Final Notes on the UML

1
Final Notes on the UML

• CS 123/231

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UML Diagramming Techniques

• Class Diagrams
• Use Case Diagrams
• Interaction Diagrams
• Sequence diagrams
• Collaboration diagrams
• State Diagrams
• Others (e.g., Activity Diagrams, Packages)

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Activity Diagram

• Represents sequence of activities
• Depicts condition, iteration, and parallel
  activities
• When to use
• Analyzing use cases
• Alternate way of describing a use case
• Depicting use case sequences/workflow
• Describing method behavior

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Activity Diagram Notation

• Oval - activity
• Start and end buttons
• Links between ovals to depict sequence
• Diamond conditional branch and merge
• Bar fork and join (concurrent activities)

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About Activity Diagrams

• Helps in understanding system behavior, but
• It does not provide an object-oriented
  perspective!
• Suggestion just use as a tool to clarify
  complex sequential/parallel relationships between
  behavioral components

6
CRC Cards

• Not really part of the UML
• But helps in construction of Class Diagrams and
  Interaction Diagrams
• CRC Class-Responsibility-Collaboration
• Role-playing
• Team members represent classes
• Each member/class holds an index card

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CRC Cards, continued

• Team goes through each use case and role-play
  object interaction
• Responsibilities (which end up being methods) are
  noted on the index card
• Use of an index card is deliberate
• Responsibilities ought to be evenly distributed
  across the classes that interact
• Overloaded classes become immediately apparent

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CRC Cards and UML Diagrams

• Role-playing activity for each use case maps
  directly to interaction diagram construction
• Each card provide class details (methods) for the
  class diagram

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Package Diagrams

• Recall Architectural Design
• Divide a system into subsystems
• Depicted using a block diagram
• OO alternative Package Diagrams
• Package lt-gt Subsystem
• Package group of classes
• Dependencies between packages

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Package Diagram Notation

• Folder Package
• Dotted arrow between folders dependency link
• Two variations
• Abbreviated name in folder
• Detailed name on folder tab, rectangles
  representing classes in folder area

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Using the UML

• Use the UML as a communication tool across the
  different stages of software engineering
• Primarily a design tool but helpful in analysis
  as well
• Important to note what stage or perspective you
  are in

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Perspectives

• Conceptual (analysis)
• Focus on domain and requirements
• Use case diagram, high-level class diagram, maybe
  some activity diagrams
• Specification (design)
• Focus on solution/programming details
• Implementation
• Focus on code

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Phases in theRational Unified Process

• Inception
• Feasibility Study
• Analysis
• Elaboration
• Analysis
• Design
• Construction
• Implementation and Testing