foodforsamurai.com

It’s so hard to say goodbye to yesterday.

Tue, 01 Jun 2010 23:53:26 -0400

It’s so hard to say goodbye to yesterday.

# Life with bundler protip alias be="bundle exec"

Mon, 03 May 2010 23:58:00 -0400

# Life with bundler protip
alias be="bundle exec"

http://code.google.com/p/autopair/

Thu, 15 Apr 2010 00:12:00 -0400

http://code.google.com/p/autopair/:

Yet another attempt to pair quotes and such in Emacs. This one, however, seems to be doing a better job than wrap-region.

http://www.blogotheque.net/-Concerts-a-emporter-

Sat, 10 Apr 2010 01:59:52 -0400

http://www.blogotheque.net/-Concerts-a-emporter-:

It feels vitally important to occasionally stay up late, catching up on these videos. All bleary-eyed.

http://ecukes.info/

Tue, 06 Apr 2010 23:17:08 -0400

http://ecukes.info/:

Cucumber for Emacs, naturally.

http://gembundler.com/

Mon, 05 Apr 2010 00:17:05 -0400

http://gembundler.com/:

A pretty good sell, and --disable-shared-gems brings the good ol’ days back.

Testing Tweetie to Tumblr… Update: …and that just hosed Tweetie, which no longer can...

Fri, 02 Apr 2010 19:03:00 -0400

Testing Tweetie to Tumblr…

Update: …and that just hosed Tweetie, which no longer can authorize me with Twitter, even after I dropped and tried to re-create the account. Less than awesome.

And... we're back

Tue, 30 Mar 2010 01:39:12 -0400

So it’s come full circle — this blog now lives at foodforsamurai.com, it’s initial home on the nets. In addition, it’s now hosted on Tumblr. At a certain point, maintaining your own blog software no longer becomes a decent use of your time.

There are still lots of small improvements to make, however, and I’m hoping to replace the logo, update the font, add links to previous/next pages and the archive, etc. etc. in a somewhat timely fashion.

Migrating the old posts was a straightforward affair with the API docs in one hand and Ruby in the other. The bulk of it was like so:

Nested attributes, becomes, and foreign keys

Fri, 04 Dec 2009 04:38:13 -0500

I love me some nested attributes in Rails, but I’ve run into some gotchas in the past few days on 2.3.4 that I’m documenting here in hopes of saving time for some wayward programmer.

STI + pre-built association + AR#becomes = FAIL

Ground rules: it’s common to pre-build associated objects in the controller in order to pass a model to the form helper, like so:

# In the controller

def new
  @child = Child.new
  @child.build_widget
end

AR#becomes is helpful when building forms for STI models, since it casts your child object as the parent class, thereby generating a route that points to the parent controller. In the common case where you have a form with a drop-down that lets you select the child class, this is the route you want:

# In the view

- form_for @child.becomes(Parent) do |form|    # Posts to parents_path
  - form.fields_for :widget do |widget_form|

But behold, in this case, the built Widget object will not be available to the form helper in the fields_for call. Instead, nil is passed and you’re certain to witness a NoMethodError. What happened?

It turns out that AR#becomes creates a new object of the specified class and clones three ivars to maintain state — @attributes, @attributes_cache, and @new_record. When you call #build_widget on the child object, however, it creates a new ivar, @widget, to hold the new record. Since this doesn’t get copied over, our associated Widget never makes it to the form helper and kablooey.

The workaround? Coerce the correct route another way:

- form_for :parent, @child do |form|    # Also posts to parents_path

Not as expressive, but it gets the job done. Finally, I’m not positively sure that this is a bug in Rails. That is, it may be too dangerous to copy over every ivar to the new object, and it may be too cumbersome to try and detect the safe ones.

belongs_to and nullifying the foreign key

Say you have the following:

class Book < ActiveRecord::Base

  belongs_to :person

  accepts_nested_attributes_for :person, :allow_destroy => true

When you delete the nested object:

book.person_attributes = {:id => book.person_id, :_delete => true}
book.save

The person will be deleted, but the person_id on the book will retain the now-invalid id. This is especially problematic if foreign key constraints are involved and the database will certainly yell at you for breaking integrity.

