Dr Nic

Future proofing your Ruby code. Ruby 1.9.1 is coming.

Bugger.

I’m a Ruby monogamist. I use the Ruby that comes with Leopard (ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]). Oh sure I’ve cheated on my Ruby a couple of times. It was just sex, I didn’t fall in love, I promise.

My machine has had various versions of jRuby, Rubinius and MacRuby installed at various times, but I don’t think it’s ever had two working copies of Ruby MRI (Matz Ruby Implementation) at a time.

Ok, that’s a lie. On Christmas Day 2007, Matz released Ruby 1.9. Yes I was a deviant. I installed it. But I didn’t inhale. ruby19 sat on my filesystem outside the $PATH. It was a trophy not a tool.

My Ruby monogamy was working out perfectly for me, whilst I collected futurist and novelty Ruby implementations as a passive hobby, until yesterday when I saw the above tweet.

That’s a bit of a bugger. I mean, why was he playing with Ruby 1.9.1 anyway?

Or perhaps having multiple version of Ruby on one computer isn’t some illicit activity. Everyone else is doing it, Your Honour.

I still didn’t care for having multiple ruby versions lying around in my path; but I had to fix rubigen. I just wanted a way to fix bugs against ruby 1.9+ and move on with my life. I didn’t want to have to do any manual work in order to set this up. Surely someone else has solved this problem already?

(more…)

iPhone dev podcast about fmdb-migration-manager and rbiphonetest

Radio is where ugly people go. Podcasts is where ugly, niche people go. It doesn’t get much uglier and nicher than talking about iPhone dev; and the tale of one desperate man X on a desperate journey Y with his desperate sidekick Z, where:

  1. X = Dr Nic
  2. Y = iPhone development
  3. Z = Ruby

From the Mobile Orchard news desk:

drnic.png

Dr. Nic talks about his migration manager for updating SQLite iPhone databases, trying to get Ruby onto an iPhone, using Ruby to unit-test Objective-C iPhone code, his company Mocra, and the Mobile Orchard Podcast’s lavish recording studios.

Dan Grigsby is the interviewer and post-production guy for the interview, and so it is entirely his handy work that it seems like I’m the only one talking for 15 minutes. The original interview took 4 hours and it was mostly him talking. He’s quite a chatterbox. I barely got a word in edgewise. [1]

Dan also created this list of “things we talked about”:

  1. 0:00: Migrations for SQLite
  2. 5:18: Getting Ruby onto an iPhone
  3. 5:59: Nu – Lisp-based language that sits atop Obj-C and would work on the iPhone
  4. 7:37: Unit testing Obj-C from Ruby
  5. 8:12: Webkit UIs
  6. 12:31: Mocra / “Used my blog for evil”


Go to Mobile Orchard (or Mobile Awkward it is accidently called at the end of the interview) to cop a listen.

[1] This paragraph starts well and ends with blatant falsehoods.

Unit Testing iPhone apps with Ruby: rbiphonetest

rbiphonetest logo

Everything to love about Ruby: the concise, powerful language; the sexy testing frameworks; and finally, the people.

Everything to love about Objective-C: hmmm; well…; and finally, its the only high-level language you can use to write iPhone apps.

On iPhone 2.0, to arrive on the 11th of July, you cannot run RubyCocoa. But you can run it on your Mac, so let’s use it to unit test your Objective-C classes. This tutorial shows you how to get started using a new project rbiphonetest [GitHub | Lighthouse | Google Group]

If you followed some of my recent tweets, this project was previously called “iphoneruby”. And alas, the screencast also calls it “iphoneruby” but that was a crap name. People thought it was a way to run Ruby on the iphone. I can’t do that yet. So, a far better name is ‘rbiphonetest’. [track on summize]

Even if you’ve never touched Objective-C, Cocoa, the iPhone SDK, nor RubyCocoa I recommend watching the video anyway. It should give you hope that if you make the transition to iPhone development you don’t have to go alone without Ruby: your trusty swiss army knife of language/libraries/tools.

