Design Pattern Driven Development of Model Transformations
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1 Design Pattern for Open Class (DRAFT) 2 Abstract Factory
1 Design Pattern for Open Class (DRAFT) Tanaka Akira <[email protected]> A design pattern describes a software architecture which is reusable and exten- sible. [GoF] is the book containing 23 design patterns for OOP languages like C++ and Java. [GoF] describes several trade offs of the patterns. In C++ and Java, a class is defined by only one module. However, there are languages which can define a class by two or more modules: Cecil, MultiJava, AspectJ, MixJuice, CLOS, Ruby, etc. Such class is called "open class" because it is extensible by modules implemented later [Chambers]. For languages with open class, more extensible and/or simpler design patterns exists. We studied design patterns with open class for each GoF design patterns. In this paper, we describe two patterns: the Abstract Factory pattern and the Visitor pattern. 2 Abstract Factory The Abstract Factory pattern is a design pattern for separating class names from the code which generates the object group of related classes for making them configurable. Following figure is the class diagram of the Abstract Factory pattern. Since the example described in [GoF] uses only one concrete factory for each binaries, the required concrete factory is selected statically. The example builds two binaries for Motif and Presentation Manager from a single source code. Two concrete factories are exist for Motif and Presentation Manager. When a binary is built, it is selected which concrete factory is linked. Such static selection can be implemented with the fewer number of classes by open class as following modules. • The module which defines Window and ScrollBar class and their methods which is independent to window systems. -
Automatic Verification of Java Design Patterns
Automatic Verification of Java Design Patterns Alex Blewitt, Alan Bundy, Ian Stark Division of Informatics, University of Edinburgh 80 South Bridge, Edinburgh EH1 1HN, UK [email protected] [email protected] [email protected] Abstract 2. Design patterns There are a number of books which catalogue and de- Design patterns are widely used by object oriented de- scribe design patterns [4, 1, 6] including an informal de- signers and developers for building complex systems in ob- scription of the key features and examples of their use. ject oriented programming languages such as Java. How- However, at the moment there are no books which attempt ever, systems evolve over time, increasing the chance that to formalise these descriptions, possibly for the following the pattern in its original form will be broken. reasons: We attempt to show that many patterns (implemented in Java) can be verified automatically. Patterns are defined 1. The implementation (and description) of the pattern is in terms of variants, mini-patterns, and constraints in a language-specific. pattern description language called SPINE. These specifi- 2. There are often several ways to implement a pattern cations are then processed by HEDGEHOG, an automated within the same language. proof tool that attempts to prove that Java source code 3. Formal language descriptions are not common within meets these specifications. the object oriented development community. Instead, each pattern is presented as a brief description, and an example of its implementation and use. Designers and developers are then expected to learn the ‘feel’ of a pat- 1. -
Design Case Study: Java Swing
Principles of Software Construction: Objects, Design, and Concurrency Part 2: Design case studies Design case study: Java Swing Charlie Garrod Chris Timperley 17-214 1 Administrivia • Reading due today: UML and Patterns 26.1 and 26.4 • Homework 4b due Thursday, October 17th https://commons.wikimedia.org/wiki/File:1_carcassonne_aerial_2016.jpg 17-214 2 Key concepts from Thursday • Observer design pattern • Introduction to concurrency – Not enough synchronization: safety failure – Too much synchronization: liveness failure • Event-based programming • Introduction to GUIs 17-214 3 GUI programming is inherently multi-threaded • Swing event dispatch thread (EDT) handles all GUI events – Mouse events, keyboard events, timer events, etc. • No other time-consuming activity allowed on the EDT – Violating this rule can cause liveness failures 17-214 4 Swing has many event listener interfaces • ActionListener • MouseListener • AdjustmentListener • TreeExpansionListener • FocusListener • TextListener • ItemListener • WindowListener • KeyListener • … class ActionEvent { int when; String actionCommand; int modifiers; Object source(); int id; … interface ActionListener { } void actionPerformed(ActionEvent e); } 17-214 5 Aside: lambdas vs. explicit class declarations? //static public void main… JFrame window = … JPanel panel = new JPanel(); window.setContentPane(panel); panel to hold the button JButton button = new JButton(“Click me”); button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.out.println(“Button -
Design Pattern Interview Questions
DDEESSIIGGNN PPAATTTTEERRNN -- IINNTTEERRVVIIEEWW QQUUEESSTTIIOONNSS http://www.tutorialspoint.com/design_pattern/design_pattern_interview_questions.htm Copyright © tutorialspoint.com Dear readers, these Design Pattern Interview Questions have been designed specially to get you acquainted with the nature of questions you may encounter during your interview for the subject of Design Pattern. As per my experience good interviewers hardly plan to ask any particular question during your interview, normally questions start with some basic concept of the subject and later they continue based on further discussion and what you answer: What are Design Patterns? Design patterns represent the best practices used by experienced object-oriented software developers. Design patterns are solutions to general problems that software developers faced during software development. These solutions were obtained by trial and error by numerous software developers over quite a substantial period of time. What is Gang of Four GOF? In 1994, four authors Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides published a book titled Design Patterns - Elements of Reusable Object-Oriented Software which initiated the concept of Design Pattern in Software development. These authors are collectively known as Gang of Four GOF. Name types of Design Patterns? Design patterns can be classified in three categories: Creational, Structural and Behavioral patterns. Creational Patterns - These design patterns provide a way to create objects while hiding the creation logic, rather than instantiating objects directly using new opreator. This gives program more flexibility in deciding which objects need to be created for a given use case. Structural Patterns - These design patterns concern class and object composition. Concept of inheritance is used to compose interfaces and define ways to compose objects to obtain new functionalities. -
