If you enter and @-sign into the textbox, a autocomplete will be shown.

I havn’t found an existing plugin for that, so I have written one. autocompleteTrigger is based on jQuery-UI Autocomplete and set/overwrite some functions only.

Url: https://github.com/experteer/autocompleteTrigger

Demo: http://jsfiddle.net/dmattes/2YRgW/1/

Code Example

$('input,textarea').autocompleteTrigger({
      triggerStart : '@',
      triggerEnd: '',
      source: [
        "Asp",
        "BASIC",
        "COBOL",
        "ColdFusion",
        "Erlang",
        "Fortran",
        "Groovy",
        "Java",
        "JavaScript",
        "Lisp",
        "Perl",
        "PHP",
        "Python",
        "Ruby",
        "Scala",
        "Scheme"
      ]
    });

For example, domain data can be the roles of users.

Role.create(:key => 'user', :description => 'A normal user')
Role.create(:key => 'admin', :description => 'The admin of the page')

The role constants can be set in the following way (based on the example in Enterprise Rails, Chapter 7)

class Role < ActiveRecord::Base
  USER = Role.find_by_key('user')
  ADMIN = Role.find_by_key('admin')
end

Now you can use this constants like

my_user.role = Role::ADMIN

My solution is, to set the constants dynamicly

class Role < ActiveRecord::Base
  # set role contants like Role::ADMIN,..
  Role.all.each do |role|
    Role.const_set(role.key.upcase, role)
  end
end

The big advantage by setting a constant through the database is that the select query will be executed only once for a running application. If you restart the application, the constants will be refreshed.

Each day, HeidiSQL publishs a Nightly Build, which I wanted to have.
Therefore I wrote a little shell-script, which makes that work for me.

#!/bin/bash
path=/home/mattesd/.wine/drive_c/prog/HeidiSQL
abs_filename=$path/heidisql.`date +%s`.exe

wget http://www.heidisql.com/latest_build.php -O $abs_filename
rm $path/heidisql.exe
ln -s $abs_filename $path/heidisql.exe

Each build will be downloaded as heidisql.<TIMESTAMP>.exe (e. g. heidisql.1263728741.exe) and linked to heidisql.exe.

Note:
I created the softlink prog before.
ln -s home/mattesd/.wine/drive_c/Program\ Files home/mattesd/.wine/drive_c/prog

Roy Wright modified it to support the state machine AASM.

Following you see an example of a model diagram, generated by
railroad -Mt | neato -Tpng > models_default.png

This is very great, but in bigger projects, I wanted to see the magic fields like id, user_id, post_id,…

Therefore, I modified the gem by adding an additional parameter  --show-magic to show the magic fields.

railroad -Mt --show-magic | neato -Tpng > models_with_magics.png creates the following diagram

The plugin can be installed via gemcutter.org
gem install dmattes-railroad_xing

Source is available on Github: http://github.com/dmattes/railroad_xing

I had to update some attributes of an object. This can easily be done by my_obj.update_attributes(params). If you want to know the updated attributes …it’s not so easy.

update_attributes internally calls the save-method, so that my_obj.changes can’t be called after update_attributes. My solution was to patch ActiveRecord, so that it additionally returns the changed attributes.

Usage example

status, changes = my_obj.update_attributes_changed(params)

config/initializers/active_record_patch.rb

module ActiveRecord
  class Base
    def update_attributes_changed(attributes)
      self.attributes = attributes
      changes = self.changes
      return save, changes
    end
  end
end

My solution is, to handle the reprocessing in background with delayed_job and aasm (acts_as_state_machine).

Media-Model
This is the “normal” Media-Model. First at all, there is AASM included, to see the current state (pending, error, ready) of processing. Furthermore, to show the image, I create a url method, which give back the path to the image (if the state is :ready) or an placeholder (if the state is NOT :ready).

media.rb

class Media

  has_attached_file( :source,
	:styles => {
	:bigger => '1600x1600>',
	:big => '800x600>',
	:album => '560x420>',
	:album_preview => '150x150>',
	:album_folder => '70x70#',
	:profile => '180x250>',
	:avatar => '50x50#' },
	:storage => :filesystem,
  )

  include AASM

  aasm_column :status
  aasm_initial_state :pending

  aasm_state :pending
  aasm_state :error
  aasm_state :ready

  aasm_event :converted do
	transitions :to => :ready, :from => [:pending]
  end

  def url(style = :original)
    if(self.ready?)
      source.url(style)
    else
      # Image is processing, please wait
      Media.find(3).source.url(style)
    end
  end
end