The screencast is also available in high-def video (55Mb QuickTime)


Unit Testing iPhone apps using Ruby from Dr Nic on Vimeo.

Installation and Usage

To summarize the video, but change ‘iphoneruby’ to ‘rbiphonetest’, you install the framework via RubyGems:

sudo gem install rbiphonetest

Then change to your project’s folder and install the test framework:

rbiphonetest .

Finally, for each generic, non-UIKit-framework-using class you want to test:

script/generate model WidgetModel

Then write your tests in test/test_widget_model.rb

Supported Cocoa & iPhone frameworks

The mysterious, magical premise upon which rbiphonetest depends is possibly erroneous: that your Objective-C class can be compiled and tested against your OS X/Intel frameworks, and if your tests pass you assume you can then compile and include your class with the the iPhone/ARM frameworks.

I’m willing to go with this assumption until its proven dangerously flawed by some angry 20-year veteran of NextStep/Cocoa/iPhone. But really, how different could NSString be on the iPhone versus your Mac?

Fortunately there is one way to check for significant differences between your available Mac-based frameworks, such as Cocoa, and the iPhone-based frameworks, such as UIKit. We need to compare the framework names, header files and method signatures.

So for example, you cannot currently unit test any class that depends on/includes the UIKit framework. Why? It doesn’t exist on your Mac, so the Mac/Intel compiler cannot link it in. We’re compiling and running our tests with RubyCocoa, which itself is built against the Mac/Intel frameworks, not the iPhone frameworks. Hell, Laurent doesn’t even own an iPhone :) [Laurent is the Apple-employee maintainer of RubyCocoa and the newer MacRuby]

Similarly, its no use including/linking the Cocoa framework into your Objective-C class. Why? It doesn’t exist on the iPhone. It has its own UI frameworks, collectively called ‘UIKit’.

So for the moment we cannot test UI-related, iPhone-API-specific code. But we can test generic Objective-C. That’s better than a kick in the teeth. Surely. I mean, in the teeth… that’d friggin’ hurt.

“Fair enough Dr Nic, so which frameworks can my code use and yet still unit test it with your oh-so-special test library thingy?” Keep your pants on, I’m getting there. [ref]

To the best of my ability, I’ve compared the two sets of frameworks and listed the available Frameworks that are available on both the iPhone and your Mac. There are about a dozen. The most important is called ‘Foundation’. It holds gold nuggets like ‘NSString’.

The list of platform differences is on the wiki as a reference.

Note, this list doesn’t guarantee that any two framework classes – the iPhone and matching Mac framework – will behave the same. This list is compiled by finding the set of Frameworks with the same name on both platforms, e.g. Foundation.

Then it compares the set of public header files (Foundation.framework/Headers/*.h files) This comparison is by method signature. It pulls all lines from each header that start with + or – (+ is a class method and – is an instance method in Objective-C) and compares the two lists. If there is a single difference in the method signatures of the header files in the two platforms it is marked on the wiki page. You’ll need to look at the two header files yourself to see the differences. Some header files are ugly. C-based anything starts ugly and goes down from there, I think.

Python testing of iPhone Objective-C?

In the Python world there is PyObjC, a bridge-based twin to RubyCocoa. If you are a Python developer you could easily port this project to use PyObjC I would think. Ping me if you are attempting this and need any help.

Summary

I think this project can give Ruby developers a happy place to work from as they write their Objective-C/iPhone code. You still need to wire up your UI views and controller classes manually, but if you push all the “oooh that code really needs some tests” classes away from the UI-dependent frameworks then you can hook it up to rbiphonetest and write your tests in Ruby.

Currently the generator creates test/unit test stubs. I personally then add the Shoulda gem into my test_helper.rb for my apps. If an rspec and/or test/spec developer can help with adding support to the generators I’m certain the large rspec user-base would be happy campers.

Similarly, someone might like to investigate using MacRuby to run the tests instead of RubyCocoa. Fast tests vs slow tests. You choose.

