CodeBits - Tested Complex Code!

Installing Ruby and RubyGems On Ubuntu 8.10

2009-04-02T21:39:00.001-04:00

     # ruby
    cd ~/rn
    wget ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p0.tar.gz
    tar -xzvf ruby-1.9.1-p0.tar.gz
    cd ~/rn/ruby-1.9.1-p0
    ./configure
    make
    make test
    sudo make install
    # zlib
    cd ~/rn/ruby-1.9.1-p0/ext/zlib
    sudo apt-get install zlib1g-dev
    ruby extconf.rb --with-zlib-include=/usr/include --with-zlib-lib=/usr/lib
    make
    sudo make install
    # gem
    cd ~/rn
    wget http://rubyforge.org/frs/download.php/45905/rubygems-1.3.1.tgz
    tar -xzvf rubygems-1.3.1.tgz
    cd rubygems-1.3.1
    sudo ruby setup.rb
    # fix ruby executable
    cd ~/rn/ruby-1.9.1-p0
    sudo make install

Using Rails Gem to Generate a New Project on Ubuntu

2009-03-14T23:29:00.004-04:00

Using the rails installed by apt-get was a bit confusing because the rails project being generated was not the rails version that I expected. I had installed the rails gem v2.2.2 but the config/environment.rb file showed rails v2.1.

I fixed this issue by removing the default rails.

sudo apt-get remove rails

And then using an alias:

export GEMDIR=`gem environment gemdir`
export RAILS_VERSION=`gem list rails | grep "rails " | cut -b8- | awk '{sub(/\)/, "");print}'`
alias rails='ruby $GEMDIR/gems/rails-$RAILS_VERSION/bin/rails'

Now when I do

rails dool

The project uses the right version of rails!

The --include-activation and --aasm parameters of the Restful Authentication Rails Plugin are mutually exclusive

2009-01-05T00:37:00.003-05:00

I was following the installation instructions for the Restful Authentication Rails plugin. So I executed:

script/generate authenticated user sessions --include-activation -—aasm --rspec

This resulted in:

premature end of regular expression: /\A

After digging into the source code, I found that the parse! method in /usr/lib/ruby/gems/1.8/gems/rails-2.2.2/lib/rails_generator/options.rb swallowed exceptions. Here is the original code.

def parse!(args, runtime_options = {})
  self.options = {}
  @option_parser = OptionParser.new do |opt|
    opt.banner = banner
    add_options!(opt)
    add_general_options!(opt)
    opt.parse!(args)
  end

  return args

  ensure
    self.options = full_options(runtime_options)
end

The OptionParser initialization may cause exceptions which are not properly handled. I don't know what should be down but added the following code immediately before the ensure line at least will show the exception.

    rescue => e
    puts("I caught a #{e.class.to_s} with message #{e.to_s}")

Now that the exception is displayed, I saw one of my underlying problems:

I caught a OptionParser::InvalidOption with message invalid option: --include-activation

So I learned that when the --aasm parameter is used, then the --include-activation must not be specified.

Using the Visualize Models plugin

2009-01-04T13:34:00.001-05:00

This is a good plugin. It works with GraphViz to generate diagrams of your object model. After installation, I ran into a problem that Visualize::Inflector was not found. This was easily resolved by using ActiveSupport::Inflector in visualize_models.rb.

The Myth of the Hero Programmer

2009-01-04T12:04:00.003-05:00

Fortunately, I have met few self-appointed heroic programmers over the years. However, late last year I was saddened to met another. People on truly agile teams might never have met this dying breed of programmer so let me present the archetype by borrowing from the Highlights magazine:

Goofus: Writes complex hard-to-understand code to prove superiority.
Gallant: Writes clear easy-to-understand code to enhance team dynamics.

Goofus: Writes code with side-effects to show his mastery of arcana.
Gallant: Writes simple code that is easy to maintain and debug.

Goofus: Disdains and deletes comments.
Gallant: Describes code context to aid maintenance and provide road maps for new team members.

