`js
// Initialize in the "opened" state
var fsm = new FSM("opened", states);
`

Trigger a transition:

`js
// Will transit to "closed", executing the onPass handler
fsm.event("pass");

// Could also transit with some data that will be received by the handler
fsm.event("pass", "6km/h", "8:30pm");
`

Get the current state:

`js
fsm.getCurrent(); // opened
`

Can also be directly advanced to a given state:

`js
fsm.advance("closed"); // will move the state machine to this state
`

The stateMachine also triggers an "entry" and an "exit" event when entering and leaving a state. Simply add the handlers like for any other event:

`js
var states = {
// It has an 'opened' state
"opened": [
...

// This handler will be called when entering the state
["entry", function onEntry(event) {
console.log("entering state...");
}],

// This handler will be called when leaving the state
["exit", function onExit(event) {
console.log("leaving state...");
}],
],

// It also has a 'closed' state
"closed": [
...
]
};
``

LICENSE
=======

MIT