Its not too late to solve a Y2K bug - I found one in 2010

5 months ago | Alex Rothenberg: Common Sense Software

I thought a historical opportunity had passed me by, but a full decade after the turn of the millennium in 2010 I found my first Y2K bug! If you, like me, were working in eCommerce (who remembers that buzzword?) in the late 1990s and thought you missed your chance I'm here to tell you its still not too late. As long as you work for the right company with the enough legacy technology around you can still find a Y2K bug of your own!

What was going on?

I was writing a new Rails application on top of an old Oracle database. The database had a constraint

graduationdate BETWEEN TO_DATE('01-JAN-1900','DD-MON-YYYY') AND TO_DATE('31-DEC-2100','DD-MON-YYYY')

validate :validate_graduation_date
def validate_graduation_date
  unless graduationdate.nil?
    earliest_date, latest_date = Date.parse('01-JAN-1900'), Date.parse('31-DEC-2100')
    errors.add(:graduationdate, 'must be between 01-JAN-1900 and 31-DEC-2100') unless graduationdate > earliest_date and graduationdate < latest_date  
  end
end

describe 'graduation date' do
  it 'should not allow July 4, 1776' do
    education = Factory.build :education, :graduationdate=>Date.parse('04-JUL-1776')
    education.should_not be_valid
  end
  it 'should allow Aug 1 1970' do
    education = Factory.build :education, :graduationdate=>Date.parse('01-AUG-1970')
    education.should be_valid
  end
  it 'should allow Mar 15 2000' do
    education = Factory.build :education, :graduationdate=>Date.parse('15-MAR-2000')
    education.should be_valid
  end
  it 'should not allow Jan 1, 2525' do
    education = Factory.build :education, :graduationdate=>Date.parse('01-JAN-2525')
    education.should_not be_valid
  end
end

select count(*) from education where graduationdate = to_date('01-jan-1900')
COUNT(*)               
---------------------- 
116232       

validate :validate_graduation_date
def validate_graduation_date
  unless graduationdate.nil?
    earliest_date, latest_date = Date.parse('01-JAN-1900'), Date.parse('31-DEC-2100')
    errors.add(:graduationdate, 'must be between 01-JAN-1900 and 31-DEC-2100') unless graduationdate >= earliest_date and graduationdate <= latest_date  
  end
end

it 'should not allow Dec 31 1899' do
  education = Factory.build :education, :graduationdate=>Date.parse('31-DEC-1899')
  education.should_not be_valid
end
it 'should allow Jan 1 1900' do
  education = Factory.build :education, :graduationdate=>Date.parse('01-JAN-1900')
  education.should be_valid
end
it 'should allow Dec 31 2099' do
  education = Factory.build :education, :graduationdate=>Date.parse('31-DEC-2099')
  education.should be_valid
end
it 'should allow Jan 1 2100' do
  education = Factory.build :education, :graduationdate=>Date.parse('01-JAN-2100')
  education.should_not be_valid
end

What to do when ActiveRecord thinks an Oracle key is a decimal

7 months ago | Alex Rothenberg: Common Sense Software

I recently created a model for an existing database table using the legacy_data gem and was confused when my primary key showed up in scientific notation. It turned out the issue was due to sloppiness in the table definition and could be easily fixed once I understood what ActiveRecord was doing.

I created a Person model connected to the people table

class Person < ActiveRecord::Base
end

$ script/console 
Loading development environment (Rails 2.3.4)
>> Person.first.id
=> #

>> Person.columns_hash['id']
=> #
>> Person.columns_hash['id'].type
=> :decimal
>> Person.columns_hash['id'].sql_type
=> "NUMBER"

NUMBER Datatype

The NUMBER datatype stores fixed and floating-point numbers. Numbers of virtually any magnitude can be stored and are guaranteed portable among different systems operating Oracle, up to 38 digits of precision.

The following numbers can be stored in a NUMBER column:

Positive numbers in the range 1 x 10-130 to 9.99...9 x 10125 with up to 38 significant digits

Negative numbers from -1 x 10-130 to 9.99...99 x 10125 with up to 38 significant digits

Zero

Positive and negative infinity (generated only by importing from an Oracle Version 5 database)

For numeric columns, you can specify the column as:

column_name NUMBER 

Optionally, you can also specify a precision (total number of digits) and scale (number of digits to the right of the decimal point):

column_name NUMBER (precision, scale) 

If a precision is not specified, the column stores values as given. If no scale is specified, the scale is zero.

Oracle guarantees portability of numbers with a precision equal to or less than 38 digits. You can specify a scale and no precision:

column_name NUMBER (*, scale) 

In this case, the precision is 38, and the specified scale is maintained.

When you specify numeric fields, it is a good idea to specify the precision and scale. This provides extra integrity checking on input.

$ sqlplus myusername/mypassword@localhost:1521/mydatabase.world

SQL*Plus: Release 10.2.0.4.0 - Production on Wed Jan 27 09:15:09 2010

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.


Connected to:
Oracle Database 10g Release 10.2.0.4.0 - Production

SQL> desc people;
 Name        Null?    Type
 ----------------------------------------- -------- ----------------------------
 ID          NUMBER
 NAME          VARCHAR2(10)

$ script/generate migration change_person_id_to_integer
STUBBING MckinseyLDAP
      exists  db/migrate
      create  db/migrate/20100127145747_change_person_id_to_integer.rb

class ChangePersonIdToInteger < ActiveRecord::Migration
  def self.up
    change_column(:people, :id, :integer)  
  end
  def self.down
    change_column(:people, :id, :decimal)  
  end
end

#config/initializers/legacy_data_type_coercion.rb
module LegacyDataTypeCoercion
  def set_integer_columns *col_names
    col_names.each do |col_name|
      columns_hash[col_name.to_s].instance_eval do
        @type = :integer
      end
    end
  end
end
ActiveRecord::Base.extend(LegacyDataTypeCoercion)


#app/models/person.rb
class Person < ActiveRecord::Base
  set_integer_columns :id
end

$ script/console 
Loading development environment (Rails 2.3.4)
>> Person.first.id
=> 10024844425
>> Person.columns_hash['id'].type
=> :integer

Freezing a gem that has native extensions

7 months ago | Alex Rothenberg: Common Sense Software

I like to freeze all the gems I use as we run in a shared hosting environment and need to our apps isolated from each other. Deployments are also handled by an operational team that does not intimately understand our applications so keeping our deployments to a single capistrano command cap deploy:migrations has been a big win for us. Freezing most gems is pretty straightforward and has been built in since Rails 2.1. When dealing with a gem that requires native extensions to be built there's only one additional step to add to your Capfil.

Let's say we want to localize hpricot which does include native C extensions.

First tell Rails about your gem by adding a config.gem line to your environment.rb

Rails::Initializer.run do |config|
  ...
  config.gem 'hpricot'
  ...
end

  $ rake gems
  (in /Users/alexrothenberg/ruby/my_project)
   - [I] hpricot 

   I = Installed
   F = Frozen
   R = Framework (loaded before rails starts)

  $ rake gems:unpack 
  (in /Users/alexrothenberg/ruby/my_project)
  Unpacked gem: '/Users/alexrothenberg/ruby/my_project/vendor/gems/hpricot-0.8.2'

  $ rake gems
  (in /Users/alexrothenberg/ruby/my_project)
  The following gems have native components that need to be built
    hpricot  

  You're running:
    ruby 1.8.6.287 at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
    rubygems 1.3.2 at /Users/alexrothenberg/.gem/ruby/1.8, /Library/Ruby/Gems/1.8, /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8

  Run `rake gems:build` to build the unbuilt gems.

  $ rake gems:build
  (in /Users/alexrothenberg/ruby/my_project)
  Built gem: '/Users/alexrothenberg/ruby/mars-admin/vendor/gems/hpricot-0.8.2'
  alex-rothenbergs:mars-admin alexrothenberg$ rake gems
  (in /Users/alexrothenberg/ruby/my_project)
   - [F] hpricot 

  I = Installed
  F = Frozen
  R = Framework (loaded before rails starts)

  $ rake gems
  (in /Users/alexrothenberg/ruby/my_project)
   - [F] hpricot 

  I = Installed
  F = Frozen
  R = Framework (loaded before rails starts)
  
  $ ls vendor/gems/hpricot-0.8.2/
  total 72
  -rw-r--r--   1 alexrothenberg  staff  4672 Jan 13 12:33 CHANGELOG
  -rw-r--r--   1 alexrothenberg  staff  1048 Jan 13 12:33 COPYING
  -rw-r--r--   1 alexrothenberg  staff  9216 Jan 13 12:33 README
  -rw-r--r--   1 alexrothenberg  staff  8242 Jan 13 12:33 Rakefile
  drwxr-xr-x   4 alexrothenberg  staff   136 Jan 13 12:33 ext/
  drwxr-xr-x   3 alexrothenberg  staff   102 Jan 13 12:33 extras/
  drwxr-xr-x   6 alexrothenberg  staff   204 Jan 13 12:39 lib/
  drwxr-xr-x  11 alexrothenberg  staff   374 Jan 13 12:33 test/

after "deploy:finalize_update" do
  # build the native extensions for hpricot gem
  run "cd #{release_path} && #{rake} RAILS_ENV=#{rails_env} gems:build GEM=hpricot"
end

  ...
  * executing "cd /opt/apps/my_project/releases/20100108185109 && rake RAILS_ENV=production gems:build"
     servers: ["your.server.com"]
     [your.server.com] executing command
  ** [out :: your.server.com] (in /opt/apps/my_project/releases/20100108185109)
  ** [out :: your.server.com] Built gem: '/opt/apps/my_project/releases/20100108185109/vendor/gems/hpricot-0.8.2'
     command finished
  ...   

Generate Models from Tables - Legacy Data Gem

10 months ago | Alex Rothenberg: Common Sense Software

Today I'd like to announce the release of a gem I've been working on Legacy Data

Getting started on a Rails project with a large existing database can be daunting. How to you extract all the information that's
encoded in the database? Do you have to understand the entire data model before you get started? The models_from_tables generator
in the legacy_data gem can help! This generator looks into your existing database and generates ActiveRecord models based on the
information encoded in it.

How to use it

• To generate an ActiveRecord model for each table in the database just type
  script/generate models_from_tables
  


• If you don't want all tables in the database tell it which table to model
  script/generate models_from_tables --table-name comments
  This uses any foreign_key constraints in the database to spider the database and model the comments table and all associated tables.
  


• If you really only want the comments table tell it not to follow any foreign_keys
  script/generate models_from_tables --table-name comments --skip-associated
  


• If you use factory girl (and everyone should) it will generate a simple factory for each model it generates
  script/generate models_from_tables --table-name comments --with-factories
  

Examples

• A simple blog database tested with MySQL and Sqlite3


• The Drupal 6.14 database tested with MySQL


• The J2EE Petstore example tested with MySQL, Sqlite3 and Oracle

What kind of information can it extract from the database?

Associations

Validation constraints

• validates_uniqueness_of - For columns where the database has an index that enforces uniqueness


• validates_presence_of - When the database column is non-nullable


• validates_inclusion_of - For non-nullable boolean columns and custom constraints with a SQL rule flag IN ('Y', 'N')


• validates_numericality_of - For integer columns (nullable and non-nullable)


• custom validation - For custom SQL validation rules in the database it puts a placeholder in your model with the original SQL for you to translate into Ruby

Non-Rails naming conventions

class Post < ActiveRecord::Base

  set_table_name  :tbpost
  set_primary_key :postid
  
  # Relationships
  has_many :comments, :foreign_key => :postid

  # Constraints
  validates_presence_of :title, :body
  
end

• Class Names - It named the model Post instead of the Rails convention Tbpost. The generator could not do this itself but knowing the conventions will often not apply to legacy databases it pauses after spidering the database giving you a chance to override the table to class name mapping. It generates a yaml file app/models/table_mappings.yml where you can verify or change any class name before proceeding to generate the models.


• Table Names - It overrode the table name since the actual name tbpost does not match the Rails naming convention posts


• Primary Keys - It overrode the primary key since the actual column postid does not match the Rails naming convention id


• Foreign Keys - It overrode the foreign key on the comment table to be postid instead of the Rails naming convention id

PL/SQL debugging information now a part of Oracle Enhanced Adapter v1.2.2

11 months ago | Alex Rothenberg: Common Sense Software

Raimonds Simanovskis has just published a version 1.2.2 of the Oracle Enhanced Adapter that includes the ability to capture dbms_output debug statements from your pl/sql code in the Rails log file. This is a bit of code that I wrote and blogged about a few months ago so not only do I think its useful but am very excited to have contributed to something many others use.

Using the Whenever gem to manage scheduled cron jobs without installing it on the server

11 months ago | Alex Rothenberg: Common Sense Software

I've been using Javan's Whenever gem to manage scheduled jobs in my project and its fantastic!! There are many existing resources where you can learn more (readme, railscast google group) but I'd like to describe the specific way I'm using it

• When the gem is not installed on my server


• How administrators can use Capistrano to both schedule and unschedule your jobs


• How to use a library such as the Oracle client that requires certain environment variables

  cap schedule_jobs
  cap unschedule_jobs

  cap schedule_jobs SOME_CONFIGURATION=false

When the gem is not installed on my server

  #Capfile
  desc "Schedule the jobs"
  task :schedule_job, :roles => :app, :only => { :primary => true } do
    some_configuration = ENV['SOME_CONFIGURATION'] || true #default to true
    arguments = ["RAILS_ENV=#{rails_env}",
                 "APP_PATH=#{current_path}",
                 "SOME_CONFIGURATION=#{some_configuration}"].join(' ')
    run "cd #{current_path} && #{rake} whenever:update_crontab #{arguments}"
  end

  desc "Unschedule the jobs"
  task :unschedule_job, :roles => :app, :only => { :primary => true } do
    run "cd #{current_path} && #{rake} whenever:update_crontab  UNSCHEDULE=true"
  end

  #lib/tasks/whenever.rake
  namespace :whenever do
    desc "updates crontab with our scheduled jobs"  
    task :update_crontab => :load_whenever_gem do     
      Whenever::CommandLine.execute({:update=>true, :identifier=>'YOUR_APP_NAME'})
    end

    task :load_whenever_gem do     
      begin
        gem_dir_root = "#{RAILS_ROOT}/vendor/gems/"
        chronic_gem_dir = Dir["#{RAILS_ROOT}/vendor/gems/*"].detect do |subdir|
          subdir.gsub(gem_dir_root,"") =~ /^(\w+-)?chronic-(\d+)/ && File.exist?("#{subdir}/lib/chronic.rb")
        end
        require "#{chronic_gem_dir}/lib/chronic"

        whenever_gem_dir = Dir["#{RAILS_ROOT}/vendor/gems/*"].detect do |subdir|
          subdir.gsub(gem_dir_root,"") =~ /^(\w+-)?whenever-(\d+)/ && File.exist?("#{subdir}/lib/whenever.rb")
        end
        require "#{whenever_gem_dir}/lib/whenever"

      rescue MissingSourceFile => e
        raise "Cannot find Whenever or Chronic : #{e}"
      end
    end
  end

How administrators can use capistrano to both schedule and unschedule your jobs

  #config/schedule.rb
  unless ENV['UNSCHEDULE']

    module MyApp
      module Job
        class CronRakeTask < Whenever::Job::Default
          def output
            path_required
            "cd #{@path} && /usr/bin/env /usr/local/bin/cron_rake #{task} SOME_CONFIGURATION=#{ENV['SOME_CONFIGURATION']} RAILS_ENV=#{@environment}"
          end      
        end
      end
    end

    set :path,        ENV['APP_PATH'] || RAILS_ROOT 
    set :environment, RAILS_ENV || 'production'
    every 1.day, :at => '10:00pm' do
      command 'do_something', :class       => MyApp::Job::CronRakeTask, 
                              :environment => @environment, 
                              :path        => @path
    end
  end

How to use a library such as the Oracle client that requires certain environment variables

  #!/bin/bash

  export PATH=/usr/local/lib/ruby-enterprise/bin:$PATH
  export ORACLE_HOME=/opt/oracle
  export LD_LIBRARY_PATH=/opt/oracle:$LD_LIBRARY_PATH

  rake $@

How to capture Oracle's dbms_output in your Rails log file

about 1 year ago | Alex Rothenberg: Common Sense Software

I have been writing a rails application on top of a large existing Oracle database where each table has 5+ triggers that each call several stored procedures and each of those PL/SQL stored procedures is hundreds of lines long. Often a simple update statement fails with an ORA-xxxx exception coming from deep in the PL/SQL code and it can be tough to figure out what's gone wrong.

