nunojob:~ dscape/08$ echo The Black Sheep

Posts tagged ‘Rails’

dreamhost insanity day

The deal was – well – insanely good.

Unlimited storage and traffic, 1 domain name (plus all the extras) for two years. If you inserted 202 as promo code you would get a final price of 11USD.

I was lucky enough to get an update from Pedro while dreamhost was working and got a great deal. Even got a new domain name I was looking for:! Yay! I had to use Google Checkout to buy as the website was not very stable and I didn’t want to risk it with a credit card transfer.

As one would expect *not* was down for most of the day after the news started spreading on twitter. Dreamhost guys called that sluggish!? A hosting company website down by self DoS attack? As Alanis Morrissette would say “isn’t that ironic?”

The only thing visible thing that dreamhost did to change this was change the price to 22USD. Whoever decided that is clearly not the brightest crayon in the box. A hosting company is about having a stable service. You never charge different prices for the same service in the same day. If you want to do an insane promo, be prepared. Is it that hard to come up with a way to get the same (or more) customers without having your website on his knees and old customers leaving your service??

Final Considerations: How many cancelled their subscriptions paying 10USD a month for this deal? How much of a money loss will that represent for dreamhost? Is this a clear sign of a urgent need for income? Is it just insanity? How much money did Google made on this (1USD per transfer)? How many new domains were registered today?

Information Retrieval using the Boolean Model in Ruby on Rails

Google reinvents the wheel

About porting Ruby on Rails to Javascript:

In an effort to increase developer productivity at Google, Steve tried to convince the company to adopt Rails (and consequently Ruby) as a programming language. When that fell on deaf ears (Google really does not want to increase the number of languages that must be supported by their infrastructure), Steve decided to do what any other frustrated programmer would do: he ported Rails to JavaScript. Line by line. In 6 months. Working 2000 hours. Steve is a coding stud.

From: Steve Yegge ported Rails to JavaScript

In this six months Steve could have contributed to the rails core and improved the framework to a great extent. If he found security issues like the article refers than he should have fixed them in rails. I cannot even begin to understand why he didn’t by the way. Or at least reported them.

My conclusion of seeing that google allowed a employee to waste 6 months of work because they don’t want to increase the number of languages that must be supported by their infrastructure is that Google is Dumb.

Steve seems like a smart guy so if I was told to rewrite Ruby on Rails by an employer I cannot understand why he didn’t – at the very least – refused to do so and pointed out how stupid it was to reinvent the wheel. I simply hate javascript and love ruby. I think javascript is the worst thing there is in the internet. That’s one of the reasons I decided to take a chance on XForms. Well but that’s a personal opinion and has nothing to do with the case!
The question is:

So will this bring something new to the web?

Yes! But it’s not that this wheel is great and the other was flat. It can bring something but just because Google has the power to do that, in any language they decide to use. They have the man power to go beyond what rails offer.

But does this make the decision less dumb?

No. They could do it in rails and improve a great open source product.
Or is it that hard for engineers at google to learn a new language??

Valid and Well-formed XML Documents in Ruby on Rails

If your working with DB2 on Rails you probably need to check if the xml document is – at least – well formed.

I found a neat plugin called validates-xml that uses REXML to see if documents are well formed.

To install it simply

svn co validates-xml-read-only

And copy that folder to vendor/plugins.

You can easily integrate schema validation with a validates_xml_with_schema method. But you should use REXML as it cames with the standard ruby bundle since version 1.8.

To use it simply restart your server and

validates_xml :xmldocument

That’s it!

Yet Another Ruby on Rails Web Application – Teaser

Rails::ActiveRecord XQuery && DB2::Mac

Most rails developers use OS-X. Mostly because rails is built-in the latest release (Leopard) and TextMate offers a great IDE to use with Rails. Some could argue that it also works nicely on Windows but I really believe that Rails ain’t done to be used on a Windows Platform. Many articles and interviews with rails creator DHH second this statement. Rails is easy to develop in OS X and deploy in a Linux distro of your choice.

In my most recent screen-cast I explored an interesting technique of taking advantage of rails RESTful design and DB2 pureXML features to easily create a web-service that could query a relational databases with XML support (like DB2). As you must know DB2 Express-C is distributed freely and offers no limitation to home users/small companies. So it would be awesome to expand ActiveRecord to support xml elements, if a schema was provided to the database.

I’m aware that a pure xml database stategy would be a bad approach but there are situations when it simply makes sense. And in those situations one would profit greatly of two things wich are missing.

  • XML Support for ActiveRecord – in construction?
  • DB2 for Mac – will this ever exist?

Antonio Cangiano is creating a plugin that revolves around this concepts, but in a DB2 centered perspective. In my opinion it would be best if the rails plugin worked not only for DB2 but for any database adapter with XML support – as long as such is provided.

Let me give you a sample. Imagine that you have a database model for translating you rails application. It could be something like:


  • ID, int

Imagine that the xml file is

<language isoname="pt-PT">
  <bye>Até a próxima!</bye>

If this makes sense in your application then you could easily do something like register your model to observe (see observer design pattern) the session[‘language’] for changes and, if it’s changed, it would get all the XML for that language – it would fall back to default if such was not available – and create the hash with the values. The problem with this approach – besides making no sense for the internationalization problem! – is that in the observer model you would have to:

Language.find :first

And fetch the whole xml and then process it. If the XML document has 10MB, it would take some time. With XQuery support on ActiveRecord we could simply

Language.find :first, 
  :xcondition => ["//language[@isoname==?]", 

Or, if we simply wanted to say hello in many languages – like flickr in their first page – we could simply

Language.find :first, :xcondition => '//hello'

There are just two problems that prevent rails developers from being able to do this kind of things. And those are the lack of XQuery abilities in ActiveRecord and the fact that Mac developers cannot use DB2.

METS Standard with IBM DB2 Express C using XForms as user-interface and Ruby on Rails as a Rest Web-services


Well, here is the long promised screen-cast. The amount of topics covered is simply huge. To get you ready for the screen-cast I prepared some other more introductory screen-cast as well as some articles on these subjects. I’m sorry that I don’t have the time to document the REST, but I really advice to invest some time learning it as it’s a very pragmatic way of delivering high quality web services.

I strongly advice you to download this screen-cast from rapidshare as both Youtube and Google Videos quality is really awful. You can download it from here.

This work was really fun to do. So I hope to have the opportunity to develop it further and manage nested rest routes like /mets/1/agents to return the agents of the first submission information package (sip) using some cool DB2 pureXML features. I really feel that with a good plugin to help users take full advantage of DB2 pureXML features and a little of imagination this web-service could be of some use.

I also expect to complete the xforms model as it is not indexing a fileptr to each category when such is selected. I hope to implement this soon enough.

Here are the associated resources I developed:

And here are the other two screencasts I produced to introduce you to XForms and METS:

I also advice you to take a look at this articles. All of them where very helpful to my work.