Tom Purl’s Web Site

Overview

One of my goals for 2010 is to gain a decent understanding of the Ruby On Rails framework.  I don’t think that this knowledge will directly help me with my current job (as a FileNet P8 administrator), but I do think that it will provide some good benefits.

First, learning about something that’s a little bit outside of your comfort zone can often help you with your day-to-day tasks.  For example, if you teach yourself the basics of Java development, then you will know how to read a stack trace.  Having this knowledge is very important if you want to administer software written in Java.

Also,  it’s just fun.  Creating something useful out of a few lines of text never ceases to amaze me.  Also, I find that learning new technical skills is good for your brain.

Finally, who knows what the future may bring?  It never hurts to know as much as you can about popular technologies in general when you work in IT.

So to get started, I purchased a copy of Agile Web Development with Rails, Third Edition from the Pragmatic Programmers’ web site.  This book seems to be one of the best for beginners, and I really love that you can buy DRM-free ebooks from the Pragmatic Programmers’ web site.

Installing Ubuntu Packages

So enough background information.  Here’s how I set up my system to get started with Rails development.  First, I installed all of the necessary software on my Ubuntu 9.10 machine that was  available as an Ubuntu package:

sudo apt-get install rails ruby-full rubygems rake mongrel git-core sqlite3

Here’s why I installed more than just the rails and ruby pacakges.  When you install Ruby from source on a Linux machine, you get a lot of software.  In addition to the Ruby runtime, you get fun tools like irb, rubygems, rdoc, ri, and rake.  However, when you install the ruby package on Ubuntu and Debian, you just get the Ruby runtime along with a a couple of libraries.  Since I’m lazy efficient guy, I decided to install the ruby-full package instead to save a few keystrokes.  Unfortunately, the ruby-full package still doesn’t include rake or rubygems, so I installed those manually.

Mongrel is a developer’s web server that is designed to work very well with Ruby on Rails development.  Since I am also impatient, I wanted a web server that would work a little faster than WEBrick.

Finally, I installed git because I wanted to share code between two different computers.  Git is a version control system that is very popular with Ruby developers, so I figured that I would use the most popular Ruby-related tools while I’m learning about Ruby.

Installing Software Without apt-get

Natrually, you can’t install everything that you need with apt-get.  For starters, the version of rails that is used in Agile Web Development with Rails, Third Edition is 2.2.2, so let’s install that using rubygems:

sudo gem install rails --version 2.2.2

This operation took a little while (~ 7 minutes) on my machine for some reason.

Note: For some reason, this bog

Next, I’m a Vim user, so I would like to see if the rails.vim plugin would help me at all.  There is an official Ubuntu package for this plugin called vim-rails, but when I try to install it using apt-get, I get the following error:

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
vim-rails: Depends: vim-full but it is not installable
E: Broken packages

When I tried to install the vim-full package on my machine, I got this error:

Package vim-full is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package vim-full has no installation candidate

Ok, so after all of that, let’s just install it the easy way:

(Download the latest version of rails.zip from the rails.vim download page)

$ cp rails.zip ~/.vim

$ cd ~/.vim

$ unzip rails.zip

Finally, open vim or gvim and execute the following command:

:helptags ~/.vim/doc

In case your interested, here are the other Vim-related packages that I have installed on my machine:

• vim-common
• vim-gnome
• vim-gui-commom
• vim-runtime
• vim-tiny

Conclusion

And that’s it!  I now appear to have everything that I need to complete the beginning examples in Agile Web Development with Rails using Ubuntu 9.10 and Vim.

Update (1/20/10) – I added the sqlite3 package to the apt-get line above.  This package is necessary if you want to query your database manually.

I am about to finish my first non-trivial application written in Groovy (a medium-sized suite of administrative scripts), and so far I’m pretty happy with the language. I thought I would share some of my notes in case anyone else is considering the language for a similar application.

Development Environment

One nice thing about Groovy is how well it works with a system administrator’s “toolbox” of applications, i.e. a text editor and command shell. The development tools that I specifically used were Vim, the command shell, and ant, and I found the pace of development to be very rapid.

References

Since Groovy is still pretty new for me, I need to read a lot of reference material. Here’s the resources that provided the most value:

• Groovy In Action – From my own experiences and what I’ve read on the groovy-user mailing list, GINA is the best Groovy reference manual available. For me, it answered about 95% of my programming questions, with tons of great examples to boot.

Note: This book is a little expensive, so I purchased the electronic version from the Manning web site. If you’re going to be doing most of you reading on a computer screen anyways, I recommend this option.

• PLEAC-Groovy – The PLEAC project’s goal is to implement the examples in the Perl Cookbook in multiple languages. Groovy is one of those languages and I believe the first one in which 100% of the examples have been implemented. The examples are very useful and easy-to-understand, so I highly recommend this resource.

Note: I recommend downloading a copy of the PLEAC-Groovy web site using something like HTTrack or the Scrapbook plugin for Firefox. You’re probably going to use this reference a lot, so you’ll want to have quick, offline access to it.

• groovy-user Mailing List – This list is very informative, and most of the people with which I’ve interacted on this list have been very knowledgeable and patient. It is highly recommended.

Application Overview

I can’t really say much about it, other than the following:

1. It’s designed to run on a server and has a command-line interface.
2. It performs a lot of filesystem-related operations.
3. It processes a lot of XML.
4. It has a lot of unit tests.
5. It integrates with a proprietary, third-party library.

First, let me say that the Groovy feature that stood out for me the most was it’s excellent, built-in XML processing libraries. I usually hate processing XML since there’s usually so much “heavy-lifting” and debugging, but Groovy makes the task trivial.

Another feature that I didn’t even know I would like be ended up loving was Groovy’s AntBuilder class, which allows you to use ant tasks in your code in a trivially-simple way. This was especially handy when it came to filesystem-related operations. And of course, the icing on the cake is that Groovy allows me to do all of this while integrating with all of the Java libraries (both standard and third-party) that I need to do my job on a daily basis.

Gripes

Of course, such a new language is going to have a few rough spots. Here’s the ones that I encountered most frequently:

Poor Error Messages

Occasionally, you will get error messages that make no sense whatsoever. My favorite is when it told me that I had a null character on a line that didn’t exist in my document in column 0 (which also doesn’t exist). The good news is that error messages in general are pretty decent, especially when you run Groovy with the debug switch.

Non-Intuitive Behavior

I ran across some truly odd functionality that border on a bug in my opinion. When I asked the mailing list for some clarification, I learned that some of Groovy’s functionality is dependent upon the brand of JDK that you’re using. Yikes. Hopefully the Groovy developers are able to normalize these sorts of anomalies in the future. In the mean time, I recommend decent unit test coverage on any non-trivial application to ensure that everything’s working like you expect it to work.

Conclusion

Even with it’s rough spots, I found Groovy to be incredibly robust, stable, and easy-to-use. Not only did it satisfy 99% of my requirements perfectly, it provided time-saving functionality that I didn’t even know I needed. Now I’m curious to see how the end users like it