TOTD #28: Getting Started with Rails 2.0 Scaffold

Rails 2.0 changes the way Scaffold works. This blog walks you through the steps to create a simple CRUD application using Scaffold in Rails 2.0.

1. Download & Install JRuby 1.1 RC2.

2. Install Rails using the following command:

   jruby -S gem install rails

3. Create a new Rails app using the following command:

   cd samples; mkdir rails; cd rails<br>
   jruby -S rails books -d mysql

4. Start MySQL server in a different shell using the following command:

   sudo /usr/local/mysql/bin/mysqld_safe --console

5. Creat the database using the following command:

   cd books<br>
   jruby -S rake db:create<br>
       

   This creates the database defined by RAILS_ENV (Development is default). Here are some other new database-related commands:

   db:create:all	Create all the databases (_Development, _Test, _Production)
   db:drop	Drops your database
   db:reset	Drop and Re-create your database, including migrations

6. Generate a scaffold using the following command:

   <br>
   jruby script/generate scaffold book title:string author:string
   isbn:string description:text

   The output of the command looks like:

   <br>
         exists 
   app/models/<br>
         exists 
   app/controllers/<br>
         exists 
   app/helpers/<br>
         create 
   app/views/books<br>
         exists 
   app/views/layouts/<br>
         exists 
   test/functional/<br>
         exists 
   test/unit/<br>
         create 
   app/views/books/index.html.erb<br>
         create 
   app/views/books/show.html.erb<br>
         create 
   app/views/books/new.html.erb<br>
         create 
   app/views/books/edit.html.erb<br>
         create 
   app/views/layouts/books.html.erb<br>
         create 
   public/stylesheets/scaffold.css<br>
     dependency  model<br>
        
   exists    app/models/<br>
        
   exists    test/unit/<br>
        
   exists    test/fixtures/<br>
        
   create    app/models/book.rb<br>
        
   create    test/unit/book_test.rb<br>
        
   create    test/fixtures/books.yml<br>
        
   create    db/migrate<br>
        
   create    db/migrate/001_create_books.rb<br>
         create 
   app/controllers/books_controller.rb<br>
         create 
   test/functional/books_controller_test.rb<br>
         create 
   app/helpers/books_helper.rb<br>
         route 
   map.resources :books

   There is no need to create the model explicitly as was the case in previous version of Rails. This creates the “db/migrate/001_create_books.rb” migration which looks like:

   class CreateBooks < ActiveRecord::Migration<br>
     def self.up<br>
       create_table :books do |t|<br>
         t.string :title<br>
         t.string :author<br>
         t.string :isbn<br>
         t.text :description<br>
       <br>
         t.timestamps<br>
       end<br>
     end<br>
       <br>
     def self.down<br>
       drop_table :books<br>
     end<br>
   end

7. Create the database tables using the following command:

   jruby -S rake db:migrate

8. Deploy the application on WEBrick using the following command:

   <br>
   jruby script/server

   The application is now available at “<a href="https://localhost:3000/books">https://localhost:3000/books</a>” and looks like:

   

9. Click on “New book” to see a page as shown below (with values entered):

   

   Click on Create button. After 2 entries have been entered, it looks like as shown below:

   

That’s it, you’ve created  a simple Rails 2.0 CRUD application.

You can also deploy this application easily on GlassFish v3 gem. Just follow the instructions here and enjoy!

I’ll post a follow up blog where this is much more simplifed using NetBeans 6.1 builds where JRuby 1.1 and Rails 2.0.2 are already integrated.

Technorati: totd ruby jruby rubyonrails rails2 scaffold crud netbeans glassfish v3 gem