Technorati Tags: agile, bsw2010, software craftsmanship

It has been my first Barcamp, so I though it was necessary to present something, and I decided to assemble a little introduction to Tdd coding for Iphone.

Here there is the video of my presentation:

AgileCamp – iPhone agile DEV (di Giordano Scalzo) from Sketchin on Vimeo.

Technorati Tags: barcamp, bdd, iphone

After the launch of http://katacasts.com/, this kind of practice has begun to spread around the world.

As far as I know, that was one of the firsts meeting held in Italy and it has been exciting (and a little scaring) to be one of the performer.

The simple problem to solve was the StringCalculator kata, proposed by Roy Osherove as simple exercise to repeat to assimilate Tdd.

Luca Marrocco performed the kata in Ruby, Raffaele Salmaso a Python version, the benevolent dictator of Xpug Milano a backup kata in Erlang, and yours truly a Scala version.

Below the live recording of my session, with errors, mistakes and pauses made during the execution:

StringCalculator in Scala Kata live at Xpug Milano from giordano scalzo on Vimeo.

Any kind of suggestion about the solution, the process, the way I performed are absolutely welcome.

Technorati Tags: bdd, scala, xpug

I could admit I didn’t know very well Bdd, but following the good old advice “teach to learn“, I got a triple win:
I taught something new to Xpug guys, I learned a lot of new things and I improved my presentation skill.

Moreover, after a couple of hours after I put online my slides, the Slideshare team promoted my presentation in home page as features presentation: what a great result for a weekend presentation hack!

Technorati Tags: bdd, presentation, xpug

See you, there!

Technorati Tags: agile, iad09

I started to read with great expectatives: most of authors are well known in Project Management world, and the format is very attractive.
Neverthless I found it too high level and, in some part, too superficial for my taste: I cought myself thinking “… and so?” too often.

In conclusion, I suggest this books only for novice project managers, otherwise a book as “Manage It!” by Johanna Rothman is more suitable.

Technorati Tags: book, project_management, review

It all started waiting for a kid’s karate lesson, and now it’s a well know practice to become a better developer.

Basicly a code kata is a small problem to be resolved without any pressure and requests, but to play with different techniques or programming language.

Another interesting point of view considers a code kata as a training for muscles of memory, focusing on repetitions, memorizations of decisions and keyboard shortcuts; the point is: if I get trained to do design decisions at subconscious level, when I’ll met similar problems I’ll be very productive, doing the right decision without any logical think.
Amazing, isn’t it?

The main argument of last Milan Xpug meeting was the Birthday Greetings Kata, a workshop Matteo Vaccari will submit to next Xp Days Benelux 2009.
Unfortunately I couldn’t be present, but I implemented the kata on my own, using Ruby instead of Java.

I enjoyed it very much, and I start thinking to try it still a couple of times and then screencasting it: I’m far behind this level, but review my actions can help me get better.

$:.unshift File.join(File.dirname(__FILE__), *%w[.. lib])
require 'rumbster'
require 'message_observers'
require 'net/smtp'
require 'gserver'
require 'birthday_service'
require 'employee_repository'

describe "Greetings Service" do
	NON_STANDARD_PORT = 10015
	def send_message(to, message)
    		Net::SMTP.start('localhost', NON_STANDARD_PORT) do |smtp|
      			smtp.send_message message, 'your@mail.address', to
    		end
	end
	before :each do
	 	@rumbster =  Rumbster.new(NON_STANDARD_PORT)
   		@message_observer = MailMessageObserver.new
		@rumbster.add_observer @message_observer
		@rumbster.start

		@birthdayService = BirthdayService.new("localhost", NON_STANDARD_PORT);
	end
	after :each do
		@rumbster.stop
	end
	context "with a file with one person born today" do
		before :each do
			@birthdayService.send_greetings EmployeeRepository.new("employee_data.txt"), "2008/10/08"
		end

		it "should send one email" do
			@message_observer.messages.size.should == 1
		end

		it "should send correct message" do
			@message_observer.messages.first.subject.should == "Happy Birthday!"
			@message_observer.messages.first.body.chomp.should == "Happy Birthday, dear John!"
			@message_observer.messages.first.to.should == ["john.doe@foobar.com"]
		end
	end

end

$:.unshift File.join(File.dirname(__FILE__), *%w[.. lib])
require "employee_repository"

