Insider Scoop From the Tutorial Divas

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Today

Tutorial Requirements

This tutorial requires the following technologies and resources.

MySQL database server.
NetBeans IDE 6.1 development build with Ruby support. A beta release is available from here.

Creating the Ruby on Rails Project

You begin by creating a Ruby on Rails project. By default, the application is created in a directory structure that conforms to the Ruby on Rails project conventions for applications.

In the NetBeans IDE, choose File > New Project.
Select Ruby from the Categories list and Ruby on Rails Application from the Projects list. Click Next.
Type rubyweblog in the Project Name text box. Accept all the other default settings on this page.
Click Next.
Select Specify Database Information Directly.
Leave the Database Name text box blank, the IDE will create default development, test, and production database names based on the project name.
Type root in the User Name text box.
If the root user requires a password, type the password in the Password text box.
Click Finish to create the new project.
The IDE creates the project directory with the same name as your project and opens the database.yml file in the editing area. Notice that the default database name for the development configuration is rubyweblog_development.
Click the small x button in the database.yml tab to close the file.

Creating the Scaffold

This weblog application is built around the Post model, which stores instances of blog posts. Here you use the Rails scaffold generator to create the model and its controller, as well as the index (list), show, new, and edit views.

The generator also creates a migration file for creating the model's database table, and creates unit test and fixture stubs for writing model tests. Last, the generator adds the map.resources :posts declaration to the routes.rb file to create named routes that are mapped to the URL paths for the controller actions.

In the Projects window, right-click the rubyweblog project node and choose Generate.
In the Rails Generator dialog box, select scaffold from the Generate drop-down list. Make sure that you select scaffold, and not use the default selected value (controller).
Type Post in the Model Name text box.
Type title:string in the Attribute Pairs text box, as shown in the following figure, and click OK.

The Output window lists the files that the scaffold generator creates and updates.

Creating the Database

In this section, you use a Rake task to create the rubyweblog_development database. Then you use the 001_create_posts.rb migration file to add the Posts table to the database.

In the Projects window, right-click the rubyweblog project node, and choose Run Rake Task > db > create.

Rake creates the MySQL database for the development configuration in the database.yml file.
In the Projects window, expand Database Migrations and expand migrate.

Double-click the 001_create_posts.rb node to open the file in the editing area.

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, as shown in the following code sample.

Code Sample 1: Code for 001_create_posts.rb

class CreatePosts < ActiveRecord::Migration
  def self.up
    create_table :posts do |t|
      t.string :title

      t.timestamps
    end
  end

  def self.down
    drop_table :posts
  end
end

Note that the create_table method adds an id column by default, and that the timestamps method adds the created_at and updated_at columns to the database table.

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.

Running the Application

Now test the application.

In the Projects window, expand the Configuration node and double-click routes.rb to open it in the editor. Find the comment:
```
# map.root :controller => "welcome"
	
```
Add the following line under the comment.
```
map.root :controller => "posts"
	
```
In the Projects window, expand the Public node, right-click index.html and choose Delete.

The index.html page 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.
Choose File > Save All from the main menu.
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.

If you are using a server other than WEBrick, you might need to enter http://localhost:3000 in the browser's address text box and press Enter.
Click the New post link to display the second page of the application.
Enter a title and click Create.
Click the Back link to return to the list of posts.

Doing More: Adding Another Table Column

Here you add a body column to posts table to hold the text for each blog entry.

Right-click the Database Migrations node and choose Generate. In the Rails Generator dialog box, type AddBodyToPost body:text in the Arguments text box and click OK.

The IDE creates the versioned migration script 002_add_body_to_post.rb. The file opens to show the self.up method, which adds a body column, and the self.down method, which removes the column, as shown in the following code sample. Notice how the generated code extracted the table name from the first argument AddBodyToPost.

Code Sample 2: Code for 002_add_body_to_post.rb

class AddBodyToPost < ActiveRecord::Migration
  def self.up
    add_column :posts, :body, :text
  end

  def self.down
    remove_column :posts, :body
  end
end

Right-click the rubyweblog node and choose Migrate Database > To Current Version.
Alternatively, right-click in the source file and choose Run File from the pop-up menu.
In the Projects window, expand Views and expand posts.
Double-click edit.html.erb to open the file in the editing area.

Add the statements shown in bold in the following code sample.

Alternatively, place the cursor before the <p> tag for the Title and drag the mouse to the position after the paragraph's ending </p> tag, then press Ctrl+Shift+Down Arrow to duplicate the lines. Replace Title with Body and replace f.text_field :title with f.text_area :body.

