Introduction to Website Development

Introduction to Website Development

Introduction

•
What is the World Wide Web?

•
What is the Internet?

•
What is a website?

•
What is website development?

Computer programming languages

Generations of computer programming
languages

•
Pre
-
computer age

–
Babbage, Ada Lovelace

–
http://en.wikipedia.org/wiki/Analytical_engine

•
1
st

generation (1950s): Machine language

–
0s and 1s

•
2
nd

generation (1960s): Assembly language

•
3
rd

generation (late 1960s): High
-
level programming

–
COBOL, Fortran, BASIC, Pascal, C, C++, Visual Basic,
Java, C#

•
Scripting: 3.5
th

generation

–
JavaScript, Perl, PHP, ASP, CFML

•
4
th

generation: Meta languages

–
SQL, HTML, XML

•
5
th

generation: Intelligent languages

Contemporary programming
Languages

•
Traditional procedural (Third generation languages
—
3GL)

–
Basic, C, COBOL, Fortran

•
Script languages (3GL)

–
Perl, JavaScript, PHP, ASP, CFML

•
Object
-
oriented (3GL)

–
C++, Java

•
Visual and component
-
oriented (3GL)

–
Visual Basic, Visual C++, Delphi

•
Markup and modeling (Fourth generation languages
—
4GL)

–
HTML, XML, VRML

•
Data querying (4GL)

–
SQL

•
Web services (4GL)

–
Microsoft .NET, Java Web Services

–
http://en.wikipedia.org/wiki/Web_service

The program translation process

1.
Source code

–
Human
-
readable instructions using programming
language

2.
Compilation/Interpretation

–
Compilation: All at once, in advance

•
Most 3
rd

generation languages and below

–
Interpretation: Line
-
by
-
line, real
-
time

•
All 4
th

generation languages and above (including all scripting
languages); also some 3
rd

generation languages

3.
Machine language

–
Computer
-
readable ones and zeros

–
Sometimes intermediary object code

The Internet

Internet Milestones

http://www.zakon.org/robert/internet/timeline/

http://en.wikipedia.org/wiki/History_of_the_Internet

•
1969: Originally called ARPANET, the Internet began as
a US military
-
academic network (originally 4 nodes)

•
1974: TCP/IP developed; later becomes lingua franca of
the Internet

•
1983: Milnet (for military) split off. After, Internet used
for academic, education and research only

•
1986: NSFNet created as US Internet backbone

•
Around 1991: commercial access to the Internet begins.

•
1993: NCSA Mosaic Web browser

•
As of 2004, the Internet had over 280 million servers
and 934 million users. Growth in the use of the Internet
continues at a rapid rate.


(see
http://www.clickz.com/stats/
)

Internet services

•
WWW

•
E
-
mail

•
FTP

•
Others

–
Instant Messaging

–
Internet telephony

–
Usenet

–
Telnet

Open source software

•
Richard Stallman and the Free Software Foundation

–
The free software revolution

•
GNU and the General Public License

–
Copyleft

•
Linus Torvalds and Linux

–
Legitimization of the free software methodology

•
Eric Raymond and the Open Source Initiative

–
Free software becomes “open source”

–
Commercial legitimization of free software

•
Netscape and Mozilla

–
First major traditional enterprise to go open source

–
Mozilla Project successfully competes in consumer market

The World Wide Web

Background of the World Wide Web

•
1989: Tim Berners
-
Lee invented HTML
and the WWW

•
1994: World Wide Web Consortium
(W3C) established to guide Web
standards

–
HTML: Standard WWW markup

–
XML: Customizable, data
-
oriented markup

–
XHTML: Extensible, well
-
formed HTML

–
CSS: Formatting

How the WWW Works

(Dennis, 2004 Figure 2
-
8)

Example of an HTTP
Request from a Web
browser

GET http://www.kelley.indiana.edu/ardennis/home.htm HTTP/1.1

Date: Mon 06 Aug 2001 17:35:46 GMT

User
-
Agent: Mozilla/6.0

Referer: http://www.indiana.edu/~aisdept/faculty.htm

Request Header

]
-

Request


Line

]
-

Web browser (this is Netscape)

Command


URL



HTTP version

URL that contained the link to the requested URL

(Dennis, 2004 Figure 2
-
9)

HTTP/1.1 200 OK

]
-

Response Status

Date: Mon 06 Aug 2001 17:35:46 GMT

]
-

Date

Server: NCSA/1.3

]
-

Web server

Location: http:// www.kelley.indiana.edu/adennis/home.htm

]
-

URL

Content
-
type: text/html

]
-

Type of file

<html>

<head>

<title>Allen R. Dennis</title>

</head>

<body>

<H2> Allen R. Dennis </H2>

<P>Welcome to the home page of Allen R. Dennis</P>


</body>

</html>

HTTP response from a Web
server


HTTP version Status code Reason

Response
Header

Response

Body

(Dennis, 2004 Figure 2
-
10)

