1. The 3 strengths of the Ruby on Rails workshop series

1. They help me to understand the concept of Ruby on Rails, how to use Ruby, the programming language, to develop a Web application.

2. The steps of each exercise are clear and easy to follow, so I can base on them to develop my skills and knowledge

3. The issues raised by those workshops are practical, it satisfies the needs for students who wish to have a good position in real industry.

2. The 3 weaknesses of the Ruby on Rails workshop series

1. Too much time and effort required for such a long subject whilst I have to read, understand, practice in a limited time to finish the subject requirements.

2. Because Ruby on Rails is new to all students, when I have problems with installing or programming, my questions were not answered properly.

3. The questions are not clear, I had a hard time to read, confused, ask my friends about many questions which I could not understand what I should do to answer them.

3. Aspects that I found most difficult

Read all documents about Ruby on Rails to answer the exercises of the subject.  In order to understand the concepts of Ruby, Rails, MVC, and so forth, I had to read long articles that took a lot of my time. Once understand them, I had to learn Ruby which is a new programming language with a lot of new terminologies and techniques.

Working with Instant Rails to develop a Web application is also a tough work as I have to learn how to type commands in black screen to create a project, controller, model, and connect to MySQL to work with database.

4. Improvements that could be made to the workshop series

The workshops should be done properly, the questions in each workshop should be clearer so that students can understand what they are asked to do. In addition, there should be a small tutorial with images that guide students step to step how to install software, how to configure them, and how to write programs in the most easiest way.

Free response and reflective questions

5. Other frameworks

I think .Net and J2EE can do as well if I try deploying OTBS application on them since them are the two most popular framworks in industry. As I have mentioned already earlier in the post, I think that Rails represents current thinking both technically and philisophically, which gives it extra value and longevity.  Perhaps a little more contrast could be given against Java or .NET given that these platforms represent the majority of the work done in industry.

6. Comments on other tools

I chose the developer team so I had to do a lot of work in writing Ruby codes and  develop the OTBS application. When I had problems with the codes, I tried to use google to search for the similar problems that others have met when they were learning like me, and posted them to forums. I also use the class forum provided by the google group to ask classmates and discuss about my problems as well as read and listen to their own problems. The replies were soon enough to solve my problems and help me to fix them ontime.

7. Further comments

I have no further comments

Which way?

The choice is up to you as this workshop present just one option and you may like to use another, such as deploying the OTBS in a .NET or J2EE environment

Deploying a Web application requires many steps involved such as installing software, platform, web servers, database, and so forth.  There are many software available on Internet allowing us to download and use.

For my OTBS application, I chose Ruby as my programming language, Rails as the framwork, and MySQL as my database. the reasons for such choices are that firstly, I have to practice what I have been taught from the class, and secondly, the convenient and comfortable those software can bring to me during the development phase.

Like other software and frameworks, I also have to learn how to configure them, understand how they work and work with them in a proper way. Actually, as recommended, I used InstandRails, a combinational software, providing a full set of both framework, database, and programming language, even available configured settings so I only have to concentrate on developing my application.

I successfully finished my OTBS application in Rails framework using Ruby. And I think that Ruby on Rails is a very powerful tools for developing such Web 2.0 applications. .NET and J2EE environment are other choices that I have not tried regarding the limited time of the subject, but I did make some research about them and found out that Ruby on Rails are more prevail and dominant among others.

Can you get the OTBS Running in production mode as a minimal production server?

In order to have a minimal production server, I should use Mongrel or Apache Web Server as the Rails application server. The database (MySQL) can be set up on the server so that the OTBS application can have access to the neccessary information like products data, user’s data. When database and servers are properly configured, I can upload my OTBS application to the server and publish it to the public so that every one can access and use the application from any where in the world.

References

1. Alameda, E. (2008), Foundation rails 2, Apress and fiends of ED books, viewed by 19 May 2009
2. Hartl, M. and Prochazka, A. (2008), Railsspace: building a social networking website with ruby on rails, Person Education, Inc., ISBN 10: 0-321-48079-1, viewed by 15 May 2009

Following the instructions from the book, I developed a Rails application named Online Taxi Booking Systems (OTBS). I first created a new project by the name otbs. Then I used ruby command to create the Site controller with 3 actions which are index, about and help and a User controller with 2 more actions named Register and Login.

When clicking on Register link, a registration form is displayed that allows a user to fill in his/her information in order to become a site member.

