Command line YQL google searcher on FSM pattern. Test of npm module "automata".

gistfile1.js

var automata = require('automata')
	, yql = require('yql')
	, readline = require('readline')
;

automata.registerFSM({
	name : "Test",
	logic : TestLogic,
	state : [
		{ name : 'idle',   onEnter : 'idle', initial : true },
		{ name : 'read',   onEnter : 'read'    },
		{ name : 'fetch',  onEnter : 'fetch'   },
		{ name : 'render', onEnter : 'render'  },
	],
	transition : [
		{ event : 'run',         from : 'idle',   to : 'read'   },
		{ event : 'userrequest', from : 'read',   to : 'fetch',  onPostGuard : 'userrequest_postGuard' },
		{ event : 'fetched',     from : 'fetch',  to : 'render' },
		{ event : 'rendered',    from : 'render', to : 'read'   },
		{ event : 'error',       from : 'fetch',  to : 'read'   },
	]
});

function TestLogic () {
	this.reader = readline.createInterface(process.stdin, process.stdout);
}

TestLogic.prototype.idle = function (session, state, transition, msg) {
}

TestLogic.prototype.read = function (session, state, transition, msg) {
	this.reader.question('Search: ', function (answer) {
		session.dispatch({msgId : 'userrequest', input:answer});
	});
}

TestLogic.prototype.fetch = function (session, state, transition, msg) {
	yql.exec('select titleNoFormatting from google.search where q = @keywords', function (res) {
		if(res.query.results) {
			session.dispatch({ msgId:'fetched', data : res.query.results });
		} else {
			session.dispatch({ msgId:'error'});
		}
	}, {keywords: msg.input});
}

TestLogic.prototype.render = function (session, state, transition, msg) {
	var i
		, results = msg.data.results
	;
	for(i = 0; i < results.length; i++) {
		console.log(results[i].titleNoFormatting);
	}
	session.dispatch({ msgId:'rendered'});
}

TestLogic.prototype.userrequest_postGuard = function (session, state, transition, msg) {
	if(msg.input === '') {
		throw 'Empty message';
	}
}

var session = automata.createSession('Test');
var logic = session.logic;
session.dispatch({msgId: 'run'});