Installing a few rubys

Once you get rvm installed, you only need to run rvm install 1.9.2. That command will download and build the latest version of ruby 1.9.2 from source. If you also work with Phusion’s ruby enterprise edition, you can install it from source by running rvm install ree.

After running those two commands, you will have three versions of ruby installed on your computer, the system version, ruby 1.9.2 and ruby enterprise edition. However, if you run ruby --version you’ll notice that the system version is the one that is getting executed. Here’s what doing so looks like on my Mac running Mac OS X version 10.6.6.

cloudraker:~ mscottford$ ruby --version
ruby 1.8.7 (2009-06-12 patchlevel 174) [universal-darwin10.0]

However, if you first run rvm use 1.9.2, the running ruby --version should give you exactly what you expect. Try switching to ruby enterprise edition with rvm use ree. Again, running ruby --version should confirm that the switch took place correctly. Should you want to return to using your system’s version of ruby, just execute rvm use system.

If you ever need to check which version of rvm is active, you can run rvm current. This will output the name of the ruby that rvm has setup. We’ll discuss a better way to determine which ruby is active a little later. But first, let’s talk about how rvm helps us manage gems for each project.

Working with gemsets

Since just having different versions of ruby is not enough, rvm also gives us the ability to create different sets of gems that are completely isolated from each other. By default each version of ruby that we install gets its own gemset. We also have the ability to create named gemsets.

We create gemsets with the command rvm gemset create gemset_name. This will create a gemset for the currently selected version of ruby. One thing to keep in mind is that creating a gemset does not automatically switch you to that gemset. To do that you’ll need to use the rvm use command, for example rvm use 1.9.2@gemset_name. If you need to figure out which gemset is active, you can run the rvm currrent command. Once again, a better way to keep track of this is on it’s way.

Here’s a longer example that shows how to create and work with gemsets.

$ rvm use 1.8.6
$ rvm gemset create funkyness
'funkyness' gemset created (/Users/mscottford/.rvm/gems/ruby-1.8.6-p399@funkyness).
$ rvm current
ruby-1.8.6-p399
$ rvm use 1.8.6@funkyness
Using /Users/mscottford/.rvm/gems/ruby-1.8.6-p399 with gemset funkyness
$ rvm current
ruby-1.8.6-p399@funkyness
$ rvm use 1.8.6
Using /Users/mscottford/.rvm/gems/ruby-1.8.6-p399
$ rvm current
ruby-1.8.6-p399

Start using .rvmrc, and stop thinking

To make it impossible to forget which of your projects are using which versions of ruby and even then which gemsets, rvm will look for a .rvmrc in each directory that you switch into with the cd command.

Here’s an example.

$ rvm current
system
$ cd funkyness
$ rvm current
ruby-1.8.6-p399@funkyness

Okay. That looks like magic. What’s going on?

To answer that question, let’s take a peek inside of ~/funkyness/.rvmrc.

rvm 1.8.6@funkyness --create

With that one line, rvm will switch to ruby version 1.8.6 and gemset funkyness. It will even create it for you if it does not exist.

Since this feature could potentially be used to trick you into running malicious code on your system, rvm asks you to trust a .rvmrc file the first time that it reads it. You only have to do this once however.

What’s this post about again?

Now that I’ve explained the finer points about using rvm, I can finally start to vent a little.

I have several ruby projects that I’m working on at the moment. Some are for fun, but most are for my paying clients. I only recently started using .rvmrc files, and I’ve yet to create them for all of my projects. This means that for some projects, I don’t really need to think about which version of ruby is getting run, because it is the version that I’ve specified in the .rvmrc file. For other projects, however, I need to remember to run rvm use with the correct version of ruby for that project.

But I’d hate to run rvm use if I don’t need to. And running rvm current all them time seems a little silly. The solution that I’ve come up with is to alter the bash prompt to always let me know the current version of ruby that is in use by rvm.