The usual way Oracle database folks figure out what's going on is to put print statements in their code. In oracle this looks like

  dbms_output.put_line('hi i hit this line of pl/sql');

  set serveroutput on;

  CREATE OR REPLACE FUNCTION
  MORE_THAN_FIVE_CHARACTERS_LONG (some_text VARCHAR2) RETURN INTEGER
  AS
  longer_than_five INTEGER;
  BEGIN
    dbms_output.put_line('before the if -' || some_text || '-');
    IF length(some_text) > 5 THEN
      dbms_output.put_line('it is longer than 5');
      longer_than_five := 1;
    ELSE
      dbms_output.put_line('it is 5 or shorter');
      longer_than_five := 0;
    END IF;
    dbms_output.put_line('about to return: ' || longer_than_five);
    RETURN longer_than_five;
  END;

  set serveroutput on;
  select MORE_THAN_FIVE_CHARACTERS_LONG('a long string') from dual;
  select MORE_THAN_FIVE_CHARACTERS_LONG('short') from dual;

  MORE_THAN_FIVE_CHARACTERS_LONG('ALONGSTRING') 
  --------------------------------------------- 
  1                                             

  1 rows selected

  before the if -a long string-
  it is longer than 5
  about to return: 1

  MORE_THAN_FIVE_CHARACTERS_LONG('SHORT') 
  --------------------------------------- 
  0                                       

  1 rows selected

  before the if -short-
  it is 5 or shorter
  about to return: 0

  module ActiveRecord
    module ConnectionAdapters
      class OracleEnhancedAdapter < AbstractAdapter
        DBMS_OUTPUT_BUFFER_SIZE = 10000  #can be 1-1000000
        DBMS_LINE_MAX_SIZE      = 1000  
        def enable_dbms_output
          @enable_dbms_output = true
          execute "BEGIN dbms_output.enable(#{DBMS_OUTPUT_BUFFER_SIZE}); END;"
        end
        def disable_dbms_output
          @enable_dbms_output = false
          execute "BEGIN dbms_output.disable(); END;"
        end
        def dbms_output_enabled?
          @enable_dbms_output
        end

        protected
          def log(sql, name)
            super(sql, name)
          ensure
            log_all_dbms_output if dbms_output_enabled?
          end

        private  
          def log_next_line_of_dbms_output
            dbms_output_text, status = @connection.exec "BEGIN dbms_output.get_line(:return, :status); END;", ' '*DBMS_LINE_MAX_SIZE, 1
            got_text = (status == 0)
            @logger.debug "DBMS_OUTPUT: #{dbms_output_text}" if got_text
            got_text
          end
        
          def log_all_dbms_output
            while log_next_line_of_dbms_output do
            end
          end
      end
    end
  end

  >> ActiveRecord::Base.connection.enable_dbms_output
  => []
  >> ActiveRecord::Base.connection.select_all("select MORE_THAN_FIVE_CHARACTERS_LONG('a long string') from dual")
  => [{"more_than_five_characters_long('alongstring')"=>1}]

    SQL (27.0ms)   BEGIN dbms_output.enable(10000); END;
    SQL (25.9ms)   select MORE_THAN_FIVE_CHARACTERS_LONG('a long string') from dual
  DBMS_OUTPUT: before the if -a long string-
  DBMS_OUTPUT: it is longer than 5
  DBMS_OUTPUT: about to return: 1

One year of blogging

about 1 year ago | Alex Rothenberg: Common Sense Software

I just noticed that its been a year since my first post and thought I'd take a moment to reflect on the experience....

I set out with a goal of writing 2-3 posts a month and have managed to write 28 articles over 12 months so I feel pretty good about that. Most of the time I've gotten excited about something I accomplished or learned during the week. The process of writing it up turned out to be as much of a learning experience for myself as the original discovery. As they say "Teaching is the best way to learn"!

I've been most surprised how easy it is to get to the top of a Google Search results list (for very specific searches of course). With my Google Analytics tracking I can see more than 1/2 of my hits coming from search engines and not all of them are me searching for my own name :) Its been great when I've gotten comments from people I don't know (especially when the comments are positive).

Writing this blog has also helped turn my focus outward so I'm not only working on internal projects at my company but feel (in a small way) a part of the broader community.

I hope to continue in the coming year as I'm having a lot of fun so far ...

Using Github Through Draconian Proxies (Windows And Unix)

about 1 year ago | Alex Rothenberg: Common Sense Software

I came across this great set of instructions on how to tunnel through a proxy to use github - http://returnbooleantrue.blogspot.com/2009/06/using-github-through-draconian-proxies.html

The proxy where I work is not quite so draconian that I need to follow these steps but its nice to have these instructions just in case :)

Metric_fu 1.1.0 released with a patch from me

about 1 year ago | Alex Rothenberg: Common Sense Software

Metric_fu just released version 1.1.0 of their gem which I'm pleased to say includes a patch submitted by me. This is exciting as its the first time I've had my code included by someone I don't know in one of the open source projects I admire.

I was not originally going to make the patch as I thought I'd just hack around to fix the problem locally just enough to get it working but my friend Matt encouraged me to fix the root cause which turned out to be not too hard and got me into the metric_fu source. I always learn something when I read source from others I admire.

The process of submitting the patch was pretty easy and I plan to make it a habit when I run into issues with other gems. I,

1. Experienced a problem and decided not to live with it
   
2. Created a fork of metric_fu on github
3. Cloned locally and iteratively made my changes until I had my fix complete
4. Rebased my changes into a single commit (I wrote an article on this a few weeks ago)
5. Pushed my patch back to github on a branch
6. Submitted my patch back to Jake's repository as an issue
   

1. Deleted the install time dependencies from metric_fu.gemspec
2. Added the runtime dependencies when a specific type of metric is instantiated by
• Inserting a verify_dependencies! strategy step to the initialization in lib/base/generator.rb
• Implementing verify_dependencies! in each of the subclasses for different metrics in lib/generators/*
  
3. Did it with TDD writing tests around everything before implementing my changes
   

Changing history with git rebase: How to combine several commits into one

about 1 year ago | Alex Rothenberg: Common Sense Software

When I look at commits on github I'm always impressed at how concise they are. When I read a commit I can understand the intent of the change without getting distracted by the author's journey to get there. In contrast when I look at my commits they tend to be smaller and more incremental and meandering as I work my way down some false starts until I get to the solution I want. I'm guessing that I'm not alone in the way I work and recently discovered git rebase and an helpful tutorial showing how I can continue to work in my meandering style but package my changes to hide the journey before publishing to the world on github.

Let me show you what I mean with some changes I recently made to metric_fu. Over the course of a few days I made 6 small commits as you can see below.

> git log

commit d4b18b16e982ac57741f7a0a12cb085bb9b0e840
Author: Alex Rothenberg 
Date:   Mon Jun 1 09:55:37 2009 -0400

    reverted rakefile

commit ebda1cb67a2f0f0a85e51469d70919fa7c27d318
Author: Alex Rothenberg 
Date:   Mon Jun 1 09:49:05 2009 -0400

    refactoring of verify_dependencies

commit 3d45903b64a772fd09ec07bf69880bdb29ae4944
Author: Alex Rothenberg 
Date:   Fri May 29 20:40:49 2009 -0400

    runtime dependency check for all gems

commit 36e269bf8f0edccfb39cc767182406cdaa16a559
Author: Alex Rothenberg 
Date:   Fri May 29 20:24:16 2009 -0400

    logic for checking dependencies in generator base

commit bb2ee9a983c6adf54a8c95ee5851c6f8d3bffaba
Author: Alex Rothenberg 
Date:   Fri May 29 19:38:21 2009 -0400

    made rcov dependency figure itself out when generating rcov metrics

commit 750b000e5563e917f21eb1b7837e8001fb53f688
Author: Alex Rothenberg 
Date:   Fri May 29 16:42:12 2009 -0400

    removed gem dependency on rcov - to allow use of relevance-rcov or other github forks

commit d6af5089adce9eeed4916a155c3bdaeb4be6771a
Author: Randy Souza 
Date:   Sat May 16 08:47:37 2009 +0800

    Added a simple fix for cases where Saikuro results with nested information
    cause metrics:all to crash
    
    Signed-off-by: Jake Scruggs 

...

> git rebase --interactive d6af5089adce9eeed4916a155c3bdaeb4be6771a

pick 750b000 removed gem dependency on rcov - to allow use of relevance-rcov or other github forks
pick bb2ee9a made rcov dependency figure itself out when generating rcov metrics
pick 36e269b logic for checking dependencies in generator base
pick 3d45903 runtime dependency check for all gems
pick ebda1cb refactoring of verify_dependencies
pick d4b18b1 reverted rakefile

# Rebase d6af508..d4b18b1 onto d6af508
#
# Commands:
#  p, pick = use commit
#  e, edit = use commit, but stop for amending
#  s, squash = use commit, but meld into previous commit
#
# If you remove a line here THAT COMMIT WILL BE LOST.
# However, if you remove everything, the rebase will be aborted.
#

pick 750b000 removed gem dependency on rcov - to allow use of relevance-rcov or other github forks
squash bb2ee9a made rcov dependency figure itself out when generating rcov metrics
squash 36e269b logic for checking dependencies in generator base
squash 3d45903 runtime dependency check for all gems
squash ebda1cb refactoring of verify_dependencies
squash d4b18b1 reverted rakefile

# Rebase d6af508..d4b18b1 onto d6af508
#
# Commands:
#  p, pick = use commit
#  e, edit = use commit, but stop for amending
#  s, squash = use commit, but meld into previous commit
#
# If you remove a line here THAT COMMIT WILL BE LOST.
# However, if you remove everything, the rebase will be aborted.
#

# This is a combination of 6 commits.
# The first commit's message is:
removed gem dependency on rcov - to allow use of relevance-rcov or other github forks

# This is the 2nd commit message:

made rcov dependency figure itself out when generating rcov metrics

# This is the 3rd commit message:

logic for checking dependencies in generator base

# This is the 4th commit message:

runtime dependency check for all gems

# This is the 5th commit message:

refactoring of verify_dependencies

# This is the 6th commit message:

reverted rakefile

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# Explicit paths specified without -i nor -o; assuming --only paths...
# Not currently on any branch.
# Changes to be committed:
#   (use "git reset HEAD ..." to unstage)
#
#       modified:   Rakefile
#       modified:   lib/base/generator.rb
#       modified:   lib/generators/flay.rb
#       modified:   lib/generators/flog.rb
#       modified:   lib/generators/rcov.rb
#       modified:   lib/generators/reek.rb
#       modified:   lib/generators/roodi.rb
#       modified:   lib/generators/saikuro.rb
#       modified:   metric_fu.gemspec
#       modified:   spec/base/generator_spec.rb
#       modified:   spec/generators/flay_spec.rb
#       modified:   spec/generators/flog_spec.rb
#       modified:   spec/generators/reek_spec.rb
#

Changed gem dependencies from install-time in gemspec to runtime when each
of the generators is loaded.  This allows use of github gems (i.e.
relevance-rcov instead of rcov) and also allows you to install only the
gems for the metrics you plan on using.

                                     
# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# Explicit paths specified without -i nor -o; assuming --only paths...
# Not currently on any branch.
# Changes to be committed:
#   (use "git reset HEAD ..." to unstage)
#
#       modified:   Rakefile
#       modified:   lib/base/generator.rb
#       modified:   lib/generators/flay.rb
#       modified:   lib/generators/flog.rb
#       modified:   lib/generators/rcov.rb
#       modified:   lib/generators/reek.rb
#       modified:   lib/generators/roodi.rb
#       modified:   lib/generators/saikuro.rb
#       modified:   metric_fu.gemspec
#       modified:   spec/base/generator_spec.rb
#       modified:   spec/generators/flay_spec.rb
#       modified:   spec/generators/flog_spec.rb
#       modified:   spec/generators/reek_spec.rb
#

> git log

commit 6f389364eb972871867d3a71677b8eb7046541a2
Author: Alex Rothenberg 
Date:   Fri May 29 16:42:12 2009 -0400

    Changed gem dependencies from install-time in gemspec to runtime when each
    of the generators is loaded.  This allows use of github gems (i.e.
    relevance-rcov instead of rcov) and also allows you to install only the
    gems for the metrics you plan on using.

commit d6af5089adce9eeed4916a155c3bdaeb4be6771a
Author: Randy Souza 
Date:   Sat May 16 08:47:37 2009 +0800

    Added a simple fix for cases where Saikuro results with nested information
    cause metrics:all to crash
    
    Signed-off-by: Jake Scruggs 

...

How to use dates in Rails when your database stores a string

about 1 year ago | Alex Rothenberg: Common Sense Software

When working with Rails there's a lot of magic that happens behind the scenes to make it easy to do complex things. Most of the time you don't need to know how that "magic" works but there are times when things don't work as expected and its helpful to dig in and understand what Rails is doing under the covers so you can change how it works. Did I just say "change how Rails works"?!? I did! Rails is opinionated software that seeks to lead you down the golden path but there are legitimate times when you have to veer off that path and Rails lets you do so. I find this most often happens to me when I'm dealing with an existing legacy database which is not setup as Rails would like.

Today I'm going to go through an example that happened to me recently when I had an existing database that stored some dates in a text column but I needed to treat them as dates in my UI. I couldn't change the type of that column as there was another legacy application that expected it to be text.

