A synchronous FSM that also triggers events when entering or leaving a state.
npm install synchronous-fsmRequire synchronous-fsm:
var FSM = require("synchronous-fsm");To initialize the statemachine we need to define states and transitions first:
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:
// Initialize in the "opened" state
var fsm = new FSM("opened", states);Trigger a transition:
// 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:
fsm.getCurrent(); // openedCan also be directly advanced to a given state:
fsm.advance("closed"); // will move the state machine to this stateThe stateMachine also triggers an "entry" and an "exit" event when entering and leaving a state. Simply add the handlers like for any other event:
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": [
...
]
};MIT