Goofus: Speaks in imperative words and derisive tones.
Gallant: Speaks with humility and guides people to solutions.

The Ruby community should guard against any tendency towards heroic programmers to avoid some of the complaints made against the Perl community. Too many 'perlers' loved complexity for its own sake which lead to unmaintainable code and a bad reputation for the language in general.

Let's focus on the agile concepts of teamwork, shared code ownership, and collaboration. They are much healthier for the community.

What Goofus/Gallant experiences have you had?

Avoiding the undefined method `use_transactional_fixtures=' error.

2009-01-01T01:34:00.004-05:00

After adding rspec to my project and generating a model with rspec_model, I tried to run the generated spec test:

$ spec -cfprofile spec/
.../toshi/spec/spec_helper.rb:12: undefined method `use_transactional_fixtures=' for # (NoMethodError)
 from /usr/lib/ruby/gems/1.8/gems/rspec-1.1.11/lib/spec/runner.rb:184:in `configure'
 from /home/medined/Workspaces/toshi/spec/spec_helper.rb:8
 from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
 from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
 from /home/medined/Workspaces/toshi/spec/models/book_spec.rb:1

After a fruitless internet search, I tried using a rake task:

$ rake spec
.
Finished in 0.061996 seconds
1 example, 0 failures

Adding RSPEC to a Rails Project

2009-01-01T00:11:00.005-05:00

$ rails toshi
$ script/generate rspec
Couldn't find 'rspec' generator
$ cd toshi/vendor/plugins
$ git clone git://github.com/dchelimsky/rspec.git
$ git clone git://github.com/dchelimsky/rspec-rails.git
$ cd ../../
$ script/generate rspec
      create  lib/tasks/rspec.rake
      create  script/autospec
      create  script/spec
      create  script/spec_server
      create  spec
      create  spec/rcov.opts
      create  spec/spec.opts
      create  spec/spec_helper.rb

How is a Use Case Different From a User Story?

2008-10-16T10:08:00.003-04:00

http://alistair.cockburn.us/Elephant+carpaccio - Alistair provides a way to think about Use Cases and User Stories. In essence, he says that Use Cases provide the overall shape of the application while User Stories provide the details.

How do I restore and change gedit key assignments?

2008-10-08T10:05:00.002-04:00

Use the vi editor to modify the .gnome2/accelsgedit. Editing the file with gedit does not work; the changes are not saved. I had reassigned my ^s key away from File>Save. I order to get the key assignment back, I re-commented the following line:

(gtk_accel_path "<Actions>/GeditWindowActions/FileSave" "<Control>s")

RCOV - Covering unit, integration, and functional testing in one analysis.

2008-10-05T16:11:00.003-04:00

Add the following code into a file called lib/tasks/rcov.rake. Notice that I used the find to gather the relevant tests then the xargs to form them into a nice line which can be added to the rcov command.

namespace :test do

  desc 'Tracks test coverage with rcov'
  task :coverage => :environment do
    rm_f "coverage"
    rm_f "coverage.data"

    rcov = "rcov --sort coverage --rails --aggregate coverage.data --text-summary -Ilib -Itest -T -x gem/*,rcov*"

    files = `find . -name *_test.rb | xargs`

    rcov = "#{rcov} " + files
    puts rcov
    system rcov

    system("firefox coverage/index.html")
  end
  
end

The new rake command can be executed using rake test:coverage

Advanced Rails Recipes - Chapter Two - The missing copy method.

