Computer Science304 Facade pattern Purpose Supplies a single interface to a set of interfaces witin a system. Use when A simple interface is needed to provide access to a complex system. There are many dependencies between system implementations and clients. Systems and subsystems should be layered. Provides a unified interface to a set of interfaces in a subsystem. It defines a higher-level interface that makes a subsystem easie.. 2021. 7. 29. Things to think about when designing a sofware structure Question What quality do you care about? Why do you thinks so? Is that really important quality? What is the design content to improve its quality? Is that really a good desing? Isn't the candidate structure too small? How did you organize the pros and cons of the candidate structure? Am I missing a design or not? Does the flow seem to break as you go thorugh each chapter? Am I trying to solve a.. 2021. 7. 29. Visitor Pattern Purpose Allowing one or more operations to be applied to a set of objects at runtime Decoupling the operations from the object structure(=the set of objests) Use when An object structure must have many unrelated operations performed upon it. The object structure can't cahnge but operations on it can Operations must be performed on the concrete classes of an object structure Operations should be .. 2021. 7. 29. Design Patter - Command Pattern Command Pattern Purpose - Encapsulates a request as an object. - This allows the request to be handled in traditionally object based relationships such as queuing and callbacks. Use When - Requests need to be specified, queued, and executed at variant times or in variant orders. - A history of requests is needed. - The invoker should be decopupled from the object handling the invocation. Every t.. 2021. 7. 29. Design Pattern - Strategy Pattern Designing for Change Design patterns help to ensure that a system can change in sepcific ways -> easier to change Extension of duck behavior type Dynamic copy duck behavior 2021. 7. 29. Design Pattern (2) MVC Structure Delegation code Extend the program that amanges each worker's salaries. Created an abstract class called EmeployeeType and made Manager and Regular classese inherit the class. Avoid inheritance and implementation and make it a delegation & compostion relationship. 2021. 7. 28. Design Pattern (1) Hierachy of Pattern Kenowledge Design Pattern - Strategy pattern : defines a family of algorithms, encapsulates each one, and makes them interchangeeable. Strategy lets the algorithm vary independetly from clients using it. OP Principles - Enacapsulate what varies - Favor composition over inheirtance - Program to interface, not implementations OO Basics - Abstraction, Encapsulation, Polymorphism.. 2021. 7. 28. Object-Oriented Analysis Design (7) Elaboration Elaboration is the initial series of iterations during which : - The core risky software acrhitecture is programmed and testsed. - The majority of requirements are discovered and stabilized. - The major risks are mitifated or retired. Important artifacts start in Elaboration : - Domain model : domain objcts and concepts - Design model : design class diagram, interaction diagram - SW .. 2021. 7. 28. Object-Oriented Analysis Design (6) System Sequence Diagram System sequence diagram(SSD) - Shows the events that external actors generate, their order, and inter-system events, for one particular scenario of a use case in sequence diagram notation. - Depict system behavior in terms of what the system does - Used in order to generate system operations. Layered Architecture UML Package Diagrams illustrate the logical architeucture. .. 2021. 7. 27. 이전 1 2 3 4 5 6 ··· 34 다음
