Capturing Hypermedia Functionality

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Capturing Hypermedia Functionality

• By
• Waleed Zaghloul

• Introduction
• OO-Navigator
• Using the Framework
• Architecture Patterns
• Summary

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Introduction

• What is Hypermedia Functionality?
• Has recently become Popular. Why?
• Authors wanted a stand alone Framework for
  Hypermedia Functionality
• The Result OO - Navigator

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OO - Navigator

• Three Main Components
• Object Model
• Hypermedia View
• Interface

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OO - Navigator Contd

• Object Model
• Application Semantics
• Separate from Navigational Front End
• Each Object is associated with One Node
• Changes should not affect Navigation

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OO - Navigator Contd

• Hypermedia Level
• Nodes
• Links
• One Object
• Different Views
• Transparent to Objects

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OO - Navigator Contd

• Interface
• Regular GUI
• Events triggered by Users
• Hypertext Aware

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Using the Framework

• Two Main Steps
• Creation of Hypermedia Components
• Interface Design

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Creation of Hypermedia Components

• Create an Instance of the Class Hypermedia
• Define a View for each Different User Profile
• Define Node Classes and Unclassified Nodes
• Specify Node Views for each User Profile
• Define Associations between Nodes
• Define Access Structures

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Interface Design

• User Interface for each Node must be defined
• Implementation comes Next
• The User needs no programming except for Filters

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Architecture Patterns

• Observer Pattern
• Composite Pattern
• Type Object Pattern
• Decorator Pattern

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The Observer Pattern

• Goal Map Data and Behavior of Application
  Objects to Hypermedia Components while preserving
  Consistency

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The Observer Pattern

• Features
• Nodes updated as Related Object changes
• Links created and destroyed accordingly
• Application Objects Separate from Nodes

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The Composite Pattern

• Goal Group Similar Complex Nodes Together to
  Capture Parts of Hypermedia Semantics
• Causes Better Organization of Hypermedia Space

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The Type Object Pattern

• Goal Capture Relationships between Nodes
• Defining a Different Subclass for Each Group of
  Nodes would cause Class Explosion
• It is Preferable to instantiate an existing Class
  instead of creating a New Class

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The Decorator Pattern

• Goal Enrich the GUI with Navigational
  Capabilities
• The Authors think this Pattern could be used to
  extend any Application

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Questions and Comments?