To get started I used my favorite search engine to see if someone had already tackled this problem. I found one really good example that even introduced some color, however it was also using some git magic to include the current branch on the prompt. A few modifications later, I came up with my own version that just displays the ruby that is in use by rvm, and it does so while looking like it was copied and pasted out of Textmate.

Here’s what it looks like.

:rvm => 'system'
~ $ cd funkyness

:rvm => 'ruby-1.8.6@funkyness'
funkyness $ cd ..

:rvm => 'system'
~ $

I’ve read some recent discussions where the question of CSS unit testing has been raised. Many of these discussions devolved into a debate about whether or not CSS was “code”. A lot of these commentators complained about CSS not being a Turing complete language. I’d like to claim that this debate, with respect to unit testing, is a giant waste of time. Whether or not CSS is Turing complete has nothing to do with the reasons why one would like to write tests against CSS.

But to avoid that debate, I’ll avoid describing CSS as code. Instead I’d to propose that CSS is actually a domain specific language that is used to control the the way a browser works. For simplicity, let’s think of CSS as a configuration syntax.

CSS is a language that affects the way that HTML documents are displayed by web browsers. As the use of CSS has increased as the primary method for altering the way information is displayed, HTML documents have become more and more semantic. The additional tags that have been added to HTML 5 have made the documents even more semantic.

This means that HTML is basically just data that is displayed by a web browser. Web browsers have a default way of presenting this information. CSS is used to alter this default presentation, which means that CSS is simply a method for configuring the workings of a browser. Since CSS has an effect on the execution of a program, the web browser in this case, that is used for displaying information, it is important to ensure that the configuration is accurate for the task at hand.

This is where testing comes in. Testing should be employed any time that we want to ensure the correct operation of an application.

So can we stop the bitching and get started on a decent method for testing CSS already? I’ve got some ideas, but I’ll have to write about them later, once I’ve had a chance to work up some experiments.

Through the Rackspace Apps control panel, I can change all of the DNS entries for any of the domains that they are hosting. To create a subdomain, all I have to do is create an A record entry for “example” that points to my home ip address. I used whatismyip.org to look that up. Clicked “save”, and then the address started resolving right away. Perfect. Well, at least until my ISP hands out a different ip address.

What I needed was a programmatic way to detect that my ip address has changed and then update the A record entry for example.vaderpi.com with the new ip address.

I dug through the Rackspace Apps API documentation looking for a published way to do this, but I was unable to find one. Then I realized that I could just treat the control panel website as an API by driving it with a headless browser, like HtmlUnit.

There are several ruby gems that provide the ability to drive headless browsers. I took a quick look at celerity, mechanize, steam, and webdriver. I settled in on using steam, because it seemed like it had the fewest number of layers between it and the headless browser. I had also never used it before, and wanted to get a feel for how well it worked.

I have posted the resulting script as a github gist. Take a peek. Comments and forks are welcome. Note that all domain names, user names, and passwords have been replaced with made up examples.

As for running the script, I set up an @hourly entry in cron. The script only contacts the Rackspace Apps control panel if it detects an ip address change, so the risk of accidentally hammering their web server with this, should be low. (I point that out in case any of my old coworkers stumbles across this. :))

The current implementation can only update an existing DNS entry, but it should not be too hard to extend it to support creating additional DNS entries. Anyone that goes to implement this should make sure to correctly handle clicking the add link if there are not any empty rows in the entry table.

In addition to supporting creating new entries, there are a few improvements that I would like to make to this script. (1) I’d like to have an external service resolve the domain. This is going to become critical, because I want my the domain to resolve to the private ip address for devices that are on the private network. (2) I’d like to not rely on whatismyip.org.

I’m thinking of writing a small web service that I can install on my server that will address both of these. The service will be able to do DNS resolution, and it will be able to detect the public ip address of the caller.

This is a ton of content. Wish me luck!