Code Sample 3: Adding the Body to the Edit View

<h1>Editing post</h1>

<%= error_messages_for :post %>

<% form_for(@post) do |f| %>
  <p>
    <b>Title</b><br />
    <%= f.text_field :title %>
  </p>

  <p>
    <b>Body</b><br />
    <%= f.text_area :body %>
  </p>

  <p>
    <%= f.submit "Update" %>
  </p>
<% end %>

<%= link_to 'Show', @post %> |
<%= link_to 'Back', posts_path %>

Double-click new.html.erb to open the file in the editing area.

Add the statements shown in bold in the following code sample. Alternatively, use Ctrl+Shift+Down Arrow to duplicate the Title paragraph and edit the duplicated code as described in Step 5.

Code Sample 4: Adding the Body to the New View

<h1>New post</h1>

<%= error_messages_for :post %>

<% form_for(@post) do |f| %>
  <p>
    <b>Title</b><br />
    <%= f.text_field :title %>
  </p>

  <p>
    <b>Body</b><br />
    <%= f.text_area :body %>
  </p>
	
  <p>
    <%= f.submit "Create" %>
  </p>
<% end %>

<%= link_to 'Back', posts_path %>

Double-click show.html.erb to open the file in the editing area.

Add the statements shown in bold in the following code sample. Alternatively, use Ctrl+Shift+Down Arrow to duplicate the Title paragraph as described in Step 5, change Title: to Body:, and change @post.title to @post.body.

Code Sample 5: Adding the Body to the Show View

<p>
  <b>Title:</b>
  <%=h @post.title %>
</p>

<p>
  <b>Body:</b>
  <%=h @post.body %>
</p>

<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>

Choose File > Save All.
Return to the browser and click the New Post link to see how Ruby recognizes the new body column.
Create a few more blog entries.

Doing More: Validating Input

Here, you add code to the Post class to ensure that the users provide values for both the title and the body fields.

In the Projects window, expand the Models node and double-click post.rb to open the file in the editor.
Open up a line inside the Class definition, type vp, then press Tab.
The IDE replaces the vp trigger with the following code template.
```
validates_presence_of :attribute
```
Type title, :body. The code should look like the following statement.
```
validates_presence_of :title, :body
```
Run the application, click New Post, and click Create.
The application now reports that the title and body cannot be blank.

Doing More: Making the List Look More Like a Blog

Expand Views > posts and open index.html.erb, which is used to show the list of blog entries. Delete the <h1> and <table> tags and replace them with the following code that is shown in bold.

Code Sample 6: Code for index.html.erb

<h1>The Ruby Blog</h1>

<% @posts.each do |post|  %>
  <h2><%=h post.title %></h2>
  <p><%=h post.body %></p>
  <small><%= link_to 'Permalink', post %></small>
  <hr>
<% end %>

<br />

<%= link_to 'New post', new_post_path %>

For each instance of a post action, this code produces a title, body, and Permalink.

Notice that the second parameter for link_to is post. You might remember that when you generated the scaffold, the generator added a map.resources :posts declaration to the routes.rb. The resources method generates named routes for the Post model, one of which is post. The post named route produces the same result as passing :action => 'show', :id => post to the link_to method. The post id is passed in the URL. When you click the Permalink link, look at the URL in the address bar. You should see a URL similar to http://localhost:3000/posts/1.

To see all the named routes for a project, right-click the rubyweblog project node and choose Run Rake Task > routes. The Output window shows the route list. The first column shows the named route, the second and third columns show the HTTP verb and URL that are passed in the request, and the last column shows the controller and action that will be called. To learn more about using named routes see the Rails API for the ActionController:Resources class.

Save the changes and run the application to see the new interface for the Post model.
To display the blog with the most recent entry first, edit the code that you just added to reverse the sort order by adding a call to the .reverse method, as shown below.
```
<% @posts.reverse.each do |post| %>
	  
```
Save the file and refresh your browser to see the list displayed in reverse order.

Posted at 01:41PM Feb 29, 2008 in Ruby | http://blogs.sun.com/divas/entry/netbeans_6_1_draft_creating | Permalink | Comments[7]

Tuesday Jan 15, 2008

Creating a Rails 2.0 Ruby Weblog in 10 Minutes

Note: On 2/25/08, I updated Code Sample 3 to take advantage the REST URLs and Path methods that the map.resources entity in the routes.rb generates. I also modified Step 3 in the last Doing More section to match the modified code.

Our Ruby weblog tutorial series for NetBeans IDE 6.0 is written for Rails 1.2.5 and uses the ActionController scaffold method. The Rails 2.0 framework dropped this method, so the tutorials do not work if you have updated to Rails 2.0.

