CNXS

How to get better error messages for an associated model.

2008-11-13T15:07:43Z

Hey there. Let's assume you have some set like this

class User < ActiveRecord::Base
  has_one :profile , :dependent => :destroy
end


class Profile < ActiveRecord::Base
  belongs_to :user
  validates_presence_of :first_name, :last_name
end

And you create the profile in the same view as your user. How do you validate those first_name and last_name fields with a friendly message for your user?
Well, you could use validates_associated, but you would end up with a message like "Profile is invalid". Now, how friendly is that?

To obtain a more precise message, use this on you user.rb

def validate
  if self.profile
    self.profile.errors.each do |error|
      self.errors.add_to_base error.join(' ')
    end
  end
end

Security idea for banking cards

2008-11-12T20:34:06Z

I'm a brazilian, and on our big cities we have a type of crime known as flash kidnap ("sequestro relâmpago" in portuguese), which is a crime that consists in one kidnapper taking a hostage and cruising around with him (probably on the hostage's own car) and forcing the victim to release his banking account numbers so money can be drawn from his banking account.

This type of crime is basically a problem that was induced by the introduction of a technology (bank credit cards). But this technology could be made safer by the introduction of an emergency number. This number would work just as the normal one, so there is plausible deniability for the victim, so money could be drawn and all, but if ever used it would raise alarms on the credit central, and the authorities could be immediately called. Since close to 100% of the ATM machines have cameras around them, and there is the location of the drawn, it would be easy to check where criminals are.

For example:

Bob uses a banking card and has 2 passwords (pass A and pass B). Bob uses pass A on his day-to-day, without a hassle. Some day Eve kidnaps Bob, and forces him do release his card and a password. Bob releases pass B. Eve uses Bob's card with pass B without a problem, but doing so warns Alice that there is an emergency happening with Bob (possibly a kidnap). Alice warns the authorities.

I'm not interested in making money at all with this idea, but I would like to see it implemented, so it perhaps could save some property and lifes, so I'm asking for some directions as to what the heck I should do with it, and also some criticism.

This idea is registered under CC Attribution-Noncommercial 2.5 Brazil

Startup school 2008

2008-11-03T22:10:35Z

Quick link to some valuable resource...

Startup school 2008!

Ahhh, we here at cnxs are busy learning some new exciting technology, so keep you heads up for some fresh new content soon....

Difference between is_a? and instance_of?

2008-10-28T03:55:15Z

Hi Sirs.

There is a difference between a bunch of methods that appear that they to the same job, but they won't.

The methods instance_of?, is_a? and kind_of? do related jobs, but not the same job.

For example is_a? and kind_of? do the same job, they return true if the caller is an instance of the method argument, if the caller is an instance of every superclass in his inheritance tree or if the argument method is a module included in the caller.

The instance_of? is more specific, it returns true just if the caller is an instance of the method argument.

Let me show some examples:

module Hand
end

class Animal
end

class Mamal < Animal
  include Hand
end

class Dog < Mamal
end

dog = Dog.new

puts dog.instance_of?(Dog)    # true
puts dog.instance_of?(Mamal)  # false
puts dog.instance_of?(Animal) # false
puts dog.instance_of?(Hand)   # false

puts dog.is_a?(Dog)    # true
puts dog.is_a?(Mamal)  # true
puts dog.is_a?(Animal) # true
puts dog.is_a?(Hand)   # true

Remember that is_a? and kind_of? do the same job.

See you.

Rails Summit Latin America 2008 - Review Day 2

2008-10-24T02:21:52Z

Second Day of Rails Summit, started hot. Phusion guys talked about Scaling Applications, what are the problems, bottlenecks, solutions, how's the possibilities to face it. Was very good and entertaining, specially when Darth Vader come into it. Slides were good with funny animations.

