appadhoc/src/adhoc.js

AppAdhoc module for A/B testing

// Only three calls are public to user app:
//   init(adhoc_app_track_id)
//   generateClientId()
//   getExperimentFlags(client_id, callback)
//   incrementStat(client_id, stat, value)
//
//   @client_id: unique ID to identify a user, preferrably a UUID.

var protocol = "https:";
var ADHOC_GETFLAGS_HOST = 'experiment.appadhoc.com';
var ADHOC_GETFLAGS_PORT = '80';
var ADHOC_GETFLAGS_PATH = '/get_flags';
var ADHOC_TRACKING_HOST = 'tracker.appadhoc.com';
var ADHOC_TRACKING_PORT = '80';
var ADHOC_TRACKING_PATH = '/tracker';
var ADHOC_FORCEEXP_HOST = 'experiment.appadhoc.com';
var ADHOC_FORCEEXP_PORT = '80';
var ADHOC_FORCEEXP_PATH = '/force_clients';

var http = require("http");

//var cache = require("node-cache");

// Canonicalize Date.now().
if (!Date.now) {
	Date.now = function() {
	 	return new Date().getTime();
 	};
}

// Micro implementaiton of AJAX.
function AJAX(host, port, path, query, callback) {
	var request = http.request(
		{
		 	host: host,
		 	port: port,
		 	path: path,
		 	method: 'POST',
			headers: {
				'Content-Type' : 'application/json;charset=UTF-8'
			}
		},
		function(response) {
			if (callback == null) {
				return;
			}

			var reply = '';
			response.on('data', function(chunk) {
				reply += chunk;
			});
			response.on('end', function() {
				callback(reply);
			});
		}
	);
	request.write(JSON.stringify(query));
	request.end();
};

var adhoc = module.exports;

adhoc.opts = {};

adhoc.init = function(appKey) {
	adhoc.ak = appKey;  // ak as appKey
};

adhoc.generateClientId = function() {
	function s4() {
    return Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);
  }
  return s4() + s4() + '-' + s4() + '-' + s4() + '-' + s4() + '-' + s4() + s4() + s4();
};

adhoc.getExperimentFlags = function(client_id, callback) {
	var data = {
		app_key: adhoc.ak,
		event_type: 'GET_EXPERIMENT_FLAGS',
		summary: {},
		client_id: client_id,
		custom: adhoc.opts
	}

	AJAX(ADHOC_GETFLAGS_HOST, ADHOC_GETFLAGS_PORT, ADHOC_GETFLAGS_PATH, data, callback);
};

adhoc.incrementStat = function(client_id, stat, value) {
	var data = {
		app_key: adhoc.ak,
		client_id: client_id,
		summary: {},
		stats: [{
				key : stat,
				value : value,
				timestamp : Math.round(Date.now() / 1000)
			}]
	};

	AJAX(ADHOC_TRACKING_HOST, ADHOC_TRACKING_PORT, ADHOC_TRACKING_PATH, data, function(){});
};


adhoc.forceExperiment = function(client_id,qr_code){
	var data = {
		client_id: client_id,
		qr_code: qr_code
	};

	AJAX(ADHOC_FORCEEXP_HOST, ADHOC_FORCEEXP_PORT, ADHOC_FORCEEXP_PATH, data, function(){});
}


adhoc.setProperties = function(opts){
	adhoc.opts = opts;
}