Overview

1. What are plugins in Rails?
2. Why use them?
3. Examples
   • Map Select Options
   • Map Select Options: REDUX
   • Findar
   • Acts as Authenticated
4. Beyond here..

What are plugins in Rails?

A Rails plugin is either an extension or a modification of the core framework. Plugins provide:

• a way for developers to share bleeding-edge ideas without hurting the stable code base
• a segmented architecture so that units of code can be fixed or updated on their own release schedule
• an outlet for the core developers so that they don't have to include every cool new feature under the sun версия для печати
• a general standard for reusable, distributable code within the framework

Why use them?

Organized, standardized, encapsulated

discover, download and manage your plugins with script/plugin

generate stub code in a standard format with script/generate plugin

update plugins from separate source repositories using svn:externals

Advice from others

Five reasons why your next Rails mod should be a plugin

Rails Views: Internal Plugins

folder_for :student do                                                                                                               
  tabs :general, :attendance, :surveys
  tab :report do
    # get report data
  end
end

Examples:

Map Select Options

Simple extension of Array using only init.rb

Map Select Options: REDUX

Simple extension of ActiveRecord::Base using only init.rb

Findar

Extending Rails and getting a little more dynamic

Acts as Authenticated

Perhaps not so much a plugin as it is a generator factory

Examples: Map Select Options

# init.rb
class Array
  def map_select_options(display = :name, value = :id)
    map { |x| [ x.send(display) , x.send(value) ] }
  end
end

# controller
@options = Model.find(
  :all, :select => 'name,id', :order => 'name'
).map_select_options

# view
select :object, :attribute, @options

Examples: Map Select Options: REDUX

# init.rb
class << ActiveRecord::Base
  def map_select_options(display = :name, value = :id, o = {})
    o = {:select => "#{display},#{value}",
         :order => display}.update(o)
    find(:all, o).map { |x| [ x.send(display) , x.send(value) ] }    
  end
end

# controller
@options = Model.map_select_options
# view
select :object, :attribute, @options

Examples: Findar

module Findar
  def self.included(receiver)
    super
    constants.each do |c|
      receiver.extend eval(c) if eval(c).is_a? Module
    end
  end
  
  module MiscFinders
    def find_random(o = {})
      o[:order] = 'rand()'
      find :first, o
    end
    alias_method :random, :find_random
  end
end

Examples: Acts as Authenticated

Author: Rick Olson

acts_as_authenticated is not really a typical plugin that modifies Rails. It's more of a generator for the authentication methods. I went with a generator because it's designed as a basic starting point that will probably (and should be) modified to fit your app's exact needs. .

• generators
  • authenticated
    • templates
    • authenticated_generator.rb
    • USAGE
  • authenticated_mailer
  • authenticated_migration
• CHANGELOG
• init.rb
• install.rb
• README

Beyond here..

The Complete Guide to Rails Plugins

In what is currently a two-part series, Geoffrey Grossenbach covers a plethora of plugin related topics including basic and more advanced integration of tests in part two.

Plugins page on wiki.rubyonrails.com

Provides information for the unitiated as well as functioning as the 'official' Rails plugin repository. If you're looking for example code to inspire and teach, this is a good place to start.

HowTosPlugins page on wiki.rubyonrails.com

Tutorials about general 'types' of plugins like "Acts as.." or plugins which modify the core framework

api.rubyonrails.com