How to setup PersistenceJS database sync using NodeJS and MySQL

Today, Javascript is capable of access to back-end database, thanks to ORM (Object-Relational-Mapper). Day by day, ORM frameworks are mushrooming on the net. I was looking for a framework that build database seamlessly, pure and simple, and I found a Javascript ORM framework called PersistenceJS.  PersistenceJS has the front-end and back-end library that make it easy to implement ORM.

The purpose of this tutorial is to setup a database synchronization for your PersistenceJS client-side web application. I use todo example (by Jacob) for this experiment, and the backend is powered by MySQl, NodeJS and persistencejs sync plugin. In short, here are the prequisites:


Stack on the back-end side:

• Nodejs, ExpressJS (NodeJS extension), MySQL & PersistenceJS
• Or use appfog (use for this tutorial's example)

For front-end library:

• PersistenceJS, AngularJS
• Or download example from http://jacobmumm.com/demos/todo/ (use for this tutorial)

First, building app.js for NodeJS (server-side scripting)

Declare & Init PersistenceJS (refer to persistencejs example)

//persistence declaration

var persistence = require('persistencejs/lib/persistence').persistence;

var persistenceStore = require('persistencejs/lib/persistence.store.mysql');

var persistenceSync = require('persistencejs/lib/persistence.sync.server');

persistenceStore.config(persistence, "localhost", 3306, "todoappdb", "root", "yourpassword");

persistenceSync.config(persistence); 

//init sync

var session = persistenceStore.getSession();

var Todo = persistence.define('todo', {

content: 'TEXT',

done: 'BOOL'

});

Todo.enableSync(); //this create table with sync attribute

session.schemaSync(); //generate the table

Declare & Init Express


//nodejs module declaration
var express = require("express");
var app = express();

//init express
app.use(express.static(__dirname));
app.use(express.bodyParser());
app.get('/todoUpdates',  function(req, res) {
console.log(" - get /todoUpdates - ");
//var session = persistenceStore.getSession();
session.transaction(function(tx){
persistenceSync.pushUpdates(session, tx, Todo, req.query.since, function(updates) {
res.send(updates);
    });
});
});
app.post('/todoUpdates',  function(req, res) {
    console.log(" - post /todoUpdates - ");
//var session = persistenceStore.getSession();
session.transaction(function(tx){
persistenceSync.receiveUpdates(session, tx, Todo, req.body, function(result) {
res.send(result);
});
});
});

app.listen(3000);

A little change on the client-side, editing services.js from jacob todo example.

Add this line of code after you define your Todo object.

Todo.enableSync('/todoUpdates'); //this will create the table with sync attributes

In the persistence.flush() function, just call the todo.syncall function (to update the back-end).


persistence.flush(function(){
Todo.syncAll(
function(){alert('Your Callback Code');},
function(){alert("Your Sync Complete Code");},
function(){alert("Your Error Handling Code");}
);
});

Finally, start nodejs (e.g. "node app.js" in your command prompt) and navigate to 
http://localhost:3002/todo.html

The example of this tutorial can be found here 
http://azee01.ap01.aws.af.cm/todo.html

Download link here
https://github.com/anthonyzee/todo-example-sync