Using Dates the Rails Way

First let's look at how easy it is to work with dates when you can follow the Rails Way. Let's create a new project and add a scaffolded Person object with a date attribute called birthday.

rails date_select_example

cd date_select_example

script/generate scaffold person name:string birthday:date

rake db:migrate

#app/views/people/new.html.erb

<h1>New person

<% form_for(@person) do |f| %>

  <%= f.error_messages %>

  <p>

    <%= f.label :name %><br />

    <%= f.text_field :name %>

  </p>

  <p>

    <%= f.label :birthday %><br />

    <%= f.date_select :birthday, :start_year=>1900 %>

  </p>

  <p>

    <%= f.submit 'Create' %>

  </p>

<% end %>



<%= link_to 'Back', people_path %>

#app/models/person.rb

class Person < ActiveRecord::Base

end

script/generate migration AddAnniversaryToPerson anniversary:string

rake db:migrate

#app/views/people/edit.html.erb

<h1>Editing person

<% form_for(@person) do |f| %>

  <%= f.error_messages %>

  <p>

    <%= f.label :name %><br />

    <%= f.text_field :name %>

  </p>

  <p>

    <%= f.label :birthday %><br />

    <%= f.date_select :birthday, :start_year=>1900  %>

  </p>

  <p>

    <%= f.label :anniversary %><br />

    <%= f.date_select :anniversary, :start_year=>1900  %>

  </p>

  <p>

    <%= f.submit 'Update' %>

  </p>

<% end %>



<%= link_to 'Show', @person %> |

<%= link_to 'Back', people_path %>

ActiveRecord::MultiparameterAssignmentErrors in PeopleController#update



1 error(s) on assignment of multiparameter attributes

RAILS_ROOT: /Users/alexrothenberg/date_select_example



Application Trace | Framework Trace | Full Trace

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:3061:in `execute_callstack_for_multiparameter_attributes'

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:3022:in `assign_multiparameter_attributes'

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:2749:in `attributes='

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:2627:in `update_attributes'

/Users/alexrothenberg/date_select_example/app/controllers/people_controller.rb:63:in `update'

...more stack trace...



Request



Parameters:



{"commit"=>"Update",

 "_method"=>"put",

 "authenticity_token"=>"qezkVq+MNzFuXxFBJ/GaSoh2BNdxM6oF3H7JP5beFFE=",

 "id"=>"1",

 "person"=>{"name"=>"Barack Obama",

 "birthday(2i)"=>"8",

 "birthday(3i)"=>"4",

 "anniversary(1i)"=>"2009",

 "anniversary(2i)"=>"5",

 "anniversary(3i)"=>"22",

 "birthday(1i)"=>"1960"}}

1. The date_select helper actually sends 3 http parameters to our application anniversary(1i), anniversary(2i) and anniversary(3i). ActiveRecord must combine those into a single Date before updating the row in the database.
   
2. Looking at assign_multiparameter_attributes in active_record/base.rb we see this this comment that talks about combining 3 http parameters into a date type by calling new on the column type
   

   Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done by calling new on the column type or aggregation type (through composed_of) object with these parameters.
   So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate written_on (a date type) with Date.new("2004", "6", "24"). You can also specify a typecast character in the parentheses to have the parameters typecasted before they're used in the constructor. Use i for Fixnum, f for Float, s for String, and a for Array. If all the values for a given attribute are empty, the attribute will be set to nil.

   
   

$ script/console

Loading development environment (Rails 2.3.2)

>> Person.columns_hash['birthday']

=> #

>> Person.columns_hash['birthday'].klass

=> Date

>> Person.columns_hash['anniversary']

=> #

>> Person.columns_hash['anniversary'].klass

=> String

require File.dirname(__FILE__) + '/../spec_helper'



describe Person do

  it "should treat anniversary as a Date column" do

    Person.columns_hash['anniversary'].klass.should == Date

  end

end



# 'Person should treat anniversary as a Date column' FAILED

# expected: Date,

#      got: String (using ==)

class Person < ActiveRecord::Base



  class << columns_hash['anniversary']

    def type

      :date

    end

  end

end

How to use dates in Rails when your database stores a string

about 1 year ago | Alex Rothenberg: Common Sense Software

When working with Rails there's a lot of magic that happens behind the scenes to make it easy to do complex things. Most of the time you don't need to know how that "magic" works but there are times when things don't work as expected and its helpful to dig in and understand what Rails is doing under the covers so you can change how it works. Did I just say "change how Rails works"?!? I did! Rails is opinionated software that seeks to lead you down the golden path but there are legitimate times when you have to veer off that path and Rails lets you do so. I find this most often happens to me when I'm dealing with an existing legacy database which is not setup as Rails would like.

Today I'm going to go through an example that happened to me recently when I had an existing database that stored some dates in a text column but I needed to treat them as dates in my UI. I couldn't change the type of that column as there was another legacy application that expected it to be text.

Using Dates the Rails Way

First let's look at how easy it is to work with dates when you can follow the Rails Way. Let's create a new project and add a scaffolded Person object with a date attribute called birthday.

rails date_select_example

cd date_select_example

script/generate scaffold person name:string birthday:date

rake db:migrate

#app/views/people/new.html.erb

<h1>New person

<% form_for(@person) do |f| %>

  <%= f.error_messages %>

  <p>

    <%= f.label :name %><br />

    <%= f.text_field :name %>

  </p>

  <p>

    <%= f.label :birthday %><br />

    <%= f.date_select :birthday, :start_year=>1900 %>

  </p>

  <p>

    <%= f.submit 'Create' %>

  </p>

<% end %>



<%= link_to 'Back', people_path %>

#app/models/person.rb

class Person < ActiveRecord::Base

end

script/generate migration AddAnniversaryToPerson anniversary:string

rake db:migrate

#app/views/people/edit.html.erb

<h1>Editing person

<% form_for(@person) do |f| %>

  <%= f.error_messages %>

  <p>

    <%= f.label :name %><br />

    <%= f.text_field :name %>

  </p>

  <p>

    <%= f.label :birthday %><br />

    <%= f.date_select :birthday, :start_year=>1900  %>

  </p>

  <p>

    <%= f.label :anniversary %><br />

    <%= f.date_select :anniversary, :start_year=>1900  %>

  </p>

  <p>

    <%= f.submit 'Update' %>

  </p>

<% end %>



<%= link_to 'Show', @person %> |

<%= link_to 'Back', people_path %>

ActiveRecord::MultiparameterAssignmentErrors in PeopleController#update



1 error(s) on assignment of multiparameter attributes

RAILS_ROOT: /Users/alexrothenberg/date_select_example



Application Trace | Framework Trace | Full Trace

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:3061:in `execute_callstack_for_multiparameter_attributes'

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:3022:in `assign_multiparameter_attributes'

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:2749:in `attributes='

/Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:2627:in `update_attributes'

/Users/alexrothenberg/date_select_example/app/controllers/people_controller.rb:63:in `update'

...more stack trace...



Request



Parameters:



{"commit"=>"Update",

 "_method"=>"put",

 "authenticity_token"=>"qezkVq+MNzFuXxFBJ/GaSoh2BNdxM6oF3H7JP5beFFE=",

 "id"=>"1",

 "person"=>{"name"=>"Barack Obama",

 "birthday(2i)"=>"8",

 "birthday(3i)"=>"4",

 "anniversary(1i)"=>"2009",

 "anniversary(2i)"=>"5",

 "anniversary(3i)"=>"22",

 "birthday(1i)"=>"1960"}}

1. The date_select helper actually sends 3 http parameters to our application anniversary(1i), anniversary(2i) and anniversary(3i). ActiveRecord must combine those into a single Date before updating the row in the database.
   
2. Looking at assign_multiparameter_attributes in active_record/base.rb we see this this comment that talks about combining 3 http parameters into a date type by calling new on the column type
   

   Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done by calling new on the column type or aggregation type (through composed_of) object with these parameters.
   So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate written_on (a date type) with Date.new("2004", "6", "24"). You can also specify a typecast character in the parentheses to have the parameters typecasted before they're used in the constructor. Use i for Fixnum, f for Float, s for String, and a for Array. If all the values for a given attribute are empty, the attribute will be set to nil.

   
   

$ script/console

Loading development environment (Rails 2.3.2)

>> Person.columns_hash['birthday']

=> #

>> Person.columns_hash['birthday'].klass

=> Date

>> Person.columns_hash['anniversary']

=> #

>> Person.columns_hash['anniversary'].klass

=> String

require File.dirname(__FILE__) + '/../spec_helper'



describe Person do

  it "should treat anniversary as a Date column" do

    Person.columns_hash['anniversary'].klass.should == Date

  end

end



# 'Person should treat anniversary as a Date column' FAILED

# expected: Date,

#      got: String (using ==)

class Person < ActiveRecord::Base



  class << columns_hash['anniversary']

    def type

      :date

    end

  end

end

Testing AJAX without a browser with Cucumber and Webrat

about 1 year ago | Alex Rothenberg: Common Sense Software

I have lately fallen in love with using Cucumber and Webrat for my integration/acceptance testing. Cucumber because it allows non-technical people to write or at least read the test scenarios and Webrat because it matches content and encourages you to write integration tests without relying on xpath to find html elements. The way I like to use these tools is to run Rails integration tests which means its fast since I don’t need to start a mongrel or fire up a browser and can use Rails’ transactional fixtures to rollback all my database changes at the end of each test scenario. The only downside is that you can’t test javascript.

Today I am going to talk about how to get around this and test a form with an ajax autocomplete field. I've built a sample application with all the code examples here and you can download it from http://github.com/alexrothenberg/testing-ajax-example if you like. The application I'm building is just some simple app created with scaffolding that just has a User resource with a name and address. I modified the /users page to not display all users but include the auto_complete typeahead to let you pick a user (imagining there may be a lot) so the page looks something like this.



My first test scenario will ignore the ajax and just test the form which is super easy and can be done by writing a single feature file.

#features/find_a_user.feature
Feature: Allow anyone to find a user and see their details
  In order to handle a large set of users
  I want search with autocomplete
 
  Scenario: View a candidate detail page without testing ajax
    Given "Mickey Mouse" is a user living at "123 Main Street"
    When I am on the homepage
      And I fill in "Which user" with "Mickey Mouse"
      And I press "Find"
    Then I should see "Mickey Mouse"
      And I should see "123 Main Street"

$ rake features
(in /Users/alexrothenberg/ruby/testing-ajax-example)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/bin/cucumber" --format pretty --require features/step_definitions/user_steps.rb --require features/step_definitions/webrat_steps.rb --require features/support/env.rb --require features/support/paths.rb features/find_a_user.feature
Feature: Allow anyone to find a user and see their details
  In order to handle a large set of users 
  I want search with autocomplete

  Scenario: View a candidate detail page without testing ajax     # features/find_a_user.feature:5
    Given "Mickey Mouse" is a user living at "123 Main Street"    # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                     # features/step_definitions/webrat_steps.rb:6
    And I fill in "Which user" with "Mickey Mouse"                # features/step_definitions/webrat_steps.rb:22
    And I press "Find"                                            # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                              # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                            # features/step_definitions/webrat_steps.rb:93

1 scenario (1 passed)
6 steps (6 passed)

<first scenario omitted>

Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/find_a_user.feature:16
    And I fill in "Which candidate" with the first typeahead result # features/find_a_user.feature:17
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

2 scenarios (1 undefined, 1 passed)
13 steps (3 skipped, 2 undefined, 8 passed)

You can implement step definitions for undefined steps with these snippets:

When /^I typeahead in "([^\"]*)" with "([^\"]*)"$/ do |arg1, arg2|
  pending
end

When /^I fill in "([^\"]*)" with the first typeahead result$/ do |arg1|
  pending
end

When /^I typeahead in "(.*)" with "(.*)"$/ do |field, value|
  field = field_labeled field
  @typeahead = AutoCompleteStepHelper.new(request)
  @typeahead.type(field, value)
end

When /^I fill in "(.*)" with the first typeahead result$/ do |field|
  When %Q[I fill in "#{field}" with "#{@typeahead.items.first}"]
end

<first scenario omitted>

Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/step_definitions/autocomplete_steps.rb:1
      uninitialized constant AutoCompleteStepHelper (NameError)
      ./features/step_definitions/autocomplete_steps.rb:3:in `/^I typeahead in "(.*)" with "(.*)"$/'
      features/find_a_user.feature:16:in `And I typeahead in "Which user" with "Mickey Mouse"'
    And I fill in "Which candidate" with the first typeahead result # features/step_definitions/autocomplete_steps.rb:7
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

2 scenarios (1 failed, 1 passed)
13 steps (1 failed, 4 skipped, 8 passed)

class AutoCompleteStepsHelper < ActionController::IntegrationTest
  def initialize(existing_request)
    @controller_name = existing_request.parameters[:controller]
    @controller_class = "#{@controller_name.to_s.camelize}Controller".constantize
    raise "Can't determine controller class for #{@controller_class_name}" if @controller_class.nil?

    @controller = @controller_class.new
    @request = ActionController::TestRequest.new
    @response = ActionController::TestResponse.new
    @response.session = @request.session
  end
 
  def type(field, value)
    visit url_for(:controller=>@controller_name, :action=>"auto_complete_for_#{field.id}", field.send(:name)=>value)
  end
 
  def items
    current_dom.search('//ul/li').map(&:inner_html)
  end
end

<first scenario omitted>

  Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/step_definitions/autocomplete_steps.rb:1
    And I fill in "Which user" with the first typeahead result      # features/step_definitions/autocomplete_steps.rb:7
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

2 scenarios (2 passed)
13 steps (13 passed)

  Scenario: Typeahead should return 2 users that match but not a third
    Given "Mickey Mouse" is a user living at "123 Main Street"
      And "Donald Duck" is a user living at "123 Pond Lane"
      And "Minnie Mouse" is a user living at "123 Disney Avenue"
    When I am on the homepage
      And I typeahead in "Which user" with "Mi"
    Then I should see in my typeahead "Mickey Mouse"
      And I should see in my typeahead "Minnie Mouse"
      And I should not see in my typeahead "Donald Duck"

Then /^I should see in my typeahead "(.*)"$/ do |text|
  @typeahead.response_body.should =~ /#{text}/m
end

Then /^I should not see in my typeahead "(.*)"$/ do |text|
  @typeahead.response_body.should_not =~ /#{text}/m
end

$ rake features
(in /Users/alexrothenberg/ruby/testing-ajax-example)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/bin/cucumber" --format pretty --require features/step_definitions/autocomplete_steps.rb --require features/step_definitions/user_steps.rb --require features/step_definitions/webrat_steps.rb --require features/support/autocomplete_steps_helper.rb --require features/support/env.rb --require features/support/paths.rb features/find_a_user.feature
Feature: Allow anyone to find a user and see their details
  In order to handle a large set of users 
  I want search with autocomplete

  Scenario: View a candidate detail page without testing ajax  # features/find_a_user.feature:5
    Given "Mickey Mouse" is a user living at "123 Main Street" # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                  # features/step_definitions/webrat_steps.rb:6
    And I fill in "Which user" with "Mickey Mouse"             # features/step_definitions/webrat_steps.rb:22
    And I press "Find"                                         # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                           # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                         # features/step_definitions/webrat_steps.rb:93

  Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/step_definitions/autocomplete_steps.rb:1
    And I fill in "Which user" with the first typeahead result      # features/step_definitions/autocomplete_steps.rb:7
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

  Scenario: Typeahead should return 2 users that match but not a third # features/find_a_user.feature:22
    Given "Mickey Mouse" is a user living at "123 Main Street"         # features/step_definitions/user_steps.rb:1
    And "Donald Duck" is a user living at "123 Pond Lane"              # features/step_definitions/user_steps.rb:1
    And "Minnie Mouse" is a user living at "123 Disney Avenue"         # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                          # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mi"                          # features/step_definitions/autocomplete_steps.rb:1
    Then I should see in my typeahead "Mickey Mouse"                   # features/step_definitions/autocomplete_steps.rb:16
    And I should see in my typeahead "Minnie Mouse"                    # features/step_definitions/autocomplete_steps.rb:16
    And I should not see in my typeahead "Donald Duck"                 # features/step_definitions/autocomplete_steps.rb:20

3 scenarios (3 passed)
21 steps (21 passed)

Testing AJAX without a browser with Cucumber and Webrat

about 1 year ago | Alex Rothenberg: Common Sense Software

I have lately fallen in love with using Cucumber and Webrat for my integration/acceptance testing. Cucumber because it allows non-technical people to write or at least read the test scenarios and Webrat because it matches content and encourages you to write integration tests without relying on xpath to find html elements. The way I like to use these tools is to run Rails integration tests which means its fast since I don’t need to start a mongrel or fire up a browser and can use Rails’ transactional fixtures to rollback all my database changes at the end of each test scenario. The only downside is that you can’t test javascript.

