HTML (Hypertext MarkUP Language)       1 HTML is the

HTML (Hypertext MarkUP Language) 1 HTML is the lingua franca for publishing hypertext on the World Wide Web Define tags html body head .etc Allow to embed other scripting languages to manipulate design layout, text and graphics Platform independent Current version is 4.x and in February W3C released the first draft of a test suite 4.01 For more info: http://www.w3.org/MarkUp/

HTML (Hypertext Markup Language) Example HTML code: HTML head title Hello World /title /head body bgcolor “#000000” font color “#ffffff” H1 Hello World /H1 /font /body /HTML 2

HTML (Hypertext Markup Language) 3

HTML (Hypertext Markup Language) Common – – – – – – – 4 features Tables Frame Form Image map Character Set Meta tags Images, Hyperlink, etc

HTML (Hypertext Markup Language) File Extensions: HTML, HTM Recent recommendation of W3C is XHTML 1.0 combines the strength of HTML 4 with the power of XML. XHTML 1.0 is the first major change to HTML since HTML 4.0 was released in 1997 More info: http://www.w3.org/TR/xhtml1/ 5

CSS (Cascading Style Sheet) Simple mechanism for adding style to web page Code be embedded into the HTML file HTML tag: style type “text/css” CODE /style Also be in a separate file FILENAME.css HTML tag: link rel “stylesheet” href “scs.css” type “text/css” Style types mainly include: 6 Font Color Spacing

CSS (Cascading Style Sheet) Controls – – – – – format: Font, color, spacing Alignment User override of styles Aural CSS (non sighted user and voicebrowser) Layers Layout User 7 Interface

CSS (Cascading Style Sheet) Client’s browser dependable Example code: p,h1,h2 { margin-top:0px; margin-bottom:100px;padding:20px 40px 0px 40px; } More info: http://www.w3.org/Style/CSS/ http://www.w3schools.com/css/css intro.asp 8

CSS (Cascading Style Sheet) HTML head title Hello World /title style type “text/css” p,h1,h2 { margin-top:0px; margin-bottom:100px;padding:40px 40px 0px 40px; } /style /head body bgcolor “#000000” font color “#ffffff” h1 Hello World h1 /font /body /HTML 9

CSS (Cascading Style Sheet) 10

HTML without CSS 11

JavaScript Compact object-based scripting language Code be embedded into HTML file HTML tag script language “javascript” CODE /script Also be in a separate file FILENAME.js HTML tag SCRIPT LANGUAGE "JavaScript" SRC “FILENAME.js" /SCRIPT 12

JavaScript Main objectives: User interface, CGI capabilities without involving server Client side compilation Server provides no support Security hazard for client’s computer SCS websites JavaScript's Examples http://www.cs.cmu.edu 13

VBScripts Microsoft’s share of scripting language Similar objectives as JavaScript and any other scripting language Similar to Visual Basic SCRIPT LANGUAGE "VBScript" CODE /script VBScript is integrated with WWW and web browsers Other Microsoft developer tools 14

PHP (Hypertext Preprocessor) PHP- HTML-embedded scripting language Syntax looks like C, JAVA, and PERL File extension: FILENAME.php Main Objective: 15 Generate Dynamic content User Interface Server side loadable module Server side execution Current version and release: 4.3.x More info: http://www.php.net

PHP (Hypertext Preprocessor) Sample Code HTML head title PHP Sample Code /title /head body bgcolor "#000000" font color "#ffffff" h1 This is a PHP TEST /h1 p ?php cnt 0; while( cnt 4) { cnt ; echo "Hello World P "; } ? /body /HTML 16

PHP (Hypertext Preprocessor) 17

PHP (Hypertext Preprocessor) PHP is getting really popular in the web developers community ODBC support PHP developer community think this is the web future SCS Undergraduate sites; done in PHP: http://www.ugrad.cs.cmu.edu/ Drawback: 18 Security Easy manipulation of code for hackers

CGI (Common Gateway Interface) Standard for external gateway programs to interface with information servers such as HTTP servers Real-time execution Main Objective: Dynamic Content User Interface Current 19 version 1.1

CGI (Common Gateway Interface) Various choice in Programming language selections C, C , PERL, Python PERL; most popular and widely used Server side execution Script runs as a stand alone process unlike PHP Basic difference with PHP is the execution approach 20

PERL (Practical Extraction and Report Language) Commonly (Modules): CGI.pm DB.pm DBI.pm CPAN.pm Mysql.pm More 21 used PERL Libraries on PERL Libraries: http://www.perl.com/CPAN-local/README.html http://www.perl.com http://www.perl.org

PERL (Practical Extraction and Report Language) Sample PERL code: #!/usr/local/bin/perl5.6.1 ## printenv -- demo CGI program which just prints its environment ## print "Content-type: text/plain\n\n"; foreach var (sort(keys(%ENV))) { val ENV{ var}; val s \n \\n g; val s " \\" g; print " {var} \" {val}\"\n"; } 22 https://superman.web.cs.cmu.edu/cgi-bin/printenv