After that comes Charles Nutter e Thomas Enebo talkin on JRuby and because the technical problems during the virtual presentation, left an impression that could be better. They gave an overview of the status of JRuby, how it runs on hotspot, and also presented some (strange) numbers of memory usage in JRuby comparing to MRI.

Jay Fields talking was about testing and some testing frameworks. Well in general was a good presentation but for him almost all solutions are imature, which I disagree and when he was questioned on what makes a framework mature, he said time, years...

David Chelimsky did 2 great talkings one about RSpec and the other about Cucumber, much more for newbies (with all respect to newbies it's just a stage). I liked a lot because he seem to be very confident on his arguments, this is a thing that I appreciate on speakers.

The others between Chelimsky's and Obie I didn't payed too much attention so I'll skip my review on them.

Obie Fernandez closed the event with a great keynote, telling about how his software consultancy deals with the agile manifesto. It's great to hear that you apply the techniques that he says that's a key of success of his company. He presented a full stack of the way his company develop software, since the first contact to the client.

Rails Summit for me was a great event, that I've met good mates from the brazilian and latin america Rails community. I will be waiting for the next one on 2009!

Diff entre respond_to? e respond_to

2008-10-21T13:18:30Z

Um pequeno tutorial em português pra diferenciar melhor respond_to? e respond_to. Não parece ter muita não? Mas o tio Chuck Norris vai me ajudar a esclarecer melhor isso aqui.

respond_to? é um método do Ruby Core como você pode ver, e não do Ruby On Rails, ele basicamente verifica se determinado objeto responde a um método, como o nome sugere mesmo.

Por exemplo:

class Chuck < Object
  def norris
    puts "the man"
  end
end
chuck_norris = Chuck.new
p chuck_norris.respond_to?("norris") # true
p chuck_norris.respond_to?("mr_t") # false

Já o respond_to, sem o ponto de interrogação (eles fazem parte do nome do método) faz parte do ActionController do Ruby On Rails. Ele coloca suporte a Web Service na sua aplicação, isso quer dizer que ele consegue resolver o tipo do recurso que você deseja.

respond_to do |format|
  format.html # render por default nome_da_acao.html.erb
  format.js # render o nome_da_acao.rjs
  format.xml { render :xml => @chuck.to_xml } # coloca o chuck pra xml e envia
end

Com esse código na action você poderia usar, por exemplo:

http://localhost:3000/nome_da_acao.html

http://localhost:3000/nome_da_acao.xml

Ou realizar uma chamada JS unobstrusive usando AJAX.

Isso ai, espero ter ajudado.

Rails Summit Latin America 2008 - Review Day 1

2008-10-21T03:10:18Z

Rails Summit Latin America 2008 was a great event at all. Nice speakers, nice people all around, good food. Only the weather wasn't so fine (above 30 C).

The event started with DHH talking on new features of Ruby On Rails 2.2 answering questions of the crowd. I didn't liked it too much, mostly common questions with common answers by him, nothing special.

Then Chad Fowler comes and well really debut the event, he made an awesome presentation about be remarkable, talking about his book "My Job Went to India", his life as a musician and Doom player :-)

After lunch, George Malamidis talked about REST. I didn't liked too much, was hard to me after lunch pay attention, after 9 hours driving in day before and an early wake up for the event.

Dr Nic Williams talked on Open Source and encouraged people to contribuite more to Open Source Projects. Dr Nic Williams presented a very funny talk and I think if he could take a shot on a Saturday Night Live, if he don't want to be a developer anymore. He's the Jerry Seinfield of Ruby On Rails community.

Chris Wanstrath, his keynote was very similar to Ruby Hoedown keynote (good IMO, but I expected a little different).

The summit ends the first day with a Birds of Feather were some participants presented random thoughts, Eduardo Bellani also gave his presentation at this time. This whole BoF was one of the funniest moments at Rails Summit Latin America 2008.

