Rolemodel Recap Day 2

Rolemodel Recap Day 2

Doug Bradbury
Doug Bradbury

January 21, 2011

My second day at role model found me pairing with Tim Irwin. Tim described this project as being “all about the data.” It was my first chance to work on a Rails 3 project.

My normal client work has kept me away from the Rails world for about a year and a half, so it was nice to dive back in and see what had happened while I was away. I learned a ton of stuff from Tim as we worked together.

It's amazing to me how even after using Ruby for so long and so much, it still has some wonderful surprises up it's sleeve for me.

  1. Rails 3 scopes

    Scopes had a previous life in Rails 2, but I saw how Tim had used them to clean up a number of fairly complicated queries and made them accessible to consumers of the model.

  2. OpenStruct

    It's one of those feature I've always wanted, and now that I think about it, it wouldn't be that hard to build. It's a super easy way to create a “data only” object From the ri for OpenStruct:

    require 'ostruct'
    record = = "John Smith"
    record.age = 70
    record.pension = 300
    puts # -> "John Smith"
    puts record.address # -> nil
    hash = { "country" => "Australia", :population => 20_000_000 }
    data =

    It is a great class that helps bridge that data and code gap in ruby. We used it to create a fake record that was the result of combining two other records.

    The resulting combinations were temporary, didn’t need to be stored in the database, and needed to be more type-tolerant than the ActiveRecord model could be.

  3. Anonymous Blocks

    At some point we were working with a collection, and I was writing something like this:

    some_array.collect { |item| item.is_something? }

    I commented that since I’d been learning Clojure, this syntax just seem clunky to me now. Tim came to the rescue with a syntax I had never seen in Ruby but it was exactly what I wanted.


    Who knew the ampersand could be so cool? This syntax makes the parameter passed to the block anonymous and just sends the method to that anonymous parameter.

    That evening we headed to the Research Triangle Park where luck would have it, two local user groups were meeting. Last week as I tweeted about my upcoming visit to the area and the Agile RTP group invited me to come open their meeting with a short talk.

    I presented my Walk ’n Code material and received an enthusiastic reception from many of the Agile practitioners there.

    After my talk and the groups networking time, I headed across the building to the Raleigh.rb meetup. Nathaniel Talbott does a great job of community building with this group. This meetup featured Stuart Halloway giving an updated version of his Clojure for Ruby Programmer talk.

    Relevance was out in full force with many of the Clojure core team member coming along to support (or egg on) Stu.

    So Colin recently did an 8LU session on clojure, and I’ve spent some time working through Project Euler problems in an effort to get familiar with the language. I have been having a lot fun with it.

    My brain has stretched in my first real study of functional programming, but to be honest with you, I hadn’t really gotten it yet. I really didn’t understand why Colin and Micah are so excited about Clojure. Stuart though, really got my attention. I'm on the bandwagon now!

    What did it for me was Stu’s take on polymorphism. He explained how object oriented languages have these great concepts like polymorphism, but they are tied to other language features like type. Clojure presents concepts like these “al a carte.”

    Really, what does the type of a thing have to do with a runtime decision about which function should be called at a particular time? Stu also blew the socks off of data encapsulation, showing how everything in Clojure uses the same collections api for data, so the need to “hide” data becomes almost absurd.

    I felt as though my world was beginning to crumble, but for some reason it made me really excited.

    There is no doubt in my mind that Clojure is going to be big, but as Stuart said, nobody is really in a hurry. The Clojure team is focusing on doing it right, learning from the feedback they are getting. They aren't trying to take over the world by next week.

    I got to meet several of the local Rubyists after the presentation and observed an epic text editor battle on the steps outside the meetup building. Nathaniel Talbott dug his heels in on TextMate and was being assaulted on all sides by passionate VIMers.

    The basic debate came down to uniformity and an editor that matched your expectations no mattter where you sat down to use it (TextMate) vs. an editor that you can completely trick out to your personal tastes, but renders anyone else sitting down at your computer helpless.

    I stayed pretty quiet, but for me, the top priority in an editor is it’s ability to refactor. Extracting a method or variable and inlining are abstractions to me. I don’t want to have to think about how to do them, I want an editor to do them for me.

    So as for me and my house, we’ll stick with the JetBrains tools for now.

    It was a very full day, and I felt privileged to have interacted with so many wonderful people.