FISMA

What is it

Fisma is a 422b (br,min) **fi**nite **s**tate _ma_chine that is built on Generators. It features entry/exit actions, events, sending signals to transition to a specific state.

How to use

import { createMachine } from 'fisma';

const m = createMachine([
    'A',
    { type: 'B' },
    {
        type: 'C',
        // Add enter and exit 
        // action as a method
        // or array of actions
        enter() {},
        exit: [() => {}]
    },
    {
        type: 'D',
        on: {
            RESTART: 'A'
        }
    },
    {
        type: 'E',
        on: {
            RESTART: {
                target: 'A',
                actions: [ () => console.log('Running actions') ]
            }
        }
    }
]);

// getters
m.current; // A (The active state)
m.done; // false (is the machine running)

// Use `next` to go to the
// next state in array order
m.next();

m.current; // B

// `.subscribe()` returns a cleanup function
const unsub = m.subscribe((ctx) => console.log(ctx));
m.next(); // { type: 'B' }
m.next(); // { type: 'C' }
unsub();

// Pass a string with the
// name of the desired next state
m.next('A');

m.current; // A

m.next('D');
// Signal to the machine a specific
// state to transition to
m.send('RESTART');

m.current; // A

m.next('E');
m.send('RESTART'); // Running actions

m.destroy(); // kills machine
m.done; // true

Things to be aware of

• There isn't a .start(initialState) method. The initial state is always the first item in the states array.
• While actions are passed a "context" object, currently the context is the active state object and it is not safe to store or alter that information.
• ~~active and done might be confusing, active is for the name of the active state, done is the status of the machine itself.~~ active has been changed to current

To Do

• [ ] Give a proper "context" object for actions and listeners
• [ ] Accept a more complex "requested state" in the .next() method
• [ ] Review method and getter names, e.g. ~~active vs. current~~, next() vs. somethingElse()
• [ ] Should there be an initial getter
• [ ] Shave bytes