This example assumes the following:

• wkhtmltopdf and wkhtmltoimage are already installed and accessible on in the PATH.
• You have an html page setup to display the record.
• You have created a pdf CSS file to help display the pdf, if you so choose.

  # config/initializers/mime_types.rb
  Mime::Type.register "application/pdf", :pdf
  Mime::Type.register "image/png", :png
 
  # app/controllers/items_controller.rb
  def show
    @item = Item.find(params[:id])
 
    respond_to do |format|
      format.html { }
      format.pdf {
        html = render :action => "show.html.erb" 
        kit  = PDFKit.new( html, :zoom => 0.75 )
        kit.stylesheets << File.join( RAILS_ROOT, "public", "stylesheets", "pdf.css" )
 
        send_data kit.to_pdf, :filename => "item.pdf", :type => 'application/pdf', :disposition => 'inline'
      }
      format.png {
        html = render :action => "show.html.erb", :layout => "application.html.erb"
 
        # I am nil'ing these options out because my version of wkhtmltoimage does
        # not support the scale options and I do not want to crop the image at all.
        snap = WebSnap.new(html, :format => 'png', :'scale-h' => nil, :'scale-w' => nil,
          :'crop-h' => nil, :'crop-w' => nil, :quality => 100, :'crop-x' => nil, :'crop-y' => nil)
 
        send_data snap.to_bytes, :filename => "item.png", :type => "image/png", :disposition => 'inline'
      }
    end

Now you should be able to access three distinct views, each producing a different result

  http://example.com/items/1 # => Generates an html page.
  http://example.com/items/1.pdf # => Generates a pdf of the html page.
  http://example.com/items/1.png # => Generates a png of the html page.

You could easily also add more image types by just created another block for each format, and
changing the :format to whatever one you would like.

skip_before_filter :login_required, :only => [:create], :if => Proc.new {|c| c.request.format.xml?}

My problem came when I was trying to create tests to verify that both html and xml requests did in fact produce the correct response. After many hours of messing around, I came up with a simple solution. First I skip the filters for every request, then I have another filter to re-enable them on anything but the xml request:

skip_before_filter :login_required, :only => [:create]
before_fiilter :only => [:create] do |c|
  c.send(:login_required) unless c.request.format.xml?
end

Voila!!! This allowed me to continue with my rails testing and browser and curl work appropriately. (I use curl to test the xml request).

def test_not_logged_in_normal_post
  post :create, :login => "test@test.com", :password => "test"
  assert_response :redirect
end
 
def test_not_logged_in_xml_post
  post :create, :format => 'xml', :login => "test@test.com", :password => "test"
  assert_response :success
end

Suppose you have the following classes:

class Client < ActiveRecord::Base
  has_many :employees
end
 
class Employee < ActiveRecord::Base
  belongs_to :client
 
  def full_name
    "#{first_name} #{last_name}"
  end
end

We want the controller to return a client with association employees and the full name in the database. Here is how we would go about doing that:

def show
  @client = Client.find(params[:id])
 
  respond_to do |format|
    format.json { render :json => @client.to_json(
      :include => {
        :employee => {
          :only => :email,
          :methods => [ :full_name ]
        }
      }
    ) }
  end
end

You will end up with the following data set:

{ client: { name: "Some client", employee: { email: "test@test.com", full_name: "John Doe" } } }

Forgive me if I messed up the json output…doing it from memory There are of course way easier uses for this too, but I just decided to spit out a more complex one.

<%= will_paginate @object, :params => { :custom_param => @custom_param_value } %>

Here are some additional custom params you can use:

Display options

• :previous_label — default: “<< Previous" (this parameter is called :prev_label in versions 2.3.2 and older!)
• :next_label — default: “Next >>”
• :page_links — when false, only previous/next links are rendered (default: true)
• :inner_window — how many links are shown around the current page (default: 4)
• :outer_window — how many links are around the first and the last page (default: 1)
• :separator — string separator for page HTML elements (default: single space)

HTML options

• :class — CSS class name for the generated DIV (default: “pagination”)
• :container — toggles rendering of the DIV container for pagination links, set to false only when you are rendering your own pagination markup (default: true)
• :id — HTML ID for the container (default: nil). Pass +true+ to have the ID automatically generated from the class name of objects in collection: for example, paginating ArticleComment models would yield an ID of “article_comments_pagination”.