There are strict form validations applied restricting the entered data before it is inserted into database, for instance:

• The length of screen name (username) must be within 4 and 20 characters

• Screen name (username) can not have spaces

• Email address must be valid (only one @ sign, no special characters such as ?, #, &…)

• Email can not be blank

• Password must be within 4 and 20 characters

There is also a mechanism that checks the available of both screen name and email. If one of them is already taken, user is informed to use another one. I tried to type wrong information into the fields, and the results are displayed as below:

The form is only submitted when entered data obeyed the rules, hence I typed again my information, the correct one

After clicking Register button, my information is inserted into database, session containing my user id is set, and the browser redirects me to the index page which also has a flash screen informing that the username I typed recently was created. Meanwhile, I am already logged in.

Once logged in, the Log in hyperlink is replaced by Log out hyperlink. By clicking Logout link, my stored session is empty, the browser sends me back to index page and another flash screen is displayed informing that I was logged out. In addition, the Logout link is replaced by Login link.

In order to login back to the site, I have to click on Login link which brings me to the Login page containing a form for filling login information

This form also have an advanced feature – remember me – allowing system to store user’s session for a long time once clicked. I filled in my subscribed screen name and password and click Login button, the browser sends me to index page with a flash screen informing that I was logged in

There is another advanced feature in this application called “protecting pages”. For example, if a non-logged-in user tries to access pages that require logging in, the browser would redirect him/her to login page with a flash screen asking user to log in first

If I enter invalid screen name and password, I would be informed by the system

Chapter 5 is a long one which teaches me about how to do testing for my application such as

• Database testing

• Site controller testing

• Functional testing

• Model testing

Chapter 6 and 7 focus on making advanced features for the application to enhance security and harden protection mechanisms.

AJAX stands for Asynchronous JavaScipt and XML. AJAX includes several technologies:

• XHTML for the markup of Web pages

• CSS for styling

• Dynamic display and interaction using DOM

• Data manipulation and interchange using XML

• Data retrieval using XMLHttpRequest

• JavaScript as the glue that meshes all this together

The Web page without being refreshed the contents of the entire page, when you retrieve data for a Web page by AJAX. In basic web architecture, when user clicks a link or submits a form, the form is submitted to the server. Then the server sends back a response new page to the user.
When AJAX is used, it loads an AJAX engine in the background. The engine is written in JavaScipt and its responsibility is to both communicate with the web server and display the results to the user. The server returns an HTML fragment that contains the server’s response and displays only the data that is new or changed as opposed to refreshing the entire page.

Rails has a simple, consistent model to implements AJAX operations. Once the brower has render and displayed the initial web page different user actions trigger an AJAX operation:

• Some trigger fires: by user clicking on a button or link, user making changes to the data on a form or in a field

• The web client calls the server: A JavaScript method, XMLHttpRequest, send data associated with the trigger to an action handler on the server.

• The server does processing: The server-side action handler does something with the data and returns an HTML fragment to the client.

• The client receive the response: The client-side JavaScript, which Rails creates automatically, receives the HTML fragment and uses it to update a specified part of the current pages.

References

Hartl, M. and Prochazka, A. (2008), Railsspace: building a social networking website with ruby on rails, Person Education, Inc., ISBN 10: 0-321-48079-1

1. I used ruby command to create animal application

2. I tried running the application on localhost:3000 Mongrel ruby server and access via Web browser at http://localhost:3000/

3. I created the controller Mammal using ruby command

4. Test the controller by starting the WEBrick server and navigating the browser to http://localhost:3000/mammal

5. Create the breath” action by editing and saving the mammal_controller.rb class in projects\animals\app\controllers

6. Started the WEBrick server and browse at http://localhost:3000/mammals/breathe where I got a “missing template” message since it was missing a view for the breathe method.

7. I created a view named breathe.rhtml for the breathe action

Restart the WEBrick server and browse again at http://localhost:3000/mammals/breathe

8. Try Ruby code and HTML in the action view by using the <%….%> wrapper around the inserted Ruby code.

And the results are

Part B: The active view: passing data from an action too a view

1. Create a new application called scenery

2. Create a controller called Demo in scenery\app\controllers

3. Add an action to demo_controller.rb as the method called rubycobe

4. Add a view template rubycode.rhtml

5. Save and restart the Web server and use browser to navigate to scenery/rubycode

6. Use the Time.now example to pass data from an action to a view

7. Modify and save the rubycode action with a value for the time instance variable in the DemoController class in app\controllers\demo_controller.rb

8. Then modify and save the corresponding view template in \app\views\demo\rubycode.rhtml by adding a call by reference to the action’s instance variable:

