Recently, as part of an interview, I’ve been asked to make the following test (in Ruby):

1) Write a program, which asks the user for a URI/URL. The program should then go off, and fetch the webpage which is on that URI/URL. You’re not allowed to use any existing HTTP library (ie use a socket connection yourself). 2) Extend the program so that it loops, until the user enter’s a q (for the URI). 3) Extend the program so that it displays the headers, separated from the body. The headers should be separated in key – value pairs.

I’ve perceived this as a very simple test, which hardly requires OOP. I would use OOP if it would simplify the solution or when it would contribute to the re-use of components. As this was a test, it’s inherently a one-off, therefor no OOP in my opinion. The testers felt otherwise, so I rewrote my entire solution as follows.

# 
#  test.rb
#  degrunt.net
#  
#  Created by Tom de Grunt on 2008-05-21.
#  Copyright 2008 degrunt.net. All rights reserved.
# 

require 'uri'
require 'socket'

class Request

  include Socket::Constants

  def initialize( uri )
    begin
      @uri = URI.parse(uri)
    rescue URI::InvalidURIError => e
      raise "Please enter a valid URI" 
    end
  end

  def get
    socket = Socket.new( AF_INET, SOCK_STREAM, 0 )
    sockaddr = Socket.pack_sockaddr_in( 80, @uri.host )
    socket.connect( sockaddr )
    puts "Path: #{@uri.path || '/'}" 
    socket.write( "GET #{@uri.path || '/'} HTTP/1.0\r\n\r\n" )
    socket.read
  end

end

class Response

  def initialize( text )
    @text = text

    headers,@body = text.split(/\r\n\r\n/)
    headers = headers.split(/\r\n/)
    @status_line = headers.shift

    @headers = {}
    headers.each do |h|
      kv = h.split(/: /)
      @headers[kv[0]] = kv[1]
    end
  end

  def to_s
    result = "" 
    @headers.each do |k,v|
      result << "#{k} - #{v}\n" 
    end
    result << @body
    result
  end

end

# ========
# = Main =
# ========
begin
  puts "Please enter a URI (press Q to quit): " 
  uri_str = gets.strip.downcase
  unless uri_str == 'q'
    request = Request.new(uri_str)
    puts Response.new(request.get)
  end
rescue Exception => e
  puts "An error occurred: #{e}" 
end until uri_str == 'q'

Please share your thought on whether using OOP or not is a good idea and whether this test successfully tests one’s qualifications as a Ruby programmer.

On the other hand, I can tell you that I’ve written Ruby Extensions (three by now) using Ruby and C-code, I wrote a Radiant CMS plugin and wrote a couple of Ruby on Rails websites in my spare time. Professionally I work on an extensive Ruby on Rails project, which tests the boundaries of Rails (if I may say so).

sudo env ARCHFLAGS="-arch i386" gem install mysql -- --with-mysql-config=/opt/local/bin/mysql_config5

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Using Ruby on Rails with PostgreSQL is fairly simple, just install the ruby-postgres gem (gem install ruby-postgres) and have your database.yml represent something like:

development:
  adapter: postgresql
  database: my_development
  username: tdegrunt
  password:
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I’ve seen a couple of people suggesting the use of SWIG for creating these kind of extensions. I managed to compile the lot (Xerces, Xalan and XQilla) on Mac OSX (10.5 I might add), but using SWIG is beyond me (for now).

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Why do I do such things? Well, it’s part of my new pet project: Barcodes on Demand

Just came across this article by James W. Long. I think the statement he’s making is a very valuable one: Rails DOES need (and deserve) something better than Engines. Not that engines are bad, on the contrary, it’s a good step in the right direction. And no, Engines are not Evil.

Today I’ve created my very first Ruby Extension: WBXML4R. It’s a pretty simple extension, but I needed it very badly. It translates WAP Binary XML to XML and back, now if somebody can explain me how to wrap this in a gem I’d appreciate it. It uses wbxml2-0.9.2 available from here. If you want it drop me a mail.

The idea for it’s use is simple: I want to write a small Ruby server which will allow my P990 to sync with it.