Overview of The Content Model for Web Applications

The content model is derived from an examination of use cases developed for the web application. This model contains structural elements that provides a view of content requirements for a web application. Structural elements include content objects like text, images, audio, video and photographs.It also contains analysis classes which cover attributes that describe it, operations that effect the behavior and collaborations.

A content object is any item of cohesive information that is to be presented to an end-user. These content objects are extracted from use cases. Content can be developed before the web application implementation, while the web application is being built or long after web application is operational.
The web engineer meets the person who has designed the use case and obtain a more detailed understanding of what descriptive and pricing information means. The descriptive information includes a paragraph of general description of component, photograph of component, a multi-paragraph technical description of component, a schematic diagram of component and a thumbnail video that shows how to install the component.

Content objects with a brief description of each object is more than enough to define the requirements for content that must be designed and implemented. In some cases, a data tree is used to represent a hierarchy of content objects. The content model may contain entity relationship diagrams that describes the relationship among content objects.

Analysis Model and analysis activities for Web Applications

The analysis model of web application is driven by information contained within the use cases that have been developed for the application. Analysis modeling focuses on four fundamental aspects - content, interaction, function, and configuration. Content that is presented by the web application is identified and functions to be performed are extracted from use case descriptions.

TYPES OF ANALYSIS ACTIVITY OCCURRING DURING MODELLING OF A WEB APPLICATION

- Content analysis: It identifies the content across the full range provided by the web application. The content includes text, graphics, images, audio and video.
- Interaction analysis: The user interaction with the web application is defined in the interaction analysis.
- Functional analysis: There are operations and some other processing functions that are applied on the web application. These operations and processing functions are defined in functional analysis. These functions are independent of content but necessary for the end user.
- Configuration analysis: The environment and infrastructure is described in which the web application resides.

All the information that is obtained from these four steps is reviewed, modified as required and then organized into a model which contains structural elements that identifies analysis classes and content objects and dynamic elements that describes all the structural elements interact with one another and with end users.

Overview of analysis for Web Applications

Web application analysis focuses on the information or content that is to be presented, the functions that are to be performed for the end user and behaviors that a web application exhibits as it presents content and performs functions.

Web application analysis model is comprised of a set of UML diagrams and text that describe content, interaction, function and configuration. Analysis of web applications is done when the following conditions are met:
- Web application to be built is large and complex.
- Number of stakeholders is large.
- Number of web engineers and other contributors is large.
- Web application's goals and objectives will effect the business bottom line.
- Success of web application will have strong bearing on the success of business.

Requirement analysis consists of formulation, requirement gathering and analysis modeling. In formulation, goals, objectives and categories of users are defined. In requirement gathering, communication between web engineering team and web application stakeholders intensifies.
Building a user hierarchy provides with a snapshot of the user population and a cross-check to ensure that the needs of every user have been addressed.

A use case diagram is created for each user category. Use cases are organized into functional packages and each package is assessed to ensure that it is comprehensible, cohesive, loosely coupled and hierarchically shallow.

Requirement analysis and modelling are iterative activities, new use cases are defined and added to packages, existing use cases will be refined and that specific use cases might be reallocated to different packages.

Introduction to Navigation Design - Navigation Semantics and Syntax

Once the web application architecture and the content is defined, navigation pathways that enable users to access the web application content and functions.
- semantics of the navigation for different users of the site should be identified.
- syntax of achieving the navigation should be defined.

NAVIGATION SEMANTICS

Each user category has a user hierarchy and related use cases. There are different navigation requirements for each actor. A set of classes are defined for the use cases developed for each user. It contains one or more content objects or web application functions. As interaction with web application occurs, series of Navigation Semantic Units(NSUs) are encountered. A NSU describes the navigation requirements for each use case. The NSU shows how an actor moves between content objects or web application functions.
Navigation Semantic Unit is a set of information and related navigation structures that collaborate in the fulfillment of a subset of related user requirements.