Today I am going to talk about how to get around this and test a form with an ajax autocomplete field. I've built a sample application with all the code examples here and you can download it from http://github.com/alexrothenberg/testing-ajax-example if you like. The application I'm building is just some simple app created with scaffolding that just has a User resource with a name and address. I modified the /users page to not display all users but include the auto_complete typeahead to let you pick a user (imagining there may be a lot) so the page looks something like this.



My first test scenario will ignore the ajax and just test the form which is super easy and can be done by writing a single feature file.

#features/find_a_user.feature
Feature: Allow anyone to find a user and see their details
  In order to handle a large set of users
  I want search with autocomplete
 
  Scenario: View a candidate detail page without testing ajax
    Given "Mickey Mouse" is a user living at "123 Main Street"
    When I am on the homepage
      And I fill in "Which user" with "Mickey Mouse"
      And I press "Find"
    Then I should see "Mickey Mouse"
      And I should see "123 Main Street"

$ rake features
(in /Users/alexrothenberg/ruby/testing-ajax-example)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/bin/cucumber" --format pretty --require features/step_definitions/user_steps.rb --require features/step_definitions/webrat_steps.rb --require features/support/env.rb --require features/support/paths.rb features/find_a_user.feature
Feature: Allow anyone to find a user and see their details
  In order to handle a large set of users 
  I want search with autocomplete

  Scenario: View a candidate detail page without testing ajax     # features/find_a_user.feature:5
    Given "Mickey Mouse" is a user living at "123 Main Street"    # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                     # features/step_definitions/webrat_steps.rb:6
    And I fill in "Which user" with "Mickey Mouse"                # features/step_definitions/webrat_steps.rb:22
    And I press "Find"                                            # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                              # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                            # features/step_definitions/webrat_steps.rb:93

1 scenario (1 passed)
6 steps (6 passed)

<first scenario omitted>

Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/find_a_user.feature:16
    And I fill in "Which candidate" with the first typeahead result # features/find_a_user.feature:17
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

2 scenarios (1 undefined, 1 passed)
13 steps (3 skipped, 2 undefined, 8 passed)

You can implement step definitions for undefined steps with these snippets:

When /^I typeahead in "([^\"]*)" with "([^\"]*)"$/ do |arg1, arg2|
  pending
end

When /^I fill in "([^\"]*)" with the first typeahead result$/ do |arg1|
  pending
end

When /^I typeahead in "(.*)" with "(.*)"$/ do |field, value|
  field = field_labeled field
  @typeahead = AutoCompleteStepHelper.new(request)
  @typeahead.type(field, value)
end

When /^I fill in "(.*)" with the first typeahead result$/ do |field|
  When %Q[I fill in "#{field}" with "#{@typeahead.items.first}"]
end

<first scenario omitted>

Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/step_definitions/autocomplete_steps.rb:1
      uninitialized constant AutoCompleteStepHelper (NameError)
      ./features/step_definitions/autocomplete_steps.rb:3:in `/^I typeahead in "(.*)" with "(.*)"$/'
      features/find_a_user.feature:16:in `And I typeahead in "Which user" with "Mickey Mouse"'
    And I fill in "Which candidate" with the first typeahead result # features/step_definitions/autocomplete_steps.rb:7
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

2 scenarios (1 failed, 1 passed)
13 steps (1 failed, 4 skipped, 8 passed)

class AutoCompleteStepsHelper < ActionController::IntegrationTest
  def initialize(existing_request)
    @controller_name = existing_request.parameters[:controller]
    @controller_class = "#{@controller_name.to_s.camelize}Controller".constantize
    raise "Can't determine controller class for #{@controller_class_name}" if @controller_class.nil?

    @controller = @controller_class.new
    @request = ActionController::TestRequest.new
    @response = ActionController::TestResponse.new
    @response.session = @request.session
  end
 
  def type(field, value)
    visit url_for(:controller=>@controller_name, :action=>"auto_complete_for_#{field.id}", field.send(:name)=>value)
  end
 
  def items
    current_dom.search('//ul/li').map(&:inner_html)
  end
end

<first scenario omitted>

  Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/step_definitions/autocomplete_steps.rb:1
    And I fill in "Which user" with the first typeahead result      # features/step_definitions/autocomplete_steps.rb:7
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

2 scenarios (2 passed)
13 steps (13 passed)

  Scenario: Typeahead should return 2 users that match but not a third
    Given "Mickey Mouse" is a user living at "123 Main Street"
      And "Donald Duck" is a user living at "123 Pond Lane"
      And "Minnie Mouse" is a user living at "123 Disney Avenue"
    When I am on the homepage
      And I typeahead in "Which user" with "Mi"
    Then I should see in my typeahead "Mickey Mouse"
      And I should see in my typeahead "Minnie Mouse"
      And I should not see in my typeahead "Donald Duck"

Then /^I should see in my typeahead "(.*)"$/ do |text|
  @typeahead.response_body.should =~ /#{text}/m
end

Then /^I should not see in my typeahead "(.*)"$/ do |text|
  @typeahead.response_body.should_not =~ /#{text}/m
end

$ rake features
(in /Users/alexrothenberg/ruby/testing-ajax-example)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/lib:lib" "/Library/Ruby/Gems/1.8/gems/cucumber-0.3.2/bin/cucumber" --format pretty --require features/step_definitions/autocomplete_steps.rb --require features/step_definitions/user_steps.rb --require features/step_definitions/webrat_steps.rb --require features/support/autocomplete_steps_helper.rb --require features/support/env.rb --require features/support/paths.rb features/find_a_user.feature
Feature: Allow anyone to find a user and see their details
  In order to handle a large set of users 
  I want search with autocomplete

  Scenario: View a candidate detail page without testing ajax  # features/find_a_user.feature:5
    Given "Mickey Mouse" is a user living at "123 Main Street" # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                  # features/step_definitions/webrat_steps.rb:6
    And I fill in "Which user" with "Mickey Mouse"             # features/step_definitions/webrat_steps.rb:22
    And I press "Find"                                         # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                           # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                         # features/step_definitions/webrat_steps.rb:93

  Scenario: View a candidate detail page testing (most of) the ajax # features/find_a_user.feature:13
    Given "Mickey Mouse" is a user living at "123 Main Street"      # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                       # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mickey Mouse"             # features/step_definitions/autocomplete_steps.rb:1
    And I fill in "Which user" with the first typeahead result      # features/step_definitions/autocomplete_steps.rb:7
    And I press "Find"                                              # features/step_definitions/webrat_steps.rb:14
    Then I should see "Mickey Mouse"                                # features/step_definitions/webrat_steps.rb:93
    And I should see "123 Main Street"                              # features/step_definitions/webrat_steps.rb:93

  Scenario: Typeahead should return 2 users that match but not a third # features/find_a_user.feature:22
    Given "Mickey Mouse" is a user living at "123 Main Street"         # features/step_definitions/user_steps.rb:1
    And "Donald Duck" is a user living at "123 Pond Lane"              # features/step_definitions/user_steps.rb:1
    And "Minnie Mouse" is a user living at "123 Disney Avenue"         # features/step_definitions/user_steps.rb:1
    When I am on the homepage                                          # features/step_definitions/webrat_steps.rb:6
    And I typeahead in "Which user" with "Mi"                          # features/step_definitions/autocomplete_steps.rb:1
    Then I should see in my typeahead "Mickey Mouse"                   # features/step_definitions/autocomplete_steps.rb:16
    And I should see in my typeahead "Minnie Mouse"                    # features/step_definitions/autocomplete_steps.rb:16
    And I should not see in my typeahead "Donald Duck"                 # features/step_definitions/autocomplete_steps.rb:20

3 scenarios (3 passed)
21 steps (21 passed)

Managing the draw of a single-elimination tournament

about 1 year ago | Alex Rothenberg: Common Sense Software

My company has been running a GO tournament and since its around NCAA March Madness time I thought it'd be easy to find a site to manage the draw. I looked but couldn't find anything that did what I wanted so I wrote my own. Caveat: I just spent a few days on this and it could stand to be enhanced with more features and a rewrite of the ui implementation but I'm open to suggestions if anyone finds this useful.

To use it

1. Edit the file lib/names.txt with a the players in your tournament


2. Run 'rake create_tournament

Managing the draw of a single-elimination tournament

about 1 year ago | Alex Rothenberg: Common Sense Software

My company has been running a GO tournament and since its around NCAA March Madness time I thought it'd be easy to find a site to manage the draw. I looked but couldn't find anything that did what I wanted so I wrote my own. Caveat: I just spent a few days on this and it could stand to be enhanced with more features and a rewrite of the ui implementation but I'm open to suggestions if anyone finds this useful.

To use it

1. Edit the file lib/names.txt with a the players in your tournament


2. Run 'rake create_tournament

Link: Search Engine in 200 lines of Ruby Code

about 1 year ago | Alex Rothenberg: Common Sense Software

I read a very interesting article by someone who works for Yahoo about how he wrote a basic search engine in Ruby in just a few files. I wouldn't use this for a production system for as an example of how search engines work its fascinating and I plan to keep following his site to see how he enhances it

Description: http://blog.saush.com/2009/03/write-an-internet-search-engine-with-200-lines-of-ruby-code/

Source: http://github.com/sausheong/saushengine

... and he's got a really cool css/javascript formatter for the source in his blog. I've gotta learn more about SyntaxHighlighter

Link: Search Engine in 200 lines of Ruby Code

about 1 year ago | Alex Rothenberg: Common Sense Software

I read a very interesting article by someone who works for Yahoo about how he wrote a basic search engine in Ruby in just a few files. I wouldn't use this for a production system for as an example of how search engines work its fascinating and I plan to keep following his site to see how he enhances it

Description: http://blog.saush.com/2009/03/write-an-internet-search-engine-with-200-lines-of-ruby-code/

Source: http://github.com/sausheong/saushengine

... and he's got a really cool css/javascript formatter for the source in his blog. I've gotta learn more about SyntaxHighlighter

Java as a Legacy Language

about 1 year ago | Alex Rothenberg: Common Sense Software

I came across this article titled Java as Legacy Language today. As an ex-Java guy who is now committed to Ruby I was amused by the title but also think he makes a good point.

One thing is for sure: If you're in the software development business, don't cling to old ways of doing development. And also, don't get too carried away thinking that something like Scrum is going to be the Bandaid that fixes your agility problems, because it may turn out that your main problem is Java itself. Keep an open mind. Try new things. Be ready when the next disruption arrives, or you may find yourself without a chair when the music stops.

Java as a Legacy Language

about 1 year ago | Alex Rothenberg: Common Sense Software

I came across this article titled Java as Legacy Language today. As an ex-Java guy who is now committed to Ruby I was amused by the title but also think he makes a good point.

One thing is for sure: If you're in the software development business, don't cling to old ways of doing development. And also, don't get too carried away thinking that something like Scrum is going to be the Bandaid that fixes your agility problems, because it may turn out that your main problem is Java itself. Keep an open mind. Try new things. Be ready when the next disruption arrives, or you may find yourself without a chair when the music stops.

Using scopes in auto_complete plugin

about 1 year ago | Alex Rothenberg: Common Sense Software

My colleague Pat Shaughnessy has spent a lot of time recently enhancing the auto_complete plugin. I suggest you read his blog posts and check out his fork of auto_complete on github to see the details.

I was reading his latest change to allow filtering of auto complete picklists and really like what he did but thought there was one thing that didn't quite feel right - the fact that you have to mix the application logic to filter the list with the plugin logic to find the list in the block in your controller.

Here's the code Pat wrote in his controller and what I'd like to avoid is having to re-implement the "LOWER(tasks.name) LIKE ?" portion that's already implemented in the filtered_auto_complete_for method of autocomplete.rb in the plugin.

# For task name auto complete, only display tasks
# that belong to the given project: 
filtered_auto_complete_for :task, :name do | find_options, params|
  find_options.merge!(
    {
      :include => :project,
      :conditions => [ "LOWER(tasks.name) LIKE ? AND projects.name = ?",
                       '%' + params['task']['name'].downcase + '%',
                       params['project'] ],
      :order => "tasks.name ASC"
    }
  )
end

class ProjectController < ApplicationController
  # For task name auto complete, only display tasks
  # that belong to the given project: 
  filtered_auto_complete_for :task, :name do | list, params |
    list.by_project(params['project']['id'])
  end
end

class Project < ActiveRecord::Base
  named_scope :by_project, 
              lambda {|project_id| {:conditions => {:project_id => project_id} } }
end

def filtered_auto_complete_for(object, method)
  define_method("auto_complete_for_#{object}_#{method}") do
    find_options = { 
      :conditions => [ "LOWER(#{method}) LIKE ?", '%' +
        params[object][method].downcase + '%' ], 
      :order => "#{method} ASC",
      :limit => 10 }
    @items = object.to_s.camelize.constantize.scoped(find_options)
    @items = yield(@items, params) if block_given?

    render :inline => "<%= auto_complete_result @items, '#{method}' %>"
  end
end

 User Load (1.2ms)   SELECT * FROM `tasks` WHERE ((`tasks`.`project_id` = '7') AND (LOWER(name) LIKE '%tas%'))  ORDER BY name ASC LIMIT 10

Using scopes in auto_complete plugin

about 1 year ago | Alex Rothenberg: Common Sense Software

My colleague Pat Shaughnessy has spent a lot of time recently enhancing the auto_complete plugin. I suggest you read his blog posts and check out his fork of auto_complete on github to see the details.

I was reading his latest change to allow filtering of auto complete picklists and really like what he did but thought there was one thing that didn't quite feel right - the fact that you have to mix the application logic to filter the list with the plugin logic to find the list in the block in your controller.

Here's the code Pat wrote in his controller and what I'd like to avoid is having to re-implement the "LOWER(tasks.name) LIKE ?" portion that's already implemented in the filtered_auto_complete_for method of autocomplete.rb in the plugin.