1. Amazing Spider-Man #529
2. Amazing Spider-Man: Decisions
3. Road to Civil War TPB
4. Amazing Spider-Man #530
5. Amazing Spider-Man #531
6. Fantastic Four #536
7. New Avengers: Illuminati Special
8. Civil War: Opening Shot Sketchbook
9. Fantastic Four #537
10. Civil War #1
11. She-Hulk #8
12. Wolverine #42
13. Amazing Spider-Man #532
14. Civil War: Front Line #1
15. Thunderbolts #103
16. Thunderbolts: Swimming With Sharks
17. Civil War #2
18. Civil War: Front Line #2
19. Amazing Spider-Man #533
20. New Avengers #21
21. Fantastic Four #538
22. Wolverine #43
23. X-Factor #8
24. Civil War: Front Line #3
25. Thunderbolts #104
26. Civil War #3
27. Civil War: X-Men #1
28. Cable & Deadpool #30
29. X-Factor #9
30. New Avengers #22
31. Black Panther #18
32. Wolverine #44
33. Civil War: Young Avengers & Runaways #1
34. Daily Bugle Special Edition: Civil War
35. Civil War: Front Line #4
36. Amazing Spider-Man #534
37. Fantastic Four #539
38. Ms. Marvel #6
39. Civil War: Front Line #5
40. Thunderbolts #105
41. Civil War: X-Men #2
42. Heroes For Hire #1
43. Wolverine #45
44. New Avengers #23
45. Cable & Deadpool #31
46. Civil War: Young Avengers & Runaways #2
47. Civil War Files
48. Ms. Marvel #7
49. Civil War #4
50. Wolverine #46
51. Civil War: X-Men #3
52. Amazing Spider-Man #535
53. Civil War: Front Line #6
54. Heroes For Hire #2
55. Cable & Deadpool #32
56. Captain America #22
57. Fantastic Four #540
58. Civil War: Front Line #7
59. Ms. Marvel #8
60. Civil War: X-Men #4
61. Wolverine #47
62. New Avengers #24
63. Civil War: Choosing Sides
64. Captain America #23
65. Heroes For Hire #3
66. Black Panther #21
67. Black Panther: War Crimes TPB
68. Civil War: Young Avengers & Runaways #4
69. Civil War #5
70. New Avengers #25
71. Iron Man #13
72. Amazing Spider-Man #536
73. Civil War: Front Line #8
74. Wolverine #48
75. Punisher War Journal #1
76. Black Panther #22
77. Captain America #24
78. Civil War: War Crimes #1
79. Civil War: Casualties of War TPB
80. Iron Man #14
81. Iron Man/Captain America: Casualties of War
82. Fantastic Four #541
83. Civil War: Front Line #9
84. Winter Soldier: Winter Kills
85. Black Panther #23
86. Civil War #6
87. Civil War: Front Line #10
88. Amazing Spider-Man #537
89. Punisher War Journal #2
90. Thunderbolts #110
91. Blade #5
92. Fantastic Four #542
93. Punisher War Journal #3
94. Civil War: The Return #1
95. Moon Knight #7
96. Moon Knight #8
97. Ghost Rider #8
98. Ghost Rider #9
99. Ghost Rider #10
100. Ghost Rider #11
101. Black Panther #24
102. Civil War #7
103. Amazing Spider-Man #538
104. Civil War Poster Book
105. Black Panther #25
106. Civil War: Front Line #11
107. Captain America #25
108. Civil War: The Confession
109. Civil War: The Initiative
110. Fallen Son: Death of Captain America TPB
111. Fantastic Four #543
112. Civil War: Battle Damage Report
113. Marvel Spotlight: Civil War Aftermath
114. Marvel Spotlight: Captain America Remembered
115. Civil War Chronicles #1
116. Civil War Chronicles #2
117. Civil War Chronicles #3
118. Civil War Chronicles #4
119. Civil War Chronicles #5
120. Civil War Chronicles #6
121. Civil War Chronicles #7
122. Civil War Chronicles #8
123. Civil War Chronicles #9
124. Civil War Chronicles #10
125. Civil War Chronicles #11
126. Civil War Chronicles #12

Read it? Good. Time for my rant.

In case you have a horrible memory (or more likely you did not actually read it, yet. Tisk. Tisk), the short version of the article is that an intellectual property group has requested that certain countries be added to the “Special 301 watchlist” because they advocate using open source technologies for government work.

