Previous Lectures: Planning of a Web site: Discussing the strategic issues of Web site engineering process –Models used for Web site planning –Compare the Web site with software Engineering –Web site planning process –Technical issues of Web site planning Factors influencing Web browsing: –Web browsing - model –Web session - anatomy –Client side –Network –Server side

Site Creation Key points –Site classification –Infrastructure –Target platforms –Content issues –Functionality requirements –Specification –Costing –Information design –Content organization models –Program design

Site classification Environment –Internet ( Traditional Web sites that are intended for access by the general public. External Web site or Public Web site. –Intranet ( Intended only for internal ( Intra-organizational) use. The medium of an intranet is much different from a public Web site: –Intranet sites run on private networks –Intranet sites run on more predictable and secure networks –Extranet (lsbu.ac.uk/~facestt)Extranet (lsbu.ac.uk/~facestt) Combination of both Internet and Intranet. They are typically private and secured areas for the use of an organization and its designated partners.

Infrastructure (General Approaches) Static (content and design) –Web sites will be a flat-file system of HTML files –The requirements for a static site are mostly content related –All pages reside on the server and have fixed content that will be served “as is” to the user –The dynamic generation of Web pages is impossible –Content and presentation are merged Dynamic (content, design and programming) –The contents be stored in a database –Dynamic site will have content requirements and functionality requirements –Database-driven site separates content from presentation

Dynamic Web sites The two main components database driven dynamic site: –Database (Access, Oracle, Sybase, MySQL) where the data resides –Template provides the structure for the document presentation. A template is a prototype HTML page that contains the code for the look-and-feel of the page, including the navigation and the layout. Example, a single site might have many different templates: one for the product pages, another for press releases, another for job opportunities, etc. –CGI Pros and Cons –Dynamic generation of pages –Individually tailored content –The use of pre-designed templates ensures uniformity in page appearance –Search capability –Ease of management and updating –Simplification of site maintenance – –Pages are not indexed –Pages difficult to bookmark –Site vulnerable to database and middleware problems –High initial cost –Requirement for programming skills

Factors Involved in Developing a Database-Driven Web Site What is involved in creating a database-driven site?  Choosing a database  Choosing middleware  Developing database schema by studying the problem and talking to users  Creating update forms How does a database-driven site differ from a static site?  Dynamic generation of pages  Individually tailored content  Search capabilities  Ease of file management  Simplification of maintenance What are the cost benefits of a database-driven site?  Eliminates heavy outsourcing  Expedites updates and redesign  Allows for multipurpose use of database  Possibly increases revenue due to site-effectiveness What are the drawbacks of a database-driven site?  Dynamically generate pages not easily indexed by robots  Transfer performance penalty for dynamically generated pages  Initially more expensive  Possibly lack of simple, consistent URL for bookmarking

Target platforms based on client profiling Technology Support (http_user_agents) Browsers Implementing Browser and Technology Profiling –What platform are currently used on the network? –What browsers are used? –What screen resolutions are supported? –Has the user been to the site before? –What language does the user speak? –What are her/his likes and dislikes? Display issues User considerations

Content issues The content requirements should list what information will e included on the Web site, if it exists, and in what format Existing contents –What to include –How much to include –Repurposing existing contents New contents –Putting “under construction” signs all over the Web is not acceptable. Amount of information

Functionality What the site will do How it will do Example (page 127): the functionality requirements for an interactive product finder on an Internet Web site

Specification Objectives were identified in week 3. This week will talk about how to translate them into requirements. The main goal of requirements specification phase is to set boundaries and limits for the project. –System (Environmental) requirements –Content requirements –What to include? –Repurposing existing Contents –Creating new content –Functionality requirements –Flowchart

Costing In-house development vs. out sourcing Design cost, graphic tool cost, programming cost

Information Design Information design describes the organization of information to provide clarity, meaning and context for the information (Mok 96) Information design involves taking data like text, pictures, multimedia elements, and programming elements Hypertext theory –A large body of information is organized into numerous pages, or, in the case of the Web, into pages –The pages relate to each other –A user needs only a small fraction of the info at any given time

Content organization models Content organization models: –Linear –Pure linear (slide show) –Linear with alternatives (hotel selection, quiz) –Linear with options (linear with skip ahead) –Linear with side trips (word explanation etc) –Grid (art gallery, etc) –Hierarchy (tree) – narrow or wide –Pure Web (no recognizable pattern) Picking the correct structure (page 149)

Design Issues of Web Site Application vs. Information: –Web site becomes an application or software tool, and not just organized information. From the developer’s view, the way this information is generated is by a software application Program Design Principle: –Modularity –Cohesion and Coupling Cohesion refers to the intra-relations, within a module. Coupling refers to the inter-relationships between modules. –Information hiding Structure Design: structured or top-down design –Objected Oriented Design Choosing a Design Approach –Printed-oriented design –Structured design –Objected-oriented design Navigation Design –Text based navigation –GUI-based navigation