node.js + Express code critique

Question

I'm learning Node. I'm working on a personal project that uses Node + Express + Node-MySQL + Generic-Pool (for MySQL pooling). I am new to the idea of module.exports and I'm still grokking it.

The following code works. However I want to organize my code in a way that is logical and optimal, and MVCish. I am wondering if those of you who have done this before could take a look at the following and let me know if this is the "right" way to structure things. (Yes I know this going to depend a lot on the developer. But at least knowing if there are obvious problems in my approach would be helpful.)

My folder structure looks roughly like this:

app.js
routes/
models/
base/

In my main app.js file I have...

var express = require( "express" ),
 mysql = require( "mysql" ),
 generic_pool = require ( "generic-pool" ),
 routes = require( "./routes" );
var app = module.exports = express(),
 pool = generic_pool.Pool({
 name: "mysql",
 create: function( cb ) {
 var db = mysql.createConnection( require( "./config/db" ) );
 db.connect();
 cb( null, db );
 },
 destroy: function( db ) {
 db.end();
 },
 });
app.configure(function(){
 app.set( "pool", pool );
 ...
});
routes( app );
app.listen(80, function());

Here is an example route/ file "stuff.js"

module.exports = function( app ){
 var model = require( "../models/stuff" );
 model.init( app );
 app.get( "/stuff", function( req, res ){
 model.get( function( result ){
 res.json( result );
 });
 });
};

Here is an example model/ file "stuff.js"

var db;
module.exports.init = function( app ){
 db = require( "../base/db" );
 db.init( app );
};
module.exports.get = function( cb ){
 var sql = "SELECT * FROM stuff";
 db.do( sql, false, cb );
};

And here is the base/db file

var pool;
module.exports.init = function( app ){
 pool = app.get( "pool" );
};
module.exports.do = function( sql, params, cb ){
 pool.acquire(function( err, db ){
 if (err) {
 // ...
 } else {
 db.query( sql, function( err, result ) {
 if ( err ) {
 // ...
 } else if ( typeof cb === "function" ) {
 cb( result );
 }
 });
 }
 pool.release( "db" );
 });
};

• toasted_flakes: what is the last line of app.js supposed to do? It lacks either an identifier to replace function(), or the actual body of the function (with the required arguments)

Answer 1

Your code looks fine.

However, you are not showing us much to review, definitely come back when there is more to review.

Some minor comments:

• Having your db connection config through ./config/db is good
• You probably want to throw an exception if ( typeof cb !== "function" ) instead of silently ignoring that
• The base/db code nests 4 levels of callback, you should look into queue management libraries for node.js