We are now learning about the 2.0 changes so that we can produce updated tutorials. In the meantime, here is a quick draft of how to do the first weblog tutorial, Creating a Ruby Weblog in 10 Minutes, using the Rails 2.0 framework and the NetBeans 6.0 IDE. We are still learning about the new Rails 2.0 features, so there will probably be many changes to come. Please consider this a temporary document.

Currently, this tutorial assumes that you are using a native Ruby interpreter, and have updated to Rails 2.0 (I believe you need to update RubyGems as well). There are many flavors of Ruby, one of which can be download from ww2.ruby-lang.org. To learn how to set up the IDE to use a native Ruby interpreter, see Installing and Configuring Ruby Support.

Note: This tutorial uses the MySQL database server. See Installing and Configuring Ruby Support for information about using a MySQL database server in a Ruby application that is built using the NetBeans 6.0 IDE.

Creating the Ruby on Rails Project

You begin by creating a Ruby on Rails project. By default, the application is created in a directory structure that conforms to the Ruby on Rails project conventions for applications.

In the NetBeans IDE, choose File > New Project.
Select Ruby in the Categories field and Ruby on Rails Application in the Projects field. Click Next.

Note: The first time that you create a Ruby project in the IDE, the IDE checks if you have any other Ruby installations in addition to the bundled JRuby software. If you do, the IDE displays a dialog box asking you to select which software to use. Choose the native Ruby interpreter.
Type rubyweblog in the Project Name field. Accept all the other default settings.
Click Finish to create the new project.

The IDE creates the project directory with the same name as your project.

Configuring the Database Environment

The next step is to edit the file database.yml, which is already configured to use the MySQL adapter and the development database. You do not need to do any configuration unless the root user requires a password.

In the editing area, edit the database.yml by providing the password in the development configuration.
Save and close the database.yml file.

Note: If your operating system's host file does not contain localhost, use 127.0.0.1 instead.
In the Projects window, right-click the rubyweblog project node, and choose Run Rake Task > db > create.
Rake creates the MySQL database for the development configuration.

Creating the Scaffold

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

In the Projects window, right-click the rubyweblog project node and choose Generate.
In the Rails Generator dialog box, choose scaffold from the Generate drop-down list.
Type Post title:string in the Model Name field and click OK (Controller Name and Actions not valid arguments in Rails 2.0).

The Rails Generator creates a model named Post, creates a migration file, and adds the controller and views for listing, creating, updating, and deleting posts. In addition, Rake edits the routes.rb file to map Post as a resource. The Output window lists the files that are created as part of the model generation.

Migrating the Database

The file that you work with next is the migration file, 001_create_posts.rb.

In the Output window, click the link for the db/migrate/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, as shown in the following code sample:

Code Sample 1: Code for 001_create_posts.rb

class CreatePosts < ActiveRecord::Migration
  def self.up
    create_table :posts do |t|
      t.string :title

      t.timestamps
    end
  end

  def self.down
    drop_table :posts
  end
end

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.
Note that Rails 2.0 provides some new db Rake tasks, such as create (which you used earlier), drop, reset, rollback, and version.

Running the Application

Now test the application.

In the Projects window, expand the Configuration node and double-click routes.rb to open it in the editor. Find the comment:
```
# map.root :controller => "welcome"
	
```
Add the following line under the comment:
```
map.root :controller => "posts"
	
```
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.
Choose File > Save All.
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.

If you are using a server other than WEBrick, you might need to enter http://localhost:3000 in the browser's address text box and press Enter.
Click the New post link to display the second page of the application.
Enter a title and click Create.

Doing More: Adding Another Field

Here you add another field so that, in addition to the Title field, the posts table includes a Body column for providing the text of the blog.

Right-click the Database Migrations node and choose Generate. In the Rails Generator dialog box, type AddBodyToPost body:text in the Arguments field and click OK.

Code Sample 2: Code for 002_add_body_to_post.rb

class AddBodyToPost < ActiveRecord::Migration
  def self.up
    add_column :posts, :body, :text
  end

  def self.down
    remove_column :posts, :body
  end
end

Choose File > Save All.
Right-click the rubyweblog node and choose Migrate Database > To Current Version.
Alternatively, right-click in the source file and choose Run File from the pop-up menu.
Typically, you would now edit the views to add the new field. For this tutorial, you will simply regenerate the scaffold. In the Projects window, right-click the rubyweblog project node and choose Generate.
In the Rails Generator dialog box, choose scaffold from the Generate drop-down list.
Type Post title:string body:text --skip-migration in the Model Name field.
Select the Overwrite radio button.
Click OK.
Return to the browser and click the New Post link to see how Ruby recognizes the new body field.
Create a few more blog entries.

