Define a state transition

var fsm = new IgeFSM();

// Define an "idle" state
fsm.defineState('idle', {
    enter: function (data, completeCallback) {
        console.log('entered idle state');
        completeCallback();
    },
    exit: function (data, completeCallback) {
        console.log('exited idle state');
        completeCallback();
    }
});

// Define a "moving" state
fsm.defineState('moving', {
    enter: function (data, completeCallback) {
        console.log('entered moving state');
        completeCallback();
    },
    exit: function (data, completeCallback) {
        console.log('exited moving state');
        completeCallback();
    }
});

// Define a transition between the two methods
fsm.defineTransition('idle', 'moving', function (data, callback) {
    // Check some data we were passed
    if (data === 'ok') {
        // Callback the listener and tell them there was no error
        // (first argument is an err flag, set to false for no error)
        callback(false);
    } else {
        // Callback and say there was an error by passing anything other
        // than false in the first argument
        callback('Some error string, or true or any data');
    }
});

// Now change states and cause it to fail
fsm.enterState('moving', 'notOk', function (err, data) {
    if (!err) {
        // There was no error, the state changed successfully
        console.log('State changed!', fsm.currentStateName());
    } else {
        // There was an error, the state did not change
        console.log('State did NOT change!', fsm.currentStateName());
    }
});

// Now change states and pass "ok" in the data to make it proceed
fsm.enterState('moving', 'ok', function (err, data) {
    if (!err) {
        // There was no error, the state changed successfully
        console.log('State changed!', fsm.currentStateName());
    } else {
        // There was an error, the state did not change
        console.log('State did NOT change!', fsm.currentStateName());
    }
});