How to structure nodejs code properly

Question

I've been playing with node.js for a while, and I've really come to appreciate how awesome it is. However, one thing I'm struggling to understand is how I should structure my code so that it is maintainable. Most tutorials I've seen on the internet have all the JS in one file, which is hardly a nice way to manage your code. I am aware there is no such thing in real-terms as a "class" in javascript, but is there a (standard) way for me to format my code for maintainability in the same way I'd structure a PHP project, for example?

Answer 1

I'd add that as far as maintainability goes, I believe the typical style of deeply-nesting callbacks using closures is the single greatest impediment to the understandability of Node programs, as well as being completely unnecessary.

For every:

a.doSomething(val, function(err,result){
  b.doSomethingElse(result,function(err,res){
    ...
  });
});

There is always a:

a.doSomething(val, onDoSomething);

function onDoSomething(err,res) {
  ...
}

My rule of thumb is: a new non-closure callback function is required for anything over three levels of nesting.

(Node.js really needs a style manual.)

Answer 2

Afaik you can use require to include your own js files (containing exported methods) using:

var req = require('./someJsFile');

Within someJsFile.js you can export methods like this:

exports.someMethod = function(){ /*...*/ };

And in your main file you can address such a method using req.someMethod()

So this way you can split up your code in different files, which you require from some central js file.

Here is an article explaining node.js require