Dirk.Net

Here’s a little XML/JSON/YAML/Hash conversion cheat sheet for Ruby:

First, let’s create an XML document:

require ‘rubygems’

require ‘nokogiri’

builder = Nokogiri::XML::Builder.new do |xml|

    xml.root {

      xml.products {

        xml.widget {

          xml.id_ “10″

          xml.name “Awesome widget”

        }

      }

    }

  end

my_xml = builder.to_xml

XML To Hash:

require ‘active_support’ #if you have Rails installed

my_hash = Hash.from_xml(my_xml)

Withou Rails/ActiveSupport, have a look at Crack which very fast and will usually give you enough fields (it eats attributes however):

my_hash = Crack::XML.parse(my_xml)

Hash To Object?

Have a look here: http://blog.jayfields.com/2008/01/ruby-hashtomod.html

Hash To JSON:

require ‘json’

my_json = my_hash.to_json

JSON back to Hash:

my_hash = JSON.parse(my_json)

Also have a look at Crack:

my_hash = Crack::JSON.parse(my_json)

Hash To YAML:

my_yaml = my_hash.to_yaml

YAML back to Hash:

my_hash =  YAML::load(my_yaml)

Bonus Points –  Hash to XML:

require ‘xmlsimple’

my_xml = XmlSimple.xml_out(my_hash, {’KeepRoot’ => true})

There is currently no way to preserve the attributes (like <person age=”10″>Joe</person>) with such conversion from Hash to XML.

Here in Thailand I currently get the page below at http://www.rubyonrails.org and http://www.rubyonrails.com. The domain name registration seems to be ok, but there was an update yesterday (April 20th). And it’s a garish parking page that in the colors of Django?! Is it some regional DNS screw-up? Am I mistyping Ruby?

UpdateJust checked via US-based proxy, the issue is confirmed, it’s not a regional Asian DNS snafu.

Update 2The same happened last year and it looks like it happens every year around April 20th, April Fools + 20 or sth.

Things are moving fast in the Rails/Ruby world with the imminent releases of Ruby 1.9.2 and Rails 3.

An essential tool for a smooth transition is RVM by Wayne Seguin (Where can i vote for this guy as Ruby Hero? Ah, it’s here.)

In the first Rails 3 Railscast RVM sounds more like an afterthought and only necessary if you don’t have Ruby 1.8.7+ installed, but it’s advisable to not even try the migration to Rails 3 without installing RVM and a dedicated version of Ruby (can be the same version as your current system Ruby).

While taking the plunge with Rails 3 and its many breaking changes, why not go all the way in a twisted pun sort of way? As Ryan Bates recommends in Railscast 208, it may be time to skip Ruby 1.9.1 and install ruby-head on RVM, which is currently 1.9.2, expected to be released in a few months.

Once you have Rails 3 (currently Beta 3) and Ruby 1.9.2 installed on RVM, perhaps with this nifty script that includes the entire starting “gemset”, you will find that the ruby-debug gem can’t be installed on Ruby 1.9.x, the installer will tell you

Can’t handle 1.9.x yet

and other stuff.

Don’t despair Mark Moseley has created all the necessary gems for you. You can install the ruby 1.9.1 and 1.9.2. compatible debugger and the debug ide with the following commands (thanks to Wayne’s exemplary documentation):

gem install ruby-debug19 — –with-ruby-include=$rvm_path/src/ruby-head/

gem install ruby-debug-ide19 — –with-ruby-include=$rvm_path/src/ruby-head/

Now when you run

rails server –debugger

it still won’t be working, saying

“You need to install ruby-debug to run the server in debugging mode.”

So, as the last step, put this in your Gemfile

gem ‘ruby-debug19′, :require => ‘ruby-debug’

Run ‘bundle install’ if you feel like it, and now the debugger should work. However, the debugger will now start every time you start the server.

To start the server without the debugger, you’ll have to uncomment the line above in the Gemfile again.

Anyone with a workaround for this please post in the comments.

Hope it helps.

P.S. Don’t forget to give back to Open Source!

Mozilla Thunderbird does not have a built-in option to right-click and forward multiple messages without sending them as attachments of a single message or sending each message inline after entering the address manually. While this makes sense as it minimizes server resources and web traffic,  sometimes it is more convenient for sender to send (bounce) multiple messages to the same recipient in one action, giving the reader single messages in her inbox. Luckily there’s the Mail Redirect Add-on that helps with this task, one of the most useful Thunderbird extensions. 

This code returns all records of your model sorted by translated field name when using Globalize2 :

#app/models/widget.rb

def self.all_sorted
Widget.find(:all, :joins => :globalize_translations,
:conditions => ['locale = ?', I18n.locale]).sort_by(&:name)

end

As outlined it this post, :joins => :globalize_translations is mandatory. The unary ampersand operator converts a Proc to a block, so in this case sort_by(&:name) is “shorthand” for

sort {|x,y| x.name <=> y.name}

Ruby sometimes feels like assembling a Swiss watch in code, where other languages feel like fixing an old car.