Doing More: Validating Input

Here, you add code to the Post class to ensure that the users provide values for both the title and the body fields.

In the Projects window, expand the Models node and double-click post.rb to open the file in the editor.
Open up a line inside the Class definition, type vp, then press Tab.
The IDE replaces the vp trigger with the following code template:
```
validates_presence_of :attribute
```
Type title, :body. The code should look like the following statement:
```
validates_presence_of :title, :body
```
Run the application, click New Post, and click Create.
The application now reports that the title and body cannot be blank.

Doing More: Making the List Look More Like a Blog

Expand Views > posts and open index.html.erb, which is used to show the list of blog entries. Delete the <h1> and <table> tags and replace them with the following code that is shown in bold:

Code Sample 3: Code for index.html.erb

<h1>The Ruby Blog</h1>

<% for post in @posts %>
  <h2><%=h post.title %></h2>
  <p><%=h post.body %></p>
  <small><%= link_to 'Permalink', post %></small>
  <hr>
<% end %>

<br />

<%= link_to 'New post', new_post_path %>

For each instance of a post action, this code produces a title, body, and Permalink.

Run the application to see the new interface for the Post model.
To display the blog with the most recent entry first, reverse the sort order by adding .reverse to the end of @posts in index.html.erb:
```
	  <% for post in @posts.reverse %>
	  
```
Save the file and refresh your browser to see the list displayed in reverse order.

Posted at 12:06PM Jan 15, 2008 in Ruby | http://blogs.sun.com/divas/entry/creating_a_rails_2_0 | Permalink | Comments[24]

Thursday Jan 03, 2008

Adding a Popup Window to a NetBeans 6.0 Visual Web Page

Here is a mini-tutorial for creating a Popup window for the user to lookup values. One scenario that you might use this for is when the page visitor needs more information then can be displayed in a drop-down list.

This is a rewrite of a previous blog entry that was written for the Sun Java Studio Creator IDE. I have modified the steps so that it works for the NetBeans 6.0 IDE.

Create a web application project with the Visual Web JavaServer Faces framework.
Add a page named Popup.
Add a Table component to the page.
Drag VIR > Tables > State from the Services window and drop it on the table.
Right-click the Table component and choose Table Layout from the pop-up menu.
In the column for the STATE.STATEID database field, set the Component Type to Hyperlink, and click OK.
Select the Hyperlink component so that its properties appear in the Properties window.
Set the value for the onClick property to doSave('#{currentRow.value['STATE.STATEID']}')

(I got the value to pass to doSave() from the Value Expression in the Table Layout dialog).
Drag a Script component from the Advanced section of the Palette and drop it on the page.
Click JSP in the editing toolbar to view the JavaServer Pages script.

In the JSP page, change the <webuijsf:script> tag as shown below.

<webuijsf:script binding="#{Popup.script1}" id="script1">
<![CDATA[
function doSave(val) {
 window.opener.setVal(val);
 window.close();
}]]>
</webuijsf:script>

The Popup page is now ready for use by another page.

Create a new page called Form1. Make it be the start page.
Drag a Text Field component and drop it on the page. In the Properties window, make sure the id is set to textField1.
Drop a Hyperlink component on the page, just above the text field, and set the text property to State Code.
Set the url property to /faces/Popup.jsp.
Set the onClick property to doPopup('form1:textField1_field')

Note: Here you are passing the id of the field to fill with the selected value. Determining the id can be tricky. To determine what to use for the id, run the application, and use a tool such as Firebug to inspect the DOM.
Click the ... button for the target property to open the target property editor.
In the property editor, click New and set both the Display and Value to popup. Click OK and click OK again.

Later you add script to open a window named popup, and this setting causes the Popup.jsp page to display in that window.
If the target property value is still blank, select popup from the value from the combobox for that property.
Drag a Script component from the Advanced section of the Palette and drop it on the page.
Click JSP in the editing toolbar to view the JavaServer Pages script.

In the JSP page, change the <webuijsf:script> tag as shown below.

<webuijsf:script binding="#{Form1.script1}" id="script1">
<![CDATA[
function doPopup(destination) {
 popup = window.open("", "popup",
 "height=300,width=200,toolbar=no, menubar=no,scrollbars=yes");
 destinationElement=document.getElementById(destination);
 popup.focus();
}

function setVal(val){
 destinationElement.value=val;
}]]></webuijsf:script>

Run the project. Click State Code to open the popup window. Click a state code to select the code, close the popup window, and populate the text field.