Tree Visitors in Clojure Update the Java Visitor Pattern with Functional Zippers
Tree visitors in Clojure Update the Java Visitor pattern with functional zippers Skill Level: Intermediate Alex Miller ([email protected]) Senior Engineer Revelytix 20 Sep 2011 JVM language explorer Alex Miller has recently discovered the benefits of implementing the Visitor pattern using Clojure, a functional Lisp variant for the Java Virtual Machine. In this article, he revisits the Visitor pattern, first demonstrating its use in traversing tree data in Java programs, then rewriting it with the addition of Clojure's functional zippers. I’ve used trees of domain objects in my Java applications for many years. More recently, I’ve been using them in Clojure. In each case, I've found that the Visitor pattern is a reliable tool for manipulating trees of data. But there are differences in how the pattern works in a functional versus object-oriented language, and in the results it yields. About Clojure Clojure is a dynamic and functional programming language variant of Lisp, written specifically for the JVM. Learn more about Clojure on developerWorks: •"The Clojure programming language" •"Clojure and concurrency" •"Solving the Expression Problem with Clojure 1.2" •"Using CouchDB with Clojure" In this article, I revisit domain trees and the Visitor pattern for the Java language, Tree visitors in Clojure Trademarks © Copyright IBM Corporation 2011 Page 1 of 27 developerWorks® ibm.com/developerWorks then walk through several visitor implementations using Clojure. Being a functional language, Clojure brings new tricks to data query and manipulation. In particular, I've found that integrating functional zippers into the Visitor pattern yields efficiency benefits, which I explore. -
Addison Wesley, 2000, Pp
------==Proudly Presented by MODELER==------ preface.fm Page xv Wednesday, June 6, 2001 4:18 PM Preface Design patterns and object-oriented programming. They hold such promise to make your life as a software designer and developer eas- ier. Their terminology is bandied about every day in the technical and even the popular press. But it can be hard to learn them, to become proficient with them, to understand what is really going on. Perhaps you have been using an object-oriented or object-based language for years. Have you learned that the true power of objects is not inheritance but is in “encapsulating behaviors”? Perhaps you are curious about design patterns and have found the literature a bit too esoteric and high-falutin. If so, this book is for you. It is based on years of teaching this material to software developers, both experienced and new to object orientation. It is based upon the belief—and our experience—that once you understand the basic principles and motivations that underlie these concepts, why they are doing what they do, your learning curve will be incredibly shorter. And in our discussion of design patterns, you will under- stand the true mindset of object orientation, which is a necessity before you can become proficient. As you read this book, you will gain a solid understanding of the ten most essential design patterns. You will learn that design pat- terns do not exist on their own, but are supposed to work in con- cert with other design patterns to help you create more robust applications. -
Object-Oriented Analysis, Design and Implementation
Undergraduate Topics in Computer Science Brahma Dathan Sarnath Ramnath Object-Oriented Analysis, Design and Implementation An Integrated Approach Second Edition Undergraduate Topics in Computer Science Undergraduate Topics in Computer Science (UTiCS) delivers high-quality instruc- tional content for undergraduates studying in all areas of computing and information science. From core foundational and theoretical material to final-year topics and applications, UTiCS books take a fresh, concise, and modern approach and are ideal for self-study or for a one- or two-semester course. The texts are all authored by established experts in their fields, reviewed by an international advisory board, and contain numerous examples and problems. Many include fully worked solutions. More information about this series at http://www.springer.com/series/7592 Brahma Dathan • Sarnath Ramnath Object-Oriented Analysis, Design and Implementation An Integrated Approach Second Edition 123 Brahma Dathan Sarnath Ramnath Department of Information and Computer Department of Computer Science Science and Information Technology Metropolitan State University St. Cloud State University St. Paul, MN St. Cloud, MN USA USA Series editor Ian Mackie Advisory Board Samson Abramsky, University of Oxford, Oxford, UK Karin Breitman, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil Chris Hankin, Imperial College London, London, UK Dexter Kozen, Cornell University, Ithaca, USA Andrew Pitts, University of Cambridge, Cambridge, UK Hanne Riis Nielson, Technical University of Denmark, Kongens Lyngby, Denmark Steven Skiena, Stony Brook University, Stony Brook, USA Iain Stewart, University of Durham, Durham, UK A co-publication with the Universities Press (India) Private Ltd., licensed for sale in all countries outside of India, Pakistan, Bhutan, Bangladesh, Sri Lanka, Nepal, The Maldives, Middle East, Malaysia, Indonesia and Singapore. -
Facet: a Pattern for Dynamic Interfaces