# For task name auto complete, only display tasks
# that belong to the given project: 
filtered_auto_complete_for :task, :name do | find_options, params|
  find_options.merge!(
    {
      :include => :project,
      :conditions => [ "LOWER(tasks.name) LIKE ? AND projects.name = ?",
                       '%' + params['task']['name'].downcase + '%',
                       params['project'] ],
      :order => "tasks.name ASC"
    }
  )
end

class ProjectController < ApplicationController
  # For task name auto complete, only display tasks
  # that belong to the given project: 
  filtered_auto_complete_for :task, :name do | list, params |
    list.by_project(params['project']['id'])
  end
end

class Project < ActiveRecord::Base
  named_scope :by_project, 
              lambda {|project_id| {:conditions => {:project_id => project_id} } }
end

def filtered_auto_complete_for(object, method)
  define_method("auto_complete_for_#{object}_#{method}") do
    find_options = { 
      :conditions => [ "LOWER(#{method}) LIKE ?", '%' +
        params[object][method].downcase + '%' ], 
      :order => "#{method} ASC",
      :limit => 10 }
    @items = object.to_s.camelize.constantize.scoped(find_options)
    @items = yield(@items, params) if block_given?

    render :inline => "<%= auto_complete_result @items, '#{method}' %>"
  end
end

 User Load (1.2ms)   SELECT * FROM `tasks` WHERE ((`tasks`.`project_id` = '7') AND (LOWER(name) LIKE '%tas%'))  ORDER BY name ASC LIMIT 10

Microsoft Office links causing InvalidAuthenticityToken in Rails

about 1 year ago | Alex Rothenberg: Common Sense Software

I started receiving a lot of error notifications recently from my ExceptionNotfier plugin for an error with ActionController::InvalidAuthenticityToken. It turned out the error was occurring because one of my users was pasting a link to my app in an MS Office document and when Office sees the link it makes a request that Rails could not handle. Here I'll show you a simple fix you can use to avoid these errors with much credit going to an article at
Dealing with Microsoft Office Protocol Discovery in Rails
.

My execptions looked something like this (lots of boring details omitted)

A ActionController::InvalidAuthenticityToken occurred in events#1164:

  ActionController::InvalidAuthenticityToken
  [RAILS_ROOT]/vendor/rails/actionpack/lib/action_controller/request_forgery_protection.rb:86:in `verify_authenticity_token'

-------------------------------
Environment:
-------------------------------
  * HTTP_USER_AGENT        : Microsoft Data Access Internet Publishing Provider Protocol Discovery
  * REQUEST_METHOD         : OPTIONS

#around line 270 of routing.rb
module ActionController
  module Routing
    HTTP_METHODS = [:get, :head, :post, :put, :delete]
  end
end

class ApplicationController < ActionController::Base
  before_filter :options_for_microsoft_office_protocol_discovery

  ...

  def options_for_microsoft_office_protocol_discovery
    render :nothing => true, :status => 200 if request.method == :options
  end
end  

  # Rails 2.3 and above 
  it 'should not throw an exception on OPTIONS request (from ms office protocol discovery)' do
    process '/any/goofy/path', nil, nil, nil, 'OPTIONS'
    response.should be_success
  end 

  # Rails < 2.3 version
  it 'should not throw an exception on OPTIONS request (from ms office protocol discovery)' do
    @request.env['REQUEST_METHOD'] = 'OPTIONS'
    process '/any/goofy/path'
    response.should be_success
  end 

curl -X OPTIONS http://localhost:3000/

Microsoft Office links causing InvalidAuthenticityToken in Rails

about 1 year ago | Alex Rothenberg: Common Sense Software

I started receiving a lot of error notifications recently from my ExceptionNotfier plugin for an error with ActionController::InvalidAuthenticityToken. It turned out the error was occurring because one of my users was pasting a link to my app in an MS Office document and when Office sees the link it makes a request that Rails could not handle. Here I'll show you a simple fix you can use to avoid these errors with much credit going to an article at
Dealing with Microsoft Office Protocol Discovery in Rails
.

My execptions looked something like this (lots of boring details omitted)

A ActionController::InvalidAuthenticityToken occurred in events#1164:

  ActionController::InvalidAuthenticityToken
  [RAILS_ROOT]/vendor/rails/actionpack/lib/action_controller/request_forgery_protection.rb:86:in `verify_authenticity_token'

-------------------------------
Environment:
-------------------------------
  * HTTP_USER_AGENT        : Microsoft Data Access Internet Publishing Provider Protocol Discovery
  * REQUEST_METHOD         : OPTIONS

#around line 270 of routing.rb
module ActionController
  module Routing
    HTTP_METHODS = [:get, :head, :post, :put, :delete]
  end
end

class ApplicationController < ActionController::Base
  before_filter :options_for_microsoft_office_protocol_discovery

  ...

  def options_for_microsoft_office_protocol_discovery
    render :nothing => true, :status => 200 if request.method == :options
  end
end  

  # Rails 2.3 and above 
  it 'should not throw an exception on OPTIONS request (from ms office protocol discovery)' do
    process '/any/goofy/path', nil, nil, nil, 'OPTIONS'
    response.should be_success
  end 

  # Rails < 2.3 version
  it 'should not throw an exception on OPTIONS request (from ms office protocol discovery)' do
    @request.env['REQUEST_METHOD'] = 'OPTIONS'
    process '/any/goofy/path'
    response.should be_success
  end 

curl -X OPTIONS http://localhost:3000/

Investigating how Symbol to_proc works

about 1 year ago | Alex Rothenberg: Common Sense Software

One of the things I love about Ruby is how expressive it is and how with open classes it can be optimized to become even more expressive. Since I started using Ruby I don't think I've written a single for or while loop - something I couldn't have imagined saying with any other language! Of course I do this by using iterators and writing code like

user_names = User.all.collect {|user| user.name}

user_names = User.all.collect(&:name)

unless :to_proc.respond_to?(:to_proc)
  class Symbol
    # Turns the symbol into a simple proc, which is especially useful for enumerations. Examples:
    #
    # # The same as people.collect { |p| p.name }
    # people.collect(&:name)
    #
    # # The same as people.select { |p| p.manager? }.collect { |p| p.salary }
    # people.select(&:manager?).collect(&:salary)
    def to_proc
      Proc.new { |*args| args.shift.__send__(self, *args) }
    end
  end
end

def was_block_given?
  block_given?
end

# As expected
was_block_given? {}
=> true 

# Passing a proc is not the same as having a block
was_block_given? Proc.new{}
ArgumentError: wrong number of arguments (1 for 0)
 from (irb):195:in `was_block_given?'
 from (irb):195

# Prefixing the proc with an & makes it like a block
was_block_given? &Proc.new{}
=> true

If the last argument to a method is preceded by an ampersand, Ruby assumes that it is a Proc object.
It removes it from the parameter list, converts the Proc object into a block, and associates it with the method.

  def collect
    ary = []
    if block_given?
      each { |o| ary << yield(o) }
    else
      each { |o| ary << o }
    end
    ary
  end

class Symbol
  # Turns the symbol into a simple proc, which is especially useful for enumerations. Examples:
  #
  #   # The same as people.collect { |p| p.name }
  #   people.collect(&:name)
  #
  #   # The same as people.select { |p| p.manager? }.collect { |p| p.salary }
  #   people.select(&:manager?).collect(&:salary)
  def to_proc
    Proc.new do |*args| 
      puts "to_proc args: #{args.inspect}"
      args_shift = args.shift
      puts "to_proc: #{args_shift.inspect}.__send__(#{self.inspect}, *#{args.inspect})"
      result = args_shift.__send__(self, *args) 
      puts "to_proc result: #{result.inspect}"
      result
    end
  end
end

# Make the call and see what happens
[1].collect( &:to_s)
# to_proc args: [1]
# to_proc: 1.__send__(:to_s, *[])
# to_proc result: "1"
# => ["1"]

[1, 'hi', :b].collect( &:to_s)
# to_proc args: [1]
# to_proc: 1.__send__(:to_s, *[])
# to_proc result: "1"
# to_proc args: ["hi"]
# to_proc: "hi".__send__(:to_s, *[])
# to_proc result: "hi"
# to_proc args: [:b]
# to_proc: :b.__send__(:to_s, *[])
# to_proc result: "b"
# => ["1", "hi", "b"]

[1,2,3].inject(&:+)
# to_proc args: [1, 2]
# to_proc: 1.__send__(:+, *[2])
# to_proc result: 3
# to_proc args: [3, 3]
# to_proc: 3.__send__(:+, *[3])
# to_proc result: 6
# => 6

1.__send__(:+, *[2])
# => 3

:b.__send__(:to_s, *[])
# => "b"

Investigating how Symbol to_proc works

about 1 year ago | Alex Rothenberg: Common Sense Software

One of the things I love about Ruby is how expressive it is and how with open classes it can be optimized to become even more expressive. Since I started using Ruby I don't think I've written a single for or while loop - something I couldn't have imagined saying with any other language! Of course I do this by using iterators and writing code like

user_names = User.all.collect {|user| user.name}

user_names = User.all.collect(&:name)

unless :to_proc.respond_to?(:to_proc)
  class Symbol
    # Turns the symbol into a simple proc, which is especially useful for enumerations. Examples:
    #
    # # The same as people.collect { |p| p.name }
    # people.collect(&:name)
    #
    # # The same as people.select { |p| p.manager? }.collect { |p| p.salary }
    # people.select(&:manager?).collect(&:salary)
    def to_proc
      Proc.new { |*args| args.shift.__send__(self, *args) }
    end
  end
end

def was_block_given?
  block_given?
end

# As expected
was_block_given? {}
=> true 

# Passing a proc is not the same as having a block
was_block_given? Proc.new{}
ArgumentError: wrong number of arguments (1 for 0)
 from (irb):195:in `was_block_given?'
 from (irb):195

# Prefixing the proc with an & makes it like a block
was_block_given? &Proc.new{}
=> true

If the last argument to a method is preceded by an ampersand, Ruby assumes that it is a Proc object.
It removes it from the parameter list, converts the Proc object into a block, and associates it with the method.

  def collect
    ary = []
    if block_given?
      each { |o| ary << yield(o) }
    else
      each { |o| ary << o }
    end
    ary
  end

class Symbol
  # Turns the symbol into a simple proc, which is especially useful for enumerations. Examples:
  #
  #   # The same as people.collect { |p| p.name }
  #   people.collect(&:name)
  #
  #   # The same as people.select { |p| p.manager? }.collect { |p| p.salary }
  #   people.select(&:manager?).collect(&:salary)
  def to_proc
    Proc.new do |*args| 
      puts "to_proc args: #{args.inspect}"
      args_shift = args.shift
      puts "to_proc: #{args_shift.inspect}.__send__(#{self.inspect}, *#{args.inspect})"
      result = args_shift.__send__(self, *args) 
      puts "to_proc result: #{result.inspect}"
      result
    end
  end
end

# Make the call and see what happens
[1].collect( &:to_s)
# to_proc args: [1]
# to_proc: 1.__send__(:to_s, *[])
# to_proc result: "1"
# => ["1"]

[1, 'hi', :b].collect( &:to_s)
# to_proc args: [1]
# to_proc: 1.__send__(:to_s, *[])
# to_proc result: "1"
# to_proc args: ["hi"]
# to_proc: "hi".__send__(:to_s, *[])
# to_proc result: "hi"
# to_proc args: [:b]
# to_proc: :b.__send__(:to_s, *[])
# to_proc result: "b"
# => ["1", "hi", "b"]

[1,2,3].inject(&:+)
# to_proc args: [1, 2]
# to_proc: 1.__send__(:+, *[2])
# to_proc result: 3
# to_proc args: [3, 3]
# to_proc: 3.__send__(:+, *[3])
# to_proc result: 6
# => 6

1.__send__(:+, *[2])
# => 3

:b.__send__(:to_s, *[])
# => "b"

Maintaining your technical chops is a full time job

about 1 year ago | Alex Rothenberg: Common Sense Software

Great quote from Uncle Bob (near the bottom of the post)

I think that maintaining your technical chops is a full time job. For that reason I have avoided becoming a business wonk. I hire people to do that for me so I can keep my technical skills as sharp as possible and remain relevant to my profession. I don’t believe I can offer technical advice unless I am living that technical advice.

Maintaining your technical chops is a full time job

about 1 year ago | Alex Rothenberg: Common Sense Software

Great quote from Uncle Bob (near the bottom of the post)

I think that maintaining your technical chops is a full time job. For that reason I have avoided becoming a business wonk. I hire people to do that for me so I can keep my technical skills as sharp as possible and remain relevant to my profession. I don’t believe I can offer technical advice unless I am living that technical advice.

Never sacrifice quality for speed!

about 1 year ago | Alex Rothenberg: Common Sense Software

I just read two really good articles by Ron Jeffries and Uncle Bob about why sacrificing quality to go faster is always a bad idea.

This is very relevant to me now as I'm working with a sponsor now who thinks that by pushing harder and 'doing it in parallel' he can get everything he wants by the date he wants avoiding any hard decisions involving tradeoffs between scope and date. I have worked on many teams over the years that could speed up without sacrificing quality by focusing on the right things basically by emphasizing working software over high ceremony (pretty much straight from the Agile Manifesto). However the idea that you can get something out the door quickly without "wasting your time on quality" to me means that the person you're talking to doesn't understand quality. They think quality means those silly engineering things developers spend their time on rather than software that works the way you want and can be reliably enhanced later.

Somehow we as technologists need to do a better job of explaining to our business sponsors that "quality" is not a technical term!

Never sacrifice quality for speed!

about 1 year ago | Alex Rothenberg: Common Sense Software

I just read two really good articles by Ron Jeffries and Uncle Bob about why sacrificing quality to go faster is always a bad idea.

This is very relevant to me now as I'm working with a sponsor now who thinks that by pushing harder and 'doing it in parallel' he can get everything he wants by the date he wants avoiding any hard decisions involving tradeoffs between scope and date. I have worked on many teams over the years that could speed up without sacrificing quality by focusing on the right things basically by emphasizing working software over high ceremony (pretty much straight from the Agile Manifesto). However the idea that you can get something out the door quickly without "wasting your time on quality" to me means that the person you're talking to doesn't understand quality. They think quality means those silly engineering things developers spend their time on rather than software that works the way you want and can be reliably enhanced later.

Somehow we as technologists need to do a better job of explaining to our business sponsors that "quality" is not a technical term!

How I refine a test spec while writing getting it to green

about 1 year ago | Alex Rothenberg: Common Sense Software

In most of the examples I've read on TDD they show the Red-Green-Refactor cycle as

1. Write a failing test


2. Write just enough code to make the test pass


3. Refactor


4. Repeat

describe FriendController do
  it 'should approve one friend requests' do
    post :update_requests, :approved_requests => ['123']
    response.should be_redirect
    response.should redirect_to(:back)
    flash[:notice].should  == "Friend requests approved."
  end
end

class FriendController < ApplicationController
  def update_requests
    FriendRequest.approve(params[:approve_requests])
    flash[:notice] = "User access changes saved."
    redirect_to :back
  end
end

describe FriendController do
  it 'should approve one friend requests' do
    FriendRequest.expects(:approve).with(['123'])
    request.env['HTTP_REFERER'] = "http://some.site.com"
  
    post :update_requests, :approved_requests => ['123']
    response.should be_redirect
    response.should redirect_to(:back)
    flash[:notice].should  == "Friend requests approved."
  end
end

How I refine a test spec while writing getting it to green

about 1 year ago | Alex Rothenberg: Common Sense Software

In most of the examples I've read on TDD they show the Red-Green-Refactor cycle as

1. Write a failing test


2. Write just enough code to make the test pass


3. Refactor


4. Repeat

describe FriendController do
  it 'should approve one friend requests' do
    post :update_requests, :approved_requests => ['123']
    response.should be_redirect
    response.should redirect_to(:back)
    flash[:notice].should  == "Friend requests approved."
  end
end

class FriendController < ApplicationController
  def update_requests
    FriendRequest.approve(params[:approve_requests])
    flash[:notice] = "User access changes saved."
    redirect_to :back
  end
end

describe FriendController do
  it 'should approve one friend requests' do
    FriendRequest.expects(:approve).with(['123'])
    request.env['HTTP_REFERER'] = "http://some.site.com"
  
    post :update_requests, :approved_requests => ['123']
    response.should be_redirect
    response.should redirect_to(:back)
    flash[:notice].should  == "Friend requests approved."
  end
end

about 1 year ago | Alex Rothenberg: Common Sense Software

I read an interesting post today by David Chelimsky who wrote RSpec A case against a case against mocking and stubbing. Its about mocking in testing and isolated vs integrated tests. I liked it all but what I particularly liked is how it describes the process of outside-in development.