The solution is creating the mirrored association and specifying that the foreign key should be nullified:

class Person < ActiveRecord::Base

  has_many :books, :dependent => :nullify

Now, book.save updates the Book first, setting person_id to nil, before it destroys the Person. Again, this doesn’t seem like a bug, since the mirrored association appears to be the Right Thing To Do anyway. Then again, maybe I’ll change my mind and fire off a couple of Lighthouse tickets.

Quick bundler notes

Mon, 17 Aug 2009 04:58:56 -0400

I have high hopes for Yehuda’s bundler — config.gems has always been troublesome and I like the merb approach of simply creating a local gem repo just for your app. With that, a few observations after diving in…

It doesn’t like source "http://gems.github.com" for now. There’s an open issue for it.

Dropping the suggested require at the top of boot.rb does the trick for Rails, but it doesn’t make use of other environments, if you have them defined (that’s the :only => [:test, :cucumber] bit).

A quick fix at the top of Rakefile:

  ENV['BUNDLER_ENVIRONMENT'] =
    case ARGV[0]
    when /^features/    then "cucumber"
    when /^(spec|test)/ then "test"
    else "default"
    end

  require(File.join(File.dirname(__FILE__), 'config', 'boot'))

Then in boot.rb, subsititute the initial require with:

  require File.expand_path(
      File.join(
        File.dirname(__FILE__), 
        '..', 'vendor', 'gems', 'environments', 
        ENV[ BUNDLER_ENVIRONMENT'] || "default"
      )
  )

At the very least, this loads the test and cucumber environments when running rake spec and rake features respectively.

Finally, if you see these:

config.gem: Unpacked gem cache in vendor/gems has no specification \
      file. Run 'rake gems:refresh_specs' to fix this.
config.gem: Unpacked gem cache in vendor/gems not in a versioned \
      directory. Giving up.

You can add the following line to config/environment.rb to suppress these warnings:

Rails::VendorGemSourceIndex.silence_spec_warnings = true

Update on August 25: looks like everything I’ve mentioned above has been resolved as of the 0.5.0.pre release. Awesome. I wonder if this is being folded into Rails 3?

A name for your number

Sat, 18 Jul 2009 05:21:29 -0400

Google Voice is here. When it comes time to pick your Google number, they provide a search tool that scopes by area or ZIP code as well as strings of letters and numbers. I quickly tried my name, to no avail, and then began searching for that elusive ten-character phrase.

To that end, here’s a quick script that will let you input T9 numbers and spit out matching words. Give it something like:

$ ruby t9.rb 347 10

And it’ll spit out words that begin with the T9 numbers “347”, up to ten characters in length. Good luck.

Toddler interface

Mon, 15 Jun 2009 04:35:05 -0400

My iPhone is not a toy. I’ve tried conveying as much to my toddler, but she still pines after it and has managed to grab it on a few occasions. Thankfully, she doesn’t fly off in a tear, but rather, plops rights down, fully absorbed.

It’s fun to watch her with the phone — tapping around, pressing the buttons, calling people — and now, she really seems to get the interface. She scrolls lists, browses photos, and taps buttons expecting results. Any doubts I have about the interface are vanquished by watching her use the phone. It just comes to her so naturally.

Of course, now she touches other displays and gets frustrated by the lack of interaction. Maybe soon all screens will be touchscreens, but engineers and interface designers better hurry up, lest they fail to meet the expectations of a different generation.

Emacs

Wed, 04 Mar 2009 07:48:38 -0500

There’s nothing like late night improvements to your editor. Tonight’s finds:

And for those so interested, my .emacs file can be found on github.

On stereotypes and choices

Tue, 03 Mar 2009 03:25:32 -0500

I’ve mentioned Radiolab here before. It’s a remarkable radio program produced by WNYC that talks about science in delightful, entertaining, thought-provoking way. If you haven’t listened, please do yourself a favor and check it out.

I’d like to talk about a recent episode, Choice, and it’ll certainly help if you’re familiar with it. I’ll do my best to summarize however, where necessary.

So there’s this experiment. I won’t pretend that I’ve read the entire paper, but in brief:

Subjects are asked to complete a simple task — memorize a number, walk down a hall into another room and recite the number. Some people are given a two-digit number, others a seven-digit number. While walking down the hall, they are interrupted by a staff member who thanks them for their participation and rewards them with a snack of their choosing, either chocolate cake or fruit salad. Those who were given seven-digit numbers overwhelming chose cake.