Posted at 11:49AM Jan 03, 2008 in NetBeans Visual Web Pack | http://blogs.sun.com/divas/entry/adding_a_popup_window_to1 | Permalink | Comments[13]

Friday Dec 14, 2007

Five-Minute Ruby on Rails jMaki Tutorial

If you have installed the NetBeans IDE support for Ruby and you are interested in integrating jMaki in your Ruby on Rails projects, here is a five-minute tutorial that will get you started. In this tutorial, you add a Yahoo data table to a Ruby on Rails view. (If you have not yet installed the NetBeans IDE 6.0 or if you need to add Ruby support to your NetBeans IDE, learn how to here.)

If you haven't installed the jMaki plugin for the NetBeans IDE, it takes just a minute. Select Tools > Plugins from the main menu, select jMaki Ajax Support, click Install and follow the instructions.
Follow the steps in the "Working With Ruby on Rails Files" section in the Getting Started With Ruby and Rails. This should take just a few minutes as no database is involved. Finish all the steps up to but not including the "Practicing What You Have Learned" subsection. It is important that you add the routing code (Code Sample 10) to the routes.rb file and delete the Public > index.html file.

Note: If you already have done these sections, but added the jMaki plugin after you created the project, you need to create a new project in order to have jMaki included.
Edit the Views > item > index.rhtml file.
Remove the <table> including the nested <tr> and <td> tags. You will replace this HTML table with the Yahoo Data Table.
Choose Window > Palette from the main menu to view the Palette window.
Expand the jMaki Yahoo section in the Palette, then drag and drop the Data Table onto the index.rhtml.

Replace the jmaki_widget tag with the following code:

<%= jmaki_widget 'yahoo.dataTable',
:value =>
{:columns => [
     { :label => 'Id', :id => 'id'},
     { :label =>'Type', :id => 'type'},
     { :label => 'Price', :id => 'price'},
     ],
  :rows => @items
  }
-%>

Click the small x button in the bottom right corner of the IDE to stop the WEBrick server.
Click the Run Main Project button and the browser should display a nice Yahoo table that contains the item data.

Posted at 04:01PM Dec 14, 2007 in AJAX | http://blogs.sun.com/divas/entry/five_minute_ruby_jmaki_tutorial | Permalink | Comments[0]

Tuesday Dec 04, 2007

How Do You Ruby?

During your daily use of the NetBeans Ruby support, you are constantly figuring out how to best use the language and the IDE to help you get your job done. Hopefully, the tutorials and articles help you towards your goals, but one size does not fit all. You all have diverse perspectives of the product as you implement your different use cases and scenarios. In addition, you bring with you different sets of habits, mental models, processes, and standards.

As you work with the product, you gain valuable nuggets of information that would be of benefit to others who run into the same situations. The NetBeans Ruby community wiki provides the means to share that knowledge.

You might think that you have to be a subject matter expert before you can contribute, but that is far from true. Often, people who are new to using the NetBeans Ruby support are the perfect teachers for other beginners. You can understand and emphasize with them, and you are probably encountering the same bumps, hurdles, and misunderstandings. Or maybe you are just one step ahead and can help others from making the same mistakes. Also, the act of writing might make your own understanding all that more concrete.

There are many ways in which you can be involved in the NetBeans Ruby community.

Users Alias. The users@ruby.netbeans.org email alias is a quick and easy way ask questions and help out others. An added advantage is that the developers are listening and many improvements have been made to the product because people took the time to write their issues and wishes. Often times, during the act of describing your problem concisely, you get the big Aha! that makes the answer obvious. In that case, since you have already written up the problem, you might as well share your problem and solution with the community.
FAQs. The FAQ is composed of easy to create and edit wiki pages. The users alias is a good place to look up solutions, but even better is when someone takes the time to summarize a long thread from the users alias into one page of essential information. Another good use for FAQs is to share gotchas and tips.
Blogs, Tutorials, and Articles. If you blog about NetBeans Ruby support, notify the users alias so we can link to you. If you want to write a tutorial or article, get in touch with the NetBeans Community Docs Contribution Coordinator Amit Kumar Saha (See Community Docs for instructions). Also let us know, so we can link to your doc from the Ruby Documentation wiki page. We will also be glad to help you with reviews and such.
Submit Code. The Ruby Participation wiki page tells how to join the development effort. The Ruby Code Ideas wiki page lists possible projects to work on -- both large and small. Two other ways to contribute are to submit Ruby hints and quick fixes (see Writing New Ruby Hints) and provide suggestions for Ruby code templates.

So, how do you Ruby? Got a nugget to share? We would love to hear from you.