To quote:

1. Write scenarios in plain text with cucumber (driven by user stories, organized in features).


2. Write the code for a step (or part of a step), run the feature, and observe the failure.


3. Optionally (yes, it depends – and why is the topic for another blog) drive out a view with a view spec. When I say “drive out,” I mean a very granular Red/Green/Refactor cycle that only involves this view, and only enough of this view to support satisfaction of the failing step in the cucumber feature.


4. Drive out a controller action using the same, granular Red/Green/Refactor cycle. And it may not be the entire controller action I think I want, covering all the cases I think I want. Just enough to support satisfaction of the failing step.


5. Drive out the parts of the model that I need to satisfy the failing step, using the same granular R/G/R process.


6. Run the cucumber feature and assess where I am.

about 1 year ago | Alex Rothenberg: Common Sense Software

I read an interesting post today by David Chelimsky who wrote RSpec A case against a case against mocking and stubbing. Its about mocking in testing and isolated vs integrated tests. I liked it all but what I particularly liked is how it describes the process of outside-in development.

To quote:

1. Write scenarios in plain text with cucumber (driven by user stories, organized in features).


2. Write the code for a step (or part of a step), run the feature, and observe the failure.


3. Optionally (yes, it depends – and why is the topic for another blog) drive out a view with a view spec. When I say “drive out,” I mean a very granular Red/Green/Refactor cycle that only involves this view, and only enough of this view to support satisfaction of the failing step in the cucumber feature.


4. Drive out a controller action using the same, granular Red/Green/Refactor cycle. And it may not be the entire controller action I think I want, covering all the cases I think I want. Just enough to support satisfaction of the failing step.


5. Drive out the parts of the model that I need to satisfy the failing step, using the same granular R/G/R process.


6. Run the cucumber feature and assess where I am.

Bug/patch with rspec-rails and helper instance variables

about 1 year ago | Alex Rothenberg: Common Sense Software

I finally got around to upgrading my version of rspec-rails from one that's almost a year old and came across an issue with the way implicit module inclusion is handled.

If you have a handler that uses memoization to cache some information in instance variables such as this (I'm not sure if this is a smell but my project has some examples of it)

module UsersHelper
 def all_users
   @users ||= User.find(:all)
 end
end

describe UsersHelper do
 it "should find all users" do
   User.expects(:find).with(:all).returns(result=mock)
   helper.all_users.should == result
 end
end

Bug/patch with rspec-rails and helper instance variables

about 1 year ago | Alex Rothenberg: Common Sense Software

I finally got around to upgrading my version of rspec-rails from one that's almost a year old and came across an issue with the way implicit module inclusion is handled.

If you have a handler that uses memoization to cache some information in instance variables such as this (I'm not sure if this is a smell but my project has some examples of it)

module UsersHelper
 def all_users
   @users ||= User.find(:all)
 end
end

describe UsersHelper do
 it "should find all users" do
   User.expects(:find).with(:all).returns(result=mock)
   helper.all_users.should == result
 end
end

Knows which specs are slowing down my spec suite

about 1 year ago | Alex Rothenberg: Common Sense Software

I often watch my specs run with the ........'s marching across my terminal and sometimes it seems to pause as it hits a particularly slow one. I figure there's some poorly written spec that's slowing my entire suite down and I should figure out what it is and fix it. But I rarely (if ever) take the time to track down the offender so never fix it. I just discovered that the clever folks writing rspec have taken away my excuse for laziness. I can tell it to report on the slowest specs by putting a line in my spec.opts file telling it to use the ProfileFormatter (see the first line below)

--format profile
--colour
--loadby mtime
--reverse

Profiling enabled.
........(a bunch more dots)

Top 10 slowest examples:
2.4908950 WikiContent should find all activity for a user
0.8061750 WikiContent should find recent activity for a user in last 15 days
0.2438460 WikiContent::Version should allow limit on results from finding recent activity
0.1821710 User should have a list of owned content
0.1700670 WikiContent should find results if access type is not same as role of the user but role of user is 'Leader'
0.1593900 ContentsController allows PUT request to 'update' action for 'member' role
0.1514150 Search::SearchResponse gets the wiki content id of an asset from the xml response
0.1470310 Content should always allow leaders to see all pages
0.1394920 Page should delete all comments when destroyed
0.1370330 ContentsController should save content and create the uploaded asset on successful POST to the 'create' action

Knows which specs are slowing down my spec suite

about 1 year ago | Alex Rothenberg: Common Sense Software

I often watch my specs run with the ........'s marching across my terminal and sometimes it seems to pause as it hits a particularly slow one. I figure there's some poorly written spec that's slowing my entire suite down and I should figure out what it is and fix it. But I rarely (if ever) take the time to track down the offender so never fix it. I just discovered that the clever folks writing rspec have taken away my excuse for laziness. I can tell it to report on the slowest specs by putting a line in my spec.opts file telling it to use the ProfileFormatter (see the first line below)

--format profile
--colour
--loadby mtime
--reverse

Profiling enabled.
........(a bunch more dots)

Top 10 slowest examples:
2.4908950 WikiContent should find all activity for a user
0.8061750 WikiContent should find recent activity for a user in last 15 days
0.2438460 WikiContent::Version should allow limit on results from finding recent activity
0.1821710 User should have a list of owned content
0.1700670 WikiContent should find results if access type is not same as role of the user but role of user is 'Leader'
0.1593900 ContentsController allows PUT request to 'update' action for 'member' role
0.1514150 Search::SearchResponse gets the wiki content id of an asset from the xml response
0.1470310 Content should always allow leaders to see all pages
0.1394920 Page should delete all comments when destroyed
0.1370330 ContentsController should save content and create the uploaded asset on successful POST to the 'create' action

Applications usually use their own data

about 1 year ago | Alex Rothenberg: Common Sense Software

I just read a very interesting post by Martin Fowler called Database Thaw. He talks about various database technologies and what the future might hold for object or relational databases but what caught my interest was his discussion of application and database integration patterns.

He says "For many organizations today, the primary pattern for integration is Shared Database Integration - where multiple applications are integrated by all using a common database." This is certainly true where I work. I've even heard it said that we have one gigantic application since all (or most) share the same underlying database so cannot be updated independently.

He also talks about Integration Databases which store data for multiple applications and Application Databases which are controlled and accessed by a single application.

Historically my company has moved toward the integration database pattern often building complex service layers to enable shared access to the data on the assumption that if you build it they will come the data would be reused if it was easy enough. However I believe that its only a very small subset of our data that is truly common and many applications want to use. For that small subset a shared database with a service layer is probably a good design. The vast majority is private to an application and by designing it into a separate application database can evolve to best meet the needs of the application without concern for a more general service that in our case is more hindrance than benefit.

One important thing to remember about an application database is that the data exists to meet the needs of the application so a design that allows the database to best meet the application's needs will be to everyone's benefit. Finally database technologies are very complex and do a lot so it is probably wise to have a good database developer on your team to make sure you're using the database appropriately but they should be a part of your team not on a separate database team as I've seen in the past - particularly on Java/Oracle projects I've been a part of.

Thoughts?

Applications usually use their own data

about 1 year ago | Alex Rothenberg: Common Sense Software

I just read a very interesting post by Martin Fowler called Database Thaw. He talks about various database technologies and what the future might hold for object or relational databases but what caught my interest was his discussion of application and database integration patterns.

He says "For many organizations today, the primary pattern for integration is Shared Database Integration - where multiple applications are integrated by all using a common database." This is certainly true where I work. I've even heard it said that we have one gigantic application since all (or most) share the same underlying database so cannot be updated independently.

He also talks about Integration Databases which store data for multiple applications and Application Databases which are controlled and accessed by a single application.

Historically my company has moved toward the integration database pattern often building complex service layers to enable shared access to the data on the assumption that if you build it they will come the data would be reused if it was easy enough. However I believe that its only a very small subset of our data that is truly common and many applications want to use. For that small subset a shared database with a service layer is probably a good design. The vast majority is private to an application and by designing it into a separate application database can evolve to best meet the needs of the application without concern for a more general service that in our case is more hindrance than benefit.

One important thing to remember about an application database is that the data exists to meet the needs of the application so a design that allows the database to best meet the application's needs will be to everyone's benefit. Finally database technologies are very complex and do a lot so it is probably wise to have a good database developer on your team to make sure you're using the database appropriately but they should be a part of your team not on a separate database team as I've seen in the past - particularly on Java/Oracle projects I've been a part of.

Thoughts?

Silly site - Netdisaster ... Destroy the Web

about 1 year ago | Alex Rothenberg: Common Sense Software

My kids just showed me a silly site http://www.netdisaster.com/ I had to share.

Silly site - Netdisaster ... Destroy the Web

about 1 year ago | Alex Rothenberg: Common Sense Software

My kids just showed me a silly site http://www.netdisaster.com/ I had to share.

Buy services and Build websites

about 1 year ago | Alex Rothenberg: Common Sense Software

Where I work there's recently been a lot of talk about how to make the decision whether to buy or build software. I've recently concluded that while you can buy a commoditized service you can not buy a website!

What I've seen is people thinking we could "buy" (or download open source) a site but then realize they want to change the branding, adapt the terminology to match our business. combine it with another product or add one extra piece of functionality that the existing site doesn't have. Whatever the APIs provided by the product you're left with custom software written on top of the product you bought. I've seen this with big commercial products like Documentum and open source products like Drupal. I now believe that there's no such thing as "a little" customization and you can only buy a site if you want 0 customization (applying a skin or inserting your logos are acceptable).

This does not mean everyone should develop custom software from scratch. There are tons of opportunities to buy commoditized services and write just a little custom code to glue them together. This allows you to focus on the aspects of your site that are business differentiators (the branding, the terminology, your workflows, your business rules, etc) without fighting the vendor's idea of those things. You don't have to write too much code as what we continually revise upward what we consider a commoditized service (i.e. it used to be document storage and is becoming document management with workflow and security).

The process of creating a blog aggregator as I described in my last post I built a Blog Aggregator showed me how true this is. I used Atom and RSS parsing and generating service which left me just to build a small site with the UI, security and glue holding it all together. Its just a small example but as I look around github I'm struck that the most interesting packages are plugins and gems for others to use and the less interesting ones are complete sites. This may be a no brainer for the Open Source community but is something that I am just realizing and I think that enterprises and commercial vendors still need to learn.

Buy services and Build websites

about 1 year ago | Alex Rothenberg: Common Sense Software

Where I work there's recently been a lot of talk about how to make the decision whether to buy or build software. I've recently concluded that while you can buy a commoditized service you can not buy a website!

What I've seen is people thinking we could "buy" (or download open source) a site but then realize they want to change the branding, adapt the terminology to match our business. combine it with another product or add one extra piece of functionality that the existing site doesn't have. Whatever the APIs provided by the product you're left with custom software written on top of the product you bought. I've seen this with big commercial products like Documentum and open source products like Drupal. I now believe that there's no such thing as "a little" customization and you can only buy a site if you want 0 customization (applying a skin or inserting your logos are acceptable).

This does not mean everyone should develop custom software from scratch. There are tons of opportunities to buy commoditized services and write just a little custom code to glue them together. This allows you to focus on the aspects of your site that are business differentiators (the branding, the terminology, your workflows, your business rules, etc) without fighting the vendor's idea of those things. You don't have to write too much code as what we continually revise upward what we consider a commoditized service (i.e. it used to be document storage and is becoming document management with workflow and security).

The process of creating a blog aggregator as I described in my last post I built a Blog Aggregator showed me how true this is. I used Atom and RSS parsing and generating service which left me just to build a small site with the UI, security and glue holding it all together. Its just a small example but as I look around github I'm struck that the most interesting packages are plugins and gems for others to use and the less interesting ones are complete sites. This may be a no brainer for the Open Source community but is something that I am just realizing and I think that enterprises and commercial vendors still need to learn.

I built a blog aggregator - waywework.it

about 1 year ago | Alex Rothenberg: Common Sense Software

I've been spending some time recently putting together a blog aggregator site for some of the folks I work with. Its now up and running at http://waywework.it. I hope this will be an interesting place to share our public community and as one of my colleagues said "this keeps my Google Reader much neater".

Today I'd like to talk about the code running this site which is posted and available on github at http://github.com/alexrothenberg/waywework.

I started thinking I would use an existing aggregator site and just apply my skin but when I did a quick search on github I most of the hard work existed in atom and rss gems and plugins and I wanted to take advantage of the just released Rails 2.2 so I decided to build my own. This turned out to be not too much work. Today I'd like to talk about how I put this together.

First I created my project with some scaffolding for feeds which would have_many posts

class Feed < ActiveRecord::Base
  has_many :posts, :dependent => :delete_all
end

class Post < ActiveRecord::Base
  belongs_to :feed
end

class Feed < ActiveRecord::Base
  def get_posts_from_atom atom_xml
    feed = Atom::Feed.new(atom_xml)
    feed.entries.each { |entry|
      link = entry.links.detect {|l| l.rel == 'alternate'}
      create_post(:contents=>entry.content.value, :url=>link.href, :title=>entry.title, :published=>entry.published.to_s(:db), :updated=>entry.updated.to_s(:db))
    }
    return !feed.entries.blank?
  end  
  
  def get_posts_from_rss rss_xml
    rss = RSS::Parser.parse(rss_xml, false)
    rss.items.each { |entry|
      create_post(:contents=>entry.description, :url=>entry.link, :title=>entry.title, :published=>entry.date.to_formatted_s(:db), :updated=>entry.date.to_formatted_s(:db))
    }
    return !rss.items.blank?
  end
end

namespace :feeds do
  desc "Load the feeds"
  task :populate => :environment do
    feeds = Feed.all
    feeds.each do |feed|
      feed.get_latest
    end
  end
end

class Feed < ActiveRecord::Base
  def get_latest
    puts "getting feed for #{name}"
    xml = get_feed
    got_atom_posts = get_posts_from_atom xml
    get_posts_from_rss xml unless got_atom_posts
  end

  def get_feed
    uri = URI.parse(feed_url)
    uri.read
  end
  
  def create_post params
    params.merge!(:feed_id=>id) 
    existing_post = Post.find_by_url(params[:url])
    if existing_post
      existing_post.update_attributes(params)
    else
      Post.create(params) 
    end
  end
end

atom_feed(:url => atom_feed_url) do |feed|
  feed.title("WayWeWork")
  feed.updated(@posts.first.published)

  for post in @posts
    feed.entry(post, :url=>post.url, :published=>post.published, :updated=>post.updated) do |entry|
      entry.title("#{post.feed.author}: #{post.title}")
      entry.content(post.contents, :type => 'html')
    end
  end
end

class PostsController < ApplicationController
  @active_feeds = Feed.by_author
  @activity_by_date = Post.activity_by_date
end

class FeedsController < ApplicationController
  before_filter :authenticate

protected
  def authenticate
     authenticate_or_request_with_http_basic do | user_name, password|
       username = YAML::load_file(File.join(RAILS_ROOT, %w[config password.yml]))['username']
       pwd = YAML::load_file(File.join(RAILS_ROOT, %w[config password.yml]))['password']
      user_name == username && password == pwd
    end
  end
end

I built a blog aggregator - waywework.it

about 1 year ago | Alex Rothenberg: Common Sense Software

I've been spending some time recently putting together a blog aggregator site for some of the folks I work with. Its now up and running at http://waywework.it. I hope this will be an interesting place to share our public community and as one of my colleagues said "this keeps my Google Reader much neater".