2008-09-29T20:23:00.002-04:00

I am reading through the Advanced Rails Recipes book. In chapter two, it refers to an Event.copy method which is not shown in the book. Shown below is the missing method from app/models/event.rb.

class Event < ActiveRecord::Base

  def self.copy(other)
    self.new(other.attributes.merge(:name => "Copy of #{other.name}"))
  end

end

JBoss Drools CLASSPATH Error; The Eclipse JDT Core jar is not in the classpath

2008-07-20T21:05:00.003-04:00

JBoss Rules v4.0.7 is compatible with Eclipse v3.3 or higher. However there is a simple workaround. Run the following commands:

export ECLIPSE_PLUGINS=/home/medined/Desktop/eclipse-3.4/plugins
ln -s 
  $ECLIPSE_PLUGINS/org.eclipse.jdt.core_3.4.0.v_874.jar 
  $ECLIPSE_PLUGINS/org.drools.eclipse_4.0.7/lib

Getting "Client.InvalidKeyPair.NotFound" Error With Selenium Grid

2008-07-13T22:10:00.002-04:00

When running the cap grid:boot command, I received the following error:

Client.InvalidKeyPair.NotFound: The key pair '/home/medined/.ec2/affy.pem' does not exist

It turned out that the EC2_KEYPAIR_NAME system variable was set incorrectly. You can find the correct value using the ec2-describe-keypairs command. Here is an example of its use:

$ ec2-describe-keypairs
KEYPAIR affy c3:e7:5f:09:50:66:f5:2b:3d:2b:ac:1d:09:52:9d:34:29:85:1b:76

So the correct value for me is affy, not the filename.

Using Capistrano to Bundle Amazon EC2 Images

2008-07-12T11:29:00.002-04:00

I've found the following bit of Capistrano script to be useful when tinkering with EC2 images. I can make a change and then bundle the image with just one command: cap admin:bundle

The most difficult part of this script was finding out how to upload files to the remote instance using scp. The rest is fairly straightforward. I am only posting this script because I haven't seen this functionality posted anywhere else.

# capfile for Amazon EC2 Bundling. Normally, a yaml file would be
# hold configuration parameters. I am using environment 
# variables because they are also used by the EC2
# programs - why have the information in two places?

# This script assumes that you are only bundling one
# instance at a time.

# EC2 Instance Hostname to be bundled.
ec2_hostname = ENV['BUNDLE_EC2_HOSTNAME']

# S3 Bucket Name (where the bundle is uploaded)
s3_bucket_name = ENV['BUNDLE_S3_BUCKET_NAME']

# If you are using ElasticFox (and if not, why not?) that
# you created in the KeyPairs tab. Specify the full
# path to the file.
ssh_keypair_file = ENV['BUNDLE_SSH_PRIVATE_KEY_FILESPEC']

# Amazon Web Services Info
amazon_account_id    = ENV['AMAZON_ACCOUNT_ID']
amazon_access_key_id   = ENV['AMAZON_ACCESS_KEY_ID']
amazon_secret_access_key = ENV['AMAZON_SECRET_ACCESS_KEY']

# Amazon EC2 Info
cert_filespec     = ENV['EC2_CERT']
private_key_filespec   = ENV['EC2_PRIVATE_KEY']

# We are only dealing with one EC2 instance.
role :libs, "#{ec2_hostname}"

# I like working with ElasticFox which seems to only
# support using the root user.
set :user, "root"

ssh_options[:keys] = ssh_keypair_file

namespace :admin do

 task :bundle do

  # Copy the certificate and private key to the remote computer.
  upload("#{private_key_filespec}", "/mnt", :via => :scp) 
  upload("#{cert_filespec}", "/mnt", :via => :scp)

  # Extract just the filename from the filespec.
  private_key_filename_start = private_key_filespec.rindex('/') + 1
  private_key_filename_end = private_key_filespec.length
  private_key_filename = private_key_filespec[private_key_filename_start, private_key_filename_end]

  # Extract just the filename from the filespec.
  cert_filename_start = cert_filespec.rindex('/') + 1
  cert_filename_end = cert_filespec.length
  cert_filename = cert_filespec[cert_filename_start, cert_filename_end]

  # Remove any old image.
  run "rm --force /mnt/image /mnt/image.*"

  # Create the EC2 Bundle
  #run "ec2-bundle-vol -d /mnt -c /mnt/#{cert_filename} -k /mnt/#{private_key_filename} -u #{amazon_account_id} -r i386"