The “Uploading” Media-Model
For uploading new images, the model MediaUpload will be used.
This model inherits from the Media-Model, but the paperclip configuration will be overriden.
There is only one style available, because it’s the feedback image for the uploading user.
After saving the image, a new MediaJob will be created in background with the help of delayed_job.

media_upload.rb

class MediaUpload < Media

  # paperclip
  has_attached_file( :source,
    :styles => { :avatar => '50x50#' },
      :storage => :filesystem
  )

  after_create :create_all_styles

  def create_all_styles
    Delayed::Job.enqueue MediaJob.new(self.id)
  end
end

The REPROCESSOR
At least, the media-job created all styles for the image …and it’s DONE.

media_jobs.rb

class MediaJob < Struct.new(:id)
  def perform
    m = Media.find(id)
    m.source.reprocess!
  end
end

Helpful links:

• http://eastblue.org/blag/2009/05/07/delaying-paperclip.html
• http://groups.google.com/group/paperclip-plugin/browse_thread/thread/8af52cc25cd97d02/05221d1a7254601d?lnk=gst&q=background&pli=1
• http://github.com/tobi/delayed_job/tree/master

For closing the dialog, the following code is described in the boxy api, but it doesn’t run for me.
It runs for a “normal” boxy window, but not for an ajax-window.

Close dialog.

My solution is, to “link” the modal-window to an DOM element. You can do this, by using the actuator option.
In this example, the DOM element is a link with the id “address_name” and it opens the modal-window.

For closing the modal-window, you can get the boxy object with Boxy.linkedTo() and can close it with hide() method.

function boxy_hide(obj_name){
  Boxy.linkedTo($('#' + obj_name)[0]).hide();
}

Helpful links:

• http://onehackoranother.com/projects/jquery/boxy/index.html
• http://github.com/jaz303/boxy/tree/master

Paperclip includes the option for id_partition, but I prefer an hashed stucture (descriped in my first blog).

For example, the image url looks like

http://my_url/medias/0d/898/0d898414092854eacbf27f8db12ce4db_avatar.jpg

This is the basic configuration in my Media-Model

  # paperclip
  has_attached_file( :source,
    :styles => {
      :original => '1600x1600>',
      :avatar => '50x50#' },
    :storage => :filesystem,
    :url => "/:class/:hashed_public_id/:public_id_:style.:extension",
    :path => ":rails_root/public/:class/:hashed_public_id/:public_id_:style.:extension"
  )

To set the public id, I used the following code and create an md5-hash.
Surely, you can use what you want, for example ActiveSupport::SecureRandom.hex(32).
My set_public_id creates a random string like “6e374ca829eaead5090f6cdd26c08017″.

  def set_public_id
    self.public_id = Digest::MD5.hexdigest(self.source_file_name + self.source_file_size.to_s + rand.to_s + Time.now.to_i.to_s)
  end

For using hashed_public_id or public_id in the paperclip configuration :url => “/:class/:hashed_public_id/:public_id_:style.:extension”, you must set the following attachment interpolations.

  Paperclip::Attachment.interpolations[:public_id] = lambda do |attachment, style|
    # e. g. "6e374ca829eaead5090f6cdd26c08017"
    attachment.instance.public_id
  end

  Paperclip::Attachment.interpolations[:hashed_public_id] = lambda do |attachment, style|
    # e. g. "6e/374"
    File.join(attachment.instance.public_id[0..1], attachment.instance.public_id[2..4])
  end

Furthermore, I need to rotate an image. Therefore, I used the follwing code.
All styles of the image (e. g. original, avatar) will be rotated.

require 'RMagick'
def rotate(degrees)

    if(degrees.class == Fixnum && degrees % 90 == 0)
      each_attachment do |n, a|
        self.source.styles.each do |styles|
          image_path = a.path(styles.first)

          image   = Magick::ImageList.new(image_path)
          image   = image.rotate(degrees)
          image.write(image_path)
        end
        return true
      end
    end
    nil

  end

Helpful links:

• http://addictedtonew.com/archives/127/rotating-images-with-rmagick-and-ruby-on-rails/
• http://jimneath.org/2008/04/17/paperclip-attaching-files-in-rails/
• http://wiki.github.com/thoughtbot/paperclip/interpolations
• http://thewebfellas.com/blog/2008/11/2/goodbye-attachment_fu-hello-paperclip

My Class Media

class Media < ActiveRecord::Base
  attr_accessible :caption
end

Usage in my media_spec.rb

it "should have protected attributes" do
  @media = Media.create!(@valid_attributes)
  @media.should accessible_attributes(:caption)
end

Here the used code in lib/rspec_attributes_accessible.rb

module RspecAttributesAccessible
  class AccessibleAttributes

    def initialize(*attributes)
      @attributes = attributes.to_a
    end

    def matches?(target)
      @target = target
      calculate_accessible_attributes()
      perform_check()
    end

    def failure_message
      "expected #{@failed_attribute} to be accessible"
    end

    def negative_failure_message
      "expected #{@failed_attribute} to not be accessible"
    end

    private

    def calculate_accessible_attributes()
      attr_access = @target.class.send("attr_accessible").to_a.map(&:to_sym)
      @failed_attribute = []
      if((@attributes - attr_access).length != 0 or (attr_access - @attributes).length != 0)
        @failed_attribute << (@attributes - attr_access)
        @failed_attribute << (attr_access - @attributes)
      end
      nil
    end   

    def perform_check()
      @failed_attribute.empty?
    end
  end

  def accessible_attributes(*attributes)
    AccessibleAttributes.new(*attributes)
  end
end

You have to include the lib in your spec_helper.rb

Spec::Runner.configure do |config|
   config.include RspecAttributesAccessible # lib/rspec_attributes_accessible.rb
end

Useful links:

• http://railspikes.com/2008/9/22/is-your-rails-application-safe-from-mass-assignment
• http://afreshcup.com/2008/12/14/auditing-for-attr_accessible/
• http://snippets.dzone.com/posts/show/4712

Hier meine verwendete Lösung, ausgelagert in lib/hashed_dir_structure.rb

module HashedDirStructure

  #p_filename md5 encrypted or number
  def HashedDirStructure.get_path_for_save(p_base_path, p_filename)

    if( p_filename.to_s.length != 32)
      p_filename = ("%05d" % p_filename)
    end

    part16 = p_filename[0..1]
    part256 = p_filename[2..4]

    path = File.join(p_base_path, part16, part256)

    # ensure the directory exists...
    FileUtils.mkdir_p(path)

    return File.join(p_base_path, part16, part256)
  end

  def HashedDirStructure.get_path_for_url(p_filename)

    if( p_filename.to_s.length != 32)
      p_filename = ("%05d" % p_filename)
    end

    part16 = p_filename[0..1]
    part256 = p_filename[2..4]

    return File.join(part16, part256)
  end

end

Verwendung:

Jedes Bild/Audio/Video ist als Medien-Objekt in der DB vorhanden. Diesen Objekten ist jeweils eine Public-ID zugewiesen, was ein MD5-Hash ist.

class Media < ActiveRecord::Base
  require 'digest/md5'

  # setzen der public_id
  # z. B. 6e374ca829eaead5090f6cdd26c08017
  def set_public_id
    self.public_id = Digest::MD5.hexdigest(rand.to_s)
  end

  def save
    # hashed_path hat z. B. folgenden Inhalt
    # "/www/medias/6e/374"
    hashed_path =" HashedDirStructure.get_path_for_save("/www/medias", self.public_id)

    # absoluter Dateiname zum speichern
    # "/www/medias/6e/374/6e374ca829eaead5090f6cdd26c08017.jpg"
    filepath = "#{hashed_path}/#{self.public_id}.jpg"

    #...jetzt kann das speichern beginnen
  end
end

Die Verzeichnisstruktur sieht dann wie folgt aus.

/www/medias
          /6e
          /...
          /6e/374
          /6e/7c0
          /6e/...
          /6e/374/6e374ca829eaead5090f6cdd26c08017.jpg

Links:

• http://jxh.bingodisk.com/bingo/public/presentations/JHoffmanRailsConf-Berlin-Sept2007.pdf
• http://www.37signals.com/svn/archives2/id_partitioning.php