Tools and Approaches for Developing Data Intensive Web Applications: A survey By: Nadi Linlett Anett

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Tools and Approaches for Developing Data-
Intensive Web Applications A surveyByNadi
LinlettAnetta KojloErkan Mustafa
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Presentation Contexts

• Perspectives on Web Development
• Tools for Web Development
• Middleware , Search Engines and Groupware
• Research Perspectives, Projects in Data-
  Intensive Web

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Objectives of Developing Data-Intensive Web
Applications

• Addressing Software Engineering
• Web Development Applications
• Classify and Compare current development tools as
  has happened in past (e.g. Databases, OOP,
  Methodologies, Middleware)
• Formulate Evaluations
• Research Perspectives

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Perspectives on Web Development
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5 Topics

• Process
• Models, Languages, and Notation
• Reuse
• Architecture
• Usability

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Process
Prototyping Verification
Maintenance Evolution
Requirement Analysis
Conceptualization
Design Structure Navigation Presentation
Implementation
The Lifecycle of Web Application
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Models, Languages and Notation

• Structure
• Navigation
• Presentation
• Reuse
• JavaBeans
• Components are reusable software programs that
  can develop and assemble easily to create
  sophisticated applications.
• e.g. Electronic payment facility

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Architecture

• Two-tier Architecture
• Application logic and data on server side
• Three-tier Architecture
• Integrate HTTP and client-server protocols
• Usability
• Visual Quality
• Customization
• Adaptivity
• Proactivity

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Tools for Web Development
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Web Development Tools

• Help to understand the state of the practice
• There are six categories
• Visual Editors and Site Managers
• Web-enabled hypermedia authoring tools
• Web-DBPL integrators
• Web from editors, report writers, and database
  publishing wizards
• Multiparadigm tools
• Model-driven application generators

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1. Visual Editors and Site Managers

• WYSIWYG editor
• Lets the user design sophisticated HTML Pages
  without programming, and a visual site manager
• Advanced products (e.g. NetObjects Fusion and MS
  FrontPage)
• Added functionalities for dynamic connection to
  live database data.

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2. Web-Enabled Hypermedia Authoring Tools

• Sharing same focus but different origin
• Authoring Metaphor e.g. Flowchart
• May require programming
• Type of database connectivity
• Type of web connectivity
• Include export language
• Offer Interoperability with third-party
  components (e.g. Inclusion of Java applets and
  ActiveX Components)

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3. Web DBPL Integrators

• Used by programmers
• Architecture Database centered and 3Tier
• Permits more effective manipulation of
  information
• Exposes different object types
• E.g. Oracle Trigger

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4. Web From Editors, Report Writers and Database
Publishing Wizards

• Collects a large number of products
• Database export support is limited to the
  publication of basic database elements,i.e.,
  tables and views, and is achieved by
  automatically mapping database content into a
  network language.

• Report writing more complex readonly
  applications obtained by defining custom reports,
  exported to the Web either statically or
  dynamically.
• Microsofts Visual InterDev, Visual Basic 5, and
  Access97, Oracle Developer 2000,
• Form based generators and database publishing
  wizards deliver complete software solutions,
  including user interface logic.

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Database Publishing Wizard
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Visual Basic 5
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5. Multipradigm Tools

• Multiparadigm tools integrate solutions from the
  abovementioned categories into a unified
  development framework.
• The most typical configuration is one in which
  visual HTML editing and site administration are
  extended with external components, which provide
  database connectivity.

• Examples of such convergent tools are
  FrontPage98, which includes database objects for
  connecting to external data sources.
• Multiparadigm tools do not introduce novel
  approaches into Web development, but combine
  already established features.

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Front Page 98
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6.Model-Driven Web Generators

• Hyperwave is an advanced document management
  environment which permits remote users to browse,
  annotate, and maintain documents distributed over
  the Web.
• Hyperwave has a very basic, yet powerful,
  high-level model of a Web application, which is
  thought of as a set of document collections
  organized hierarchically.

• Top of the proposed categories, provide the
  highest level of automation and lifecycle
  coverage.
• Applying conceptual modeling and code generation
  techniques to the development of Web
  applications.
• We review Hyperwave Server 4.0, and Oracles Web
  Development Suite.

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Hyperwave
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• A more database-centric approach is
• taken by the Oracle Web Development Suite,
  which comprises Designer 2000
• CASE tool for generating Web applications
  from bigger entity-relationship diagrams.
• Designer 2000 is an environment for
• business process and application modeling,
  integrated with software generators originally
  designed to target traditional client-server
  environments, namely Oracle Developer 2000 and
  Visual Basic.

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Hyperwave v Designer 2000

• Hyperwave and Designer
• 2000 diverge in the underlying conceptual
  model, and both exhibit limits in the description
  of Web applications.
• Hyperwave adopts a simplified hypermedia model,
  which is well suited to represent navigation, but
  lacks a proper structural model as a
  consequence, the information base is reduced to a
  set of flat documents annotated with metadata.