Advanced options

• :param_name — parameter name for page number in URLs (default: :page)
• :params — additional parameters when generating pagination links (eg. :controller => “foo”, :action => nil)
• :renderer — class name, class or instance of a link renderer (default: WillPaginate::LinkRenderer)

str = "Somereallylongstring"
if str.length > 10
  puts str[0..7] + '...'
else
  puts str
end
# => "Somerea..."

This is the basic idea of what I wanted to do. I decide to make it cleaner and override the String class like so:

class String
  def lfill(len = self.length, fill = '.')
    tmp = self[0..(len|> - 3)] + '...' if self.length - 3 > len
    return tmp || self
  end
end
 
str = "Somereallylongstring"
puts str.lfill(10)
 
#=> "Somerea..."

Basically all it is doing is looking for other objects of the same class, that have some related value.

Git it here: http://github.com/freezzo/acts_as_similar/tree/master

Example 1
=========
Look for similar playlists, using the videos as what defines similarity.
This will look for all playlists that have a similar video as the playlist you are looking against.

class Playlist
  has_many :playlists_videos
  has_many :videos, :through => :playlists_videos
 
  acts_as_similar :videos
end

Example 2
=========
Look for similar playlists, using the title of the playlist as the similarity item.
This will look for all playlists that have a similar title as the playlist you are looking against.

class Playlist
  has_many :playlists_videos
  has_many :videos, :through => :playlists_videos
 
  acts_as_similar :field => :title
end

Example 3
=========
Look for similar playlists, using the video_id of the playlists_videos as the similarity item.
This will look for all playlists that have a similar video_id as the playlist you are looking against.

class Playlist
  has_many :playlists_videos
  has_many :videos, :through => :playlists_videos
 
  acts_as_similar :playlists_videos, :field => :video_id
end

Execute
=========

@playlist = Playlist.first
@playlist.similar

Note: This is a work in progress.

script/plugin install git://github.com/blythedunham/eload-select.git

Here are some ways to use the plug-in:

Employee.find :all,
    :select => 'addresses.city, address.state, employees.*',
    :include => :address

Employee.find :first,
    :select => 'now() as current_time, addresses.city, DATE(addresses.created_at) as addresses.created_at, employee.*',
    :include => :address

Employee.find :all,
    :select => 'addresses.city, employees.name, employees.start_date',
    :include => :address

Examples taken from:
http://www.snowgiraffe.com/tech/329/eager-loading-select-plugin-when-select-plays-nice-with-include/

In your config/environments/development.rb (or production.rb, or whatever.rb) do the following:

config.active_record.table_name_prefix = "whatever_"

You can also select any of the following options instead of table_name_prefix to configure active record globally. Here is the list:

ActiveRecord::Base includes a variety of configuration options:

* logger accepts a logger conforming to the interface of Log4r or the default Ruby 1.8.x Logger class, which is then passed on to any new database connections made. You can retrieve this logger by calling logger on either an ActiveRecord model class or an ActiveRecord model instance. Set to nil to disable logging.

* primary_key_prefix_type lets you adjust the naming for primary key columns. By default, Rails assumes that primary key columns are named id (and this configuration option doesn’t need to be set.) There are two other choices:
o :table_name would make the primary key for the Customer class customerid
o :table_name_with_underscore would make the primary key for the Customer class customer_id

* table_name_prefix lets you set a global string to be prepended to table names. If you set this to northwest_, then the Customer class will look for northwest_customers as its table. The default is an empty string.

* table_name_suffix lets you set a global string to be appended to table names. If you set this to _northwest, then the Customer class will look for customers_northwest as its table. The default is an empty string.

* pluralize_table_names specifies whether Rails will look for singular or plural table names in the database. If set to true (the default), then the Customer class will use the customers table. If set to false, then the Customers class will use the customer table.

* colorize_logging (true by default) specifies whether or not to use ANSI color codes when logging information from ActiveRecord.

* default_timezone determines whether to use Time.local (if set to :local) or Time.utc (if set to :utc) when pulling dates and times from the database. The default is :local.

* schema_format controls the format for dumping the database schema to a file. The options are :ruby (the default) for a database-independent version that depends on migrations, or :sql for a set of (potentially database-dependent) SQL statements.

* timestamped_migrations controls whether migrations are numbered with serial integers or with timestamps. The default is true, to use timestamps, which are preferred if there are multiple developers working on the same application.

* lock_optimistically controls whether ActiveRecord will use optimistic locking. By default this is true.