TOTD #28: Getting Started with Rails 2.0 Scaffold

Rails
2.0 changes the way href="http://wiki.rubyonrails.org/rails/pages/Scaffold">Scaffold
works. This blog walks you through the steps to create a simple CRUD
application using Scaffold in Rails 2.0.

1. Download & Install href="http://dist.codehaus.org/jruby/">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:
   
   
   
   border="0" cellpadding="2" cellspacing="2">
   

   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>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exists&nbsp;
   app/models/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exists&nbsp;
   app/controllers/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exists&nbsp;
   app/helpers/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/views/books<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exists&nbsp;
   app/views/layouts/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exists&nbsp;
   test/functional/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exists&nbsp;
   test/unit/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/views/books/index.html.erb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/views/books/show.html.erb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/views/books/new.html.erb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/views/books/edit.html.erb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/views/layouts/books.html.erb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   public/stylesheets/scaffold.css<br>
   &nbsp; dependency&nbsp; model<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   exists&nbsp;&nbsp;&nbsp; app/models/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   exists&nbsp;&nbsp;&nbsp; test/unit/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   exists&nbsp;&nbsp;&nbsp; test/fixtures/<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   create&nbsp;&nbsp;&nbsp; app/models/book.rb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   create&nbsp;&nbsp;&nbsp; test/unit/book_test.rb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   create&nbsp;&nbsp;&nbsp; test/fixtures/books.yml<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   create&nbsp;&nbsp;&nbsp; db/migrate<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   create&nbsp;&nbsp;&nbsp; db/migrate/001_create_books.rb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/controllers/books_controller.rb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   test/functional/books_controller_test.rb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; create&nbsp;
   app/helpers/books_helper.rb<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; route&nbsp;
   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 &lt; ActiveRecord::Migration<br>
   &nbsp; def self.up<br>
   &nbsp;&nbsp;&nbsp; create_table :books do |t|<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.string :title<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.string :author<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.string :isbn<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.text :description<br>
       <br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.timestamps<br>
   &nbsp;&nbsp;&nbsp; end<br>
   &nbsp; end<br>
       <br>
   &nbsp; def self.down<br>
   &nbsp;&nbsp;&nbsp; drop_table :books<br>
   &nbsp; 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 "http://localhost:3000/books"
   and looks like:
   
   
   
   alt="Rails2 CRUD Blank Page" title="Rails2 CRUD Blank Page"
   src="http://blogs.sun.com/arungupta/resource/ror/rails2-crud-blank-page.png">
   
9. Click on "New book" to see a page as shown below (with
   values entered):
   
   
   
   alt="Rails2 CRUD New Entry" title="Rails2 CRUD New Entry"
   src="http://blogs.sun.com/arungupta/resource/ror/rails2-crud-new-entry.png">
   
   Click on Create button. After 2 entries
   have been entered, it looks like as shown below:
   
   
   
   alt="Rails 2 CRUD Multiple Entries"
   title="Rails 2 CRUD Multiple Entries"
   src="http://blogs.sun.com/arungupta/resource/ror/rails2-crud-multiple-entries.png">

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



You can also deploy this application easily on href="http://rubyforge.org/projects/glassfishgem/">GlassFish
v3 gem. Just follow the instructions href="http://blogs.sun.com/arungupta/entry/glassfish_v3_gem_0_1">here
and enjoy!



I'll post a follow up blog where this is much more simplifed using href="http://bits.netbeans.org/netbeans/trunk/nightly/latest/">NetBeans
6.1 builds where JRuby 1.1 and Rails 2.0.2 are already
integrated.



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