• Conversely, Designer 2000 draws the development
  abstractions from the database world, and adapts
  such concepts as entities and relationships to
  Web modeling by adding to them some navigation
  and presentation flavor.

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Middleware , Search Engines and Groupware
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Middleware

• The key to multitiered applications is the
  capability to separate data, interfaces, and
  application logic, and to distribute each aspect
  to distinct network nodes.
• Such distribution leverages Internet-enabled
  application protocols like Corba.

• Industrial strength data-intensive applications
  require not only proper design tools but also a
  solid architecture,
• Good performance, availability, scalability, and
  security. These goals have prompted the extension
  of the original two-tier HTPP architecture.

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Search Engines

• The proper design of structure and navigation
  normally results in Web site with a self-evident
  organization
• Examples of Web development tools that bundle
  integrated search functions are Hyperwave (which
  also comes with a separate commercial search
  engine)
• Stand-alone search engines, we mention Verity
  Search97, Harvest,
• OpenTexts LiveLink Search and Spider.

• Search engines basically consist of two main
  components a user interface and query processor,
  whereby users can pose queries and obtain a
  ranked list of pages whose content satisfies the
  query and an indexing component (also called
  spider or crawler) which creates and maintains
  indexes over the data sources.

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Research Perspectives, Projects in Data-
Intensive Web
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Research Projects

• Araneus - Last published in 1999
• Autoweb - No further information published
• Strudel - No further information published
• Web Architect No further information
  published.
• W3I3 - Can be found at www.WebML.org

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W3I3 - WebML

• Four Models
• Data Model
• Hypertext Model
• Presentation Model
• WebML Process

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WebML Data Model
Relationships an example Relationship roles can
be annotated with minimum and maximum cardinality
constraints, respectively denoting the minimum
and maximum number of objects of the destination
entity to which any object of the source entity
can be related.
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WebML Hypertext Model

• Composition describes which pages compose the
  hypertext, and which content units make up a
  page. The pages of the Web site are the
  containers of information actually delivered to
  the reader.

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WebML Hypertext Model

• Five Main Concepts
• 1. Areas and Siteviews
• 2. Pages
• 3. Units
• 4. Operations
• 5. Links

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WebML - Presentation

• Presentation is the orthogonal task of
  defining the look and feel of pages in a site
  view. WebML does not include a specific model for
  expressing presentation at the conceptual level,
  but leverages standard approaches, more familiar
  to graphic and communication experts.

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WebML The WebML Process
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Modelling Notation

• Two Ancestors
• Entity Relationship Model Chen 1976
• Database field
• Dexter Model Halasz Schwarz 1994
• Hypermedia

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The Dexter Model

• the first of workshop was held in the Dexter Inn
  in New Hampshire in 1988
• Based on three layers
• the within-component layer
• the storage layer
• the run-time layer

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The Dexter Model

• Developed into
• HDM (Garzotto et al. 1993)
• RMM (Isakowitz et al. 1995)

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RMM

• Relationship Management Model
• RMM facilitates the design of WWW sites, and
  their seamless integration with databases and
  enterprise-wide information systems.
• RMM applies best to applications that are large
  and dynamic, where data is stored in databases,
  and where hyper-links are computer generated.
• RMM has been applied to applications such as
  On-Line Conference Proceedings, directories,
  academic journals, course-ware, and
  electronic-commerce, among others.
• RMM consists of a series (seven) of
  well-delineated steps to guide in Web Systems
  design and development.
• The design of a WWW application can be succinctly
  represented with RMM diagrams so that designers,
  programmers and users have a clear understanding
  of the scope and structure of the application.
• RM-CASE is a software tool currently under
  construction, that supports RMM design and
  development.

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RMM - Process

• Concentrated on seven activities
• Entity relationship design
• Slice design
• Navigation design
• Conversion protocol design
• Interface design
• Behaviour design
• Implementation and testing

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In Conclusion
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Perspectives and Tools a Conclusion

• Considerable overlap between tools
• Differences in the level of maturity
• Plausible choice based on application
  requirements
• The paper shows a trend towards dynamic web sites

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Middleware , Search Engines and Groupware a
conclusion

• Now considered to be an integral part to complete
  the development of a web implementation

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Research a conclusion

• General move towards object orientated web sites
• New style of database has prompted new research

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References

• PIERO FRATERNALI (1999), Tools and Approaches for
  Developing Data-Intensive Web Applications A
  Survey, ACM Computing Surveys, Vol. 31, No. 3,
  September 1999
• John Placer (1993), The promise of
  multiparadigm languages as pedagogical tools -
  ACM Annual Computer Science Conference archive
  Proceedings of the 1993 ACM conference on
  Computer science table of contents Indianapolis,
  Indiana, United States, 1993
• Hailpem, Brent. "Multiparadigm Languages and
  Environments", IEEE Software, 3, 1, January 1986
• Useful links
• www.webdevelopersjournal.com
• www.webml.org
• www.netobjects.com

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Thank you for listeningQuestions?