The Web application designer creates a navigation semantic unit for each use case associated with each user role. During initial stages of navigation design, the web application content architecture is assessed to determine one or more ways of navigating for each use case. Ways of navigating identifies navigation nodes and the links that enable navigation between them.

NAVIGATION SYNTAX

The syntax of navigation design are:
- Tabs: a variation of navigation bar or column.
- Individual navigation link: test based links, icons, buttons and graphical metaphors.
- Horizontal Navigation bar: lists major content or functional categories in a bar containing appropriate links.
- Vertical Navigation column: lists major content or functional categories and second lists virtually all major content objects within web application.
- Site maps: provide an all-inclusive table of contents for navigation to all content objects and functionality contained within web application.

Introduction to Architecture Design - WebApp Architecture

The design process for identifying the subsystems making up a system and the
framework for sub-system control and communication is architectural design. An architectural design is :
- early stage in system design process.
- conducted in parallel with other design activities.
- establishes a link among goals established for web application, content, users visiting it, and the navigation criterion.
- identifying system components and their communications.

A web application is an application that is accessed over a network such as the Internet or an intranet.Web application architecture provides an infrastructure that enables a web based system to achieve its business objectives.
The Model View Controller (MVC) architecture decouples the user interface from web application functionality and information content.

The MVC design pattern divides applications into three components:
- The Model maintains the state and data that the application represents.
- The View allows the display of information about the model to the user. It contains all interface specific functions.
- The Controller allows the user to manipulate the application. It coordinates the flow of data between model and view.

Web application architecture is defined within the context of the development environment in which the application is to be implemented.

Introduction to Architecture Design - Content Architecture

The design process for identifying the subsystems making up a system and the
framework for sub-system control and communication is architectural design. An architectural design is :
- early stage in system design process.
- conducted in parallel with other design activities.
- establishes a link among goals established for web application, content, users visiting it, and the navigation criterion.
- identifying system components and their communications.

Content architecture emphasize on the fact how are the content objects structured for presentation and navigation. It focuses on overall hypermedia structure of the web application. It focuses on
- identifying links and relationships among content and documents.
- defining the structure of content.
- specifying consistent document requirements and attributes.

The design can choose from four different content structures:
- Linear Structures : a predictable sequence of interactions is common. The sequence of content presentation is predefined and linear in nature.
- Grid Structures : applied when the web application content can be organized categorically in two dimensions. This web application architecture is useful when highly regular content is encountered.
- Hierarchical Structures : it is the most common web application architecture. It is designed in a manner that enables flow of control horizontally, across vertical branches of the structure.
- Networked Structures : architectural components are designed so that they may pass control to virtually every other component in the system. It provides navigational flexibility but at the same time it can be a bit confusing to a user.
- Composite Structures : the overall architecture of the web application may be hierarchical, but part of the a structure may exhibit linear characteristics, while another part of the architecture may be networked.

Introduction to Content Design - Content Objects and Content Design Issues

Content design focuses on two different design issues, each addressed by individuals with different skill sets. In content design :
- a design representation is developed for content objects and
- mechanisms are represented that are required to initiate their relationships to one another.
- representation of information within a specific content object is concerned.

It is design activity that is conducted by copywriters, graphic designers, and others who generate the content to be used within a web application.

A content object is closely aligned with a data object. A content object has attributes that include content specific information and implementation specific attributes that are specified as part of design.
UML association and aggregation may be used to represent relationships between content objects.

Once all the content objects are modeled, the information that each object is to deliver must be authored and then formatted to best meet the customer's needs. Content authoring is the job of specialists who design the content object by providing an outline of information to be delivered and an indication of the types of generic content objects that will be used to deliver the information.

As content objects are designed, they are chunked to form web application pages. The number of content objects incorporated into a single page is a function of user needs, constraints imposed by download speed of internet connections, and restrictions imposed by the amount of scrolling that the user will tolerate.