The first issue that came to mind when I read that is that the organization forgot to request the same status for Oregon and Massachusetts. You know, states that are part of the United States. I am sure that I could have dug up more states if I had spent more time with my pal Google. But 2 minutes seemed like enough to prove my point.

To address the second issue, I need to draw your attention to the organization’s own words. Let me paraphrase.

“The Indonesian government’s policy … weakens the software industry … [because] it fails to build respect for intellectual property rights.”

Ugh! Without strong intellectual property rights open source would not be possible. Every open source license builds on the foundation of the author’s copyright as established by law. These licenses provide authors with a legal framework for granting permissions to others.

<sigh/>

I really hope this request was not taken seriously. I had thought that fear, uncertainty and doubt (FUD) attacks against open source were behind us. This was a tactic that Microsoft employed very heavily during its spats with Netscape and the U.S. Department of Justice.

But in recent years, Microsoft has started developing new products out in the open that are under open source licenses. This is in addition to the large amount of code that was initially developed internally and then later released to the public as open source. New projects include, IronRuby and the ASP.NET MVC library. While the other class includes WiX[1] and a host more.

[1]: Shameless plug: I have contributed code to the WiX project, and it was accepted!

The final issue that I will point out is the incredibly large number of companies that this group represents. It does not represent any company directly, but instead does so through other industry groups. But the list is quite large. And amusingly enough, if you dig deep enough into the member lists, you will find some big corporate open source supporters such as Adobe, Apple, IBM and Microsoft.

• Association of American Publishers (AAP) – [274 members]
• Business Software Alliance (BSA) – [35 members]
• Entertainment Software Association (ESA) – [29 members]
• Independent Film & Television Alliance (IFTA) – [143 members]
• Motion Picture Association of America (MPAA) – [6 members]
• National Music Publishers’ Association (NMPA) – [more than 800 members]
• Recording Industry Association of America (RIAA) – [3905 members]

(Note: the member counts may be a little misleading, because many companies are represented by several of these groups. Don’t just add them all up if you are trying to get a total count.)

This is normally where I would stick a nice little conclusion paragraph to tie my whole post together, but I am too tired. So, I’ll leave that part as an exercise for the reader. What conclusions do you draw from this information? Leave them in the comments.

Furthermore, the shinning star of the Fingerworks product line up, the TouchStream, supported a multitude of firmware enabled keyboard layouts. One of these was an experimental layout, named Qwerak. It was meant to be a modified version of the Dvorak keyboard layout with the hope of addressing two problems. (1) The difficulty involved when typing on a surface with no tactile feedback, and (2) the steep learning curve that is involved in switching from Qwerty to Dvorak. (<bragging>Although, it can’t be too steep, because Andrea was able to pick it up in about three weeks. But then again, she is super smart.</bragging>)

Did Wayne Westerman use the Qwerak keyboard layout himself? I don’t know; I can only speculate. But as an RSI sufferer myself that types in a non-Qwerty layout, I can confidently state two facts. (1) Without a doubt, typing with Dvorak induces less pain than typing in Qwerty, and (2) when forced to use the Qwerty keyboard layout to interact with a computer, my productivity becomes dramatically reduced. I estimate that my productivity when using Qwerty is about 1/5th of my productivity when I am using Dvorak. From these two pieces of data, I speculate that if Mr. Westerman found Qwerak to be even easier to type with than either Qwerty or Dvorak, then it would be very painful, frustrating, and counter-productive for him to type with any other keyboard layout.

So this brings me back to my original question: When Wayne Westerman turns on an iPad, launches the email app, touches the compose email icon and then touches inside the address bar, what keyboard layout is displayed on the screen? I’d be willing to bet a whole bunch of donuts that it is not Qwerty.

Hopefully, one day, when I repeat those same steps, I’ll be presented with a Dvorak keyboard layout. Until I can assure that I will, I won’t be spending a dime on an iPad. Who knows, maybe Google will come out with a Android based tablet device. If so, I’ll flock to that. On that platform, developers have the ability to write custom input methods, including alternative keyboard layouts.

