## Web Programming
##
## $Id: programming.atm,v 1.1 2004/09/28 00:32:50 rho Exp $



(is-subclass-of)
superclass: application
subclass: web-application

web-application
bn: Web Application
in: any application which is using HTTP as carrier -- mostly using a web browser (with or without client-side programs)

(is-created-via)
activity: web-application-programming
object: web-application

#-- special applications

(is-subclass-of)
superclass: web-application
subclass: proxy

proxy
bn: Proxy
in: gateway between 'inside' and 'outside' -- HTTP on both ends
in: can be used for annotation, filtering -- special form: caches

(is-subclass-of)
superclass: proxy
subclass: proxy-cache

proxy-cache
bn: Proxy Caches
in (purpose): security enforcement point: filtering and control on the HTTP level
in (purpose): bandwidth need reduction: cache stores documents according to the document metadata (expiry, ...) -- delivers it locally as long as it is not stale

squid (proxy-cache)
bn: Squid

(is-subclass-of)
superclass: web-application
subclass: web-gateway

web-gateway
bn: Web Gateway
in: gateway between HTTP on one side and some other protocol on the other -- has to mediate between conceptual differences
in: usually formats content into HTML on the HTTP side
in (example): LDAP gateway
in (example): CVS browser

(is-subclass-of)
superclass: web-gateway
subclass: stateless-web-gateway

stateless-web-gateway
bn: Stateless Web Gateway
in: maintains no state itself (e.g. logging into a server, making a query, logging out again)
in (problem): expensive and wasteful for some databases

(is-subclass-of)
superclass: web-gateway
subclass: stateful-web-gateway

stateful-web-gateway
bn: Stateful Web Gateway
in: maintains the state on behalf of the client (e.g. logging into LDAP server)
in (problems): back button on browsers -> what does that mean? --\
  client caches -> users sees wrong information, next request may confuse the gateway --\
  interuption of requests -> how does the gateway recover? --\
  user abandons service -> when does session time out?


# client and server-side programming

(is-subclass-of)
superclass: activity
subclass: application-programming

(is-subclass-of)
superclass: application-programming
subclass: web-application-programming

web-application-programming
bn: Web Application Programming
in (definition): implementing a particular application in a client/server scenario
in: common denominator is the HTTP protocol and mostly HTML FORMs
in (history): started with CGI programming -- many application infrastructures have been developed over the years

(is-based-on)
basis: web-application-protocol
structure: web-application-programming

(is-subclass-of)
superclass: protocol
subclass: application-protocol

application-protocol
bn: Application protocol
in: defined by the application developer -- uses some low-level protocol for communication -- THIS IS NOT HTTP!!!
in: message format -- openess, adhoc vs standards -- serialisation (marshalling, encoding), error handling
in: has to operate above of HTTP -- HTTP is stateless -> applications need to maintain state shared between client and server -> cookies
in (example): shopping basket -- login/logout


(is-subclass-of)
superclass: protocol-engine
subclass: application-protocol-engine

application-protocol-engine
bn: Application Protocol Engine
in: part of application software to deal with network messages -- usually provided as an API to the application
in: connect, disconnect, wait_for_message, send_message, ...

(system-implements-concept)
system: application-protocol-engine
concept: application-protocol

(is-hosted-at)
host: web-client
guest: application-protocol-engine

(is-hosted-at)
host: web-server
guest: application-protocol-engine

#-- C/S architecture

(is-architected-via)
architecture: client-server-architecture
application: web-application-programming

(is-subclass-of)
superclass: software-architecture
subclass: client-server-architecture

client-server-architecture
bn: Client-Server, C/S Architecture
in: client side deals with one part of an application, server with the other -- connected via a network
in: separation depends on the consistency requirements of the particular application
in: examples: X, Citrix (visualisation), HTTP, RPC, ...
oc (definition): http://www.webopedia.com/TERM/C/client_server_architecture.html

(is-part-of)
whole: client-server-architecture
part: web-client


web-client
bn: WWW browser/client
in: interacts with (human) user, requests documents from a HTTP server, presentation aspects
oc (zoom): http://topicmaps.bond.edu.au/mda/internet/web/web-server

(has-feature)
feature: document-presentation
object: web-client

document-presentation (web-client-feature)
bn: document presentation
in: HTML, CSS, WML, Applets, ...