Posted at 01:58PM Dec 04, 2007 in Ruby | http://blogs.sun.com/divas/entry/how_do_you_rubh | Permalink | Comments[4]

Friday Nov 30, 2007

The NetBeans Ruby Screencast Library

Recently we posted a list of tutorials to help you get started with NetBeans Ruby and Rails. Another way to get started is by watching the NetBeans Ruby screencasts, starring Tor Norbye and Roman Strobl, and produced by Cindy Church. These screencasts provide an overview of the features of NetBeans Ruby, including the Ruby Editor and Debugger, and also provide scenarios for creating Ruby and Rails applications. Sit back, relax, and enjoy.

Creating Ruby and Rails Applications

Using the Ruby Editor

Testing and Debugging

Posted at 02:10PM Nov 30, 2007 in Ruby | http://blogs.sun.com/divas/entry/screencasts_of_netbeans_ruby | Permalink | Comments[0]

Tuesday Nov 27, 2007

My Ruby Learning Path: Constructing the Constructor

When I started learning Ruby, all of the code samples that I looked at used positional arguments in the constructor, such as with the following code:

  def initialize(id, type, price)
    @id, @type, @price = id, type, price
  end

By positional arguments, I mean that the first argument must pass the id, the second must pass type, and the third must pass price. Having worked with C and Java, this feels very familiar, and so that is how I did it in my own code. However, when I posted my code samples to the dev@ruby.netbeans.org alias, a few developers suggested that I use a hash, like in the following code.

  def initialize(attributes)
    @id = attributes['id']
    @type = attributes['type']
    @price = attributes['price'].to_f
  end

I can see some advantages of using a hash instead of requiring arguments in a certain order. For one, with positional arguments, there is the possibility of passing the values in the wrong order. Another advantage of a hash is that if you add more attributes to a class, the constructor's signature does not change.

There was a bit of a debate about which version to use. Some developers like the constructor with positional arguments because it clearly documents the intent of the class. Others feel that keyword arguments, along with RDoc, make the code more clear than depending on argument ordering to convey meaning. Comparing the two types of method invocations, I have to agree that the hash seems easier to read.

  Item.new 'id' => 'ABC', type' => 'book',  'price' => 17

  Item.new 'ABC', 'book', 23

How about you? What are your preferences? Do you carry it even further? Would you ever consider doing something like this?


  def initialize(&block)
    instance_eval &block
  end

  item = Item.new do
    self.id = 'ABC'
    ...
  end

Do you know of scenarios where it might be appropriate to use code like this?

  def initialize(attributes)
    @attributes = attributes.with_indifferent_access
  end
 
  def method_missing(symbol, *args)
    @attributes[symbol] ? @attributes[symbol] : super
  end

Charles Nutter has blogged about how to extend Class with a field-initializing 'new' method. Jay Fields posted in his blog code forcreating constructors that can take either positional arguments or a hash. For someone starting out with Ruby, I find these latter methods a bit uncomfortable, but it does save a bit of finger work. What do you think?

Posted at 04:09PM Nov 27, 2007 in Ruby | http://blogs.sun.com/divas/entry/ruby_learning_path_constructing_the | Permalink | Comments[4]

Monday Nov 26, 2007

Getting Started With NetBeans Ruby and Rails

Do you need help getting started with NetBeans Ruby? If so, we have three learning trails to get you going. Our first trail gives you a whirlwind tour of the NetBeans Ruby and Ruby on Rails environment. The second trail provides the nuts and bolts for creating a basic Ruby on Rails application. The third trail is an all-in-one lesson for working with Ruby and Java applications. You can start at whatever trail best meets your needs.

Trail 1: Getting Started

Trail 2: Creating a Ruby on Rails Application

Trail 3: Integrating Ruby and Java Development

Mixing Java and Ruby Applications

Posted at 06:02PM Nov 26, 2007 in Ruby | http://blogs.sun.com/divas/entry/getting_started_with_netbeans_ruby | Permalink | Comments[0]

Tuesday Nov 13, 2007

Getting Your Feet Wet With Java in JRuby

If you haven't tried calling Java classes from a JRuby application yet, here is a simple code snippet to get you started. Paste the following code into the Ruby shell (JRuby IRB), press Enter, and a small desktop app opens (To open the Ruby shell in the NetBeans IDE, choose Ruby > Other > Ruby Shell (IRB) from the main menu). This code is an updated version of an example in the JRuby and the Java Platform article.

Note: A current known bug causes the JRuby IRB to report an ExitSecurityException, this bug does not affect the output.