Today I'd like to talk about the code running this site which is posted and available on github at http://github.com/alexrothenberg/waywework.

I started thinking I would use an existing aggregator site and just apply my skin but when I did a quick search on github I most of the hard work existed in atom and rss gems and plugins and I wanted to take advantage of the just released Rails 2.2 so I decided to build my own. This turned out to be not too much work. Today I'd like to talk about how I put this together.

First I created my project with some scaffolding for feeds which would have_many posts

class Feed < ActiveRecord::Base
  has_many :posts, :dependent => :delete_all
end

class Post < ActiveRecord::Base
  belongs_to :feed
end

class Feed < ActiveRecord::Base
  def get_posts_from_atom atom_xml
    feed = Atom::Feed.new(atom_xml)
    feed.entries.each { |entry|
      link = entry.links.detect {|l| l.rel == 'alternate'}
      create_post(:contents=>entry.content.value, :url=>link.href, :title=>entry.title, :published=>entry.published.to_s(:db), :updated=>entry.updated.to_s(:db))
    }
    return !feed.entries.blank?
  end  
  
  def get_posts_from_rss rss_xml
    rss = RSS::Parser.parse(rss_xml, false)
    rss.items.each { |entry|
      create_post(:contents=>entry.description, :url=>entry.link, :title=>entry.title, :published=>entry.date.to_formatted_s(:db), :updated=>entry.date.to_formatted_s(:db))
    }
    return !rss.items.blank?
  end
end

namespace :feeds do
  desc "Load the feeds"
  task :populate => :environment do
    feeds = Feed.all
    feeds.each do |feed|
      feed.get_latest
    end
  end
end

class Feed < ActiveRecord::Base
  def get_latest
    puts "getting feed for #{name}"
    xml = get_feed
    got_atom_posts = get_posts_from_atom xml
    get_posts_from_rss xml unless got_atom_posts
  end

  def get_feed
    uri = URI.parse(feed_url)
    uri.read
  end
  
  def create_post params
    params.merge!(:feed_id=>id) 
    existing_post = Post.find_by_url(params[:url])
    if existing_post
      existing_post.update_attributes(params)
    else
      Post.create(params) 
    end
  end
end

atom_feed(:url => atom_feed_url) do |feed|
  feed.title("WayWeWork")
  feed.updated(@posts.first.published)

  for post in @posts
    feed.entry(post, :url=>post.url, :published=>post.published, :updated=>post.updated) do |entry|
      entry.title("#{post.feed.author}: #{post.title}")
      entry.content(post.contents, :type => 'html')
    end
  end
end

class PostsController < ApplicationController
  @active_feeds = Feed.by_author
  @activity_by_date = Post.activity_by_date
end

class FeedsController < ApplicationController
  before_filter :authenticate

protected
  def authenticate
     authenticate_or_request_with_http_basic do | user_name, password|
       username = YAML::load_file(File.join(RAILS_ROOT, %w[config password.yml]))['username']
       pwd = YAML::load_file(File.join(RAILS_ROOT, %w[config password.yml]))['password']
      user_name == username && password == pwd
    end
  end
end

Using Ruby for shell scripting

about 1 year ago | Alex Rothenberg: Common Sense Software

Someone came to me the other day with a problem. He had downloaded a directory containing a large number of files with spaces in their filenames and needed to get rid of the spaces so he could load them into the tool he was using. He asked me if I knew of a mass rename tool. I didn't know of such a tool but thought it wouldn't be too hard to write something simple.

First I thought of capturing the output of a find and using a text editor search-and-replace create a whole number of mv old_file new_file_without_spaces commands that could all be run. But then I would have to work with some editor's search-and-replace syntax.

Then I thought of writing a shell script. I started to think about find . -e ... but realized I always get confused about the -e syntax and using sed or awk.

Suddenly I realized I could do this with Ruby. About 10 minutes later I had this simple 3 line script, ran it and was done.

  Dir[File.expand_path("#{~/file_with_spaces}/*")].uniq.sort.each do |file|
    system "mv '#{file}' '#{file.gsub(' ', '_')}'"
  end

Using Ruby for shell scripting

about 1 year ago | Alex Rothenberg: Common Sense Software

Someone came to me the other day with a problem. He had downloaded a directory containing a large number of files with spaces in their filenames and needed to get rid of the spaces so he could load them into the tool he was using. He asked me if I knew of a mass rename tool. I didn't know of such a tool but thought it wouldn't be too hard to write something simple.

First I thought of capturing the output of a find and using a text editor search-and-replace create a whole number of mv old_file new_file_without_spaces commands that could all be run. But then I would have to work with some editor's search-and-replace syntax.

Then I thought of writing a shell script. I started to think about find . -e ... but realized I always get confused about the -e syntax and using sed or awk.

Suddenly I realized I could do this with Ruby. About 10 minutes later I had this simple 3 line script, ran it and was done.

  Dir[File.expand_path("#{~/file_with_spaces}/*")].uniq.sort.each do |file|
    system "mv '#{file}' '#{file.gsub(' ', '_')}'"
  end

Undefining a constant in a rspec test

about 1 year ago | Alex Rothenberg: Common Sense Software

I want to share something I just figured out. I had to write some code that used a class from a plugin if it was there and but did not require the plugin. The problem I faced was how to test this.

My method looked like this

class User 
 def lookup_additional_person_info
   if defined? CommonServices::Person
     person = CommonServices::Person.find_by_id(@person_id)
     @address = person.address
   else
     @address = 'not available'
   end
 end
end

  it 'should default additional parameters if CommonServices::Person is not defined' do
   defined?(CommonServices::Person).should be_nil
   user = User.new(:person_id=123)
   user.lookup_additional_person_info
   user.address.should == 'not available'
 end

 it 'should not populate additional parameters if CommonServices::Person is not defined' do
   begin
     defined?(CommonServices::Person).should be_nil
     module CommonServices
       class Person
       end
     end
     CommonServices::Person.expects(:find).with(123).returns(person=mock)
     person.expects(:address).returns(address_from_service=mock)
  
     user = User.new(:person_id=123)
     user.lookup_additional_person_info
     user.address.should == address_from_service
   ensure
     CommonServices.send(:remove_const, :Person)
   end
 end

Undefining a constant in a rspec test

about 1 year ago | Alex Rothenberg: Common Sense Software

I want to share something I just figured out. I had to write some code that used a class from a plugin if it was there and but did not require the plugin. The problem I faced was how to test this.

My method looked like this

class User 
 def lookup_additional_person_info
   if defined? CommonServices::Person
     person = CommonServices::Person.find_by_id(@person_id)
     @address = person.address
   else
     @address = 'not available'
   end
 end
end

  it 'should default additional parameters if CommonServices::Person is not defined' do
   defined?(CommonServices::Person).should be_nil
   user = User.new(:person_id=123)
   user.lookup_additional_person_info
   user.address.should == 'not available'
 end

 it 'should not populate additional parameters if CommonServices::Person is not defined' do
   begin
     defined?(CommonServices::Person).should be_nil
     module CommonServices
       class Person
       end
     end
     CommonServices::Person.expects(:find).with(123).returns(person=mock)
     person.expects(:address).returns(address_from_service=mock)
  
     user = User.new(:person_id=123)
     user.lookup_additional_person_info
     user.address.should == address_from_service
   ensure
     CommonServices.send(:remove_const, :Person)
   end
 end

Testing with RSpec stories

about 1 year ago | Alex Rothenberg: Common Sense Software

I recently completed a project where we used RSpec stories for our integration testing and wanted to share some of my experiences. Overall RSpec Stories are an incredibly powerful tool and have allowed us to take a huge step towards business analysts writing functional specifications (in the form of plain text stories) then allowing the developers to make them pass. Today I'd like to share how we setup our stories and some of the decisions we made along the way.

The first goal was to run the stories from rake so we created a rake task in lib/tasks/stories.rake to run the stories and fail if any of them fail - this was useful when running this from our cruise server.

  task :all do
    args = ENV['story_prefix'] || ''
    stories_passed = system 'ruby', File.join(RAILS_ROOT, "stories", "run_with_all_steps.rb"), args
    raise('story failed') unless stories_passed
  end

  file_pattern = ARGV[0] || "*"
  ENV["RAILS_ENV"] = "test"
  require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
  require 'spec/rails/story_adapter'

  def all_local_stories(story_pattern = "")
    story_path = "#{File.dirname(__FILE__)}/stories"
    Dir[File.expand_path("#{story_path}/**/#{story_pattern}*.story")]
  end

  def all_steps_for_local_stories
    steps_path = "#{File.dirname(__FILE__)}/steps"
    step_files = Dir[File.expand_path("#{steps_path}/*.rb")].sort
    step_files.collect do |file|
      require file
      file.match(/(\w+)\.rb\Z/).captures[0].underscore.to_sym
    end
  end

  stories = all_local_stories(file_pattern)
  stories.each do |file|
    with_steps_for(*all_steps_for_local_stories) do
      run file, :type => RailsStory
    end
  end

Story: Manage Users
As an Administrator
I want to manage the users who have access to my application
So that private stuff isn't seen by the wrong people

  Scenario: Revoke access for a user
  Given Alex is a registered user
  When I delete the user Alex
  Then Alex should not be able to access the sensitive content

require File.dirname(__FILE__) + '/../../../spec/spec_helper'

steps_for(:user_management) do
  Given('$user_name is a registered user') do |user_name|
    @users ||= []
    @users << name =""> user_name})
  end

  When('I delete the user $user_name') do |user_name|
    this_user = @users.detect {|a_user| a_user.name == user_name}
    this_user.should_not be_nil
    this_user.destroy
  end

  Then('$user_name should not be able to access the site') do |user_name|
    get("/login?username=#{user_name}")
    response.response_code.should == 401
  end
end

• Having our business analysts write most of the story files and the developers write the steps.
  
• Thinking of ways to keep the steps files DRY
• Working with WATIR or Selenium to create stories that drive the browser
  

Testing with RSpec stories

about 1 year ago | Alex Rothenberg: Common Sense Software

I recently completed a project where we used RSpec stories for our integration testing and wanted to share some of my experiences. Overall RSpec Stories are an incredibly powerful tool and have allowed us to take a huge step towards business analysts writing functional specifications (in the form of plain text stories) then allowing the developers to make them pass. Today I'd like to share how we setup our stories and some of the decisions we made along the way.

The first goal was to run the stories from rake so we created a rake task in lib/tasks/stories.rake to run the stories and fail if any of them fail - this was useful when running this from our cruise server.

  task :all do
    args = ENV['story_prefix'] || ''
    stories_passed = system 'ruby', File.join(RAILS_ROOT, "stories", "run_with_all_steps.rb"), args
    raise('story failed') unless stories_passed
  end

  file_pattern = ARGV[0] || "*"
  ENV["RAILS_ENV"] = "test"
  require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
  require 'spec/rails/story_adapter'

  def all_local_stories(story_pattern = "")
    story_path = "#{File.dirname(__FILE__)}/stories"
    Dir[File.expand_path("#{story_path}/**/#{story_pattern}*.story")]
  end

  def all_steps_for_local_stories
    steps_path = "#{File.dirname(__FILE__)}/steps"
    step_files = Dir[File.expand_path("#{steps_path}/*.rb")].sort
    step_files.collect do |file|
      require file
      file.match(/(\w+)\.rb\Z/).captures[0].underscore.to_sym
    end
  end

  stories = all_local_stories(file_pattern)
  stories.each do |file|
    with_steps_for(*all_steps_for_local_stories) do
      run file, :type => RailsStory
    end
  end

Story: Manage Users
As an Administrator
I want to manage the users who have access to my application
So that private stuff isn't seen by the wrong people

  Scenario: Revoke access for a user
  Given Alex is a registered user
  When I delete the user Alex
  Then Alex should not be able to access the sensitive content

require File.dirname(__FILE__) + '/../../../spec/spec_helper'

steps_for(:user_management) do
  Given('$user_name is a registered user') do |user_name|
    @users ||= []
    @users << name =""> user_name})
  end

  When('I delete the user $user_name') do |user_name|
    this_user = @users.detect {|a_user| a_user.name == user_name}
    this_user.should_not be_nil
    this_user.destroy
  end

  Then('$user_name should not be able to access the site') do |user_name|
    get("/login?username=#{user_name}")
    response.response_code.should == 401
  end
end

• Having our business analysts write most of the story files and the developers write the steps.
  
• Thinking of ways to keep the steps files DRY
• Working with WATIR or Selenium to create stories that drive the browser
  

Perhaps outsourcing is harder than offshoring

about 1 year ago | Alex Rothenberg: Common Sense Software

I've been thinking a lot recently about why my current company seems to have so much trouble working with our offshore development partner in India. Most of the people I work with spend their time thinking about how to work with a bunch of people who are halfway around the world with only a few hours when we're all awake at the same time. The way we've approached the problem is to take about 20% of the developers and temporarily move them to the US to work alongside us while trying to use technology to collaborate as best we can with the remaining developers (conference calls, IM, email and occasional visits of the US staff to India). We have managed to overcome some of the distance and I personally know many of the developers by all these channels and have met a large number in person (in the US and India), but problems still remain.

I know we're not the only company to face these problems (in fact a recent blog by Jay Fields Is Distributed Development Viable is what got me thinking on this topic this week). I agree with most of Jay's post but have been wondering If we solved the distributed development problem ... would the problems I see everyday disappear? I have to say they wouldn't and when I ask myself why I've concluded that our problem has less to do with the geographic distribution issues we face (which are certainly formidable!!) and more to do with the basic fact that most of our developers work for a different company than we do. I think outsourcing seems to be as big if not a bigger problem than offshoring.

What do I mean by that...In my experience successfully developing software is largely dependent on having a team of good people who know each other, have worked together before and are comfortable using their critical thinking and expressing their opinions. I imagine that we decided the rate differential wasn't important and flew the entire India based development team to the US to sit next to us tomorrow. The problem we would still have is that the members of my development team would still work for a different company than I do. My company spends a lot of time helping its employees think about their professional development and how to advance their careers. For our developers at our outsourced partner we do none of that (one of the advantages outsourcing is supposed to grant us the advantage of a bigger pool of resources to use but I believe that we don't need "resources" we need "developers" - sorry to dive into my liberal arts education and deconstructionism a little bit :) With outsourcing we give up on thinking of our developers as individuals and spending time and energy (and money) on their professional development and ensuring that they are challenged and want to continue working with us. The effect is that the average tenure of most of these developers is measured in months instead of years. The problem cuts both ways as the developers have an institutional loyalty to their employer and know they will likely not be working with us for the long term so its very hard for many of them to assume the role of trusted team member who makes decisions for the long term.

