jwt-redis-session/lib/utils.js

JSON Web Token session middleware backed by Redis

var _ = require("lodash"),
	jwt = require("jsonwebtoken"),
	uuid = require("node-uuid");


var extendSession = function(session, data){
	_.reduce(data, function(memo, val, key){
		if(typeof val !== "function" && key !== "id")
			memo[key] = val;
		return memo;
	}, session);
};

var serializeSession = function(session){
	return _.reduce(session, function(memo, val, key){
		if(typeof val !== "function" && key !== "id")
			memo[key] = val;
		return memo;
	}, {});
};

// these are bound to the session
module.exports = function(options){

	var SessionUtils = function(){};

	_.extend(SessionUtils.prototype, {

		// create a new session and return the jwt
		create: function(claims, callback){
			if(typeof claims === "function" && !callback){
				callback = claims;
				claims = {};
			}
			var self = this,
				sid = uuid.v4();
			var token = jwt.sign(_.extend({ jti: sid }, claims || {}), options.secret, { algorithm: options.algorithm });
			options.client.setex(options.keyspace + sid, options.maxAge, JSON.stringify(serializeSession(self)), function(error){
				self.id = sid;
				callback(error, token);
			});
		},

		// update the TTL on a session
		touch: function(callback){
			if(!this.id){
				return process.nextTick(function(){
					callback(new Error("Invalid session ID"));
				});
			}
			options.client.expire(options.keyspace + this.id, options.maxAge, callback);
		},

		// update a session's data, update the ttl
		update: function(callback){
			if(!this.id){
				return process.nextTick(function(){
					callback(new Error("Invalid session ID"));
				});
			}
			options.client.setex(options.keyspace + this.id, options.maxAge, JSON.stringify(serializeSession(this)), callback);
		},

		// reload a session data from redis
		reload: function(callback){
			var self = this;
			if(!this.id){
				return process.nextTick(function(){
					callback(new Error("Invalid session ID"));
				});
			}

			options.client.get(options.keyspace + self.id, function(error, resp){
				if(error)
					return callback(error);
				try{
					resp = JSON.parse(resp);
				}catch(e){
					return callback(e);
				}
				extendSession(self, resp);
				callback();
			});
		},

		// destroy a session
		destroy: function(callback){
			if(!this.id){
				return process.nextTick(function(){
					callback(new Error("Invalid session ID"));
				});
			}
			options.client.del(options.keyspace + this.id, callback);
		},

		toJSON: function(){
			return serializeSession(this);
		}

	});

	return SessionUtils;
};