Code Sample: Using Java Classes in the IRB Console

include Java

import javax.swing.JFrame
import javax.swing.JLabel
import javax.swing.JPanel
import javax.swing.JButton
import java.awt.BorderLayout

frame = JFrame.new
panel = JPanel.new
panel.layout = BorderLayout.new
panel.background = java.awt.Color::white
frame.get_content_pane.add(panel)
frame.default_close_operation = JFrame::EXIT_ON_CLOSE
button = JButton.new "Click Me"
text = JLabel.new "I'm a Simple Program"

panel.add(BorderLayout::CENTER, text)
panel.add(BorderLayout::SOUTH, button)

class Click
    include java.awt.event.ActionListener

    def initialize(button, text)
        @button, @text = button, text
        @click_me_mode = true
    end

    def actionPerformed(event)
        source = event.source
        if (source == @button)
            if (@click_me_mode)
                @text.text = "Button Clicked"
                @button.text = "Click Again"
                @click_me_mode = false
            else
                @text.text = "I'm a Simple Program"
                @button.text = "Click Me"
                @click_me_mode = true
            end
        end
    end
end

button.add_action_listener(Click.new(button, text))
frame.title = "Example"
frame.pack
frame.visible = true

The IRB is a nice way to test out your code. However, with the NetBeans IDE, it is just as easy to test out code in a scratch program. To see what I mean, right-click in the NetBeans Projects window and choose New > Project. In the New Project wizard, select Ruby in the Categories pane, select Ruby Application in the Projects pane, and click Next. Name the project Scratch (or whatever you want) and click Finish. The main.rb file opens in the editor.

Replace the contents of the main.rb file with the code sample. Then click the Run Main Project button in the main toolbar (the green arrow) to run the application.

As you can see by the following screenshot, the advantage of testing your code in a scratch project as opposed to using the IRB is that you get syntax coloring and all the other wonderful NetBeans Ruby editing features.

To learn about the editing features, see the NetBeans Ruby Editing wiki page, or look at Tor's screenshot of the week entries, such as Ruby Screenshot of the Week #18: Errors and Snippets (as of today, he is up to screenshot #23). We are also working on a getting started guide that will cover some of the editing features. Last, you can watch Roman's Editing screencast.

There are a couple of FAQs that you might find helpful

You also might want to check out the Swing with JRuby: Developing a Desktop Application with the JRuby and Java Swing APIs tutorial that was written by Sun campus ambassador Teera Kanokkanjanarat.

Posted at 03:35PM Nov 13, 2007 in Ruby | http://blogs.sun.com/divas/entry/getting_your_feet_wet_with | Permalink | Comments[2]

Monday Nov 12, 2007

Help Us Design Our Docs Pages

We are redesigning the documentation lists and learning trails to include more than just written articles and tutorials. We are asking for your help in coming up with a design that works best for you. Below are links to four designs. Please take a look at each of the designs in terms of identifying the media type for a title.

Of the four, which page (v1, v2, v3, or v4) do you think makes it easiest to find what you are looking for in the desired media? Please briefly explain the benefits of that page and why you prefer it over the others.

Which page (v1, v2, v3, or v4) do you think is the worst for finding information in the desired media? Please briefly explain why you rate it last.

So as to not bias other people's opinions, please do not post your feedback as a comment. Instead, send your response to nbdocsfeedback@emailias.com

Thank you very much for your time. Hopefully your input will make it easier to find the right docs at the right time.

Posted at 01:38PM Nov 12, 2007 in Ruby | http://blogs.sun.com/divas/entry/help_us_design_our_docs | Permalink | Comments[1]

Wednesday Nov 07, 2007

NetBeans Ruby Shortcuts

The other day, Tor Norbye sent us an email listing some NetBeans Ruby navigation shortcuts, which we thought we'd highlight in the blog. We did a little further research on the subject and also list here some favorite user shortcuts that we undercovered.

(For a complete list of NetBeans Ruby Keyboard Shortcuts, see Ruby Shortcuts).

Navigation Shortcuts

Navigation is important - jumping between files and their tests, or between Rails actions and views. Here are some navigation shortcuts:

If you're in a controller file, and realize you need to modify its corresponding view, press Ctrl-Shift-A (Command-Shift-A on the Mac) to jump to it. Press again to go in the opposite direction.

Similarly, if you're in a Rails controller file (for example) and want to go edit its unit test, hit Ctrl-Shift-T (Command-Shift-T on the Mac) to jump to it - and again to jump back.

User Favorite Shortcuts

Here are some more frequently used shortcuts.