  # Upload the EC2 Bundle to S3
  run "ec2-upload-bundle -b #{s3_bucket_name} -m /mnt/image.manifest.xml -a #{amazon_access_key_id} -s #{amazon_secret_access_key}"

  exec "ec2-register #{s3_bucket_name}/image.manifest.xml"

 end

 task :update do
  run "apt-get update"
  run "apt-get upgrade -y"
 end

end

Using SCP with Capistrano

2008-07-10T14:07:00.002-04:00

It took me several hours to find out how to send a file to my remote computer via scp using Capistrano. It's actually quite easy. There is a method called upload which has a via option. Here is an example of its use:

upload("products.txt", "/home/medined", :via => :scp)

If you need to change the files name, you can also specify it in the second parameter. For example,

upload("products.txt", "/home/medined/products_new.txt", :via => :scp)

Capistrano, ElasticFox & EC2

2008-07-09T19:35:00.002-04:00

What a nice combination of tools! I just installed Capistrano and created a capfile. From then on, I could run commands across all my virtual istances in one shot. This setup took just minutes. The only change that I made to my existing instances was to add a capistrano userid. My capfile looks like this:

role :files, 
  "capistrano@ec2-75-101-225-105.compute-1.amazonaws.com", 
  "capistrano@ec2-67-202-59-118.compute-1.amazonaws.com"

namespace :files do
  desc "Show free disk space"
  task :show_free_space, :roles => :files do
    run "df -h /"
  end
end

The best thing of all? No XML configuration!

ElasticFox: How to SSH to Amazon EC2 Image Without Entering a Password

2008-07-07T10:24:00.003-04:00

1. Download and install the ElasticFox plugin.
2. Enter your credentials.
3. Enter your account information.
4. Select the KeyPairs tab.
5. Click Create a New Pair.
6. Save to a file; for example ~/.ec2/affy.pem.
7. Select the AMIs and Instances tab.
8. Click Launch Instance(s).
9. In the dialog box, select the keypair that you created in step 5.
10. When the AMI is running, you should be able to connect to it without a password prompt.

Captain Kirk Teaches SCRUM and Agile Development

2008-07-06T18:16:00.001-04:00

Episode One: Change the Playing Field

"The odds are against us and the situation is grim." - Star Trek: Generations

STARDATE 11234.2

Students, Starfleet has asked to me say a few words about SCRUM while I'm visiting your base. Fortunately, my meeting with the Ambassadors isn't until 0930 so I have just enough time to talk and then answer a few questions.

Some years ago, I was in a situation that by most accounts (especially Bones') would be considered bleak. Our software team was handed a Klingon application to calculate the expansion rate of exploding warheads. Our Quality Assurance staff was located in the beta quadrant. While my Klingon interpreter and product owner (Kveld of house K'mpok) was in the brig for attempting to kill Scottie. I needed to act, and fast! But what were my options?

Yes, I could have outsourced the work to the Romulons. But they are the enemy! Let's get serious. Other suggestions?

Ok, that's another approach. We could bring everyone together onto a single starbase to form a co-located team. That suggestion is a classic. And workable except for the inter-species issues. My product owner, the klingon in the brig, is also responsible for other projects. He can't be co-located for all of them, can he? Additionally, co-location means additional costs in the form of housing, food, time away from family. In this situation, co-location is not possible.

Hmm. Good idea. Use the holodeck as a virtual meeting room. I like that and that is the approach that we took. Along with some others as well.

Since the team is so dispersed the issue of time was quite important. The team agreed to a daily standup (a scrum, some like to say) but at what time? The meeting time changed every three months. Thus, no one location was impacted more than another - all were inconvenienced equally.

Scottie agreed to import a case of Ra'taj for Kveld and to refrain from further mentioning his mother's similarity to a Gagh.

