This document provides an overview of key web technologies including HTTP, XML, HTML, XHTML, CSS, JavaScript, DOM, SVG, and Unicode. It discusses what each technology is, the latest versions, and basic properties and functionality. For example, it states that HTTP is the underlying protocol for the web, XML is a simplified version of SGML used for data exchange, and CSS is used to separate style from content in HTML and XML documents.

1. Reintroducing to Web
Technology
Isriya Paireepairit

2. Agenda
• HTTP
• XML
• HTML/XHTML
• CSS
• JavaScript
• DOM
• SVG
• Unicode

3. HTTP
• “HyperText Transfer Protocol”
• Latest version: 1.1
• Familiar terms for web developers
• GET, POST, 404
• Encrypted version called HTTPS vis SSL
(now TLS)
• Port 80

4. HTTP role in Internet
Protocol
• TCP/IP Stack pic

5. HTTP Advantage
• All browsers support HTTP 1.1
• Other protocol can be blocked via Firewall
• SMTP, POP3, IMAP, IRC, NNTP, BitTorrent
• So that all web frameworks are built on
HTTP
• We will cover this again in AJAX topic

6. Technologies on top of
HTTP
• XML-RPC
• XMLHttpRequest (used in AJAX)
• SOAP
• Web Service

7. XML
• “Extensible Markup Language”
• Latest version is 1.1
• Simplified version of SGML
• De Facto format for data exchange via web
• Simply text file, with HTML-like syntax
• Tag scheme is definable by users

8. XML schema
• The document for checking XML syntax
• There are big 3
• DTD - oldest, not in XML format
• XML Schema (or XSD) - designed to
replace DTD, XMLed but too complex
• RELAX NG - newest, reduce complication

9. XML Correctness
• 2 States
• Well-formed
• Correct in term of XML syntax rules
• Validate
• Logically correct with XML schema

10. HTML
• HyperText Markup Language
• The language that describes “Web Page”
• Simply text file, human readable
• Latest version is HTML 4.0

11. XHTML
• XHTML is XMLified HTML
• or “HTML in XML format”
• XHTML 1.0 is very similar to HTML 4.0
• XHTML has all XML properties (e.g. well-
formed, valid)

12. XHTML Version
• XHTML 1.0
• Transitional - allow deprecated elements
• <center> <u> <strike>
• Strict - deprecated are not allow
• Use CSS instead for presentation
• XHTML 1.1
• Modularized XHTML 1.0 Strict

13. CSS
• Cascading Style Sheet
• Simply text file to describe XML/HTML
presentation
• Separate “style” from “content”
• 3 levels: CSS1, CSS2, CSS3
• There is no browser support full CSS2
• IE has many problem with CSS1

14. JavaScript
• A programming language
• Formal name is “ECMA Script”
• Interpreting (or scripting) not compiling
• Not related with Java (only name)
• De Facto script for web
• Latest version is 1.5, but 1.0 is enough
• IE6 supports only JavaScript 1.0

15. DOM
• Document Object Model
• W3C Standard
• A “method”, not implementation
• Tell us how objects in page are related to
each other
• Using Tree diagram

16. DOM Demo
• Using Mozilla DOM Inspector
• Very useful for web developers

17. What is DHTML?
• “Dynamic HTML”
• Technic that makes web interactive
• Not technology itself, just set of existing
technology
• Including HTML, CSS, DOM, JavaScript

18. SVG
• Scalable Vector Graphics
• XML-based vector graphics format
• Compete with Macromedia Flash
• Can do animation
• Browser support is rapidly growing

19. SVG Demo
• Mozilla SVG Tiger

20. Unicode
• Unicode is universal character encoding
• Unicode has some mode, UTF-8 is most
popular
• Each Thai character uses 3 bytes in UTF-8
• Compare with 1 byte in TIS-620
• Anyway, Unicode is recommended for new
web

21. Canvas
• Another HTML extension from Apple
• De Facto
• Intend to render scriptable bitmap image
• Used in Mac OS X Dashboard
• Currently supported by Mozilla and KDE
• Use by <canvas>