9. Restart the Web server and navigate the browser to http://localhost:3000/demo/rubycode

Part C: Screen layouts and forms processing with text fields, check boxes, radio buttons and multiple list controls

1. I created a new application called cabs

2. I created a controller called Vehicle in cabs\app\controllers

3. Add an action to vehicle_controller.rb as the method called cabtype

4. Add the view template cabtype.rhtml

5. Save the view and restart the Web server and navigate to http://localhost:3000/cabs/cabtype

6. Create a file in the public directory – \cabs\public called input.html

7. Edit the vehicle_controller.rb here is a start. The data in each form element in the Rails application can be accessed via its name and a hash called params

8. Edit the view template cabtype.rhtml

9. Start the Web server and go to the opening page of this application at http://localhost:3000/input.html

10. When I submitted the data, I got the following results

Assignment 1 – audio – Hung Khoa Tuan.mp3 –

Hello, this is the audio file presented by Hung, Khoa, and Tuan for subject ITC594 – E-Systems Infrastructure Development. We have done assignment 1 including 11 exercises and 4 workshops, posted in wordpress blog at url itc594.wordpress.com in which we created categories for easy access. The 11 exercises aim to provide answers to all questions relating to Information Technology from general aspects like Internet, protocols, etc… to specific ones such as Model – View – Controller (MVC) design pattern, Ruby programming language, Ruby on Rails, XML, etc…

The 4 workshops focus on answering questions about MVC design, some basis of Ruby on Rails and a series of tutorials and practical activities. On workshop 2 and 3, we did create a small Web 2.0 application named Online Taxi Booking System using InstantRails software. We have tested and made screen shots for major parts of the application; all are already posted to blog entries which you can find by clicking on categories which are named Workshop 2 and Workshop 3

That’s all for the presentation. Thank you for your attention.

First, he briefly describe about Ruby on Rails (RoR); how RoR was developed, and some of the basics of RoR.

After that, he reviewed some knowledge about Web application 1.0, MVC, with doing some tutorials of Ruby project examples with explanations

Then, he had mentioned about the convention of naming in RoR as well as how it is work in RoR and show us how to written all these automatic configurations.

Advanced model relations

Introduce to AJAX & intro to testing

And finally how easy to configure and deploy a Ruby program.

5.Read the Flash article using ActionScript by Colin Moock titled “The Model-View-Controller Design Pattern “at http://www.adobe.com/devnet/flash/articles/mv_controller.html

I have read the article, and following here, I am going to summarize it:

Firstly, the article explained the concept of the Model-View-Controller (MVC) design pattern. Basically, it separates the user interface code into three distinct classes:
• Model: stores the data and application logic for the interface
• View: renders the interface (usually to the screen)
• Controller: responds to user input by modifying the model
The basic principle of MVC is the separation of responsibilities. In an MVC application, the model class concerns itself only with the application’s state and logic. The view class concerns itself only with creating the user interface in response to generic updates it receives from the model. Finally, the controller class is occupied solely with translating user input (provided by the view) into updates that it passes to the model.
Furthermore, by separating the code that governs a user interface into the model, view, and controller classes could bring back to us many advantages such as allows multiple representations (views) of the same information (model) or allows user interfaces (views) to be easily added, removed, or changed, at both compile time and runtime.
Secondly, the article also mentions about the architecture of MVC design pattern. In communication in MVC, although the model, view, and controller classes in MVC are intentionally segregated, they must communicate regularly. The model must send notifications of state changes to the view. The view must register the controller to receive user interface events and, possibly, request data from the model. The controller must update the model and, possibly, update the view in response to user input.
Class Responsibilities in MVC implementation are divided among the model, view, and controller. The model manages data and logic, the view creates the interface, and the controller processes user input. Those general responsibilities break down into many specific tasks.

Here is the script code of dognames.rb

puts “Please enter the name of your first dog”
$dog1 = STDIN.gets
puts “Please enter the name of your second dog”
$dog2 = STDIN.gets
puts “Please enter the name of your third dog”
$dog3 = STDIN.gets
puts “Here are the names of your dogs in alphabetical order “
puts [$dog1, $dog2, $dog3].sort
And following is the output

1. Write a Ruby program called fizzbuzz.rb that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”.

Here is the script code of fizzbuzz.rb

for n in 1..100

         if (n % 3 == 0 && n % 5 == 0)

               puts “FizzBuzz”

         elsif n % 3 == 0

               puts “Fizz”

         elsif n % 5 == 0

               puts “Buzz”

         else 

               puts n

         end

end

And following is the output

3. Compare the Ruby and Python versions of the dog years calculator:

#!/usr/bin/ruby

# The Dog year calculator program called dogyears.rb

def dogyears

# get the original age

  puts “Enter your age (in human years): “

  age = gets # gets is a method for input from keyboard

  puts # is a method or operator for screen output

#do some range checking, then print result

  if age < 0

    puts “Negative age?!?  I don’t think so.”