First, there is no cake. Now that we’ve gotten that out of the way…

So what was the conclusion? Simply put, our rational minds are feeble, so much so that a simple seven-digit number blows the fuse and our ability to make sensible decisions, like fruit over cake, are impaired. The fruit salad is there to gauge the logical response, since it speaks to our sensibilities concerning weight and appetite and overall health. Chocolate cake, is well, chocolate cake — the mental meltdown after heartache.

Almost immediately, I thought of the stereotype of the fat programmer/IT worker. Our job is to be logical all day — juggle numbers, variables and contexts, keeping all the threads between them tidy and organized. Our rational brains are chock full, and all the other decisions in our lives that could make use of some logic get stuck with a short stick. So we eat pizza, too much. Ignore significant others. Get too little sleep, say things before we think about them and beat up helpless puppies. Granted, a bit much of a generalization/overinflation, but it’s interesting to see a possible explanation for a common stereotype.

More so, perhaps we can learn something from this. If we’re really wired this way, then it should pay to unplug from time to time. Spool down in order to save capacity for other important decisions. Your logic is a limited resource.

I had something else to say about this episode, but it’s getting late. I’ll spit it out later.

Dot gov

Wed, 25 Feb 2009 05:29:59 -0500

The existence of Recovery.gov impresses me. I mean, that was quick. And it runs on Drupal.

Another great site focusing on the recovery effort is Stimulus Watch, and in the same fashion, the story of its timely rise is inspiring. CodeIgniter, wow.

So where’s the Ruby love?

A busy winter

Wed, 25 Feb 2009 04:21:40 -0500

I dare say, life’s moved pretty quickly, both professionally and personally. A quick rundown is in order.

First and foremost, our second child is on the way. Unexpected, surely, but we’re looking forward to a new arrival this summer. I plan to have a whole army by the time that I’m through.

On the working front, I spent some time at the end of last year chasing freelance, but after a pleasant courtship, I’ve landed at Pivotal Labs. It’s a great company and I feel fortunate to work with such a talented crew. These days, I have a renewed sense of excitement and fun going into the office and that’s never a thing to take for granted.

I guess that’s it for now.

Auditorium

Mon, 08 Dec 2008 05:14:04 -0500

Beautiful, fun Flash game. This is what we should be doing with our spare (and not so spare) time. Well done.

Pies

Tue, 02 Dec 2008 03:50:22 -0500

For Thanksgiving this year, my contribution was pies. Witness:

These were the apple pies. I also made two pumpkin pies. Nearly everything was cooked from scratch — the crusts, the apples, the pumpkin filling. I only neglected to make the pumpkin puree myself since that would have involved wrestling with too-large vegetables. Even I have my limits.

Thankfully, I had some good recipes in my corner: Martha Stewart and Cooking for Engineers. Each of the recipes, however, targeted only a single pie, which led to my greatest problem.

You see, I decided upon two of everything as a redundancy measure. One crappy pie. One good pie. I could live with that. The original plan even budgeted for time to make each pie from start to finish as a self-contained whole, so that mistakes would be isolated.

As holidays are wont to do, however, I was left short on time and decided to work in parallel, doubling the recipes. Sadly, the resulting amount of pie crust ingredients wouldn’t fit into my food processor. The same goes for my pumpkin pie filing and I had to perform a fair amount of eyeballing, not necessarily a recommended technique in that scientific art known as baking.

And peeling, coring and slicing nine pounds of apples was a chore indeed.

Later, I was also informed that doubling recipes doesn’t necessarily work when baking. Something about excess moisture.

In any case, a flour-covered kitchen, six hours and a good night’s sleep in between finally resulted in some decent pies, thank you very much. Not perfect by any means, but serviceable for a rookie pie maker. I may even have to give up my day job.

In all seriousness, the holiday, as it’s known to me, is about giving. It’s not what’s on the table that matters, or how many guests arrive, or how the turkey came out… it’s simply the small or large or unknown acts of giving that occur around the table and the kitchen and the day that truly makes it. So that was the pies. They were my giving. End sentimentality.

Halloween pics

Wed, 19 Nov 2008 05:47:03 -0500

Go vote

Tue, 04 Nov 2008 02:23:58 -0500

There aren’t any excuses tomorrow. Please remember that. Your local polling station probably opens pretty early, so try getting out of bed and running over before work. Or take off a few hours early, making sure you get to vote even if there is a line.

Whatever your affiliation or preference, tomorrow’s the big day and it’s time to have your say.