Eduardo Bellani on Rails Summit Latin America 2008

2008-10-20T06:26:42Z

Apresentação de Eduardo Bellani sobre voto eletrônico no Rails Summit Latin America 2008, em São Paulo.

Votação caixa preta (Black box voting)

2008-10-10T19:36:50Z

For the english readers (if any) => sorry, this one will be in portuguese (except the article with a ++ in front)

Aqui embaixo vai uma coletânea de artigos sobre esse assunto (revisitei de novo o esquema de votação digital depois de assitir este documentário, o qual recomendo fortemente). Pretendo escrever algum artigo a respeito futuramente, mas não pude deixar de compartilhar estas fontes, dada a gravidade deste assunto:

entrevista com um especialista brasileiro
++Analysis of an Electronic Voting System, artigo que é citado no documentário sobre a fragilidade do sistema eleitoral americano
versão tupiniquim inpirada no artigo acima
neste aqui, o nome diz tudo
livro disponível sobre fraudes na urna eleitoral brasileira

Não esqueçam, ser um líder nada mais é do que agir pensando no coletivo, e por incrível que pareça nós (uso essa palavra pra descrever todo mundo que esteja lendo um blog sobre tecnologia como este) somos a elite de nossa sociedade, e isso implica em agirmos como líderes, sob pena de ruir a mesma com nossa apatia.

New article on pedagogical development

2008-09-29T17:49:28Z

Hey there readers.

I've written a new small article, and I'm not even sure on what do to with it (if someone has a clue, drop me a line).

It's based on the works of Seymour Papert and constructionism.

Anyway, here it is.

Rails Summit Latin America by Locaweb

2008-09-24T13:24:53Z

Here we go!

My thesis short article

2008-07-28T23:43:52Z

Hey there. I've closed college (finally) and for the last project we had to built an extensive conclusion work and an article on this work.

The full length work is in portuguese, so it's a bit inaccessible to most readers, but I've tried to write the article in english, since it was permitted and it increased the potential reader base.

So here it is. It's about using the Getting Real philosophy as a way to be competitive in an ever increasingly competitive and integrated world. Hope you guys enjoy it, and any grammar mistakes, please point them out, english is not my first language, and mistakes do happen :P

Hugs

Export the database models to YML fixtures

2008-07-08T17:12:49Z

Hi Sirs,

Many tutorials over the web shows how to load data from fixtures. But, if you want to migrate your mysql data to a postgresql database?

We can export our data to fixtures, and after that we can load the fixtures to every database management system we wish.

Let's go to the rake task:

desc "export the database models to YML fixtures" 
task(:models_to_fixtures => :environment) do 
  ActiveRecord::Base.establish_connection(
    :adapter => 'postgresql', # mysql, sqlite3
    :encoding => 'utf8',
    :database => 'cnxs_development',
    :username => 'username',
    :password => 'secret'
  )
  ActiveRecord::Base.connection

  if ENV['MODELS'].nil? || ENV['MODELS'].blank?
    raise "Please enter valid models names separated by coma. Ex: MODELS=User,Account"
  end

  models = ENV['MODELS'].split(',').collect { |arg| arg.camelize.constantize }

  models.each do |model|
    output = {}
    collection = model.find(:all)
    collection.each do |object|
      output.store(object.to_param, object.attributes)
    end
    file_path = "#{RAILS_ROOT}/tmp/#{model.table_name}.yml" # /tmp/
    File.open(file_path, "w+") { |file| file.write(output.to_yaml) }
  end
end

Here you need to fill your database attributes like you do in the /config/database.yml.

You will call the command line:

$ rake models_to_fixtures MODELS=<your model names separated by coma>

For example:

$ rake models_to_fixtures MODELS=User,Post

All your model data will be stored on /tmp/ directory.

Download this rake task here.

See you.

Better than grep? You bet!

2008-06-26T13:58:57Z

Well, long time no post here.

I'm going to talk about a tool that changed the way I do search on the programming front.