What do you think Google will call such a device, if they develop one? I like Nexus Prime. But, since I name my computers after Transformers, I might not be the best person to ask about potential names.

Over the weekend I pulled down OC ReMix’s Final Fantasy VII: Voices of the Lifestream project. I listened to the entire four-disc set while coding at work yesterday, and about half of it while coding in bed last night.

I really enjoyed listening to the album while coding, but I did not enjoy listening to the songs as my primary focus. I have two theories about this. One, these songs were composed to be background music, so if you pay too much attention to them, you break the spell. Or two, listening to these songs directly conjures up images of tireless sitting in front of a small television with a Playstation controller in my sweaty hands, desperately trying to figure out where to go next, and hoping that I don’t run into a battle along the way, because the battle music always makes me jump out of my skin when it starts at 3 AM, and I am pretty low on life anyway, though I really could use the XP, all the while wondering why Aeris had to die.

Yeah, my money is on the second theory.

[Disclaimer: I worked on this game on and off from mid 1998 through about 2005. I never finished, stuck in the ice mountains on the third disc. Oh, and the movie was beautiful, but it sucked, so I protested by buying it anyway.]

Monkey patch Pathname for Windows paths

Since I am using the Pathname class to build paths in my examples, I need to give you the monkey patch that I use to make Pathname correctly display win32 paths.

require 'pathname'
class Pathname
  alias_method :original_to_s, :to_s
  def to_s
    original_to_s.gsub('/', '\\')
  end
end

Visual Studio command line environment

Running command line Visual Studio tools requires having certain environment variables loaded. This can be done by running vsvars32.bat directly or by launching a Visual Studio command prompt from the start menu. This is something that I always forget to do; my terminal windows spring into life by typing cmd in the run box. So, I wanted to write a task to ensure that the environment was properly set up.

I am working with Visual Studio 2005. If you want to use the Visual Studio 2008 tools then you will need to adjust the vsvars32_bat variable accordingly.

vsvars32_bat = Pathname.new(
  "c:\\program files\\") +
  "microsoft visual studio 8" +
  "common7\\tools\\vsvars32.bat"
task :vsvars do
  if ENV["VSINSTALLDIR"].nil?
    `\"#{vsvars32_bat}\" && set`.each do |line|
      if line =~ /(\w+)=(.+)/
        ENV[$1] = $2
      end
    end
  end
  raise "Eek!" if ENV["VSINSTALLDIR"].nil?
end

This code is the product of about 30 minutes of googling. I eventually found this trick in the shoes rakefile[1].

Now any task that needs to call a Visual Studio command line tool just needs to declare vsvars as a prerequisite, like so.

task :csc => [:vsvars] do
  sh "csc test.cs"
end

Building with msbuild

This is actually pretty easy once we have the environment set up correctly. Just create a task that calls msbuild from a sh call.

namespace :build do
  desc "Build the core project"
  task :core => [:vsvars] do
    sh "msbuild #{core_solution_path}"
  end
end

Controlling Cassini (or webdev.webserver)

There is a lot going on here, so let me first overwhelm you with the code, and then explain what it is doing.

def wait_until_site_loaded
  puts "Please be patient. Waiting for site to respond...."
  site_loaded = false
  until site_loaded
    site_loaded = system
      "curl -L -I -f http://localhost:2088/Default.aspx > NUL 2>&1"
  end
  puts "done."
end

namespace :web do
  desc "Start the local web server"
  task :start => [:vsvars] do
    Thread.new do
      sh "webdev.webserver /path:#{web_root_path} /port:2088 /vpath:/"
    end    

    wait_until_site_loaded
  end

  desc "Stop the local web server"
  task :stop => [:vsvars] do
    `taskkill /im webdev.webserver.exe > NUL 2>&1`
  end

  desc "Restart the local web server"
  task :restart => [:vsvars, :stop, :start]
end

Before the code block above will work, you will need to create a web_root_path variable that points to the absolute path of your website. Relative paths will not work.

