9/11/12 Notes

IT 231 -- 9/11/12

Review Questions

Why should you set the Windows Explorer to show file extensions?
Ans: So that you see exactly what the filename looks like. If the file extension is hidden, you can't change it and will have to guess what the file extension is, based on the icon associated with the file.
What would you write in your XHTML source code file to get the browser to literally display this tag?
Show HTML source code to literally display the answer to Question 1.
How is a non-breaking space different than an ordinary space in HTML?
Ans: Nonbreaking spaces cannot be eliminated by the browser. Two words joined by a non-breaking space cannot be split across two lines if the width of the browser window is reduced.

List four things that are wrong with this XHTML tag:

<IMG SRC=myphoto.jpg>
Ans: (1) IMG should be in lower case.
     (2) SRC should be in lower case.
     (3) myphoto.jpg should be in double quotes.
     (4) The tag should end with /> (combination start-end tag).

What is the difference between a property and a value in CSS?
Ans: Examples of properties are color, background-color, font-family; examples of property values are red, beige, Verdana.

What are the delimiters for a comment in these languages?

HTML:       <!-- Comment -->
CSS:        /* Comment */
JavaScript: // Comment
Ruby:       # Comment

Explain the difference between static and dynamic webpages.
Ans: a static webpage is not changed after it is displayed; a dynamic webpage can change its content based on user or other input.
Explain the difference between server-side and client-side processing.
Ans: Client-side processing is performed by the browser without any help from the server; server-side processing means that information is sent from the page back the the server and processed there. The results can be sent back to the client and displayed on a new webpage.
What are some server-side scripting languages, other than Ruby? Ans: PHP, ASP.Net, Python/Django, Cold Fusion. Less common server-side scripting languages are Lua, Lasso, WebDNA, SMX.

What is a CSS class? How do you define and use such a class?
Ans: A CSS class is a style with a name given by the programmer. Here is an example:

/* CSS code that defines the style /*
.tt { font-family; Lucida Console;
      font-weight: bold; }

<!-- HTML code that shows how the class is used -->
<p class="tt">Text displayed in typewritter font</p>

The DRY and CoC Principles

DRY means Don't Repeat Yourself.
Here are some of the ways that Rails developers can be DRY:
CoC means Convention over Configuration.
CoC is a software design paradigm that reduces the number of decisions that developers must make; only the non-conventional aspects of the software design must be explicitly specified.
An example of CoC: if the Ruby class representing a database table row is GroceryItem, then the database table itself is named grocery_items.

The HTML5 Header

The HTML5 validation header is simpler than previous XHTML headers

Here is the XHTML transitional header:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Most current browsers do not fully support HTML5, so using it may give unexpected results.
The recommended initial html tag for HTML5 is
although
works for most web pages.

What are Ruby and Rails?

Ruby is a general purpose programming language.
Other popular general purpose programming languages are Java, C++, C#, Python, and Perl.
Ruby on Rails (Rails for short) is a server-side web framework for creating websites.
The Rails framework contains tools for automatic code generation.
Other popular server-side web frameworks are PHP, ASP.Net, Django, TurboGears, Zope.
Rails server software: WEBrick, Mongrel, Phusion Passenger, mod_ruby.
We will not post our Rails projects on the internet; we will view them on localhost (URL = http://localhost:3000), using the WEBrick server.
To actually post a Rails projects on the internet, we would move the project to a machine running a server such as Apache (Unix or Linux) or IIS (Windows).

What You Need to Create Rails Projects

A Text Editor Some popular text editors are
We will use JEdit for class demonstrations. You can download it for free from
Ruby on Rails Software Directions for installing Rails are posted on the Documents Page.

Command Prompt Windows and DOS Commands

Rails projects are created by entering commands in a Command Prompt Window.

To open a Command Prompt Window:

Start >> All Programs >> Accessories >> Command Prompt

Some useful DOS commands.

The Windows Explorer

When creating Rails projects, you will probably work with both a Command Prompt Window and a Windows Explorer Window open at the same time.

To open the Windows Explorer:

Start >> All Programs >> Accessories >> Windows Explorer

Set Windows Explorer to show file extensions. See the last announcement on the Announcements Page.

Introduction to Rails

Look at Examples 4, 5, 6, and 7 on the Examples Page.
A list of rails folders that are created by the rails command.

Project 1

Discuss Project Proj1.
Look at HTML Fonts and Extended HTML Colors for font and color suggestions.

Submitting Projects

In your Rails project, include a cover document named coverdoc-projx-smith.doc, where you replace projx by the project name and smith by your last name.
This cover document describes what you did to create the project and any special features or styling in the project that deserves special attention.
To submit a Rails project:
Some sources recommend using the 7-zip for compressing files instead of Windows Compressed Folders.
Submit your zipped project on the CDM COL Project Submission site col.cdm.depaul.edu.