The approach that I take to every situation is:

What is the operant set of relationships and rules? And how can they be changed to resolve the issue?

Once you know how the forces arrayed against you are deployed, you can find the levers needed to tip the scale in your direction.

Any questions?

Thank you.

Dup dor a'az Mubster (live long and prosper)

Getting flickrfs to Work on Ubuntu Heron

2008-06-02T08:22:00.002-04:00

I found this site which provides step-by-step instructions how to use flickrfs in order to mount your Flickr account as a file system. The steps required a little tweaking to work. Here are the steps that I followed:

sudo apt-get install libfuse2 fuse-utils python2.4-fuse imagemagick - the original instructions used a capital i for imagemagick.
sudo modprobe fuse
sudo chmod 755 /bin/fusermount - the original instructions used /usr/bin
sudo chmod u+s /bin/fusermount - the original instructions used /usr/bin
sudo chmod 666 /dev/fuse
cd ~
Download flickrfs package from sourceforge.
tar -xzvf flickrfs-*.tar.gz
screen -S flickrfs
lsmod | grep -i fuse # Rerun commands in step 2 if not loaded.
cd flickrfs-1.3.95 - make sure to check the version number.
mkdir ~/flickrfs/mount - use a mount point under your home directory or use sudo
mkdir ~/flickrfs/mount/stream
python flickrfs.py ~/flickrfs/mount
tail -f ~/.flickrfs/log

Installation and Configuration of LocalSolr.

2008-05-04T18:01:00.006-04:00

A client of mine asked me to investigate localsolr which= extends Apache Solr server with the ability to perform text searches filtered on geographical distance from a given point specified by latitude and longitude. Here are the steps that I followed:

Download the Software

Downland Ant from http://apache.mirror99.com/ant/binaries/apache-ant-1.7.0-bin.tar.gz
Download Tomcat from http://mirror.nyi.net/apache/tomcat/tomcat-6/v6.0.16/bin/apache-tomcat-6.0.16.tar.gz
Download LocalLucene from http://downloads.sourceforge.net/locallucene/locallucene-r1.5.tar.gz
Download LocalSolr from http://downloads.sourceforge.net/locallucene/localsolr-r1.5.tar.gz

Download Solr-1.3-dev, via svn, to get the source code

svn checkout http://svn.apache.org/repos/asf/lucene/solr/trunk apache-solr-1.3.dev

Uncompress all of the software packages.

Create Environment Variables

In Unix variants, update your .bash_login script to include the following. Of course, you'll need to set the variables correctly according to where you uncompressed the software. And don't forget to source the .bash_login file after you have changed it.

export SUPPORT_DIR=/home/medined/support
export LOCAL_LUCENE_HOME=$SUPPORT_DIR/locallucene-r1.5
export LOCAL_SOLR_HOME=$SUPPORT_DIR/localsolr-r1.5
export SOLR_HOME=$SUPPORT_DIR/apache-solr-1.3-dev
export SOLR_CONFIG=/home/medined/.solr
export TOMCAT_HOME=$SUPPORT_DIR/apache-tomcat-6.0.16

export JAVA_OPTS="$JAVA_OPTS -Dsolr.solr.home=$SOLR_CONFIG"

Create Apache Solr War

cd $SOLR_HOME
ant dist

Configure Local Solr

cp -R $SOLR_HOME/example/solr $SOLR_CONFIG
cp $SOLR_HOME/libs/solr/apache-solr-1.3-dev.war $TOMCAT_HOME/webapps/solr.war mkdir $SOLR_CONFIG/lib
cp $LOCAL_LUCENE_HOME/dist/locallucene.jar $SOLR_CONFIG/lib
cp $LOCAL_SOLR_HOME/dist/localsolr.jar $SOLR_CONFIG/lib
cp $LOCAL_LUCENE_HOME/lib/gt2-referencing-2.3.1.jar $SOLR_CONFIG/lib
cp $LOCAL_LUCENE_HOME/lib/geoapi-nogenerics-2.1-M2.jar $SOLR_CONFIG/lib
cp $LOCAL_LUCENE_HOME/lib/jsr108-0.01.jar $SOLR_CONFIG/lib

