ActiveRecord.touch_without_callbacks

When updating to 2.3.4 I noticed that touch is
no longer a simple ‘update :updated_at’, but a save!,
which caused some code to break
(e.g. touch`ing in after_save == loop)

Usage

User.first.touch_without_callbacks
User.touch_without_callbacks([User.first.id, User.last.id])

Install
Paste somewhere…

# Provide .touch as it was in 2.3.2, simply update the :updated_at field.
class ActiveRecord::Base
  def touch_without_callbacks
    now = Time.now.utc
    self.class.touch(id, now)
    self.updated_at = now
  end

  def self.touch_without_callbacks(ids, time=Time.now.utc)
    update_all({:updated_at=>time}, :id=>ids)
  end
end

Hash.pass and Hash.block that also work with HashWithIndifferentAccess

A new version of the old pass/block hack, but this time they also work as expected on HashWithIndifferentAccess (params/session…)

When attr_protected or attr_accessible are just to complicated, a simple user.attributes = params[:user].pass(:name, :email) just works.
Or user.attributes = params[:user].block(:admin) for the opposite…

# lets through the keys in the argument
# >> {:one => 1, :two => 2, :three => 3}.pass(:one)
# => {:one=>1}
def pass(*selected_keys)
  tmp = self.dup
  dup.block(*selected_keys).keys.each{|k| tmp.delete k }
  tmp
end

# blocks the keys in the arguments
# >> {:one => 1, :two => 2, :three => 3}.block(:one)
# => {:two=>2, :three=>3}
def block(*blocked_keys)
  tmp = self.dup
  blocked_keys.each{|k| tmp.delete k }
  tmp
end

Solving Background Processing with a Single, Generic Background Job

Again I read an article about background processing that generates many different jobs which all do the same: call method a on b with parameter z. At the moment we are using one GenericJob to handle all those cases.

It serializes ActiveRecord objects to a string representation, so that they do not get submittet as instance(often too large or deserialisation problems), if you do not need this feature, :send_later could be a good option for starting with generic jobs.

Usage

GenericJob.publish UserMailer, :deliver_notification,
  :args=>[user, comment], :priority=>2

Install

class GenericJob < DelayedJobBase
  DEFAULT_JOB_PRIORITY = 5

  # GenericJob.publish( Product, :find, :args=>[:all, {:conditions=>"1 = 2"}], :priority=>3 )
  def self.publish(klass, method, options={})
    args = options[:args] || []
    args = GenericJob.serialize_ar(args)
    priority = options[:priority] || DEFAULT_JOB_PRIORITY
    Delayed::Job.enqueue self.new(:class_name => klass.to_s, :method_name => method, :args => args), priority
  end

  def perform
    klass = message[:class_name].constantize
    args = GenericJob.deserialize_ar(message[:args]||[])
    klass.send(message[:method_name], *args)
  end

  private

  def self.serialize_ar(args)
    args.map do |arg|
      if arg.is_a?(ActiveRecord::Base)
        "ActiveRecord:#{arg.class}:#{arg.id}"
      else
        arg
      end
    end
  end

  def self.deserialize_ar(args)
    args.map do |arg|
      if arg.to_s =~ /^ActiveRecord:(\w+):(\d+)$/
        $1.constantize.find($2)
      else
        arg
      end
    end
  end
end

Ubuntu Karmic Koala is here, time for a fresh install

Since my old Ubuntu lived a long live and saw numerous hacks, I chose to reinstall from scratch, here are the steps I took:

1. install dotfiles
2. Skype
3. Multi-clipboard: sudo apt-get install glipper
4. Application laucher: sudo apt-get install gnome-do + enable skype plugin
5. Ruby enterprise
6. Rubymine + Desktop icon+ Meta key for Rubymine
7. Mysql: sudo apt-get install mysql-server mysql-client libmysql-ruby
8. Apache:  sudo apt-get install apache2 apache2-mpm-prefork apache2-prefork-dev
9. Passenger
10. SSL for apache/passenger
11. gem sources -a http://gems.github.com
12. gems…
13. Java: sudo apt-get install sun-java6-jre
14. Git: sudo apt-get install git-core

No more hacks, everything works, very fast startup (~10s), faster graphics (for intel chips)

My new desktop

SSL/HTTPS for Passenger in development on Ubuntu Jaunty

Making a certificate

sudo mkdir /etc/apache2/ssl
sudo /usr/sbin/make-ssl-cert /usr/share/ssl-cert/ssleay.cnf /etc/apache2/ssl/apache.pem

sudo nano /etc/apache2/sites-available/default-ssl
  #deactivete other crt/key files (snakeoil)
  SSLCertificateFile /etc/apache2/ssl/apache.pem

sudo a2ensite default-ssl
sudo a2enmod ssl
sudo /etc/init.d/apache2 restart

Configure passenger

<VirtualHost *:80>
 ServerAlias *.something.com
 RailsEnv development
 DocumentRoot /apps/something/public
</VirtualHost>
<VirtualHost *:443>
 SSLEngine on
 SSLCertificateFile /etc/apache2/ssl/apache.pem
 ServerAlias *.something.com
 RailsEnv development
 DocumentRoot /apps/something/public
</VirtualHost>

host