Since I really don't like grep for common searches (it's a great tool but it's interface is a bit clunky) I used to use the Regexxer for those kind of project searches (it's a great GUI tool, I recommend it to anyone).

But since I'm more of a minimalist command line kind of guy, I was happy as a bonobo when I found ack, a grep like program hat has a interface for human beings (yeah, ubuntu reference, sue me). To give a little example on how simple is to search in a ruby project for example:

cd ~/project/path

ack-grep --ruby string_to_be_searched

And that's it, if you want any more details, the ack home page has a great little tutorial.

Hugs everyone.

Windows in Ubuntu 8.04 with VirtualBox

2008-06-24T16:01:13Z

I have a Windows on my machine, cause for some stuff I still need it, (MS Visio, MindMaps and couple of others application that doesn't run fine with Wine). It's a pain in the ass to always boot machine to access 2 or 3 files and stay 15 minutes on Windows.

A couple of years ago I was a big fan of VMware (old times that I virtualize ubuntu on windows), and I felt a lack of OSS on this area. So the solution it's virtualization, with VirtualBox it all comes easy!

VirtualBox, was recently bought by Sun, has 2 licenses: one commercial and one open source. I use OSE and to install it you have to follow these steps:

$ sudo apt-get install virtualbox-ose virtualbox-ose-modules-generic

Then add your current user on 'vboxusers' group

$ sudo adduser someuser vboxusers

Go to applications > system tools > VirtualBox

Now create your Windows VM with the almost NNF (next, next,finish) wizard. It's a piece of cake!

RSpec view test for render :partial with :locals?

2008-06-18T13:38:37Z

I was working on some rspec views tests and I've noticed that partial renderization can be tricky.

For example, if we have an index page that renders the objects list in a partial template.

In my case I was testing using a 'GivingClub' list:

describe "giving_clubs" do
  before do
    @giving_clubs = [mock_model(GivingClub)]
    assigns[:giving_clubs] = @giving_clubs
  end

  it "expect render giving clubs list" do
    template.expect_render(:partial => "/giving_clubs/list", :locals => { :giving_clubs => @giving_clubs })
    render "/giving_clubs/index"
  end
end

Do not forget the assigns before call template.expect_render. Locals works fine in this way.

HP Acquired EDS

2008-05-13T12:12:26Z

Well another big player buying other big player. Big acquisitions in the last couple of months! For around $13 billion ($25 per share). HP said that they could double their service revenue. Well seems that market doesn't believe too much in HP since their shares are down on 6% now...

Source: market watch

Clean Objects with find method

2008-03-02T12:51:19Z

Hi Sirs.

An important trick on the famous ActiveRecord::Base find method.

When you are in development time of your application, and you do some query on your database query editor, is a good practice to use the limit clauses and selects just the columns you want.

In the find method we can do it with the :limit and :select arguments.

For example in our code when we try to authenticate some user we got it like:

find(:first, :conditions => [query, hash], :select => "id, email, login")

The returned object contains just the id, email and login attributes. Clean object.

Password and other attributes do not appears in the returned object =]

Simple development practice, but very important too.

See you.

Rspec quickref

2008-02-21T20:05:53Z

Hey wanderers

Sorry for all this time frozen, the crew and I have a lot to post about, but our current assignments has kept everyone pretty busy(but that's not an excuse, so let me blow the dust off this blog).

So, just stumbled on Dave Astels (for those of you who don't know the guy, he's one of the responsible for the creation of the rspec behavior driven development framework, I'll post more specifically about it later, but you can find tons of info on the web about it) rspec QuickRef. For those of us who are using rspec a lot, this might come in handy. I know it did for me.

Just a tip this time folks, but I'll try and get some cooler tutorial next time.

Hugs to you all

Installing RMagick on Ubuntu

2008-02-05T09:18:31Z

Last week I was installing again rmagick on a Ubuntu server, then I discovered an very easy way to do it.