History of web browsers

•
Initial, and text
-
only

•
NCSA Mosaic

–
First GUI browser, with images
—
gave a face to the Internet

•
Netscape Navigator

–
First commercial browser

•
Microsoft Internet Explorer

–
Today’s #1 browser in market share

•
Mozilla Firefox

–
The first successful open source browser

•
Other browsers

–
Apple Safari, Google Chrome, Opera,
Konqueror

A grammatical note

•
“Web” or “web”, “Internet” or “internet”?

•
In English, you normally capitalize any noun that is unique in its entire
domain, except when it is very commonly used

–
“The prime minister of India”
—
a description

–
But “the Prime Minister of India”
—
a title

–
“the Prime Minister”
—
unique, referring to the PM of Canada

–
“the Milky Way Galaxy”, but “the sun” and “the solar system”

•
Thus, it all depends on how unique and common you feel the Web and
Internet are


•
My personal preferences:

•
I always capitalize “the Internet”, even as an adjective, as in, “Internet
resources”. On the rare occasion that I refer to “the Net”, I also capitalize it.

•
The Web is more complicated:

–
The “World Wide Web” is always all capitalized

–
When referring directly to the WWW, I always capitalize “the Web”

–
When using the term as an adjective, I usually use small letters, as in “web
resources”.

–
I spell “websites” and “webpages” as single words

Standards

Why Standards?

•
Standards provide a fixed way for hardware
and/or software systems to communicate

•
For example, since XHTML is a standard,

–
Any web developer can create XHTML pages

–
that can be reliably served by any HTTP server

–
and that can be correctly viewed on any Web
browser

–
at least, that’s the idea

•
By allowing hardware and software from
different companies to interconnect,
standards help promote competition

Types of Standards

1.
Formal
: a standard developed by an industry
or government standards
-
making body


e.g. USB, 802.11g, XML, CSS

2.
De facto
: standards that emerge in the
marketplace and are widely used, but lack
official backing by a standards
-
making body


Intel 4x86 processor, Microsoft Windows,
Macromedia Flash, Adobe PDF

The Standardization Processes:

Three Steps

1.
Specification
: developing the
nomenclature and identifying the
problems to be addressed.

2.
Identification of choices
: identify
solutions to the problems and choose
the “optimum” solution.

3.
Acceptance
: defining the solution,
getting it recognized by industry so
that a uniform solution is accepted.

Some Major Standards Making
Bodies

•
ISO
: International Organization for
Standardization (www.iso.ch)

•
ITU
-
T
: International Telecommunications Union
–
Telecom Group (www.itu.int)

•
ANSI
: American National Standards Institute
(www.ansi.org)

•
IEEE
: Institute of Electrical and Electronic
Engineers (see
standards.ieee.org
)

•
IETF
: Internet Engineering Task Force
(
www.ietf.org
)

•
W3C
: World Wide Web Consortium (
www.org
)

Components of website
development

Components of website development

•
Content

•
Structure

•
Format and design

•
Dynamics and interactivity

–
Forms

–
Client
-
side programming

–
Server
-
side programming

–
Databases

Content

•
Purpose, goal and objectives of the site

•
Audience

•
Structure of content

•
Format and design of content

•
Interactivity and enhancement of
content presentation

Structure

•
HTML vs. XHTML

–
HTML: Anything goes

–
XHTML: Strict conformation to standards

•
Internal file structure

–
Page sections

–
Templates

•
Site structure

–
Folder hierarchy

–
Content vs. resources

–
Maintaining file links

Format and design

•
Graphics and aesthetics

•
Functionality, usability, and accessibility

Dynamics and interactivity

•
Forms

•
Client
-
side programming

–
JavaScript, VBScript

•
Server
-
side programming

–
Perl, PHP, ASP, ASP.NET, ColdFusion,
Python, JSP

•
Databases

–
MySQL, Access, Oracle, SQL Server

Summary

•
Computer programming languages of various
generations and complexities are used for various
purposes

•
The Internet connects computers worldwide to provide
various information resources

•
The World Wide Web is the richest and most flexible
Internet service

•
Standards are necessary to ensure a prolific and
competitive atmosphere for web development

•
Components of website development:

–
Content

–
Structure

–
Format and Design

–
Dynamics and Interactivity

References

•
Dennis, Alan, 2002.
Networking in the
Internet Age
. Wiley: New York.