WebEngineering WS 08/09

Part 1 - Introduction and Overview

World Wide Web and the early beginning

Vannevar Bush

l

Memex

Ted Nelson

"hyptertext = non-sequential writing"

How to Feed your Head

What is Hypertext

Navigate through Information Space

Non-linear nodes of information

Hypertext-Documents

Node

Link

Anchor

Hypermedia?

Hypertext History

Bush

Englebart

Nelson

Atkinson

World Wide Web

History

Tim Berners-Lee at CERN

Concept

Idea

Uniform Adressing

Uniform Access

WWW is...

Consequences

W3C

6 Document types

6 Document types

A look at resources

the change of technology

Web Application Production

influence factors

The Need for Process

Different requirements views

Different requirements views

high qualitiy

low cost

quality requirements

reliable

aesthetic and cognitive aspects

webengineering

4 disciplines

Softwareengineering

Hypermedia

Information systems

storage devices

Network Engineering

history

different definitions

Engineering is about the systematic application of scientific knowledgein creating and building cost-effective solutions to practical problems

Web Engineering – is the application of systematic, disciplined,and quantifiable approaches to the design, production,deployment, operation, maintenance and evolution of Webbasedsoftware products. [Gaedke, 2000]

Part 2 - Technology: Basic & Principles

Standards and Organisations

Standards

Why

understand processes

understand requirements

interoperability

reusability

How

workshops

w3c - iterative establishing process

SOAP

Simple Object Access Protocol

SOA

Service Oriented Architecture

Protocol Layers Overview

TCP/IP

OSI

Open Systems Interconnection Reference Model

DNS host name resolution

DNS host name resolution

Multi-homed hosts

round robin

retrieving information

prepare request

adress?

adress resource

find resolver

Unter-Topic

request resource

server side

handle request

process

send resource

handle response

process/render data of resource

Uniform Adressing

Adressing ressources

URI

Reserved characters

URN

URL

Example: http-URL

URN vs. URL

Content-Type

MIME

Markup

HTML

XML

XML Language Family

XML Language Family

Part 3 - Aspects of the lifecycle

Part 4 - Pre-Planning

Understanding the problem

Requirements and the Web

Dealing with requirements

Stakeholders

Stakeholder analysis

What is a requirement ?

Types of requirements

Requirements engineering

performing RE

Goal of requirements engineering

Levels of requirements

Business

User

Operational

Environmental

RE & Project Lifecycle

Prepare for RE activities

Prepare a glossary

Initiate Phase

Objective

Description Documentation of Project for authorization purpose

links project in business environment

Developing Solution Concept

Business requirements

Use Case

Use Case Realization

Use Case Scenario

Alistair Cockburn Classification

l

Brief

consists of a few sentences summarizing the use case. It can be easily inserted in a spreadsheet cell, and allows the other columns in the spreadsheet to record priority, technical complexity, release number, and so on.

Casual

onsists of a few paragraphs of text, summarizing the use case.

fully dressed

is a formal document based on a detailed template with fields for various sections

Vision and Scope

Market Requirement Document

Drafting the vision

Project initiation

Preparation

Finalisation

Memorandum of agreement

Blackboard Approach

Ein Blackboard-Modell basiert auf der Vorstellung einer Gruppe von Experten, die durch Zusammenarbeit ein Problem lösen, das sich aufgrund seiner Komplexität der Lösung durch einen einzelnen Experten entzieht

Elicit Phase

why

what

how

Performing Elicitation

Identify stakeholder

change control

Goal: Better understanding

Gather more information

Requires finding stakeholder representatives

Refining Scope

Use-Case Diagram

Example: E-Concierge

Techniques for Gathering

Mind-Maps

Categories of information

Business

UI-Experience

UIX-Experience

Accessibility

Navigation

RNA's Taxonomy

Operations

Technology

Update Vision and Scope

Assess Phase

Assessing Requirements

Prototype

Mockup

Product Dimensions

Features

Must-solution

Business Rules

Quality Attributes

Requirements Prioritization

by value

by readiness

by risk

Specification and ValidationPhases

Documenting and SRS

Specification

Name

Description

Priority

Prepare for planning

Work breakdown structure

Tree structure

Manage Scope

Beyond SRS

Managing requirements and change

A Web-based system must be treated like a garden

Managing Change

Simple Change control

Part 5 - Planning

Tech-Map

Data

Process

DSA

Dialogue

Presentation

Navigation

Building releases

Testing and Evolution in Context

Standard XML-Schemas

Just Enough XML to Survive

Media Type Image 1

image/gif

image/jpg

some other formats

XLink

r

Das zugrundeliegende Problem, nämlich der Wunsch durch einen Link mehrere Ressourcen gebündelt referenzieren zu können, tritt in praktischen Anwendungen häufig auf. Beispielsweise beim Verweis auf mehrere Versionen eines Dokuments, alternativen Downloadservern oder Bildern verschiedener Auflösung.Zu Realisierung erlaubt XLink die Bündelung von verschiedenen Verweisen zu einem einzigen erweiterten XLink. Nachfolgend ein Codeausschnitt, der dies für die Projektverwaltung zeigt.

XPath

Zur Extraktion beliebiger Teile eines wohl-geformten XML-Dokuments verabschiedete das W3C 1999 die Sprache XPath.

CSS

Why you should use CSS

XSL

Learing XSLT

HTML-Forms

XForms

Client-Side Code

DHTML

Dhtml just for laught's

XSS

Cross Site Scripting

AJAX

Combine different technologies for creating web pages that“behave” like desktop applications

Webserver

SSI

CGI

HTTP

Cookie

SOAP

Security Concerns

Federation Technologies

Part 6 - Developement

test & coding

Building releases

Testing & Evolution in Context

Data Technologies

There is no "the standard"

Standard XML Schemas

Domain Specific standards

Other Media Types

Media Type Image I

GIF

JPEG

PNG

Advantages?

Differences?

SVG

Bewerbung Karibik

Poster

XLink

XPath

CSS

Applying Styles

Inheritance

Positioning

Cascading the style sheets

Conflicts Resolving

XHTML

&

DTD

XSL-Transformations

HTML Forms

ENCTYPE

XForms

hint nur bei XForms

Cookie

Request/Response

Preserving State

Jackie fragt

SOAP