What's the solution... I don't know. All I know is that the current situation is very difficult and only focusing on shrinking the geographical distance between the US and India does not seem likely to work.

If you made it hear thanks for reading, I needed to get this off my chest. I hope to get back to more technical topics with my next post!

Perhaps outsourcing is harder than offshoring

about 1 year ago | Alex Rothenberg: Common Sense Software

I've been thinking a lot recently about why my current company seems to have so much trouble working with our offshore development partner in India. Most of the people I work with spend their time thinking about how to work with a bunch of people who are halfway around the world with only a few hours when we're all awake at the same time. The way we've approached the problem is to take about 20% of the developers and temporarily move them to the US to work alongside us while trying to use technology to collaborate as best we can with the remaining developers (conference calls, IM, email and occasional visits of the US staff to India). We have managed to overcome some of the distance and I personally know many of the developers by all these channels and have met a large number in person (in the US and India), but problems still remain.

I know we're not the only company to face these problems (in fact a recent blog by Jay Fields Is Distributed Development Viable is what got me thinking on this topic this week). I agree with most of Jay's post but have been wondering If we solved the distributed development problem ... would the problems I see everyday disappear? I have to say they wouldn't and when I ask myself why I've concluded that our problem has less to do with the geographic distribution issues we face (which are certainly formidable!!) and more to do with the basic fact that most of our developers work for a different company than we do. I think outsourcing seems to be as big if not a bigger problem than offshoring.

What do I mean by that...In my experience successfully developing software is largely dependent on having a team of good people who know each other, have worked together before and are comfortable using their critical thinking and expressing their opinions. I imagine that we decided the rate differential wasn't important and flew the entire India based development team to the US to sit next to us tomorrow. The problem we would still have is that the members of my development team would still work for a different company than I do. My company spends a lot of time helping its employees think about their professional development and how to advance their careers. For our developers at our outsourced partner we do none of that (one of the advantages outsourcing is supposed to grant us the advantage of a bigger pool of resources to use but I believe that we don't need "resources" we need "developers" - sorry to dive into my liberal arts education and deconstructionism a little bit :) With outsourcing we give up on thinking of our developers as individuals and spending time and energy (and money) on their professional development and ensuring that they are challenged and want to continue working with us. The effect is that the average tenure of most of these developers is measured in months instead of years. The problem cuts both ways as the developers have an institutional loyalty to their employer and know they will likely not be working with us for the long term so its very hard for many of them to assume the role of trusted team member who makes decisions for the long term.

What's the solution... I don't know. All I know is that the current situation is very difficult and only focusing on shrinking the geographical distance between the US and India does not seem likely to work.

If you made it hear thanks for reading, I needed to get this off my chest. I hope to get back to more technical topics with my next post!

Working with Excel data without working with Excel

over 2 years ago | Alex Rothenberg: Common Sense Software

I am currently working on an application to replace manual MS Excel files that get emailed around and while the business users are looking forward to an interactive web app they are also wedded to their excel files. One of the key requirements we need to meet is allowing them to move their data back and forth.

In the past I've worked with COM and Java libraries to manipulate the files in their native formats and both were painful experiences I did not want to relive. I'm going to talk about how we solved the problem without the need to work with any Office libraries.

Loading Excel data into our Application
The approach we took was to let the users extract the data themselves with a simple copy-and-paste. The user would copy the cells of the excel file and then paste that tab delimited plain text into an HTML form.

Let's say we're trying to import a list of people with a first and last name. The Excel sheet would look like this

We start with a form with a big text area and submit button and an area to show any errors we may encounter while parsing

<% form_tag do -%>
 Paste your Excel data : <%= text_area_tag :data, @data %>
 Click to validate the data <%= submit_tag 'Validate' %>

 <ul>
 <% @errors.each do |error| %>
  <li><span ><%=error%></span></li>

 <% end unless @errors.blank? -%>
 </ul>

Then the controller action which let's the model parse the text and only saves if every person model is valid.

class PeopleController <  ApplicationController
 def import
  @errors = []
  people = Person.all_from_tab_delimited_text(params[:data])

  people.each  do |person|
   person.errors.each { |error| @errors << "#{error} on #{person.inspect}"} unless person.valid?
  end
 end
end 

Now we move onto the Person model where the parsing actually takes place
class

class Person < ActiveRecord::Base
def Person.all_from_tab_delimited_text(data)
 people = []
 CSV::Reader.parse(@data, "\t") do |row|
  person = Person.new(:first_name"> row[0], :last_name => row[1])
  people << person
 end
 people
end
end

We now have a working allbeit simple implementation that even does some simple error checking to give the user feedback if their data cannot be imported. Of course the example here is simple and the real system has additional features and complexity that I didn't show here. Some of these are

• The import into a 2-step operation where we first ask the user to click 'Validate' then return a table showing the data as we parsed it. This allows the user to review and verify it was parsed correctly (i.e. the columns were in the correct order). Only on this second page do we provide an 'import' button that actually persists the new data.
• The data can not only create new people but also update existing ones. The example above with just first and last name is contrived so this wouldn't make sense but imagine an example where there are many other columns like address, phone number, etc. Our model code is a bit more complex in that it first tries to find a person with the same first and last names. If it succeeds it will then update that person and only creates a new one if there is no match.
• Some of the additional columns in the real system refer to other models in our system. To deal with these our model code must find other kinds of model objects and pass those into the Person.new. Ensuring the proper errors are sent back to the user in this case is fairly tricky as they may not always show up as part of the ActiveRecord validations.
  

Downloading data from our app into Excel
Moving data in this direction was even easier as we just relied on the fact that Excel will open csv files as long as our Rails app returns an Excel MIME type. We add a line to register the mime type with the csv extension

# config/initializers/mime_types.rb
Mime::Type.register 'application/vnd.ms-excel', :csv

Then we had to do for this was add a respond_to.xsl in the appropriate places of our controller

class PeopleController < ApplicationController
def index
 people = Person.all
 respond_to do |format|
  format.html # index.html.erb
  format.csv  do
   render :text => @people.collect { |person| person.to_csv}.join("\n")
  end
 end
end

and then add a to_csv to the model

class Person < ActiveRecord::Base
def to_csv
 "#{first_name}\t#{last_name}"
end
end

This only works for very simple Excel data on a single worksheet but when that's true it makes your job of working with that data so much simpler!

Working with Excel data without working with Excel

over 2 years ago | Alex Rothenberg: Common Sense Software

I am currently working on an application to replace manual MS Excel files that get emailed around and while the business users are looking forward to an interactive web app they are also wedded to their excel files. One of the key requirements we need to meet is allowing them to move their data back and forth.

In the past I've worked with COM and Java libraries to manipulate the files in their native formats and both were painful experiences I did not want to relive. I'm going to talk about how we solved the problem without the need to work with any Office libraries.

Loading Excel data into our Application
The approach we took was to let the users extract the data themselves with a simple copy-and-paste. The user would copy the cells of the excel file and then paste that tab delimited plain text into an HTML form.

Let's say we're trying to import a list of people with a first and last name. The Excel sheet would look like this

We start with a form with a big text area and submit button and an area to show any errors we may encounter while parsing

<% form_tag do -%>
 Paste your Excel data : <%= text_area_tag :data, @data %>
 Click to validate the data <%= submit_tag 'Validate' %>

 <ul>
 <% @errors.each do |error| %>
  <li><span ><%=error%></span></li>

 <% end unless @errors.blank? -%>
 </ul>

Then the controller action which let's the model parse the text and only saves if every person model is valid.

class PeopleController <  ApplicationController
 def import
  @errors = []
  people = Person.all_from_tab_delimited_text(params[:data])

  people.each  do |person|
   person.errors.each { |error| @errors << "#{error} on #{person.inspect}"} unless person.valid?
  end
 end
end 

Now we move onto the Person model where the parsing actually takes place
class

class Person < ActiveRecord::Base
def Person.all_from_tab_delimited_text(data)
 people = []
 CSV::Reader.parse(@data, "\t") do |row|
  person = Person.new(:first_name"> row[0], :last_name => row[1])
  people << person
 end
 people
end
end

We now have a working allbeit simple implementation that even does some simple error checking to give the user feedback if their data cannot be imported. Of course the example here is simple and the real system has additional features and complexity that I didn't show here. Some of these are

• The import into a 2-step operation where we first ask the user to click 'Validate' then return a table showing the data as we parsed it. This allows the user to review and verify it was parsed correctly (i.e. the columns were in the correct order). Only on this second page do we provide an 'import' button that actually persists the new data.
• The data can not only create new people but also update existing ones. The example above with just first and last name is contrived so this wouldn't make sense but imagine an example where there are many other columns like address, phone number, etc. Our model code is a bit more complex in that it first tries to find a person with the same first and last names. If it succeeds it will then update that person and only creates a new one if there is no match.
• Some of the additional columns in the real system refer to other models in our system. To deal with these our model code must find other kinds of model objects and pass those into the Person.new. Ensuring the proper errors are sent back to the user in this case is fairly tricky as they may not always show up as part of the ActiveRecord validations.
  

Downloading data from our app into Excel
Moving data in this direction was even easier as we just relied on the fact that Excel will open csv files as long as our Rails app returns an Excel MIME type. We add a line to register the mime type with the csv extension

# config/initializers/mime_types.rb
Mime::Type.register 'application/vnd.ms-excel', :csv

Then we had to do for this was add a respond_to.xsl in the appropriate places of our controller

class PeopleController < ApplicationController
def index
 people = Person.all
 respond_to do |format|
  format.html # index.html.erb
  format.csv  do
   render :text => @people.collect { |person| person.to_csv}.join("\n")
  end
 end
end

and then add a to_csv to the model

class Person < ActiveRecord::Base
def to_csv
 "#{first_name}\t#{last_name}"
end
end

This only works for very simple Excel data on a single worksheet but when that's true it makes your job of working with that data so much simpler!

How to unit test a Java class with static initializers

over 2 years ago | Alex Rothenberg: Common Sense Software

We have a large Java codebase that we're trying to put under test. Since this class was not designed for testability we often run into code that cannot be tested as is. Most often this involves code that assumes it will always be run inside our J2EE Application Server because it depends on classes provided by the server.

I was recently working with someone on this Java class

class Person {
static {
Logger logger = new ContainerLogger();
}

public String doSomething() {
...
logger.info("I did something");
...
}
}

class MyClass {
public static Logger _logger;
public Logger logger() {
if (_logger == null) {
logger = new ContainerLogger();
}
return _logger;
}

public String doSomething() {
...
logger().info("I did something");
...
}
}

public class TestMyClass extends TestCase {
public void testSomething() {
MyClass._logger = new MockLogger();
assert(MyClass.doSomething(), "expected return");
}
}

How to unit test a Java class with static initializers

over 2 years ago | Alex Rothenberg: Common Sense Software

We have a large Java codebase that we're trying to put under test. Since this class was not designed for testability we often run into code that cannot be tested as is. Most often this involves code that assumes it will always be run inside our J2EE Application Server because it depends on classes provided by the server.

I was recently working with someone on this Java class

class Person {
static {
Logger logger = new ContainerLogger();
}

public String doSomething() {
...
logger.info("I did something");
...
}
}

class MyClass {
public static Logger _logger;
public Logger logger() {
if (_logger == null) {
logger = new ContainerLogger();
}
return _logger;
}

public String doSomething() {
...
logger().info("I did something");
...
}
}

public class TestMyClass extends TestCase {
public void testSomething() {
MyClass._logger = new MockLogger();
assert(MyClass.doSomething(), "expected return");
}
}

Some things are inherently complicated and slow ... put them in the right place

over 2 years ago | Alex Rothenberg: Common Sense Software

One of the first lessons I learned when I started working as a software developer professionally was that you don't always have to make an action fast, sometimes its just enough to make it seem fast to a user. This lesson was learned in the 1990s in the context of a Windows application. What we did was quickly draw part of the screen (or a splash image) immediately then do the time consuming work in the background so that by the time the user was ready to interact with the application we'd be ready for them.

Recently I was reminded of this lesson on a website I'm working on. We have a complicated report to show on the user's homepage. My first implementation involved generating the report in real-time when the page is loaded but this was very slooooow. Some profiling and analysis let us make it somewhat faster but not fast enough.

I was stumped until I remembered my old lesson. If it wasn't possible to generate the report quickly, perhaps we could do it sometime when the user wouldn't mind.

Luckily this is a Rails application and ActiveRecord Callbacks make it easy to do this. I could pregenerate the report and update a portion of it each time something is saved. Users expect a save to take some time and don't do it that often. Then generating the homepage becomes just a simple matter of displaying the existing rows.

First I setup my models to call into the report generator every time they change

class Person < ActiveRecord::Base
  after_destroy {|person| ReportGenerator::Person.destroyed(person)}
  after_create  {|person| ReportGenerator::Person.created(person)  }
  after_update  {|person| ReportGenerator::Person.updated(person)  }
end

module ReportGenerator
  class Executive
    def destroyed(executive)
      #figure out which rows to delete from the report and persist with the Report model
    end
    def created(executive)
      #figure out which rows to add to the report and persist with the Report model
    end
    def updated(executive)
      #figure out which rows to update in the report and persist with the Report model
    end
  end
  #Similar classes corresponding to the other models that trigger recalculations would go here
end

class Report < ActiveRecord::Base
end

class ReportsController < ApplicationController
 @report =" ReportRows.find_by_user(current_user)">

<% for row in @report %>
  Display the row
<% end %>

Some things are inherently complicated and slow ... put them in the right place

over 2 years ago | Alex Rothenberg: Common Sense Software

One of the first lessons I learned when I started working as a software developer professionally was that you don't always have to make an action fast, sometimes its just enough to make it seem fast to a user. This lesson was learned in the 1990s in the context of a Windows application. What we did was quickly draw part of the screen (or a splash image) immediately then do the time consuming work in the background so that by the time the user was ready to interact with the application we'd be ready for them.

Recently I was reminded of this lesson on a website I'm working on. We have a complicated report to show on the user's homepage. My first implementation involved generating the report in real-time when the page is loaded but this was very slooooow. Some profiling and analysis let us make it somewhat faster but not fast enough.

I was stumped until I remembered my old lesson. If it wasn't possible to generate the report quickly, perhaps we could do it sometime when the user wouldn't mind.

Luckily this is a Rails application and ActiveRecord Callbacks make it easy to do this. I could pregenerate the report and update a portion of it each time something is saved. Users expect a save to take some time and don't do it that often. Then generating the homepage becomes just a simple matter of displaying the existing rows.

First I setup my models to call into the report generator every time they change

class Person < ActiveRecord::Base
  after_destroy {|person| ReportGenerator::Person.destroyed(person)}
  after_create  {|person| ReportGenerator::Person.created(person)  }
  after_update  {|person| ReportGenerator::Person.updated(person)  }
end

module ReportGenerator
  class Executive
    def destroyed(executive)
      #figure out which rows to delete from the report and persist with the Report model
    end
    def created(executive)
      #figure out which rows to add to the report and persist with the Report model
    end
    def updated(executive)
      #figure out which rows to update in the report and persist with the Report model
    end
  end
  #Similar classes corresponding to the other models that trigger recalculations would go here
end

class Report < ActiveRecord::Base
end

class ReportsController < ApplicationController
 @report =" ReportRows.find_by_user(current_user)">

<% for row in @report %>
  Display the row
<% end %>