A Quick Node.js Jumpstart | Hacker News Reader

A Quick Node.js Jumpstart

intridea.com

52 pointsrenaebair10 comments

You should be using coffeescript though, makes the javascript in the example look like:

  fs = require('fs')

  for i in [1..3]
    fs.readFile 'test.coffee', (err, data) ->
      console.log("#{i}. Finished reading file")
    console.log("#{i}. doing something important...")

And if you want to get rid of that "gotcha" (which is a javascript one, not a node.js one):

  fs = require('fs')

  for i in [1..3]
    do (i) ->
      fs.readFile 'test.coffee', (err, data) ->
        console.log("#{i}. Finished reading file")
    console.log("#{i}. doing something important...")

This will output the number you'd intuitively inside the file read callback function.

do you need to preprocess the coffescript somehow before node runs it, or will node run it directly?

You have to compile it.

http://jashkenas.github.com/coffee-script/

Not necessarily. The distributed `coffee` script will automatically compile before running the script. Plus it shows you coffeescript-friendly tracebacks on error.

Whether I manually compile it or it's automatically compiled it still has to be compiled which was the question I was responding to. Which is to say Node.js will not run CoffeeScript directly.

As someone who has read about node but never actually looked at any demo code, this was a pretty good example. Now I understand what all the fuss is about!

If folks have node questions, we would be happy to help - wompt is built on node.

http://wompt.com/chat/nodejs

what is a good way to share something like a db connection between modules?

One way might be with a closure that wraps the entire module though taking a more OO approach would probably be safer, such as initializing objects with the DB connection as an argument.

I think using require would do the trick. Something along the line like:

/* foo.js /

var date = new Date();

exports.Date = date;

/ bar.js /

var foo = require('./foo.js');

exports.Date = foo.Date;

/ foobar.js */

var foo = require('./foo.js');

var bar = require('./bar.js');

console.log(foo.Date);

console.log(bar.Date)

> console.log(foo.Date);

Sat, 09 Apr 2011 01:05:12 GMT

> console.log(bar.Date)

Sat, 09 Apr 2011 01:05:12 GMT

We are dealing with the same date variable between modules.

[edited. not a good place to share code. gist over github: https://gist.github.com/910994]

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