What the?

Sometimes I re-read what I’ve written and notice things that don’t seem to make sense, but are in my vocabulary nonetheless. Yep, the things you learn living in Australia.

“Keep your pants on” – this seems to imply that until I mentioned otherwise you were about to take your pants off. Hardly relevant at any stage during this article, we’d both agree. Most code-based blog articles are “pants on”. This phrase means “don’t get upset”. You can try to figure out how you go from “don’t get upset” to “keep your pants on”. I have no idea.

Using Ruby within TextMate snippets and commands

I didn’t know you could run Ruby within TextMate snippets. As a consequence, a lot of the TextMate bundles I work on either have simplistic Snippets or the advanced code is run via Commands with code pushed into explicit Ruby files in the Support folder.

But sometimes I just want a clever snippet. For example, I want the ‘cla’ snippet to use the current filename to create the default class name instead of the current ‘ClassName’ default. I want default foreign key names to be meaningful.

I’ve now figured this out (thanks to Ciaran Walsh), and …

Um, lost already? Ok, let me show you via screencast on Snippets and Commands with Ruby (QuickTime (11Mb)):


TextMate Snippets running Ruby from Dr Nic on Vimeo.

Want to learn more about living with TextMate and Ruby?

The TextMate website has a series of videos, including one by the Ruby.tmbundle’s own James Edward Gray II (JEG2).

In addition, there is the latest TextMate for Rails 2 Peepcode written by myself and spoken by Geoffrey Grosenbach. Its cheap at $9, good value at $15.50, and perhaps overpriced in the $20-$30 range. Lucky its only $9.

The snippets used throughout the video

The current Ruby.tmbundle snippet (activated via ‘cla’):

class ${1:ClassName}
	$0
end

An attempt to use regular expressions to convert the filename to a classname:

class ${1:${TM_FILENAME/[[:alpha:]]+|(_)/(?1::\u$0)/g}}
	$0
end

The final snippet, with embedded Ruby to do the heavy lifting (note: added ‘singluarize’ to the snippet):

class ${1:`#!/usr/bin/env ruby
    require 'rubygems'
    require "active_support"
    puts ENV['TM_FILENAME'].gsub(/\.rb$/, '').camelize.singularize
    `}
	$0
end

Add this to your own Ruby.tmbundle, or clone mine (which is a clone of the original subversion repo).

Get ready for the TextMate “Trundle to Rails 2.0 Bundle”

logo_bundle.png

Have you noticed lately that the Rails TextMate git pull origin two_point_oohbundle (also installed with e – the Text Editor for Windows) isn’t quite as helpful as it once was – guiding and amplifying your rails app development.

Your resourceful/restful rails apps are now filled with named routes, but none of the helpers (link_to, redirect_to, etc) use them. The default view template was still rhtml for a long time (latest svn trunk fixes this to be html.erb, though Marc Jeanson is having a crack at supporting both through a per-project config file).

Or perhaps you were hoping for some snippets for new features of Rails 2.0: assert_difference (asd), assert_select (ass), respond_to (rst).

Or just maybe, you’ve been updating your local bundle to Rails 2.0 already? Please say yes, please say yes. If you are saying “yes”, read at the bottom for how/where to send me the patches. If you are saying “no”, read at the bottom for how/where to start creating patches and sending them to me.

Firstly, DHH didn’t write the Rails bundle

I didn’t know this – I just assumed the guy who created Rails and helped promote TextMate also created the Ruby on Rails TextMate bundle. Instead if was WWF’s “The Rock” himself Duane Johnson (figurines sold separately, and may look different to the real Duane Johnson who writes Rails code instead of prancing around in his underpants with other adult males in confined spaces).

The TextMate SVN logs say that it the bundle was first committed in Jan 2005. Its now Jan 2008. That’s three years of maintaining a suite of code that thousands of people take for granted every day writing Rails code. What a champion.

Like the Australian Cricket team’s wicketkeeper, Adam Gilchrist, he’s also retiring at the top of his game.

