npm install applicationcontext --save

var AppContext = require('applicationcontext');

AppContext.set("username","Jimmy Song");
console.log(AppContext.get("username"));

//Use Plain Object like this 
AppContext.set({
	session : {
		name : "user",
		expire : 3000
	},
	
	// do not name key that look like 'a.b.c', it's error
	"local.name" : "good"
});
console.log(AppContext.get("session.name")); // output : user
console.log(AppContext.get("local.name")); // output : undefined

// add event listener for some key
AppContext.on('session.name',function(value,message){
	// 'value' is stored value , and 'message' is extra information while the event is triggered
	console.log("the value is ",value);
	console.log("and extra message is ",message);
});

// emit event named 'session.name', and use extra message
AppContext.set('session.name','Freeman'); 
AppContext.emit('session.name','hi, there is extra information, just tell you the session.name value is changed');

// Remove the specified listener for 'session.name'
AppContext.off('session.name',listener);

// Remove all listener for 'session.name'
AppContext.off('session.name');