State diagrams Interaction diagrams –Sequence diagrams –Collaboration diagrams Object orientation Part 4: Dynamic Modeling

Stimulate 2005 Instructor: Luz M. Quiroga University of Hawaii Information and Computer Science / Library and information Science POST 314b; System Analysis and Design (SA&D) Object Oriented modeling Part 4: Dynamic modeling: state and interaction diagrams

State diagrams STATE: a condition during the life of an object during which it –Satisfies some conditions –Performs some actions –Waits for some events State transitions

State diagrams State: rectangle with round corners Event: something that takes at a certain point of time. –It triggers a state transition –It spans a period of time –Initial (solid, filled circle) and final state (bull’s eye: solid, filled circle surrounded by another circle ) –Transition depicted as solid arrow from source state to target state –Transition: labeled with name of the event, parameters of the event, [guard condition] and “/”action expression –Examples: registering to a class, dropping from a class, getting married, being hired, etc.

State diagram for the student object States, transitions, events

Sequence diagrams Depicts interaction among objects during a certain period of time –One diagram for each use case: e.g Class registration –Scenarios –Messages: e.g checkIfopen Synchronous: needs answer Simple: transfering the control –Messages have arguments –Persistent objects –Activation: time period during which the object performs an operation

Sequence diagram for a class registration scenario with prerequisites Objects, lineline, activation, messages

Dynamic Modeling: State Diagrams State –A condition during the life of an object during which it satisfies some conditions, performs some actions or waits for some events –Shown as a rectangle with rounded corners State Transition –The changes in the attribute of an object or in the links an object has with other objects –Shown as a solid arrow –Diagrammed with a guard condition and action Event –Something that takes place at a certain point in time A.8

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Dynamic Modeling: Sequence Diagrams Sequence Diagram –A depiction of the interaction among objects during certain periods of time Activation –The time period during which an object performs an operation Messages –Means by which objects communicate with each other 10.10

Dynamic Modeling: Sequence Diagrams Synchronous Message –A type of message in which the caller has to wait for the receiving object to finish executing the called operation before it can resume execution itself Simple Message –A message that transfers control from the sender to the recipient without describing the details of the communication 10.11

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OO paradigm: Key terms Unified Modeling Language (UML) Associations, relationships Concepts Object Object class Use case Class diagram Event Operation Sequence diagram State State transition

OO scope Source: Sinha OO Is not LIMITED to Information System

Source: Martin