The web:start task will start the web server. If an instance is already running at the specified port, then you will get an error message in the form of a dialog box. I wish I knew how to make it fail silently. (I also wish I knew how to prevent it from displaying an annoying balloon notification.)

After starting the web server, the web:start calls out to curl to make sure that the site is responding to get requests. I have curl installed as a result of installing cygwin. There are other ways to get curl, but you will need to make sure your path points at it’s location to use the code above without modifications. curl is pretty chatty, so I have silenced it by routing its standard out and standard error streams to NUL.

The web:stop task will kill all instances of Cassini. This might be annoying if you have more than one instance running. If that is the case, then you will need to write in some form of accounting for the process id of the web server process, or develop a way to figure out which process id owns the port you want. Once you know the specific pid, you can call taskkill /pid and pass it the pid of the process you want to kill.

The web:restart task will call web:stop task followed by web:start task.

One more thing: display available tasks from default task

Note: This recipe does not apply to just Windows development. It will work on any platform.

You can get a list of documented tasks by calling rake -T, but I always forget to do that. I usually just call rake when I want to know what it does. So I created a :default task that displays the same task list that you get when you call rake -T.

task :default do |task|
  puts "You must specifiy a task. Available tasks are listed below:"
  task.application.options.show_task_pattern = /.*/
  task.application.display_tasks_and_comments
end

That’s it. I hope you found these recipes helpful. Happy coding!

[1]: This is way off topic, so I stuck it in a footnote. I know it’s old news, but the way _why, the creator of shoes, committed Internet suicide really irritates me. There were a lot of people benefiting from his contributions to the ruby world, and then one day he just decides to take his toys and go home. He could have bowed out graciously, explaining that he had moved on, but he instead chose identity death. His works remain in archived form, but I am not sure if there is still any energy behind them.

The application that I am working with performs a lot of client-side DOM manipulation. This can create instances where my script was asking Watir to perform operations on DOM objects that didn’t exist. To defend against that, every time that I called click or set or select on various DOM objects, I wrote two additional statements. One to make sure the browser had finished whatever it was working on, and one to make sure that the element I was about to interact with actually existed.

The code looked something like this.

  @browser = Watir::Browser.new
  @browser.goto("http://localhost")

  @browser.wait
  Watir::Waiter.wait_until { @browser.text_field(:name, /UserName/).exists? }
  @browser.text_field(:name, /UserName/).set("Admin")

  @browser.wait
  Watir::Waiter.wait_until { @browser.text_field(:name, /Password/).exists? }
  @browser.text_field(:name, /Password/).set("Password")

  @browser.wait
  Watir::Waiter.wait_until { @browser.button(:name, /Submit/).exists? }
  @browser.button(:name, /Submit/).click

While that works, I got really sick of having to re-type the selector for the DOM element that I wanted to muck with. What I wanted to do was write code that looked something like this.

  @browser = Watir::Browser.new
  @browser.goto("http://localhost")

  @browser.text_field(:name, /UserName/).wait_to_set("Admin")
  @browser.text_field(:name, /Password/).wait_to_set("Password")
  @browser.button(:name, /Submit/).wait_to_click

Wow. That is much more concise and easier to understand. Even a non-programmer can understand what is happening now.

To make this code actually work, I decided to write a quick monkey patch that adds a “wait_to_” alternative for every method that can be called on input elements and links. These methods call @browser.wait, ask Watir::Waiter to wait for the element to exist, and then call the requested method.

I called my monkey patch Watir Wait. (Get it? I crack myself up! :)) Take a peek and let me know what you think. If I get enough positive feedback, I’ll rework this into a proper patch and submit it to the Watir team for inclusion.

• Christmas Plans
• Abstraction
• Natural Parenting
• The Sun
• Experiment
• Sagan-Man – Andrea has to take a look at this one!
• Sympathy
• Lego
• Movie Narrative Charts – my favorite is the one for Primer.
• Bag Check
• Tech Support Cheat Sheet
• Lease
• Estimation