(has-feature)
feature: document-presentation-logic
object: web-client

document-presentation-logic (web-client-feature)
bn: document presentation logic
in: DHTML (DOM + JavaScript)

(is-subclass-of)
superclass: web-client
subclass: thick-client

thick-client
bn: Thick client
in: web browser on a PC with much technology on board (JVM, Flash, JavaScript, ...) -- good bandwidth

(is-subclass-of)
superclass: web-client
subclass: thin-client

thin-client
bn: Thin client
in: web browser behind limited bandwidth and with limited hardware resources
in: Handhelds, mobiles

#-- server

(is-part-of)
whole: client-server-architecture
part: web-server

web-server (web-application-architecture-part)
bn: WWW server
in: serves documents via HTTP
in: communication tier
oc (zoom): http://topicmaps.bond.edu.au/mda/internet/web/web-server


#-- 1-tier

(is-architected-via)
architecture: one-tier-model
application: web-application-programming

(is-subclass-of)
superclass: software-architecture
subclass: one-tier-model

one-tier-model
bn: 1-tier model
in: tightly integrated solution -- everything in one

#-- N-tier

(is-architected-via)
architecture: N-tier-model
application: web-application-programming

(is-subclass-of)
superclass: software-architecture
subclass: N-tier-model

N-tier-model (application-architecture)
bn: N-tier model
in: separation of concerns
in: data stored in 'pure' form at backend -- application servers provides business logic --\
 presentation tier either at server or client

#-- browser

(is-subclass-of)
superclass: web-application-programming
subclass: browser-side-web-programming

browser-side-web-programming
bn: Client-side Web Programming
in: application (or part thereof) is executed on the client side -- mostly for presentation, sometimes also business logic
in (advantage): very fast execution -- no server request necessary
in (disadvantage): only for trivial cases -- mostly server has to full knowledge (according to the business model) --\
  client software is not under the control of developers -- new browser may behave differently -- security problem with \
  a language may force users to turn technology off -- have to use often different technology on the server (heterogenous \
  development)
in (usage-scenario): form validation -- problem: full data consistency can only determined on the server
in (usage-scenario): games -- problem: no decent graphical output, slow, source code can be read
in (usage-scenario): pull-down menues -- problem: everyone does it differently -- new GUI paradigms everywhere -- how does user know what to do?
in (usage-scenario): animations -- problem: very few applications involve animations natively -- mostly 'gadgets' from web developers who should know better
in (usage-scenario): DOM manipulation -- hide/show parts of the document, move things around, create new options in FORMs, ... -- useful if used very carefully -- problem: not all browsers support all DOM levels, developer's nightmare
in (usage-scenario): XML transformation -- problem: who - seriously - ships original XML data to the client?

(can-be-used)
tool: visual-basic
purpose: browser-side-web-programming

(is-supported-natively)
language: visual-basic
system: internet-explorer

visual-basic (programming-language)
bn: Visual Basic, VBScript
in: Microsoft supported programming language -- only runs on Windows platform

#-- JavaScript

# is-reified-by javascript-as-client-language
(can-be-used)
tool: javascript
purpose: browser-side-web-programming

javascript (programming-language)
bn: JavaScript
oc (mda-zoom): http://topicmaps.bond.edu.au/mda/programming/javascript/javascript
in: procedural programming language -- similar to Java (yeah)

javascript-as-client-language
bn: JavaScript as Client Language
in: most browsers support it now -- smaller, but annoying differences to JScript
in (disadvantage): does not come with a security model -- early implementations had a lot of vulnerabilities
in: can be used together with DOM (Document Object Model) to access the page content

(is-supported-natively)
language: javascript
system: mozilla

(is-supported-natively)
language: javascript
system: opera

(is-supported-natively)
language: javascript
system: firebird

(is-supported-natively)
language: javascript
system: safari

(is-clone-of)
clone: jscript
original: javascript

(can-be-used)
tool: jscript
purpose: browser-side-web-programming

(is-supported-natively)
language: jscript
system: internet-explorer

jscript (programming-language)
bn: JScript
oc (homepage): http://msdn.microsoft.com/scripting/jscript/
in: Microsoft's version of JavaScript

#-- DHTML

(can-be-used)
tool: dhtml
purpose: browser-side-web-programming

dhtml (client-side-presentation-technology)
bn: Dynamic HTML
in: actually JavaScript + DOM
in: embedding code into HTML pages which can access the structure and the content of the page -- reading and modifying --\
  mainly for rendering effects (fading, moving, resizing)
oc (tutorial) : http://hotwired.lycos.com/webmonkey/authoring/dynamic_html/tutorials/tutorial1.html

#-- Java ---

# is-reified-by java-as-client-language
(can-be-used)
tool: java
purpose: browser-side-web-programming

java (programming-language)
bn: Java Programming Language
in (history): invented by Sun Microsystem -- meant for 'consumer devices' -- James Gosling: 'Oak' --\
  very slow in the early years -- write once, test everywhere -- now very efficient compilation
oc (history): http://java.sun.com/features/1998/05/birthday.html
oc (history): http://www.ils.unc.edu/blaze/java/javahist.html
oc (homepage): http://java.sun.com/
oc (tutorial): http://java.sun.com/docs/books/tutorial/

java-as-client-language
bn: Java as Client Language
in: most browsers support it now -- language now stable -- most machines powerful enough
in: still not too many applications for it -- only in particular niches
in: comes with a security model -- only particular commands can be executed -- protects file system and restricts network access

