My buddies Michael and Andrew made the trip last month, and we climbed the mountain together!

They’re both quite good photographers, so I didn’t even bother carrying a camera. The shot above’s from Michael’s Tanzania photoset on Flickr, and Andrew’s are up (with hilarious comments) on his site.

On the climb, you really come to appreciate the strength and tirelessness of the guides and porters—and to realize (machismo notwithstanding) that there’s no way you could make it up the mountain without all these guys carrying your stuff for you.

We climbed with Marangu Hotel, who take good care of their porters. Many, many companies don’t, so I’d encourage you to check out the Kilimanjaro Porters Assistance Project and lend a hand as you’re able.

One thing you’ll run into, though, is that AtomPub posts application/atom+xml data rather than the usual application/x-www-form-urlencoded stuff, so you’ll have to write some extra code to handle it.

The good news is that ActionController::Base helps you out. Instead of having to branch on the request type and fatten your controller, you can register a custom param_parser.

So, we wrote Hash.from_atom to transform the incoming xml into the usual { :entry => { ... } } params. Then, we registered it in an initializer:

ActionController::Base.param_parsers[Mime::ATOM] = lambda do |body|
  Hash.from_atom(body)
end

And our controller can now handle either regular form postings or AtomPub entries with the same line of code:

class EntriesController < ApplicationController
  def create
    @entry = @collection.entries.build(params[:entry])
    # ...
  end
end

Not bad.

5 Rails tips

Each day this week, Joachim and I will post something we’ve learned in our time programming together. It’s fun to do, and we might just win something as well.

So far, we’ve written:

1. Reloadable custom FormBuilder
2. Faking DATA in tests
3. Filter BLOBs from ActiveRecord logging
4. Writing Capistrano recipes to be loaded from gems
5. Atom param parser

On your first pass, you’ll probably do what I did: gank and modify capistrano/recipes/deploy.rb.

This works great, but you’ll find it’s a little tricky to use your new recipes from a Capfile. It turns out you can’t just “require mygem” and “load 'mygem/recipes/deploy'” because Capistrano doesn’t load from ruby’s $LOAD_PATH—it keeps its own minimally-initialized load_paths setting instead.

So, you have to either modify the load_paths or use an absolute path, like this:

%w( rubygems wordpress ).each { |lib| require lib }
load Gem.required_location('wordpress', 'wordpress/recipes/deploy.rb')
load 'config/deploy'

This is what I did for a while, but something didn’t seem right. My Capfile didn’t look as nice as I expected, and I wasn’t using require, whose comments clearly mention third-party recipes.

Take two

Staring at capistrano/configuration/loading.rb until it made sense, I saw instance, which triggered some vague distant memory that somehow turned into a productive thought:

If you wrap your deploy.rb recipes in a load block, like this:

Capistrano::Configuration.instance(:must_exist).load do
  # previous file contents here
end

You can simplify your Capfile with a shorter require statement:

require 'rubygems'
require 'wordpress/recipes/deploy'
load    'config/deploy'

Nice. I’m still a little bummed by the require / load imbalance, but on the whole this feels more like things were supposed to be.

5 Rails tips

Each day this week, Joachim and I will post something we’ve learned in our time programming together. It’s fun to do, and we might just win something as well.

So far, we’ve written:

1. Reloadable custom FormBuilder
2. Faking DATA in tests
3. Filter BLOBs from ActiveRecord logging
4. Writing Capistrano recipes to be loaded from gems

In the meantime, we’ve got blob after blob flying by in the script/server output, and it’s messing up our Terminal fonts. No good.

Here’s a quick fix, config/initializers/filter_db_files_logging.rb:

class ActiveRecord::ConnectionAdapters::AbstractAdapter
  def format_log_entry_with_db_files_filtering(message, dump = nil)
    dump = 'INSERT INTO db_files' if dump.to_s =~ /^INSERT INTO db_files/
    dump = 'UPDATE db_files'      if dump.to_s =~ /^UPDATE db_files/
    format_log_entry_without_db_files_filtering(message, dump)
  end

  alias_method_chain :format_log_entry, :db_files_filtering
end

Note that this isn’t yet a general solution (other tables’ blobs will still be logged), but it’s good enough for our needs, and we’ve got a known place we can come back to should we need to filter more blobs in the future.

Also, looking at AbstractAdapter#log_info just now, we notice that could have written our own Logger and saved the monkeypatch. Maybe we’ll look into doing that some day.

5 Rails tips

Each day this week, Joachim and I will post something we’ve learned in our time programming together. It’s fun to do, and we might just win something as well.

So far, we’ve written:

1. Reloadable custom FormBuilder
2. Faking DATA in tests
3. Filter BLOBs from ActiveRecord logging

Sometimes you’d like to use DATA in a test. You’ll find it works when you run the test individually but then fails when you run the whole suite. (Remember DATA comes from $0, the currently running file, only.)

We’ve found a nice way to fake it in the rubyforge gem: read __FILE__ instead, then split the results.

