Introduction to Website Development
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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
• 1st generation (1950s): Machine language– 0s and 1s
• 2nd generation (1960s): Assembly language• 3rd generation (late 1960s): High-level
programming– COBOL, Fortran, BASIC, Pascal, C, C++, Visual Basic,
Java, C#• Scripting: 3.5th generation
– JavaScript, Perl, PHP, ASP, CFML• 4th generation: Meta languages
– SQL, HTML, XML• 5th 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
language2. Compilation/Interpretation
– Compilation: All at once, in advance• Most 3rd generation languages and below
– Interpretation: Line-by-line, real-time• All 4th generation languages and above (including all scripting
languages); also some 3rd generation languages
3. Machine language– Computer-readable ones and zeros– Sometimes intermediary object code
The Internet
Internet Milestoneshttp://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/1.1Date: Mon 06 Aug 2001 17:35:46 GMTUser-Agent: Mozilla/6.0Referer: 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 StatusDate: Mon 06 Aug 2001 17:35:46 GMT ]- DateServer: NCSA/1.3 ]- Web serverLocation: http:// www.kelley.indiana.edu/adennis/home.htm ]- URLContent-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, CSS2. 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.
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