#-- Active-X --

# is-reified-by active-x-as-client-language
(can-be-used)
tool: activex
purpose: browser-side-web-programming

activex (client-side-programming-technology)
bn: Active-X
in: highly proprietary, single platform technology, highly insecure

active-x-as-client-language
bn: Active X as Client Language
in: only works on Windows platform -- major security concerns -- signed (certified) Active-X controls
in (observation): maybe make more sense in controlled environments

#-- server side

(is-subclass-of)
superclass: web-application-programming
subclass: server-side-web-programming

server-side-web-programming
bn: Server-side Web Programming
in: using an application server infrastructure and a programming language -- server executes scripts/programs
in: can be in a variety of solutions and languages: Perl/CGI, Java/J2EE, VB/ASP, Python/Zope, Java/WebObjects, ....

#-- PHP

(can-be-used)
tool: php
purpose: server-side-web-programming

php (web-application-infrastructure)
bn: PHP
in: infrastructure and web programming language to deliver server-generated documents
in: embed PHP commands into an HTML page: <? echo "Rumsti was here" ?> -- syntax similar to C/Java/Perl
in (advantage): very broad user base -- runs on many platforms (UNIX, Windows, ...) -- very fast processing -- very rich libraries (various databases, HTTP, IMAP, SNMP, ...)
in (disadvantage): despite recent efforts PHP is no 'real' programming language -- mainly for web pages -> makes it difficult to do background processing -- XML support still lagging behind
oc (homepage): http://www.php.net/

#-- Java Servlet

(can-be-used)
tool: java-servlet
purpose: server-side-web-programming

java-servlet (web-application-infrastructure)
bn: Java Servlets
in: writing code to handle GET or POST requests -- application only deals with request, response and context object -- rest is done by the servlet engine
in: servlet is put into a 'container'
in: has support for cookies, session handling
in: only works for Java (and Perl/Wombat) -- javax.servlet
in (advantage): portable code (Java) -- specification open -- rather performant (modulo Java) -- runs directly in the server (no separate process) -- stays in memory between requests -- sandboxing is possible (security)
oc: http://java.sun.com/products/servlet/
oc (tutorial): http://java.sun.com/docs/books/tutorial/servlets/
oc (tutorial): http://www.apl.jhu.edu/~hall/java/Servlet-Tutorial/
oc (introduction): http://developer.java.sun.com/developer/onlineTraining/Servlets/Fundamentals/
oc (introduction): http://www.webdevelopersjournal.com/articles/intro_to_servlets.html
in (implementation): Tomcat Apache, iPlanet Web Server, Microsoft IIS, BEA WebLogic Application Server, IBM WebSphere, et.al.

#-- JSP

(can-be-used)
tool: jsp
purpose: server-side-web-programming

jsp (web-application-infrastructure)
bn: Java Server Pages
in: embedding Java Code into HTML pages -- or just invoking Java Beans (components) from the page
in: technically based on servlets which parse the page, compile it and run it at every request
oc: http://java.sun.com/products/jsp/
oc (documentation): http://java.sun.com/products/jsp/docs.html
oc (tutorial): http://www.apl.jhu.edu/~hall/java/Servlet-Tutorial/

#-- CGI

(can-be-used)
tool: cgi
purpose: server-side-web-programming

cgi (web-application-infrastructure)
bn: CGI, Common Gateway Interface
in: dinosaur of all server-side methods -- still in heavy use -- language independent -- many servers have it implemented
in (observation): mostly used with Perl
in (disadvantage): rather slow compared to other methods -- server has to exec process for every request
in: interface describes how FORM content is passed into the script/program and how content is passed back to the server
in: all functionality handled in the script, no server-side functionality
in (advantage): easy to deploy for simple applications -- isolated processes -- architecture independent -- open standard -- language independent
in (disadvantage): code difficult to maintainability

#-- NSAPI

(can-be-used)
tool: nsapi
purpose: server-side-web-programming

nsapi (web-server-api)
bn: NSAPI, Netscape Server API
oc (faq): 
oc (introduction): http://developer.netscape.com/docs/manuals/enterprise/nsapi/svrop.htm
in: mechanism for extending the functionality of the Netscape servers
in: low-level: good for high-security and high-performance
in: currently in version 3.x -- C++ library -- 
in: supported by Netscape servers (Communication, Commerce, Proxy) -- on several platforms