$ sudo aptitude install librmagick-ruby

Edit 10/20/08: Avoid this tutorial it doesn't work, if you wanna install rmagick use the old fashion way:

$ sudo apt-get install imagemagick

$ sudo apt-get install libmagick9-dev

$ sudo gem install rmagick

SQL Lite for Ruby On Rails

2008-01-28T13:19:07Z

Hi all.

If your Operacional System is Ubuntu and you are using Ruby on Rails 2.0.2 you can easily use it:

$ sudo apt-get install sqlite3

$ sudo gem install sqlite3-ruby

SQLite3 does not use authentication and needs only a pointer to the database file on database yml.

development:
  adapter: sqlite3
  database: db/development.sqlite3
  timeout: 5000
test:
  adapter: sqlite3
  database: db/test.sqlite3
  timeout: 5000
production:
  adapter: sqlite3
  database: db/production.sqlite3
  timeout: 5000

When you run "rake db:create:all" on your RAILS_ROOT it creates all 3 databases.

More information about other plataforms?

Here: http://wiki.rubyonrails.org/rails/pages/HowtoUseSQLite

See you.

Atom Feed Helper Example

2008-01-23T18:21:26Z

Hi all,
Rails 2 makes the Atom RSS Feed much more sophisticated and elegant. If you are using the Ruby on Rails by RubyGems installer, maybe you have an old version of the Atom Feed Helper. To fix it you can check out the atom_feed_helper version inside the Ruby on Rails repository and after that, copy and paste it to /vendor/plugins/ directory.
The repository is: http://svn.rubyonrails.org/rails/plugins/atom_feed_helper.
In there you will find plugins that are more up to date.
In the README you will find a simple example to build your feed. Like when you click in our Cnxs feed at the navigation bar, if you are browsing with Firefox.
Here comes our example:

# rss.builder
atom_feed(:schema_date => @posts.last.created_at.year) do |feed|
  feed.title("CNXS")
  feed.updated(@posts.first ? @posts.first.created_at : Time.now.utc)
  @posts.each do |post|
    feed.entry(post) do |entry|
      entry.title(post.title)
      entry.content(post.body, :type => 'html')
      entry.author do |author|
        author.name(post.user.name)
        author.email(post.user.email)
      end
    end
  end
end

You can note the the atom_feed method has 4 arguments, but just one of them is required, that is the :schema_date. You can read at http://feedvalidator.org/docs/error/InvalidTAG.html, you see that the URI tag needs a year to be fix in the validators, month and day parts are optional. The others arguments are :language, that defaults to "en-US", :root_url, that defaults to the root path on the current host and :url that defaults to the current URL.
Another thing that you can look is that the ".builder" extension has higher precedence. So, if you code it in your rss action in the PostsController:

respond_to do |format|
  format.atom { render :layout => false }
end

the atom format respond int the same way to rss.builder and rss.atom.builder.
See you.

Some Thoughts on Some Thoughts on Security

2008-01-18T09:33:27Z

I've been reading a great paper by Daniel J. Bernstein, the creator of a qmail, and wow, what a pearl of wisdom. One of the most clarifying and straight to the point works on code security I have ever read. He (quite correctly) makes a parallel between the code security and the amount on exploitable bugs (EB), stating that it is the major problem on the code, regarding security. And then gives some answers to that problem, along with a couple of common distractions of the programmer while coding that helps those EB creep on our code base (CB). Let's review then, starting with the distractions, and I'll try to make some links with my favorite unambiguous tool of choice, Ruby.