describe "EmployeeRepository" do
	it "should read Employees from a file" do
		repository = EmployeeRepository.new "employee_data.txt"
	end

	it "should have a well know size" do
		repository = EmployeeRepository.new "employee_data.txt"
		repository.size.should == 3
	end
	it "should return first employee" do
		repository = EmployeeRepository.new "employee_data.txt"
		expected_employee = Employee.new("Doe, John, 1982/10/08, john.doe@foobar.com")
		repository.first.should == expected_employee
	end
	it "should return employees born an a given date" do
		repository = EmployeeRepository.new "employee_data.txt"
		expected_employee = Employee.new("Doe, John, 1982/10/08, john.doe@foobar.com")
		repository.born_on('2008/10/08').first.should == expected_employee
	end
end

$:.unshift File.join(File.dirname(__FILE__), *%w[.. lib])
require "message"
require "employee"

describe "Message" do
	before :each do
		@message = Message.new Employee.new("Doe, John, 1982/10/08, john.doe@foobar.com")
	end

	it "should have employee's email as destination" do
		@message.to.should == "john.doe@foobar.com"
	end
	it "should construct a complete body" do
		@message.body.should == "To: john.doe@foobar.com\nSubject: Happy Birthday!\n\nHappy Birthday, dear John!"
	end
end

require "message"

class BirthdayService
	def initialize(host, port)
		@host = host
		@port = port
	end
	def send_greetings(employees, date)
		employees.born_on(date).each do |employee|
			send_message(Message.new employee)
		end
	end
	def send_message(message)
    		Net::SMTP.start(@host, @port) do |smtp|
      			smtp.send_message message.body, 'your@mail.address', message.to
    		end
	end
end

class Employee
	attr_reader :firstname
	attr_reader :lastname
	attr_reader :birthdate
	attr_reader :email
	def initialize(args)
		tokens = args.split(',').map { |e| e.strip }
		@firstname = tokens[1]
		@lastname = tokens[0]
		@birthdate = tokens[2]
		@email = tokens[3]
	end

	def ==(other)
		other.instance_of?(self.class) &&
			@firstname == other.firstname &&
			@lastname == other.lastname &&
			@birthdate == other.birthdate &&
			@email == other.email
	end
end

require 'employee'

class String
	def same_day?(other)
		date1 = split('/')
		date2 = other.split('/')
		date1[1] == date2[1] && date1[2] == date2[2]
	end
end

class EmployeeRepository
	private
	def skip_header
		@employees.shift
	end

	public
	def initialize(employees_filename)
		@employees = []
		File.open(employees_filename).each_line do |line|
			@employees << Employee.new(line)
		end
		skip_header
	end

	def size
		@employees.size
	end

	def first
		@employees.first
	end

	def born_on(current_date)
		@employees.find_all { |e| e.birthdate.same_day?(current_date) }
	end
end

class Message
	def initialize(employee)
		@employee = employee
	end
	def to
		@employee.email
	end
	def body
		["To: #{to}",
		"Subject: Happy Birthday!",
		"",
		"Happy Birthday, dear #{@employee.firstname}!"].join("\n")
	end
end

Interesting I wrote more specs code than production code.

I do like I didn't used any IF, but I don't like to open String to model date and the use of split to tokenize things: I'll focus on thant in next attempt!

Technorati Tags: kata, ruby

Technorati Tags: SCTAGS2009

I’m on my way to become a better developer, and Clean Code wristband is a sign of my commit.
After a small donation, today I got mine:

Clean Code Green Wristband

I’ve to admit I don’t feel I deserve it: the current project I’m working on is a doomed legacy system and the tempations to write dirt code are very appealing , but wearing it should help me to resist.

“Manage Your Project Portfolio” is the last of an virtual trilogy devoted to improve the art of Project Management and to implante the seeds for a Pragmatic Project Management craft; it could be considered as a long appendix to Manage It, as long it expands one of its final chapter.

This book is a must read for everyone involved in IT world, from junior developer ’till C-level executive.
As usual, Johanna Rothman uses a very simple language and she provides a lot of exahustive examples so that everyone can understand the goals and the principles behind a project portfolio management.

If I had to choose only one chapter, maybe I’ll choose the sixth, about collaboration, obstacles and human behaviour during projects evolution, beacuse, usually, people are the problem and the solution.

With this book, Pragmatic Bookshelf confirms itself as one of the best publisher about computer things, and I’m looking forward to reading something in theirs Pragmatic Life Serie.