  elsif age < 3 or age > 110

    puts “Frankly, I don’t believe you.”

  else

    puts “That’s”, age*7, “in dog years.”

  end

dogyears

Python

#!/usr/bin/python

# The Dog year calculator program called dogyears.py

def dogyears():

# get the original age

    age = input(“Enter your age (in human years): “)

    print       # print a blank line

# do some range checking, then print result

    if age < 0:

       print “Negative age?!?  I don’t think so.”

    elif age < 3 or age > 110:

       print “Frankly, I don’t believe you.”

    else:

       print “That’s”, age*7, “in dog years.”

### pause for Return key (so window doesn’t disappear)

    raw_input(‘press Return>’)

def main():

    dogyears()

main()

The two script code versions of Ruby and Python are written with familiar structure and purpose but different in syntax. They produce the same results if the end user enters the same input to both of them. In general, Ruby and Python are quite similar in both syntax and structure but they have some different syntax with negligibility.

The purpose of two script codes are to allow the end user entering his age for input which is assigned to a variable name ‘age’. A comparison is made through the condition statement. If the assigned age is less than 0, a message of “Negative age?! I don’t think so” is displayed to the screen. And if the assigned age is less than 3 and more than 110, another message is displayed to the screen, “Frankly, I don’t believe you”. And in the remaining cases, a message with the result of multiplying between the assigned age and seven is display to the end user.

Working on 46 Ruby coding examples in this tutorial, There are many noticeable points about Ruby syntax and structure need to be regarded as following

- Put, print, and printf are commands to produce outputs.
- Gets is the command used to read inputs from the console
- Basically, the syntax of a function definition starts with ‘def’ and ends with ‘end’. Other optional values such as parentheses and return values declared within the functions are available.
- A specific class starts with the keyword ‘class’ followed with a name and ends with the keyword ‘end’. And the class name starts with a capital letter.
- Variable naming are differently declared based on available rules. Global variables start with ‘$’, class variables start with ‘@@’, instance variables start with ‘@’, and etc.
- There are interesting tidbits about Ruby to be considered
o ’#’ is the line comment character, all characters after this are ignored.
o No semi-colons are needed to end lines, but may be used to separate statements on the same line.
o A backslash (\) at the end of a line is used for continuation
o Indenting is not significant, unlike python
o Types of variables do not need to be declared
o Lines between =begin and =end are ignored
o Lines following “__END__” on its own line with no white space, are ignored
- Variable don’t have specific type associated with them which all known as type of object.
- String among double quote allows special character to be interpreted while this is not applied with single quotes.
- An array which is known as a collection of values can be created by enclosing them in square brackets.
- Similar with other programming languages, Ruby have control statements with the own syntax and structure. Such as condition statement, iteration statement, and etc.
- Regular expressions are available in Ruby that used to compare with a specific string for validation purpose.
- Ruby also provides File I/O for manipulating on file.

2. What are the syntax differences in the way that Ruby and Javascript use the if statement?

if expressions are used for conditional execution. The values false and nil are false, and everything else are true. Notice Ruby uses elsif, not “else if” nor “elif”.

In addition in case of Ruby, the ‘if’ clause may be placed at the end of a statement. The command will execute left hand side expression, if right hand side expression is true. JavaScript does not provide this syntax of IF statement

Syntax:
 expression if condition

For example:

age = 18
print “Older than 18” if age > 18

3. While Ruby and Python are quite similar, can you find some similarities between Ruby and JavaScript?

The JavaScript language is dynamic enough to support many of the concise concepts of Ruby on Rails. JavaScript has many of the same language features Ruby has, including
- ducking typing
- arbitrary class and object extension (i.e. adding methods/properties to classes or specific objects at any time)
- simple arrays and hashes
- closure
- Lisp-like features
- metaprogramming
- eval
- aspect oriented programming
- blocks (first-class functions)
 

Reference
Trimpath, 2007, Ruby on Rails Versus JavaScript on Junction code, viewed by 08 April 2009
http://code.google.com/p/trimpath/wiki/RubyRailsVsJavaScriptJunction

Derkeiler, 2006, JavaScript vs. Ruby, viewed by 08 April 2009
http://newsgroups.derkeiler.com/Archive/Comp/comp.lang.ruby/2006-02/msg02949.html