Add the following to the end of $SOLR_CONFIG/conf/solrconfig.xml (just before the closing CONFIG tag:

  <updateRequestProcessor>
    <factory name="standard" class="solr.ChainedUpdateProcessorFactory" default="true">
      <chain class="com.pjaol.search.solr.update.LocalUpdateProcessorFactory">
        <str name="latField">lat</str>
        <str name="lngField">lng</str>
        <int name="startTier">9</int>
        <int name="endTier">17</int>
      </chain>
      <chain class="solr.LogUpdateProcessorFactory" >
       <!-- <int name="maxNumToLog">100</int> -->
      </chain>
      <chain class="solr.RunUpdateProcessorFactory" />
    </factory>
  </updateRequestProcessor>

 <requestHandler name="geo" class="com.pjaol.search.solr.LocalSolrRequestHandler">
    <!-- Custom latitude longitude fields, below are the defaults if not otherwise
    specified -->
     <str name="latField">lat</str>
     <str name="lngField">lng</str>
  </requestHandler>

Add the following to the fields tag of $SOLR_CONFIG/conf/schema.xml

<field name="lat" type="sdouble" indexed="true" stored="true"/>
   <field name="lng" type="sdouble" indexed="true" stored="true"/>
   <dynamicField name="_local*" type="sdouble" indexed="true" stored="true"/>

Controlling Tomcat

$TOMCAT_HOME/bin/startup.sh - this command starts Tomcat.
tail -f $TOMCAT_HOME/logs/catalina.out - this command lets you watch Tomcat's output log.
$TOMCAT_HOME/bin/shutdown.sh - this command stops Tomcat.

If you're lucky enough to be using Unix then combine the first two commands onto one line:

$TOMCAT_HOME/bin/startup.sh; tail -f $TOMCAT_HOME/logs/catalina.out

Importing Data Into Apache Solr

When LocalSolr is deployed into Tomcat, the default port is 8080. However, the Apache Solr import tools use a different hardcoded port. This causes me a but of angst until I realized that I could easily copy the SimplePostTool and change the port. So copy $SOLR_HOME/src/java/org/apache/solr/util/SimplePostTool.java, change the port specified on line 46 (see below) and compile it.

public static final String DEFAULT_POST_URL = "http://localhost:8080/solr/update";

I create a data file that looked like this

<add>
 <doc>
   <field name="id">01</field>
   <field name="name">HOUSE01</field>
   <field name="lat">39.36</field>
   <field name="lng">-77.4027</field>
   <field name="text">zxy</field>
 </doc>
 <doc>
   <field name="id">02</field>
   <field name="name">HOUSE02</field>
   <field name="lat">38.36</field>
   <field name="lng">-77.4027</field>
   <field name="text">zxy</field>
 </doc>
</add>

Then I simply executed the SimplePostTool program passing it the name of the data file as the program argument.

Apache Solr Admin Screen

With Tomcat running, you should be able to connect with http://localhost:8080/solr/admin/

Local Solr GIS Query

With Tomcat running, you should be able to execute a GIS-based query by connecting to http://localhost:8080/solr/select?&qt=geo&lat=38.8700&long=-77.4027&q=zxy&radius=1. The q=zxy tells Apache Solr to return all documents. The lat and long parameters indicate the center of the circle to search using decimal degrees. While the radius parameter indicates the radius, in miles, of the circle.

Good Luck!

