Now, having done this, trying to call <%= I18n.t(‘hello_world’) %>, you might receive the following error:

NoMethodError: undefined method `to_sym’ for false:FalseClass

You look in your YAML files, say en.yml and no.yml, and what you have is this:

# English locale file:

en:
  hello_world: ‘Hello world!’

… and…

# Norwegian locale file:

no:
  hello_world: ‘Hej verden!’

The above is a classical YAML thing: the no: contained in the no.yml file is interpreted as a boolean, and this renders the Norwegian YAML file useless — and thus, your dandy I18n attempts bork up.

The solution is simple:

# Norwegian locale file:

"no":
  hello_world: ‘Hej verden!’

Escape the no: with quotation marks and you’re good to go.

sudo gem update –system

(Those are two dashes and not just one, in cause your browser displays them as one.)

There you go.

Prototype will soon be out in version 1.7. Prototype, you ask? What is it and why should you care? Let’s dive into what it’s all about.

You know it from apple.com, nbc.com, cnn.com, digg, DailyMotion and other huge web sites on the Internet. You know it from Meeho!™. Even though you may not be aware of it, they all use Prototype for DOM selecting, element manipulation etc., and have been doing so for quite a while now.

So, Prototype is a JavaScript framework for working with the DOM. It makes it easy to select and manipulate elements in your HTML code and besides, it’s got functions that aim to eliminate the differences of browsers when developing web sites — the Element.Layout methods is a prime example of this.

Prototype was originally developed by Sam Stephenson, a core developer of Ruby on Rails. It was developed to underline the whole render :update do |page| functionality in Rails — or what you know as AJAX. In February 2005, the first version of Prototype was released.

Some of you might know Prototype, and you may know jQuery. But jQuery was released nearly a year later, in January 2006, and is more of a library than a framework, which is what Prototype is (architecturally anyway, someone should really write a post on the differences between the two).

Now, Prototype got released, and lots of developers ditched their own home grown code in favor of the dollar function and all the other cool features that Prototype sported. User-centered manipulation of the elements of a web page took the stage, and so did an Austrian web developer, who came to play an important — and yet to be fully acknowledged — part of the Web 2.0 revolution. His name is Thomas Fuchs.

Alright, revolution is a somewhat worn-out word when talking computers and the Internet. But Thomas Fuchs’ work was and still is important. What he did? He released his script.aculo.us JavaScript extension of Prototype.

All of a sudden, web developers worldwide gained access to all sorts of effects, controls and handy utilities (like the effect queue), which rapidly got implemented on web sites across the globe — including the web sites of Apple, Gucci, and IKEA. This is when you began to see the Internet develop past completely static pages into the more user-driven experience it has become today.

But this is not the whole story. Without the help of Microsoft, the notorious bad guy of the lot, without their XMLHttpRequest API originally developed for the Outlook Web Access feature of the Exchange 2000 mail server, the whole revolution would never have started. The whole story consists of numerous small nodes in the giant tree that is the current state of the Internet, and everyone has played a small but vital part in what we now have created.

In my opinion, we would never have come this far without the help of Sam Stephenson and the whole Prototype JS framework, without the eye-opening experience that script.aculo.us brought us thanks to Thomas Fuchs, and without the massive support that these guys gained throughout the web development community.

For now, I wish to say a big thank you to Sam Stephenson and Thomas Fuchs. You guys are brilliant. Thank you.

respond_to do |format|
  format.xml { render :xml => @users.to_xml
end

The above will create and return fully functional XML which is all good and dandy.

Well, it’s not. The above will mirror each and every detail about your users table in your database. But what if you don’t want to include the user passwords in the XML? What if you want to rename one of the fields to something else in your XML?

You use the Builder. With the help of the Builder, you can modify the XML to look like anything you want and not just mirror your table structure completely. Here is how you use the Builder:

xml = Builder::XmlMarkup.new
xml.instruct!
xml.users do
  @users.each { |user|
    xml.username user.username
    xml.email user.email_address
    xml.write-whatever-you-want-here user.whichever-field-you-need
  }
end

respond_to do |format|
  format.xml { render :xml => xml.target! }
end

The above code creates a new Builder object, then defines for a set of users to be shown in the XML. Then, the @users array is processed, and inside each user node in the XML you’re pretty much able to do whatever you want – including calling other methods you might need on-the-fly.

So whenever you need just a tad bit more freedom when working with XML, discard the .to_xml approach and create your own Builder object. That works like a charm!