Archive

NodeJS

Yes, I’m getting very intoxicated with coffescript as I’m writing this yet another blog on coffeescript. It’s because coffeescript has made my life easier while I’m writing javascript whether applications or libraries or RIA. Here, I’m going to share some useful resources that might help everyone who are interested in learning coffeescript.

First, starting with what is coffeescript and an detailed overview blogged by krawaller, the writer has given a very good overview on coffeescript which I’m sure will help beginners. This article has referenced links that any new beginner can treat as a learning resource.

Second, coffeescript site. http://www.coffeescript.org. it has very good tutorials an online compiler and many more useful code snippets.
Third, a conversion tool js2coffee or coffee2js http://www.js2coffee.org

Enjoy! Coffee!

Advertisements

I have been using coffeescript lately a lot to build a javascript library. The experience so far has been great as far as the complex programming I’m doing instead of using javascript. Coffeescript does the conversion for my code. I’m using jquery with coffeescript which is really easy to use nothing complex at all.

Here’s how I do it

$ ->
  $(some_link_id).click () ->
    # do something

which translates to

$(function() {
  return $(some_link_id).click(function() {
    // do something
  });
});

If you are going to use underscore you can just use as you would in your javascript functions i.e

_.map () ->

Yeah it’s that simple.

The coffeescript author has a coffee port of underscore which you can use directly if you are interested.

Mostly I have enjoyed using the loops in coffeescript since I’m more familiar with ruby syntax. It follows kind of the same way as I would do in ruby for ‘for loop’ or if using ‘when’

show = console.log # I like doing this to print in console
for code of codes
  show code

Coffeescript has great deal of resource in it’s website www.coffeescript.org. It’s really simple if you have ruby background and even if you don’t it’s just that simple to understand. I’m enjoying writing 300 lines of coffeescript instead of writing 1000 lines of javascript when coding OO style programming which transforms in javascript prototypical programming.

I hope you’ll like coffeescript as much I do. Enjoy!

I have always appreciated the things you can achieve with javascript. The power of javascript has been shown over the years and there’re very few web sites which doesn’t use Javascript today. Although javascript is powerful and great but the syntax and debugging had never been so easy. Writing a object oriented javascript required skill and discipline and lots of patience. And those who are programming javascript kudos because you are all doing great work!

Javascript is an object oriented but a prototypical language where harnessing the power of prototypal inheritance is a little cumbersome. The jQuery library did help us all by taking care of the DOM but it always lacked the structured programming like OOP, it simply isn’t designed to help you organize your code outside of vanilla JavaScript. Then there is Prototype JS framework which  lets you write OOP style dynamic web applications and Moo4q by Ryan Florence also gives you the ability to write OOP style on top of jQuery.

Then in 2009 came Jeremy Ashkenas released Coffeescript, a programming language that transcompiles to Javascript. Writing applications and managing your code can never been easier because of the simplicity used in Coffeescript.  “The language adds syntactic sugar inspired by Ruby, Python and Haskell to enhance JavaScript’s brevity and readability, as well as adding more sophisticated features like array comprehension and pattern matching. CoffeeScript compiles predictably to JavaScript and programs can be written with less code (typically 1/3 fewer lines) with no effect on runtime performance“- [wikipedia].

Speaking of fewer lines of code and simplicity here’s an example of simple Person class in coffeescript

class Person
  constructor: (name) -> 
  @name = name

Defining constructors (functions that get invoked upon instantiation) is simple, just using function named constructor. This is akin to using Ruby’s initialize or Python’s __init__. Which compiles to javascript as this

var Person;

Person = (function() {

  function Person(name) {
    this.name = name;
  }

  return Person;

})();

By prefixing argument’s with @, CoffeeScript will automatically set the arguments as instance properties in the constructor. You can try playing with Coffeescript here. Coffeescript is website a great resource for learning.

Installing Coffeescript:

You can download and install nodejs and then use npm to install coffeescript in your environment with the following command:

 npm install -g coffeescript

You can then type coffee and it will invoke the interactive coffee. Or you can start writing your script in a *.coffee file and compile to js with following command and require in your html file for testing.

 coffee -c somefile.coffee

Then it will generate a samename.js file to require in your html. You can also direclty use coffee files in your html, I’ll show an example in later post.

%d bloggers like this: