Bryan Ash

Providing markdown engine options in HAML

2010-12-05T22:45:00.010-05:00

I've started looking into using Markdown in Rails. I use HAML for rendering views, so markdown is handled by a HAML filter:

%h1 Here's some rendered Markdown
  :markdown
    = @model.markdown

This worked great, but I was concerned about javascript injection since the markdown would be provided by a user using a WMD editor. I found that I could explicitly call RDiscount, with the :filter_html option, to render the markdown myself:

%h1 Here's some rendered Markdown
  != RDiscount.new(@model.markdown, :filter_html).to_html

This worked great, but I didn't want to have to remember this incantation every time I want to render some Markdown. After some discussion with Nathan Weizenbaum the current maintainer of Haml, I realized that the answer is actually presented (somewhat indirectly) through the documentation. The section on Custom Filters says "You can also define your own filters. See Haml::Filters for details.". You have to then follow on to Haml::Filters::Base for the full story.

In my Rails app, I created a custom Haml filter that overrides the original :markdown (so I don't accidentally forget and use an unsafe :markdown) config/initializers/haml.rb:

module MyApp
  module Filters
    module Markdown
      include Haml::Filters::Base
      lazy_require 'rdiscount'

      def render(text)
        ::RDiscount.new(text, :filter_html).to_html
      end
    end
  end
end

Now, whenever HAML renders a :markdown filter, it will filter the HTML and protect me against javascript injection attacks.

Stop deploying unneccessary Gems in your Heroku slug

2010-12-02T20:57:00.000-05:00

Heroku published a handy tip in their newsletter today:

$ heroku config:add BUNDLE_WITHOUT=development:test

Having set this and pushed a change to my Gemfile, my slug size went from 39.4MB down to 10.9MB.

Smaller slugs compile and load faster.

Thank you Heroku!

Rake duplicate task descriptions

2010-11-22T16:44:00.001-05:00

Using Rake I can define tasks that get added to a collection of tasks for execution. For example:

desc "one"
task :one do
  puts "one"
end

desc "all"
task :all => [:one]

desc "two"
task :two do
  puts "two"
end

desc "all"
task :all => [:two]

Now, if I look at rake --tasks I will see:

> rake --tasks
rake one     # one
rake two     # two
rake all     # all / all

Rake has duplicated the description for the :all task. Looking at the code for Rake I discovered that this can be avoided by terminating the :all task description with a period:

desc "one"
desc "all."
task :all => [:one]

desc "one"
desc "all."
task :all => [:one]

> rake --tasks
rake one     # one
rake two     # two
rake all     # all.

Blogging software for Mac

2009-11-07T14:25:00.002-05:00

I used to use Windows Live Writer in the old days but now I'm a trendy Mac user I need something suitable. Seems like there are a number of paid options that people rate quite highly but I'm too cheap to pay for software.

I just tried Quamana and it looked promising. Unfortunately it kept throwing errors, didn't download tags from Blogger and then failed to actually publish the post!

I'm now trying Flock which is a full featured browser built on the same stuff as Firefox, that happens to have a blog editor built in. I don't think it's as clean as Live Writer, but appears to have enough functionality for my basic use.

MacBook Pro AirPort autoconnect

2009-11-07T10:13:00.001-05:00

We just installed a new wireless router with WPA security (with the last one we were using WEP). My MacBook Pro connected just fine first time. The problem was that whenever I close the lid and reopen, the Airport would not automatically connect, it would ask me which network to connect to.

The surprising solution was to move /Applications/Utilities/System Preferences.app into /Applications/System Preferences.app

Now AirPort reconnects all by itself every time.

Using simple_auto_complete

2009-06-27T00:23:00.001-04:00

I'm working on my first public Rails application for managing small skydiving businesses. The primary feature is to track when a person gets in an aircraft to make a skydive. In skydiver speak, that's: "Jumpers are manifested in a Slot on a Load". I'm using a model named Account to hold Jumpers, Pilots and in fact anyone who does business with the dropzone.

So, My models look like:

class Load < ActiveRecord::Base
  has_many :slots, :dependent => :destroy
end

and:

class Slot < ActiveRecord::Base
  belongs_to :account
end

The form for editing a load contains:

<%= render :partial => 'slot', :collection => @load.slots %>

and the _slots.html.erb partial contains something like:

<% fields_for "load[slot_attributes][]", slot do |slot_form| -%>
  <%= slot_form.label :account_name, 'Jumper:' %>
  <%= slot_form.text_field :account_name %>
<% end -%>

This all works great, so it's time for a little flair ... what I'd like is for the Account.name field to present a list of accounts that match the text that I've typed so far and allow me to pick one (like the Google search field does these days).

Enter simple_auto_complete.

The instructions in the README describe the steps to get the simplest example working but left me scratching my head. What I needed was the following...

In SlotsController (something I didn't even need before):

class SlotsController < ApplicationController
  autocomplete_for :account, :name, :order => 'name ASC'
end

in _slot.html.erb, I changed to:

<% fields_for "load[slot_attributes][]", slot do |slot_form| -%>
  <%= slot_form.label :account_name, 'Jumper:' %>
  <%= slot_form.text_field :account_name, :class => 'autocomplete', 
      :autocomplete_url => autocomplete_for_account_name_slots_path %>
<% end -%>

I updated my routes.rb to include:

map.resources :slots, :collection => { :autocomplete_for_account_name => :get}

Finally, I added to my application.html.erb layout:

<%= stylesheet_link_tag 'site', 'jquery.autocomplete' %>
<%= javascript_include_tag 'jquery', 'jquery.autocomplete', 'application', 'prototype' %>

And it works like a champ!

Permission denied - db/test.sqlite3

2009-02-28T03:07:00.001-05:00

I'm investigating creating a plugin for Redmine and having a good old time when I decide to clear out the test database:

C:\dev\redmine>rake db:test:purge
(in C:/dev/redmine)
rake aborted!
Permission denied - db/test.sqlite3

Boo!

I don't know what made me think of it but I tried unsetting my RAILS_ENV environment variable (I had it set to "test"):

C:\dev\redmine>set rails_env=

C:\dev\redmine>rake db:test:purge
(in C:/dev/redmine)

C:\dev\redmine>

Hurrah!

Formatting README.rdoc on github

2009-02-22T11:06:00.001-05:00

Github has a neat feature that displays a README file, that it finds in the root directory of a project, on the project page. The README formatting page describes a number of different formats that it will render based on the file extension. I tried renaming to README.rdoc but it still rendered as plain text. The trouble was that the file was intended to be used with a full RDOC site for the source. When I removed the "link" tags from the file and pushed ... Github renders it correctly ... Hurrah!

BDD WxRuby applications with Cucumber and Nobbie

2009-02-14T22:57:00.002-05:00

For a long time now, I've been wanting to write some Cucumber features to describe a WxRuby application I have. A couple of weeks ago, I found a library called wx-nobbie on Rubyforge that seems to be almost exactly what I was looking for. It provides a simple, high level interface for driving WxRuby applications through commands like "click", "choose" and "type". I had a little trouble getting the tests to pass to start with, but with a few minor tweaks I got there. I contacted the original author and got his permission to take it forward.

I created a GitHub repository for Wx-Nobbie and have made a few updates over the last week. Currently, I've got 4 feature scenarios with 10 steps:

C:\dev\wx-nobbie>rake features
(in C:/dev/wx-nobbie)
In order to test drive a WxRuby application  # features/acceptance_test.feature
As a developer
I want Nobbie to provide acceptance test access to the application
  Scenario: Choosing a radio button  # features/acceptance_test.feature:5
    Then "radio_button" is not chosen# features/step_definitions/acceptance_test_steps.rb:21
    When I choose "radio_button"     # features/step_definitions/acceptance_test_steps.rb:1
    Then "radio_button" is chosen    # features/step_definitions/acceptance_test_steps.rb:17

  Scenario: Choosing a check box  # features/acceptance_test.feature:10
    Then "check_box" is not chosen# features/step_definitions/acceptance_test_steps.rb:21
    When I choose "check_box"     # features/step_definitions/acceptance_test_steps.rb:1
    Then "check_box" is chosen    # features/step_definitions/acceptance_test_steps.rb:17

  Scenario: Type into a text control        # features/acceptance_test.feature:15
    When I type "123" into "text_ctrl"      # features/step_definitions/acceptance_test_steps.rb:5
    Then I should see "123" in "text_ctrl"  # features/step_definitions/acceptance_test_steps.rb:9

  Scenario: Type into a combo box           # features/acceptance_test.feature:19
    When I type "456" into "combo_box"      # features/step_definitions/acceptance_test_steps.rb:5
    Then I should see "456" in "combo_box"  # features/step_definitions/acceptance_test_steps.rb:9


4 scenarios
10 steps passed

With just these 4 scenarios, RCov tells me I have 62.9% coverage.

Hurrah!

Building a Ruby Extension With Visual C++ Express 2008

2009-01-25T10:29:00.002-05:00

Edit March 29, 2009: While the instructions below describe how to build the Win32::GuiTest extension, I didn't get very far with using it before I found Wx::Nobbie which I much prefer and have taken up the maintenance of at Github.

I'd like to be able to use Cucumber to drive the development of Windows applications so I went looking for something like Webrat for desktop GUI's. I found Win32::GuiTest. There is a project of the same name on RubyForge that contains the same source but that's as far as that went.

Win32::GuiTest is a C extension that was compiled with Cygwin, so I wanted to rebuild a native version. I found some instructions on Kevin Kleinfelter's blog that look much like below, but using VC++ 2008 I got to skip a couple of steps:

Download and install Visual C++ Express Edition (this is free, I got the 2008 version)
Edit $RUBY_HOME/lib/ruby/1.8/i386-mswin32/config.h and delete the “#error MSC version unmatch” line
Open a Visual Studio 2008 Command Prompt
- Start
- All Programs
- Microsoft Visual C++ 2008 Express Edition
- Visual Studio Tools
cd C:\temp\guitest020218\ext\cguitest
- I'm building the guitest extension
ruby extconf.rb
nmake
mt.exe -manifest cguitest.so.manifest -outputresource:cguitest.so;2
- Copy and paste the command above. You need it all from the 'mt' to the ';2'
nmake install
cd \temp\guitest020218
ruby install.rb config
ruby install.rb install
To test:
- irb
- require 'win32/guitest'
- check response is '=> true'

My first Rails bug – accepted!

2009-01-14T23:01:00.002-05:00

At the time that I posted about My first Rails bug the tests that existed for Action Pack contained failures and the only test in integration_upload_test.rb was:

assert_equal(:multipart_form, SessionUploadTest.last_request_type)

I felt that my change could be submitted with no tests because:

The change was trivial (6 characters)
The change was for a well known Windows file issue
The tests that existed didn’t pass
There were no example tests for me to build on

Three months after I submitted the ticket, Pratik dismissed it by changing its state to incomplete with the comment “Missing a test case.” Are these guys CRAZY? No, no they are not. Just because there were broken windows in the neighborhood did not give me the right to break any more.

So, I sucked it up, cloned the latest rails repository again and to my surprise … all the Action Pack tests passed! … and there was a nice simple example in multipart_params_parsing_test.rb:

  test "uploads and reads file" do
    with_test_routing do
      post '/read', :uploaded_data => fixture_file_upload(FIXTURE_PATH + "/hello.txt", "text/plain")
      assert_equal "File: Hello", response.body
    end
  end

This is too easy! I added a test for my issue:

  test "uploads and reads a binary file in windows" do
    with_test_routing do
      fixture_file = FIXTURE_PATH + "/mona_lisa.jpg"
      post '/read', :uploaded_data => fixture_file_upload(fixture_file, "image/jpg")
      assert_equal 'File: '.length + File.size(fixture_file), response.content_length
    end
  end

Watched it fail. Added the magic 6 characters (“, ‘rb’”). Watched it pass. Wrapped it up and shipped it off. The following morning I pick up an email letting me know that Pratik has reopened the ticket and assigned it to Joshua Peek for review. The change was committed before the day was out!

Many thanks to Pratik and Josh for attending to this so promptly.

Restful-Authentication with Cucumber features (Step 2)

2009-01-12T22:13:00.002-05:00

Knowing that all the stories that ship with restful-authentication pass, I’m ready to convert to Cucumber features. The process is actually fairly simple and is described quite clearly on this Cucumber wiki page. I did have to tweak a couple of the step matchers and create ra_env.rb:

Before do
  Fixtures.reset_cache
  fixtures_folder = File.join(RAILS_ROOT, 'spec', 'fixtures')
  Fixtures.create_fixtures(fixtures_folder, "users")
end
 
# Make visible for testing
ApplicationController.send(:public, :logged_in?, :current_user, :authorized?)

I’d have liked to put this in the support directory but Cucumber loaded it before env.rb, so I put in with the step_definitions.

Once that was done, all that was left was to update authenticated_generator.rb to copy the template features instead of stories.

The result is available from my fork on github.

Enjoy!

Restful-Authentication with Cucumber features (Step 1)

2009-01-10T12:18:00.004-05:00

My latest exercise is to update the restful-authentication Rails plugin to generate Cucumber features instead of RSpec stories. There is already a Lighthouse ticket open for this, so I guess I'm not the first one to think of it. The first steps make sure that restful-authentication is set up correctly:

Create an empty Rails application
Put in version control (git init, git add ., git commit -a -m "init")
Add plugins as shown on the Cucumber Rails wiki page
Add my fork of restful-authentication in the same manner
Complete the restful-authentication installation per the directions
Create the database tables (rake db:migrate)
Run the RSpec stories (stories\rest_auth_stories.rb)

Stories won't even run, let alone pass! I'm not going to show all the errors along the way, but the steps to get to passing stories were:

Added AthenticatedSystem into ApplicationController with the following 2 lines:

  include AuthenticatedSystem
  helper :all # include all helpers, all the time

Uncommented the routes.rb map.root line(map.root :controller => "welcome")
Removed line 1 of user_steps.rb (require File.dirname(__FILE__) + '/../helper')
Created a minimal WelcomeController with an index method
Created a minimal layout

16 scenarios: 16 succeeded, 0 failed, 0 pending

Hurrah!

Cucumber scenarios need a title

2008-10-19T21:18:00.007-04:00

So I'm playing with Behavior Driven Development (BDD) and Ruby on Rails using Cucumber and Webrat. I thought I'd start with the simplest feature I could think of, "I want to see the application name in the title". So, off we go with features/site_layout.feature:

Feature: Site Layout
  In order to build familiarity
  As a user
  I want to see the application name in the title

  Scenario:
    Given I am on the home page
    Then the title tag should be "WOW App"

I create features/steps/site_steps.rb:

Given /^I am on (.*)$/ do |page|
  visits case page
         when "the home page"
           "/"
         else
           raise "Can't find mapping from \"#{page}\" to a path"
         end
end

Then /^the (.*) tag should be "(.*)"$/ do |tag, content|
  response.should have_tag(tag, content)
end

And run it with "rake features". What I get is:

C:\dev\temp>rake features
(in C:/dev/temp)
Feature: Site Layout  # features/site_layout.feature
  In order to build familiarity
  As a user
  I want to see the application name in the title
  Scenario: Given I am on the home page     # features/site_layout.feature:6
    Then the title tag should be "WOW App"  # features/steps/site_steps.rb:10
      You have a nil object when you didn't expect it!
      The error occurred while evaluating nil.content_type (NoMethodError)
      ...
      ./features/steps/site_steps.rb:11:in `Then /^the (.*) tag should be "(.*)"$/'
      features/site_layout.feature:8:in `Then the title tag should be "WOW App"'


1 steps failed
rake aborted!

Not quite what I had in mind, I was expecting a failure, but got an error. Nevermind, this is all very new to me, so I'll push on and it'll all become clear right? I create an app/views/layouts/application.html.erb:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
       "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
  <head>
  <meta http-equiv="content-type" content="text/html;charset=UTF-8" />
    <title>WOW App</title>
  </head>
  <body>
  </body>
</html>

Run the feature again ... no joy, same error. Hours of web searching leads me nowhere. Finally while looking at some examples I noticed that my Scenario doesn't have a description, so I add one on line 6:

Feature: Site Layout
  In order to build familiarity
  As a user
  I want to see the application name in the title

  Scenario: On the home page
    Given I am on the home page
    Then the title tag should be "WOW App"

Now I get:

C:\dev\temp>rake features
(in C:/dev/temp)
Feature: Site Layout  # features/site_layout.feature
  In order to build familiarity
  As a user
  I want to see the application name in the title
  Scenario: On the home page                # features/site_layout.feature:6
    Given I am on the home page             # features/steps/site_steps.rb:1
      No route matches "/" with {:method=>:get} (ActionController::RoutingError)
...
      features/site_layout.feature:7:in `Given I am on the home page'
    Then the title tag should be "WOW App"  # features/steps/site_steps.rb:10


1 steps failed
1 steps skipped
rake aborted!

A quick addition to config/routes.rb:

map.root :controller => 'example'

And a stub controller from "ruby script\generate controller Example index", I get:

C:\dev\temp>rake features
(in C:/dev/temp)
Feature: Site Layout  # features/site_layout.feature
  In order to build familiarity
  As a user
  I want to see the application name in the title
  Scenario: On the home page                # features/site_layout.feature:6
    Given I am on the home page             # features/steps/site_steps.rb:1
    Then the title tag should be "WOW App"  # features/steps/site_steps.rb:10


2 steps passed

Hurrah!

Where to put sqlite3.dll on Windows

2008-10-05T21:21:00.003-04:00

When I first started using SQLite3 on Windows, most people suggested downloading sqlite3.dll from www.sqlite.org and storing it in ruby/bin so Windows could find it. For a while, this strategy worked fine but I really didn't like the application requiring users to put that DLL into an acceptable place. I don't know why it didn't occur to me earlier, but, given that this is only intended to be a Windows application, why not just modify the PATH environment variable within the application. So that's what I've done. In config/boot.rb:

# Make sqlite3.dll available
ENV['PATH'] += ";#{RAILS_ROOT}/vendor/bin/sqlite3"

class << self

2008-10-02T13:08:00.008-04:00

I've come across this construct many times while browsing a number of open source projects:

class MyClass
  class << self
    def a_class_method
      ...
    end
  end

  def an_instance_method
    ...
  end
end

I finally got it today ... there's no black magic ... all "class << self" means is:

add the following class method definitions to the class MyClass.

Or,

open the class MyClass, and add the following class methods.

Now that I'm in the gang and understand this incantation, I'm not sure I like it. It seems like a nice way to group all your class methods together, but if you define several class methods then it becomes harder to recognize whether a method belongs to the class or an instance. I think it's cleaner to explicitly state the ownership of each method:

class MyClass
  def self.a_class_method
    ...
  end

  def an_instance_method
    ...
  end
end

My first Rails bug

2008-09-20T22:46:00.012-04:00

UPDATE January 14, 2009 -> The patch for this bug was accepted!

I'm pretty new to Rails and my first project included uploading videos. Shouldn't be too difficult I thought, after a little Google searching, I came up with the perfect example by Jim Neath: Converting Videos with Rails: Converting the Video Wanting to practice new skills with RSpec and Cucumber I wrote my first feature spec:

Feature: Upload videos
  In order to provide videos to users after hours
  As a videographer
  I want to upload videos

  Scenario: A valid filename is provided
    Given I go to the new video page
    And I browse to the file "Movie_0001.avi"

    When I submit the upload

    Then I should see "success"
    And the file should be uploaded

and the supporting steps file, upload_steps.rb:

require 'ftools'
require 'mime/types'

When /I browse to the file \"(.+)\"/ do |path|
  @original_filepath = File.join('features/fixtures/', path)
  mime_types = MIME::Types.of(@original_filepath)

  attach_file 'video[source]', @original_filepath, mime_types[0].content_type
end

When 'I submit the upload' do
  click_button 'Create'
end

def uploaded_filepath
  uploaded_basename = File.basename(@original_filepath)
  File.join(RAILS_ROOT, "public/videos/1", uploaded_basename)
end

Then /the file should be uploaded/ do
  assert File.compare(@original_filepath, uploaded_filepath)
end

what I got was:

...
    And the file should be uploaded
       is not true. (Test::Unit::AssertionFailedError)
      c:/ruby/lib/ruby/1.8/test/unit/assertions.rb:48:in `assert_block'
      c:/ruby/lib/ruby/1.8/test/unit/assertions.rb:500:in `_wrap_assertion'
      c:/ruby/lib/ruby/1.8/test/unit/assertions.rb:46:in `assert_block'
      c:/ruby/lib/ruby/1.8/test/unit/assertions.rb:63:in `assert'
      c:/ruby/lib/ruby/1.8/test/unit/assertions.rb:495:in `_wrap_assertion'
      c:/ruby/lib/ruby/1.8/test/unit/assertions.rb:61:in `assert'
      ./features/upload/steps/upload_steps.rb:22:in `And /the file should be uploaded/'
      features/upload/upload.feature:14:in `And the file should be uploaded'
...

On closer inspection, the test was failing because the uploaded file was truncated in some bizarre way. However, if I ran the application and manually upload a file from the browser, everything worked fine. After much hunting I ended up in rails/actionpack/lib/action_controller/integration.rb where in multipart_body, the mode is not specified in the call to File.open, so it defaults to "r". This is all well and good on anything but Windows, which I happen to be using! Windows requires that the mode be specified as "rb" to ensure the file is read as binary. I submitted a patch but I'm not holding my breath for it to be pulled in anytime soon.

Ruby PCAN DLL Wrapper

2008-09-20T20:34:00.001-04:00

Inspired by System Testing In Ruby (Systir), I have published a small Ruby PCAN USB DLL Wrapper. Now with a small device available for less than $300 and some free software, I can write automated system test scripts of the form:

send tftp_rrq("autoexec.bat").with(blksize(2036)) verify_target_sends oack(blksize(2036) send ack(0) verify_target_sends autoexec_bat send ack(1)

If you have rubygems installed, PCAN DLL Wrapper is easily obtained:

set http_proxy=http://my_proxy_host.com:80 gem install pcanusb

and then use:

require 'pcan_usb' PCAN_USB.init(PCAN_USB::BAUD_1M) PCAN_USB.write(0x0E100501, "Hello World!") PCAN_USB.close

Collection o quotes

2008-09-20T20:29:00.000-04:00

Ricky Hustler, a friend of mine, used to use this one on a regular basis:

"You never see a luggage rack on a hearse"

I came across this on James Grenning's blog:

"It's easier to act your way into thinking differently than to think your way into acting differently"

From a friend's coffee cup:

"Lead, follow, or get out of my way"

Susan Jeffers:

"Feel the fear and do it anyway"

ActiveRecord requires RAILS_ROOT for relative Sqlite path

2008-06-10T20:40:00.004-04:00

I'm writing a little time tracking tool for Windows in Ruby. The data is stored in a database so I figured I'd use ActiveRecord and maybe learn something about Rails along the way. Everything I found about ActiveRecord tells me that it "can be used independently outside of Rails". One minor detail that I just figured out:

If you want to use a relative path for a sqlite3 database in your database.yml, you have to define RAILS_ROOT.

For example, if config/database.yml =>

production:
  adapter: sqlite3
  database: db/production.sqlite

ActiveRecord initialization (mine's in config/boot.rb) looks like:

RAILS_ROOT = "#{File.dirname(File.expand_path(__FILE__))}/.."
RAILS_ENV  = ENV['RAILS_ENV'] || 'production'

$LOAD_PATH.unshift "#{RAILS_ROOT}/vendor/sqlite3"
config = YAML::load(IO.read("#{RAILS_ROOT}/config/database.yml"))
ActiveRecord::Base.configurations = config
ActiveRecord::Base.establish_connection(config[RAILS_ENV])