Chasing attackers. The point here is give some thought to respond to tomorrow's attacks, and not being trapped by the anti-virus mentality of being only responsive to aggressors. Perhaps the dynamic nature of Ruby would help with that, but I think it is more a personal posture problem than anything else.
Minimizing privilege. Here, what is being said is that the old principle of least privilege is fundamentally wrong. How so? Well, it might (!) reduce the damage done by security holes, but never fixes these. Plus, IMO, it might even give users a false sense of security. Again, it is more of a way of a personal way of thinking (but what isn't? :P ).
Speed, speed, speed. Here I think rubists have some advantage. Since we work on a language that is 'slow', usually we tend to not place emphasis on premature optimization. I think this quote summarizes the thinking here:
Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efﬁciencies, say about 97% of the time; premature optimization is the root of all evil. —Knuth in [13, page 268]

Now, to the answers. These are also 3, and they are codependent connected to each other:

Eliminating bugs. I think everyone saw that one coming. But even so, Daniel's down to earth advices on it are a very worthwhile reading. I think I can summarize him on this section by saying (and that is a plus to rubists too), simplify stuff. Simplify interfaces, UI, parsing. Elegance is not a luxury, it is a way to obtain security. Following that logic we come to.
Eliminating code. Heck, here I'll quote his quote, and be done with it.
To this very day, idiot software managers measure 'programmer productivity' in terms of 'lines of code produced,' whereas the notion of 'lines of code spent' is much more appropriate. —Dijkstra in [9, page EWD962–4]
But as our systems grow, and our time and budgets remain the same or are diminished, and as programmers get more dumb, something has to give right? Wrong (don't know about the last part though).
Eliminating trusted code. That is somewhat more difficult I think, but it says that a program should do what it is meant to do, nothing more, and trust as few sources of data as possible. KISS and all that stuff.

I would love to hear any input on that. Until next time people.

Oracle Acquired BEA

2008-01-16T20:07:26Z

What a day huh? Oracle bought BEA for around U$ 8.5 billions. I don't like this kind of acquisition, cause means less competitors in some market that they used to compete.

MySQL Acquired by SUN

2008-01-16T18:52:28Z

Huh? Sun acquired MySQL as announced today. I was very surprised by this notice, I guess soon we gonna have a much better DBMS. How does it sound for you?

Work Environment

2008-01-14T23:29:16Z

What's your work environment? Which IDE or whatever you use for code? I will describe mine:
I use Eclipse as my IDE for Rails Java or ColdFusion (I use a separate version/dist of Eclipse for each). I don't have too much to complain about memory usage, cause everytime I prefer spend a hundred bucks more on my pc's to get much more memory that I would use. By the way here's a tip for those who want to reduce the memory usage of Eclipse, or just want to not have some tools that they will not use (that's me!). Download only the Eclipse Plataform Binary (around 40MB) that comes without the JDT and without other unnecessary plugins.
Ok that will save some MB on your memory. Now build your own environment, with only plugins that you want!
Here is mine for Ruby on Rails: Aptana, RadRails, Subclipse.
ColdFusion: CFEclipse, Aptana, Subclipse
Java: WTP, Subclipse.

Ext JS

2008-01-14T21:35:07Z

Hey people, here is my first post and I expect you enjoy it.
Have you ever heard about the javascript library Ext JS? If your answer is no, you should visit their website. It's an amazing javascript library, build in the top of Yahoo UI library (another amazing), with a impressive variety of pretty beautiful and fully featured components. It's also extensible, customizable and very well documented. This last point I want to give a special focus, cause the documentation of the api is very good (part are inherit of YUI).
So if you want to deliver web 2.0 applications, don't forget to take a look closely on this library.

HTML Filtering with sanitize helper

2008-01-14T13:08:17Z

Hi sirs,
another important feature that we need to use is the 'sanitize' helper. This Ruby on Rails helper filters HTML nodes and attributes and strips invalid protocols. Here in our case the use it on the simpler way:
<%= sanitize(post.body) %>
Other time you can choose the options ':tags' and ':attributes' to do a custom use where just the HTML tags and attributes pointed here are allowed to be interpreted.
It is another little tip that helps in malicious posts or comments containing javascripts codes or comments with different enconding. Here comes the Rails API link to more information about this: SanitizeHelper.
See you.

