Tutorial Requirements

This tutorial requires the following technologies and resources:

Creating the Sample Database

Creating the Ruby on Rails Project

Configuring the Database Environment

1. Open Configuration > database.yml
2. Edit the database.yml by providing the password in the development configuration.

3. Save and close the database.yml file.

   Important Note: If your operating system's host file does not contain localhost, use 127.0.0.1 instead. Note also that with some systems, the database setting must be in lower case letters.

Creating the Model

Here you use the Rails Generator to create a model for the application. The RubyWebLog application requires a Post model for storing instances of blog posts.

1. In the Projects window, right-click the Models node, and choose Generate.

2. In the Rails Generator dialog box, type Post in the Arguments field and click OK.

   The Rails Generator creates a model named Post. The Output window lists that files that are created as part of the model generation:

   • app/models/post.rb. A file that holds the methods for the Post model. This file is also opened in the editing area.
   • test/unit/post_test.rb. A unit test for checking the Post model.
   • test/fixtures/posts.yml. A test fixture for populating the model.
   • db/migrate/migrate/001_create_posts.rb. A migration file for defining the initial structure of the database.

Migrating the Database

1. In the Output window, click the link for the 001_create_posts.rb file.

   The file opens to show the self.up method, which creates a table called posts, and the self.down method, which tears the posts table down.

2. Add the title column (shown in bold) to create_table in the self.up method as shown in the following figure:

   Code Sample 1: Code for 001_create_posts.rb

   class CreatePosts < ActiveRecord::Migration def self.up create_table :posts do |t| t.column "title", :string end end def self.down drop_table :posts end end

   
   
3. From the main menu, choose File > Save All.

4. In the Projects window, right-click the RubyWebLog node and choose Migrate Database > To Current Version.

   This action updates the the database to include the posts table. The Output window indicates when the migration is complete.

Creating a Controller

1. In the Projects window, right-click the Controllers node and choose Generate.

2. In the Rails Generator dialog box, type Blog in the Name field. Leave the Views field blank. Click OK.

   This action creates the file blog_controller.rb and opens the file in the editing area. A blog_controller.rb node is added under the Controllers node in the Projects window.

3. Edit blog_controller.rb by adding the following scaffolding code, which provides a simple CRUD application around the Post model.

   Code Sample 2: Code for blog_controller.rb

   class BlogController < ApplicationController scaffold :post end

Running the Application

1. Under the Configuration node, open routes.rb. Find the following line:

   # map.connect '', :controller => "welcome"
   	

2. Edit the line by removing the comment sign (#) and changing welcome to blog.

3. Expand the Public node, right-click index.html and choose Delete.

   index.html displays a default Welcome page, which is not what you want. By deleting index.html, Rails looks in routes.rb to figure out what page to display, which you set to the blog in the previous step.

4. Choose File > Save All.

5. Click the Run Main Project button in the toolbar.

   This action starts the WEBrick server, which is part of the Ruby on Rails framework, and launches the web browser. Following is the first page of the application.

   Figure 1: RubyWebLog Home Page

   
   

6. Click New post.

   Figure 2: Page for Creating a New Post

   
   

7. Enter a title and click Create.

   Following is a sample blog post.

   Figure 3: Successful Creation of Blog Post

   

Doing More: Adding Another Field

1. Right-click the Database Migrations node and choose Generate. In the Rails Generator dialog box, type AddBody in the Arguments field and click OK.

   The IDE creates and the versioned migration script 002_add_body.rb and opens the file in the editing area.

2. Modify 002_add_body.rb as follows:

   Code Sample 3: Code for 002_add_body.rb

   class AddBody < ActiveRecord::Migration def self.up add_column 'posts', 'body', :text end def self.down remove_column 'posts', :body end end

   
   This migration adds a body column to the posts table and removes it again, if you are backing out of the migration.
3. Choose File > Save All.
4. Right-click the RubyWebLog node and choose Migrate Database > To Current Version.

5. Return to the browser and click the New Post link to see how Ruby recognizes the new body field.

   Figure 4: New Post With Body Field

   

6. Create a few more blog entries. For example:

   Figure 5: More Blog Posts

   

Doing More: Making the List Look More Like a Blog

1. In the Projects window, right-click the Views node and choose Generate.
2. In the Rails Generator dialog box, choose scaffold from the Generate drop-down list.

3. Type Post in the Model Name field and Blog in the Controller Name field. Leave the Actions field blank. Select Overwrite to force the BlogController to be regenerated, and then click OK.

   The IDE creates a view for the Post model and lists the contents in the Output window.

4. Expand Views > blog and open list.rhtml, which is used to show the list of blog entries. Delete the <h1> and <table> tags and replace them with the following code:

   Code Sample 4: Code for list.rhtml

   <h1>The Ruby Blog</h1> <% @posts.each do |post| %> <h2><%= post.title %></h2> <p><%= post.body %></p> <small> <%= link_to 'Permalink', :action => 'show', :id => post %></small> <hr> <% end %>

   
   

   For each instance of a post action, this code produces a a title, body and Permalink, as shown in Figure 6.

5. Choose File > Save All and then refresh your browser to see the new interface for the Post model.

   Figure 6: New and Improved Model Interface

   

6. To display the blog with the most recent entry first, reverse the sort order by adding .reverse to the end of @posts in list.rhtml:

   	  <% @posts.reverse.each do |post| %>
   	  

   When you save the file and refresh your browser, the blog displays as shown in the following figure:

   Figure 7: Blog Posts in Reverse Order