Action	Shortcut	Mac Shortcut
Show code completion alternatives	Ctrl-Space. If Ctrl-Space does not work for your language, try using Ctrl-\	Ctrl-Space
Open File by name prefix (not path)	Alt-Shift-O	Ctrl-Shift-O
Show name of current parameter (when editing an argument list for a method call)	Ctrl-P	Command-P
Format Code	Alt-Shift-F	Ctrl-Shift-F
Reformat the current comment paragraph	Ctrl-Shift-P	Command-Shift-P
Jump to matching parenthesis / brace / bracket, or other matching	Ctrl-[	Command-[
Show Documentation	Ctrl-Shift-Space	Command-Shift-Space

NetBeans Shortcuts

You can download a shortcut card that lists the highlights of the NetBeans IDE 6.0 keyboard shortcuts and code templates. In the NetBeans IDE, choose Help > Keyboard Shortcuts Card from the main menu. Similarly, you can view the shortcuts online from the NetBeans IDE 6.0 Keyboard Shortcuts Specification.

Posted at 11:16AM Nov 07, 2007 in Ruby | http://blogs.sun.com/divas/entry/netbeans_ruby_shortcuts | Permalink | Comments[0]

Friday Nov 02, 2007

Confessions of a NetBeans Ruby User

Teera Kanokkanjanarat is a Sun campus ambassador who recently contributed the tutorial Swing with JRuby: Developing a Desktop Application with the JRuby and Java Swing APIs. Here we interview Teera to find out more about his interest in NetBeans Ruby.

First, tell us a little bit about yourself.

I've been working as a freelance software developer for about 8 years ever since finishing high school. My work mainly focuses on the web platform with various technologies ranging from Java, ASP.NET, PHP, and recently I got started on Ruby and Rails. Since November 2006, I've been hired by Sun as a campus ambassador at Simon University in British Columbia, Vancouver, where I'm completing my degree in Computing Science and Business Administration.

What is your interest in Ruby?

Coming from the strongly-typed language world of Java and C#, I find the flexibility and dynamic of the Ruby language to be very interesting. I believe that the productivity of developers has a heavy impact on the cost of software projects. I often find that I waste time waiting for the project to compile and re-deploy to web or application servers. So that's the first thing I found really appealing when I started working with the Ruby and Rails framework. Ruby seems to gain a lot of momentum on the web platform with the Rails framework. Now I'm more interested in the future of Ruby as a rich client on the desktop.

How did you learn Ruby?

I started out on Hal Fulton's The Ruby Way book to learn the Ruby language itself and the Ruby way of doing things. I often watch screencasts and vodcasts for techniques on learning Rails. I'm also a member of the Vancouver Ruby and Rails user group, where I attend monthly meetings. This is an interesting group; as a Java guy, I learn so much from others who work with Ruby on a daily basis.

What do you like and dislike about Ruby?

The Ruby language itself is beautiful. There are not many programming languages that are as intuitive and give me that "wow this is cool stuff!" sort of thrill. Of course, this is also because of Ruby's coding conventions and key principles.

I actually did a small experiment re-creating one of my old, small Java-based web projects with Ruby on Rails. I found that the entire project on RoR actually contains fewer lines of code than that in the previous version's configuration files!

In my opinion, performance and deployment are still the key issues of Ruby. JRuby and other initiatives are really aiming on these two issues.

How has NetBeans helped you build Ruby apps?

I tried RadRails, TextMate, and InstantRails. Yet, I like Netbeans Ruby support the most, especially in code editing, the Ruby debugger, and the auto-complete capability. Netbeans is tightly integrated with JRuby as well.

Tell us about the NetBeans Ruby app you are currently building?

I'm developing JSF web components for one of the my clients. There's future planning to release these components in rich client version (Swing and SWT). I'm doing an experimental project on how to leverage JRuby for developing these desktop components.

What was your favorite experience as a Sun ambassador?

Meeting with people! I made a lot of friends from around the world through this program. I also learned a lot from talking to people when I do evangelizing work, whether it's a tech demo or a presentation at a user group. Nothing beats learning from those who do real work out there in the field.

What are some things you like to do outside school and work?

I started a small coffee shop back when I was 19 and opened up a day-spa with my sister about two years ago. Both of them are in Thailand. So, I'm helping my sister run them remotely.

Where do you see yourself in five years?

Completing my degree is my first priority (it has been delayed several times due to my work). After finishing my term at Sun at the end of this year, I'll be joining Business Objects as a software developer. In the next five years, I might do another startup if there some good ideas come along, but things change, you never know.

Posted at 09:02AM Nov 02, 2007 in Ruby | http://blogs.sun.com/divas/entry/confessions_of_a_netbeans_ruby | Permalink |