Useful Rails Plugins

Rails Plugins Navjeet Chabbewal Javaah Enterprises [email_address]

Agenda

Brief Introduction to Rails Plugins

Installation, removal, install directory

Discuss usage of some useful plugins

tabnav

acts_as_authenticated

file_column (file upload)

acts_as_state_machine

So What are Rails Plugins

Self contained libraries made specifically for Rails

Reuse code, yours or somebody else’s

Installation

Installed per Rails app

First run ./script/plugin discover to add new plugin repositories (on windows => ruby script/plugin discover)

./script/plugin install plugin_name

./script/plugin install svn://svn.seesaw.it/tabnav

./script/plugin install -x svn://svn.seesaw.it/tabnav

Installation Contd.

Installs in vendor/plugins sub folder of Rails app root directory

Remove Plugin

Remove folder under vendor/plugins

./script/plugin remove tabnav

Unlink with " svn propdel svn:externals vendor/plugins "

Tabnav

Provides tabbed navigation

./script/plugin install svn://svn.seesaw.it/tabnav

./script/generate tabnav Main

Generated two files

app/models/main_tabnav.rb

app/views/tabnav/_main_tabnav.rhtml

Tabnav Contd.

app/models/main_tabnav.rb

Modify this file to add tabs

class MainTabnav < Tabnav::Base add_tab do named 'Dashboard' links_to :controller => 'dashboard' end

add_tab do named 'My Projects' # name assigned in the tab titled 'Summary of project status' links_to :controller => 'project', :action => 'list' end add_tab do named 'Admin' links_to :controller => 'admin' show_if "params[:admin] == true" end

end

Tabnav Contd.

app/views/tabnav/_main_tabnav.rhtml

partial that generates tabs defined in main_tabnav.rb

also has default stylesheet code

Add this to layout/view

<%= start_tabnav :main %>

<%= @content_for_layout %>

<%= end_tabnav %>

Tabnav Contd.

Tab screenshot - http://localhost:3001/dashboard

Tabnav contd.

The titled method gives your tabs a html ‘title’ attribute so you can have tooltips over your tab link.

The links_to method creates the tab’s link. You can use the same options as the usual ActionView’s url_for .

You can conditionally choose to show or not show a tab given a certain condition with the show_if method.

acts_as_authenticated

Simple authentication generator plugin Quote from plugin website "The whole idea behind the plugin is that you generate the code once and add in your application specific authentication actions. This makes no attempt to decide how your application's authorizing works."

AAA contd.

./script/generate authenticated user account

creates model user and it's migration (which can be skipped)

creates account controller that has methods like login, signup, logout etc.

include AuthenticatedSystem in application.rb

Add the line before_filter :login_required in every controller you want protected.

AAA Contd.

Extend the basic plugin

To set up email notifications refer to wiki (http://technoweenie.stikipad.com/plugins/show/Mailer+Setup).

Can be used with authorization plugin by Bill Katz

permit “railists or wanna_be_railist”, :except => :public

file_column

Quote from plugin website " This library makes handling of uploaded files in Ruby on Rails as easy as it should be. It helps you to not repeat yourself and write the same file handling code all over the place while providing you with nice features like keeping uploads during form redisplays , nice looking URLs for your uploaded files and easy integration with RMagick to resize uploaded images and create thumb-nails. Files are stored in the filesystem and the filename in the database. "

file_plugin contd.

/script/plugin install http://opensvn.csie.org/rails_file_column/ plugins/file_column/trunk

rename trunk to file_column

create migration for <products> table

file_column contd.

class CreateProducts < ActiveRecord::Migration def self.up create_table :products do |t| t.column :name, :string t.column :price, :float t.column :image, :string # stores uploaded file name end end def self.down drop_table :products end end

file_column contd.

Created a scaffold for <product> model

Just make the "image" column ready for handling uploaded files

class Product < ActiveRecord::Base file_column :image end

Update view (e.g. add product page)

<%= file_column_field "product", "image" %>

file_column contd.

display uploaded images in your view (e.g. in view product page)

<%= image_tag url_for_file_column("product", "image") %>

image from http://www.cafepress.com/rubyonrailsshop

acts_as_state_machine

install from http://elitists.textdriven.com/svn/plugins/acts_as_state_machine/trunk

rename trunk to acts_as_state_machine

Create a model < Project> and table < projects>

AASM contd.

Migration script example

class CreateProjects < ActiveRecord::Migration def self.up create_table :projects do |t| t.column :name, :string t.column :state, :string end end def self.down drop_table :projects end

end

AASM contd.

Update model <Project>

class Project < ActiveRecord::Base acts_as_state_machine :initial => :created

# can specify :column => 'column_name' default column name is state # specify different states state :created state :estimating state :bid state :won, :enter => Proc.new {|project| Mailer.spread_the_good_news(project)} state :executing # specify events that change states event :estimate do transitions :to => :estimating, :from => :created end event :submit_bid do transitions :to => :bid, :from => :estimating end end

Resources