New Maintainer… me

Instead of maintaining my own projects, I’ve decided to maintain this one. I love the TextMate bundles. Before I had a Mac, I ported them across to RadRails and many RadRailers entered a golden era of snippet happiness.

My bundle-fu may not be the equivalent of Bruce Lee, but I’m keen to see my favourite Rails tool live on strong.

Bleeding edge bundle

Whilst the TextMate SVN administrators process the maintainer change request (Allan is on holidays somewhere and he took the house keys with him), you might think all is lost!

Never.

The straight-off-the-cow bleeding edge Rails bundle can be accessed via Git. Specifically the branch two_point_ooh.

So, let’s all do away with our pre-existing Rails bundle and live on the edge.

cd ~/"Library/Application Support/TextMate/Bundles/"
mv "Ruby on Rails.tmbundle" "RoR.tmbundle.orig"
git clone git://github.com/drnic/ruby-on-rails-tmbundle.git "Ruby on Rails.tmbundle"
cd "Ruby on Rails.tmbundle"
git checkout --track -b two_point_ooh origin/two_point_ooh
git pull

Now, back in TextMate, go to menu “Bundles” > “Bundle Editor” > “Reload Bundles”.

You, my friend, are sitting pretty.

Upgrading to when newer blood is on the bleeding edge

Coming back for more?

cd ~/"Library/Application Support/TextMate/Bundles/Ruby on Rails.tmbundle"
git checkout two_point_ooh  # optional; only if you changed to another branch etc
git pull

Now, back in TextMate, go to menu “Bundles” > “Bundle Editor” > “Reload Bundles”.

Bathe yourself in glory. Splash it all over yourself.

Submitting patches

If you go into TextMate, launch the Bundle Editor (Cmd+Alt+Ctrl+B) and change something in the Ruby on Rails bundle, then files will added/changed within your local git clone.

What I mean is, you can very simply submit patches now. [When I say "simply", I mean, "I think this is the best approach but I could be completely wrong here..."] Git is so cool that I don’t know what its doing most of the time; but let’s hang in there as a team.

cd ~/"Library/Application Support/TextMate/Bundles/Ruby on Rails.tmbundle"
git add .   # to add any new files/snippets/commands you created; TextMate uses one file per snippet
git commit -a -m "Useful message about this patch goes here"
git diff -p HEAD^ HEAD

[Theoretically] this creates a patch based on your most recent commit. So you can easily create patches for changes even if your repository and the remote/central/bleeding edge repository look different.

If your patch was created over several commits, then replace HEAD^ with HEAD~4, if there were 4 commits.

I think. God I could be wrong about this though.

Just try your best and if it works, let me know and I’ll remove all this “I don’t know what I’m talking about” text and future readers will think I know everything. Web 2.0 rocks.

Send patches to…

Me drnicwilliams@gmail.com [update] or via the new Google Group.

Update: Note there is a new Google Group (rails-textmate) created in Feb 2009 due to Spam and loss of admin control on original group.

Want to fork the git repo? Use a free account at Gitorious or GitHub.

Google Groups
Ruby on Rails: TextMate
Visit this group

Trundle to Rails 2.0 Bundle

Arguably, we just keep patching the bundle forever and bleeding edges will continue to live happily within the blood and muck of said existence.

But, lots of other people want nicely zipped up bundles. No doubt “e – the Text Editor” will want a “released” version so they can clean it of all the ugly things they can’t yet replicate like Macros. And eventually I’ll push it all down to the SVN repo and it will be released with future TextMate upgrades.

So, there will be a “Rails 2.0 compatible” grand opening one day soon. Probably before 14th of March 2008, when I’m giving a “What’s new in Rails 2.0?” talk at QCON London. Showing off the new bundle will be sweet.

That gives us 6 wks to refactor this bundle to make it a shining example of all that is wonderful in Rails 2.0. Every patch helps.

[Please consider Rails 1.2.6 and before developers when conceiving of patches, and please consult your doctor if pain persists.]