PERL (Practical Extraction and Report Language) More Example of PERL CGI Scripts: http://calendar.cs.cmu.edu/scsEvents/ submit.html http://calendar.cs.cmu.edu/scs/ additionalSearch Drawback: 23 Security Easy manipulation of code for hackers

Mod PERL (PERL Module for Apache) Module that brings together the power of PERL and Apache HTTP server PERL interpreter embedded in Web Server Can provide 100x speedups for CGI scripts execution due to Apache::Registry module Reduce load on server Less coordination of server process More info: 24 http://perl.apache.org/ http://www.modssl.org/docs/2.8/ssl intro.html

Secured Web Server (HTTPS, MOD SSL) Provide strong cryptography for web server Mod ssl is the module for Apache to enable encrypted web connection Use Secured Socket Layer (SSL v2/v3) and Transport Layer Security Two categories of cryptographic algorithms 25 Conventional (Symmetric) Public Key (Asymmetric)

Secured Web Server (HTTPS, MOD SSL) Conventional Sender and Receiver share a key Public or Symmetric key or Asymmetric Solve the key exchange issue Certificate 26 A certificate associates a public key with the real identity of an individual, server Includes the identification and signature of the Certificate Authority that issued the certificate

Secured Web Server (HTTPS, MOD SSL) 27

WebISO (Initial Sign-on and Pubcookie) One time authentication process Typically username/password-based central authentication Use standard web browser Eventually the session time-out Commonly uses double encryption 28

WebISO (Initial Sign-on and Pubcookie) Pubcookie Main Model: User-Agent: Web browsers Authentication Service: Kerberos, LDAP, NIS 29 Example: https://wonderwoman.web.cs.cmu.edu/Reports

WebISO (Initial Sign-on and Pubcookie) 30

Cookies Web cookies are simply bits of software placed on your computer when you browse websites WebISO (Pubcookie) use cookie implementation to keep track of a user Drawback: Security 31

Kerberos Network authentication protocal Developed in MIT Strong cryptography Private (shared) key Use ticket to authenticate Never sends password over the network Single sign-on approach for network authentication 32

Database Technology (MYSQL) Database driven backend infrastructure Content is independent from design CGI and PHP are widely used Provide the flexibility of data storage Popular database for web systems: MYSQL, MSQL, Cold Fusion, MS-ACCESS, ORACLE SCS database driven sites USE MYSQL Example of SCS database driven sites 33

Database Technology (MYSQL) Great database package for handling text Drawback – – – – – View Multi-master replication Locking Support for sub quires Character set handling More 34 info: http://www.mysql.com

XML XSLT (Extensible Stylesheet Language Transformations) XSLT is designed for use as part of XSL Stylesheet language for XML XSLT is also designed to be used independently of XSL Work under the umbrella of XML Example: http://wonderwoman.web.cs.cmu.edu:8888/ xml/ 35

JAVA Applets Precompiled code Included in HTML page HTML tag: applet code FILENAME.class LIST OF PARAMETER /applet 36 The class is executed by clients browser’s JVM (Java Virtual Machine) JAR (Java Archive) Bundle multiple files into a single archive file More info: http://java.sun.com/applets/

Flash Multimedia web development Audio, video, animation really flashy web content 3D graphics More info: http://www.macromedia.com/devnet/mx/flash/ SCS Web site (Flash): http://www.cs.cmu.edu/fla/ Performance 37 on low bandwidth is an issue

Server, Web Server, Load balancing Servers SUN, High-end INTEL Operating Systems: Solrais, Linux, Windows Web Server Apache, IIS, Enterprise, SUN ONE Load Balancing Commercial vs Non-commercial product 38

VoiceXML (Voice Extensible Markup Language) Designed for creating Audio Dialog that feature synthesized speech Digitized audio Recognition of spoken and DTMF(Dual-tonemulti-frequency) key input Recording of spoken input Telephony Mixed initiative conversation http://www.w3.org/TR/voicexml20/ http://www.voicexml.org/ 39

List of Useful Links http://www.w3.org/MarkUp/ http://www.w3.org/Style/CSS/ http://www.w3schools.com/css/css intro.asp http://www.php.net http://www.perl.com/ http://www.perl.org http://www.perl.com/CPAN-local/README.html http://perl.apache.org http://www.modssl.org/docs/2.8/ssl intro.html http://web.mit.edu/kerberos/www/ http://www.mysql.com http://www.w3.org/TR/xslt http://www.xml.com/pub/a/2000/08/holman/s1.html?page 2 http://java.sun.com/applets http://www.macromedia.com/devnet/mx/flash/ http://www.w3.org/TR/voicexml20/ http://www.voicexml.org/ http://www.w3.org/TR/xhtml1/ 40