Struts Error/Exception: No getter method available for property name for bean under name

2008-04-30T14:47:00.002-04:00

Recently I was using Struts v1.x and I needed to display a select list. The information about how to use the html:optionsCollection tag was sketchy. I was able to get the tag working this way:

On the JSP page, I added this inside the html:form tag:

<html:select property="selectedEquipment">
  <html:optionsCollection property="equipment" label="name" value="id"/>
</html:select>

Then I create a Java class called SelectOption like this:

package com.codebits.struts;

public class SelectOption {

    String id;
    String name;

    SelectOption() {
    }

    SelectOption(final String _id, final String _name) {
        setId(_id);
        setName(_name);
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

Next I created an ActionForm bean:

package com.codebits.struts;

public class AddForm extends ActionForm {

    private Integer           selectedEquipment = null;

    private List              equipment         = new ArrayList();
    
    public Integer getSelectedEquipment() {
        return selectedEquipment;
    }
    
    public void setSelectedEquipment(Integer selectedEquipment) {
        this.selectedEquipment = selectedEquipment;
    }
    
    public List getEquipment() {
        return equipment;
    }
    
    public void addEquipment(final String equipmentId, final String emtEquipmentId) {
        this.equipment.add(new SelectOption(equipmentId, emtEquipmentId));
    }
    
    public void setEquipment(List equipment) {
        this.equipment = equipment;
    }

}

And finally, in my action class, I prepopulated the ActionForm bean:

  AddForm addForm = (AddForm)form;
  addForm.addEquipment("1", "AAA");
  addForm.addEquipment("2", "BBBB");

How to Format Dates in Ruby & Rails

2008-04-22T16:01:00.002-04:00

I have seen several techniques used to format dates in blogs and forums threads. This is the technique that worked for me.

Create a file called config/initializers/date_formats.rb with the following contents:

ActiveSupport::CoreExtensions::Time::Conversions::DATE_FORMATS.merge!(
 :date => '%m/%d/%Y',
 :date_time12  => "%m/%d/%Y %I:%M%p",
 :date_time24  => "%m/%d/%Y %H:%M"
)

Set the date variable:
```
@cacheExpiresAt = 10.minutes.ago
```

Format the date:

<%= @cacheExpiresAt.to_s(:date_time12) %>

The :date_time12 parameter to the to_s method simply chooses the formatting from the DATE_FORMATS hash. This technique lets you centralize all date formatting in your application.

Workaround For Minor Hibernate Bug - Blank hibernate.default_schema Property Adds Period

2008-04-18T09:42:00.003-04:00

We are using the hibernate.default_schema property with Oracle in production. Today I tried to use HSQL for our integration tests. When I blanked the hibernate.default_schema property, Hibernate tried to create tables named like '.FOO' - notice that pesky leading period! You can workaround this issue for HSQL by setting hibernate.default_schema to 'sa'.

ActiveRecord Without Rails, Refined

2008-04-09T00:11:00.003-04:00

About a year ago Aizat Faiz, a software developer in Malaysia wrote a blog entry about using ActiveRecord outside of the Rails framework. This is definitely something that I want to do for a variety of reasons, the simplest being that I'd like to write utility programs that access the database without needing to also write a user interface for them.

In any case, Aizat wrote a nice understandable entry. However, he seemed to make the assumption that developers using ActiveRecord without Rails would not have a Rails application at all. This is not the case for me.

If your utility script resides in the top level directory, then you can use your already existing database.yml file instead of creating a new one. Just use the following as a guide.

dbconfig = YAML::load(File.open('config/database.yml'))
ActiveRecord::Base.establish_connection(dbconfig['development'])

Also, there is no reason to have your models in your script when they are already in your Rails application. You can load existing modesl like this:

require 'app/models/event.rb'
require 'app/models/senator.rb'

That's it. Very simple and no duplication of code.

How To Add a Datasource To Tomcat Server.XML File.

2008-04-04T09:51:00.002-04:00

... ... factory oracle.jdbc.pool.OracleDataSourceFactory validationQuery select 1 from dual url jdbc:oracle:thin:USERNAME/PASSWORD@localhost:1521:XE maxActive 4 maxWait 5000 driverClassName oracle.jdbc.OracleDriver maxIdle 2 ... ..