Ruby on Rails pagination

2007-12-27T22:09:33Z

Hi sirs.

I really recommend the official Ruby on Rails paginator. Very easy to use. Like 95% of the plugins =).

I just checkout the project on SVN, change one line of code on my controller, appends a line of code on the ".html.erb" template index file, and paste a piece of CSS code on the stylesheet, and it works. The piece of CSS code is defined on the README file inside the plugin's root directory.

In my case, I just insert on my controller:

@posts = Post.paginate(:page => params[:page], :per_page => 10, :order => "created_at DESC")

and just insert on the view's bottom:

<%= will_paginate @posts %>

The CSS code I just change the color =).

The SVN repository is svn://errtheblog.com/svn/plugins/will_paginate.

The page that contains most of instructions is the err.the_blog, but if you just read the README in the will_paginate plugin you will be prepared to do all the work.

See you.

New file extensions on Ruby on Rails

2007-12-27T08:17:28Z

The very best point to participate of a developers group like CNXS is when you found a problem, everyone tries to help faster they can.
Rafael Souza shows me this post on another blog and it helps a lot. Just change the extension ".rhtml" to ".html.erb" and ".rxml" to ".builder" on you Ruby on Rails application in version 2.0.2. Your problems is gone.
See you.

Problems on Ruby on Rails 2.0.2

2007-12-27T07:37:51Z

Hi all,
Ruby on Rails 2.0.2 is released... and I do not like this version, because of 2 modifications.
1. Database default: Postgresql is my favorite database management system, but I know that Mysql is very easy to use on Windows and Linux. I respect the preference about Mysql. But I do not like what I read on "Riding Rails" that says "This is especially so under OS X 10.5 Leopard, which ships with SQLite3 and the driver gems preinstalled as part of the development kit". Sincerelly, for me, it is not a good point to change the default database :P
2. ".rxml" files was fired. Our feed on the site just blow up... because we use the .rxml files to render the xml version of the site.

Our host is using just Rails 2.0.2, living on the edge has problems too.
=)
See you.

CV with Curve and LaTeX in Ubuntu 7.10

2007-12-19T14:52:22Z

Hey there. In our little how-to I'll explain something that was very useful to me, this great tutorial by Didier Verna, on using the Latex curve class to build Cvs (pretty nice and standardized ones). That will be a superb reading for a more detailed tutorial. If you want to take a peek before reading on, here is my CV sample(a little past upgrade time :P), using a modified version of the sample used on the aforementioned tutorial, plus the source files here.

Anyway, I'll use the Ubuntu 7.10 distro, and all the wonderful free tool that are at our disposal in there. First, lets download the, IMO, best latex docs editor, kile. Then let's proceed to fetch the LaTeX packages so our Kile can compile smoothly our docs.

$ sudo apt-get install kile tetex-extra

Now bake a cake and go play soccer (looong download). Then download the Curve (or take the compiled one with my source files) class and place it on the docs root tree. So, now build a new project, add all the necessary files on that, including the curve class. If click on the pdflatex button (the big gear with a little pdf symbol) it should generate the cv.pdf nicely (don't forget to only use PDF, JPG, JBIG2, and PNG graphics formats, kile use pdflatex on this command, do yourself a favor and read the manual).

On some future post I'll go step by step on my modifications and the meanings of the commands. But if you just change the text and go hacking stuff you'll eventually find out what things mean. Oh, and please write on open office or something else that has a grammar correction, a CV with grammar mistakes don't look so good :)

First page on google.com.br

2007-12-18T18:26:23Z

Hi all,
I am very happy to type 'cnxs' on google.com.br, and found our name in the first page.
Thanks to meta tags =)
See you.

Installing Postgresql on Ubuntu 7.10

2007-12-16T21:19:54Z

Hi Sirs.

Now I am using Ubuntu 7.10 and my favorite Database Management System is Postgresql.