#-- SSI

(can-be-used)
tool: SSI
purpose: server-side-web-programming

SSI (server-side-technology)
bn: SSI, server side include
in: started as simple mechanism to include files (HTML snippets) -- executed before content is shipped to the client
in: features added: simple database access -- simple program execution -- simple program logic (if-then)
in (problem): performance at earlier implementations -- hiding commands in HTML comments? -- security: how to protect files on the server -- not a full programming language -- difficult to maintain
in: not standardized, security concerns, dead-end technology
oc (tutorial): http://hoohoo.ncsa.uiuc.edu/docs/tutorials/includes.html
oc (tutorial): http://httpd.apache.org/docs/howto/ssi.html
oc (implementation): http://httpd.apache.org/docs/mod/mod_include.html
oc (tutorial): http://www.apacheweek.com/features/ssi

#-- J2EE

(can-be-used)
tool: j2ee
purpose: server-side-web-programming

j2ee (web-application-infrastructure)
bn: J2EE
oc (homepage): http://java.sun.com/j2ee/
in: rich infrastructure for Java applications -- more for high-profile web-apps -- platform neutral, but only for Java
in: has support for session handling -- authentication -- security
in (history): developed by Sun Microsystems 
oc (tutorial): http://java.sun.com/j2ee/tutorial/
in: has many implementations: Tomcat/Apache, Masslight, JBoss, WebLogic, Sun, ....
oc (download): http://java.sun.com/j2ee/download.html

#-- ASP

(can-be-used)
tool: asp
purpose: server-side-web-programming

asp (web-application-infrastructure)
bn: ASP, Active Server Pages
in: Microsoft technology -- now obsoleted by ASP.NET
oc: http://www.asp101.com/
oc: http://www.microsoft.com/windows2000/en/server/iis/htm/asp/iiwawelc.htm
oc (introduction): http://www.microsoft.com/windows2000/en/server/iis/htm/asp/iiwaabt.htm

(is-obsoleted-by)
obsolete: asp
new: asp-net

#-- ASP.NET

(can-be-used)
tool: asp-net
purpose: server-side-web-programming

asp-net (web-application-infrastructure)
bn: ASP.NET
oc (homepage): http://www.asp.net/

#-- Mason

(can-be-used)
tool: mason
purpose: server-side-web-programming

mason (web-application-infrastructure)
bn: Mason
oc (homepage): http://www.masonhq.com/
in: Perl-based templating system -- applying templates automatically -- supports session handling --\
  persistent database connections -- server-side caching -- component based

#-- XML apps servers

(is-subclass-of)
superclass: application-server
subclass: xml-application-server

xml-application-server
bn: XML Application Server
in: XML pipelines -- very flexible way to publish content in various ways

#-- AxKit

(can-be-used)
tool: axkit
purpose: server-side-web-programming

axkit (xml-application-server)
bn: AxKit
in: application development environment for Perl, using XML, XSLT and XPathScript to convert content in pipelines
in: use of taglibs for application specific functionality
oc (homepage): http://axkit.org/

#-- Cocoon

(can-be-used)
tool: cocoon
purpose: server-side-web-programming

cocoon (xml-application-server)
bn: Cocoon
in: application development environment for Java, using XML, XSLT and XPathScript to convert content in pipelines
oc (homepage): http://xml.apache.org/cocoon/
oc (homepage): http://cocoon.apache.org/
oc (introduction): http://www.xml.com/pub/a/2002/02/13/cocoon2.html
oc (book): http://www.amazon.com/exec/obidos/tg/detail/-/0735712352?v=glance
oc (article): http://www.webreference.com/xml/column52/

#-- Zope

(can-be-used)
tool: zope
purpose: server-side-web-programming

zope (web-application-infrastructure)
bn: Zope
in: Python-based infrastructure and web programming language to deliver server-generated documents
in: object-oriented by design -- oo programming -- oo database
in: can import 'packages' which implement specific object classes or whole applications
in: is the basis of other infrastructures: CMF (Content Management Framework), Plone (collaboration)
oc: http://www.zope.net/

#-- ColdFusion

(can-be-used)
tool: coldfusion
purpose: server-side-web-programming

coldfusion (web-application-infrastructure)
bn: ColdFusion
oc (download): http://www.coldfusion.com/
in: very mature programming environment -- advanced templating system -- rich libraries
oc (tutorial): http://hotwired.lycos.com/webmonkey/programming/coldfusion/tutorials/tutorial2.html

allaire (company)
bn: Allaire
oc: http://www.allaire.com/
in: merged with Macromedia (March, 2001)

(is-produced-by)
product: coldfusion
producer: allaire

#-- 

(can-developed-according-to-pattern)
pattern: mvc
system: web-application

mvc (computation-paradigm)
bn: Model-View-Controller, MVC
oc (original): http://st-www.cs.uiuc.edu/users/smarch/st-docs/mvc.html
oc: http://ootips.org/mvc-pattern.html
in: used in GUI programming: events are analyzed and sent to parts of a model -- model responds and changes state -- view(port) displays the changes
in: helps to reduce the complexity