Here’s an example of the technique in use, functionally testing a wiki parser we’ve been tinkering with. It can often be painful to work with metaprogrammed tests like this, but on balance, we like the results here:

require 'test_helper'

class TestParser < Test::Unit::TestCase
  EXAMPLES = /={80}\n/m
  PARTS    = /-{80}\n/m

  # Faking data = DATA.read
  data = File.read(__FILE__).split('__END__').last

  data.split(EXAMPLES).map { |example| example.split(PARTS) }.each do |comment, markup, html|
    define_method "test_#{comment.strip.downcase.gsub(/\W/, '_')}" do
      assert_equal html, Parser.new.parse(markup).result.to_html
    end
  end
end

__END__
A single wiki word should be linked and wrapped in a paragraph.
--------------------------------------------------------------------------------
WikiWord
--------------------------------------------------------------------------------
<p><a href="WikiWord">WikiWord</a></p>
================================================================================
Two wiki words on separate lines should become two paragraphs
--------------------------------------------------------------------------------
WikiWord
WikiWord
--------------------------------------------------------------------------------
<p><a href="WikiWord">WikiWord</a></p>
<p><a href="WikiWord">WikiWord</a></p>

5 Rails tips

Each day this week, Joachim and I will post something we’ve learned in our time programming together. It’s fun to do, and we might just win something as well.

So far, we’ve written:

1. Reloadable custom FormBuilder
2. Faking DATA in tests

Create a new file called config/initializers/setup.rb. Or, if you’re on pre-2.0, add it to the bottom of config/environment.rb:

ActionView::Base.default_form_builder = LabellingFormBuilder

Though “proper,” this approach requires restarting the server to see changes in LabellingFormBuilder.

You can avoid restarting the server by doing this instead:

class ActionView::Base
  def self.default_form_builder
    LabellingFormBuilder
  end
end

It’s a subtle difference, but it provides a nice window into understanding the Dependencies mechanism:

In August’s version, const_missing loads the LabellingFormBuilder class only once, when the initializer is run.

In our version, we’ve tricked const_missing into running on each request by not holding onto the class it loads. That is, instead of caching the class lookup in @@default_form_builder, we’re allowing the lookup to be performed on demand.

Sweet.

5 Rails tips

Each day this week, Joachim and I will post something we’ve learned in our time programming together. It’s fun to do, and we might just win something as well.

I last wrote about Doh in August. You may remember this part:

DDDDDDDDDDDDD                         hhhhhhh
 D::::::::::::DDD                      h:::::h
 D:::::::::::::::DD                    h:::::h
 DDD:::::DDDDD:::::D                   h:::::h
   D:::::D    D:::::D    ooooooooooo    h::::h hhhhh
   D:::::D     D:::::D oo:::::::::::oo  h::::hh:::::hhh
   D:::::D     D:::::Do:::::::::::::::o h::::::::::::::hh
   D:::::D     D:::::Do:::::ooooo:::::o h:::::::hhh::::::h
   D:::::D     D:::::Do::::o     o::::o h::::::h   h::::::h
   D:::::D     D:::::Do::::o     o::::o h:::::h     h:::::h
   D:::::D     D:::::Do::::o     o::::o h:::::h     h:::::h
   D:::::D    D:::::D o::::o     o::::o h:::::h     h:::::h
 DDD:::::DDDDD:::::D  o:::::ooooo:::::o h:::::h     h:::::h
 D:::::::::::::::DD   o:::::::::::::::o h:::::h     h:::::h ......
 D::::::::::::DDD      oo:::::::::::oo  h:::::h     h:::::h .::::.
 DDDDDDDDDDDDD           ooooooooooo    hhhhhhh     hhhhhhh ......

Since then, some nice things have happened:

• It’s a (somewhat documented) gem:

  $ gem install doh --source http://gems.matthewtodd.org

• It has git support!

  Doh tries to be smart about git commit -a, staying out of your way if you’ve only modified or deleted tracked files (exactly the things -a notices). See also the test case.

I cued up “Where the Streets Have No Name” on Karen’s iPod at the starting line, waiting to push play until they said go. I hadn’t remembered the first line, but as I was turning left out the cooperative college gate onto the main road, Bono came in with “I want to run,” and holy cow, I almost lost it.

Running itself was pretty much normal. I was worried about starting off too fast, so I found a few people who looked like they were going at a good pace, and we stuck together through the first half of the race.

After that, Karen’s marathon support plan kicked into full gear—she’d stationed people every mile with all sorts of gummy bears, jelly beans, water bottles, potato chips, and sponge buckets. It was fun!

Some of them even ran along with me for a while, which was super encouraging. Jen pushed Benjamin in the stroller, Joe told me corny programmer jokes, and Aaron just kept running—for 11 miles! Here we are coming down the hill with 2½ left.

During those last couple of miles, my quads started cramping and a blister popped on my little toe, but by then it was hard to care about much of anything.

By the time I got to the finish line, I could keep running, but I think that was only because of developed habit, not because I actually had anything left. I don’t think I’ve ever felt so right cursing in desperation before.

Two and a half weeks later, I’m feeling great, and totally eager to keep running. There’s supposed to be a half-marathon in the Serengeti in June, and it looks like there are some other folks here who’d also be interested—though it’ll be one heckuva road trip to get all the way out there!

Also, thanks so much to all of you who helped support the Porters Assistance Project. We came in over our goal, and Karen’s thrilled!