The best tutorial that I found is the Ubuntu tutorial about Postgresql and pgAdmin installation.

Very easy to learn by every developer. This tutorial shows how to install both the Database Management System and the Administration and Development Platform.

https://help.ubuntu.com/community/PostgreSQL

Easy to install and configure.

Just one line to install the 'Sophisticated open-source Object-Relational DBMS' and the 'graphical Open Source management, development and administration tool'.

$ sudo apt-get install postgresql pgadmin3

Other two commands to configure your new account:

$ sudo -u postgres psql template1
$ template1=# ALTER USER postgres WITH ENCRYPTED PASSWORD '<***password***>';

I recommend this tutorial =]

See you.

Filter sensitive information on logs

2007-12-13T21:44:39Z

Hi Sirs,

a very important thing that I can remember about security on web environment is 'logs'.

Ruby on Rails provide a very simple way to protect us of store sensitive information on the logs. Every information that goes through the parameters is writed on the log. In websystem development phasis logging information is important, but in the production phasis, is dangerous. Hackers in general can take information through many ways. Our tip to protect sensitive information in the logs is the method 'filter_parameter_logging' of the Class ActionController::Base.

ActionController is the mother class of every controller in your applications, so the best place to call it is in the app/controllers/application.rb.

Just insert this example line of code:

filter_parameter_logging :password, :password_confirmation

and than it replaces the values of all keys that matches the arguments name with "[FILTERED]", and you are protecting your informations in the logs.

Is a simple tip, but very important. Do not forgot to use it.

See you.

Rails 2

2007-12-10T00:12:04Z

Hi all,

I am very happy to give you the notice that our website here, is installed in Ruby on Rails 2.0.1 just 3 days after the release is finished. Installed and tested in the weekend =].

That's the way that the CNXS team likes to work. Ever living on the edge.

Congratulations to Ruby on Rails Development Staff and to CNXS Team.

See you sirs.

A good testing idea

2007-12-10T00:05:34Z

The approach of Douglas Sellers about testing their AJAX heavy system really sounded to me as an excellent idea. I can imagine in the future this being adopted by more and more web systems, as they embrace javascript for building RIAs more and more.

Essentially they have built a DSL on top of selenium using ruby (yay), for testing the AJAX stuff on their page, aiming at easiness to write the tests, trading the complexity of writing the tests for the complexity of the DSL itself, trying even for the non technical people on the company to write their own tests.

Really recommended for a fresh and no nonsense view on testing.

Freedom of our thoughts and works

2007-12-10T00:04:34Z

If you have not yet seen or read Lawrence Lessig, I urge you to. I'll try to make a small analysis on his work, just as a appetizer for for those still ignorant about it :).

His point is that we are moving away from a read-only culture, where the content is controlled and governed by producers and broadcasters, and consumers have little saying on the content, to a read-write culture.

What is a read-write culture? One that is governed by the freedom to modify. Where distribution costs are next to zero, and each individual now has a shot at producing her own content, and to mix and remix work of a third party, without being worry of a lawsuit. A new (we could argue that for most of the human history it has been that way, just in the 20 century the paradigm has changed) way of looking at our own freedoms, and how we can not only consume work of others, but create ours, based or not on all the free content available.

Introduction to cnxs

2007-12-10T00:03:34Z

Hey Folks. This is the first post, so I'll manage to keep myself away from technological ramblings and just say some words about us and our purpose here.

This is not exactly a company, it is more a group of friends with some mutual interests who got together because they thought it would be fun to do it and each could learn and teach the others a lot.

What bought us together here is a passion for developing good software, with tools that help us not only accomplish this, but to have some fun while we are doing it. We like what we do, and I can say that we don't view this as a job, but as a pleasant thing, which fortunately happens to be payed sometimes (yay). I think that's that for now, but we'll be back tomorrow.

Hugs everyone, and welcome to the joy of connected thoughts :D