Facet: A pattern for dynamic interfaces Author: Eric Crahen SUNY at Buffalo CSE Department Amherst, NY 14260 201 Bell Hall 716-645-3180 <[email protected]> Context: Wherever it is desirable to create a context sensitive interface in order to modify or control the apparent behavior if an object. Problem: How can I modify the behavior of an existing object so that different behaviors are shown under different circumstances; and yet still maintain a clean separation between the policy (when each behavior is available) and implementation of each behavior allowing them to be developed independently of one another? Forces: Interfaces provide an essential level of abstraction to object oriented programming. Generally, objects are able define aspects of their function very well using interfaces. At times, this may not be enough. When dealing with two or more classes whose responsibilities are distinctly separate, but whose behavior is closely related, classes can begin to resist modularization. For example, adding security to an application means inserting code that performs security checks into numerous locations in existing classes. Clearly, these responsibilities are distinct; the original classes being responsible for the tasks they were designed to perform, and the security classes being responsible for providing access control. However, making those original classes secure means intermingling code that deals with security. When the classes dealing with security are changed many classes are going to be impacted. One method of adding new behavior to an existing class might be to simply create a subclass and embed that new behavior. In the security example, this would mean creating a subclass for each class that needs to be secure and adding calls to the security code. -
Object-Oriented Desgin Visitor Pattern George Blankenship 1
Object-Oriented Desgin Visitor Pattern CSCI 253 Object Oriented Design: Visitor Pattern George Blankenship Visitor Pattern George Blankenship 1 Overview Creational Patterns Structural Patterns Behavioral Patterns Singleton Composite Chain of Respons. Abstract factory Façade Command Factory Method Proxy Interpreter Prototype Flyweight Iterator Builder Mediator Adapter Memento Bridge Observer Decorator State Strategy Template Method Visitor Pattern George Blankenship Visitor 2 The Elements of a Design Pattern • A pattern name • The problem that the pattern solves – Including conditions for the pattern to be applicable • The solution to the problem brought by the pattern – The elements (classes-objects) involved, their roles, responsibilities, relationships and collaborations – Not a particular concrete design or implementation • The consequences of applying the pattern – Time and space trade off – Language and implementation issues – Effects on flexibility, extensibility, portability Visitor Pattern George Blankenship 3 George Blankenship 1 Object-Oriented Desgin Visitor Pattern The Visitor Pattern: The Problem Represents an operation to be performed on the elements of an object structure. Visitor lets you define a new operation without changing the classes of the elements on which it operates • many distinct and unrelated operations need to be performed on objects in an object structure an you want to avoid “polluting” their classes with these operations • the classes defining the object structure rarely change but you often want to define new operations over the structure Visitor Pattern George Blankenship 4 Visitor Example • The root of the structure accepts a visitor: root.accept( visitor ) • The root and every child object in the structure have a an accept method: void accept( visitor ) { visitor.visit( this ); for each child of mine child.accept( visitor ) next } • In short order our visitor gets a visit() call from each object in the collection. -
Lecture 1 for Chapter 8, Object Design: Reusing Pattern Solutions
Object-Oriented Software Engineering Using UML, Patterns, and Java Chapter 8, Object Design: 8, Object Chapter Reuse and Patterns I and Patterns Reuse Object Design Object design is the process of adding details to the requirements analysis and making implementation decisions The object designer must choose among different ways to implement the analysis model with the goal to minimize execution time, memory and other measures of cost Requirements Analysis: Use cases, functional and dynamic model deliver operations for object model Object Design: Iterates on the models, in particular the object model and refine the models Object Design serves as the basis of implementation System Development as a Set of Activities System Problem Application objects Analysis Solution objects Design Custom objects - Object Design Off-the-Shelf Components - System Design Existing Machine Examples of Object Design Activities Identification of existing components Full definition of associations Full definition of classes (System Design => Service, Object Design => Subsystem interfaces/API) Choosing algorithms and data structures Identifying possibilities of reuse Detection of solution-domain classes Optimization Increase of inheritance Decision on control …… A More Detailed View of Object Design Activities Select Subsystem Specification Reuse Identifying missing Identifying components attributes & operations Specifying visibility Adjusting components Specifying types & signatures Identifying patterns Specifying constraints Specifying exceptions -
Designpatternsphp Documentation Release 1.0
DesignPatternsPHP Documentation Release 1.0 Dominik Liebler and contributors Jul 18, 2021 Contents 1 Patterns 3 1.1 Creational................................................3 1.1.1 Abstract Factory........................................3 1.1.2 Builder.............................................8 1.1.3 Factory Method......................................... 13 1.1.4 Pool............................................... 18 1.1.5 Prototype............................................ 21 1.1.6 Simple Factory......................................... 24 1.1.7 Singleton............................................ 26 1.1.8 Static Factory.......................................... 28 1.2 Structural................................................. 30 1.2.1 Adapter / Wrapper....................................... 31 1.2.2 Bridge.............................................. 35 1.2.3 Composite............................................ 39 1.2.4 Data Mapper.......................................... 42 1.2.5 Decorator............................................ 46 1.2.6 Dependency Injection...................................... 50 1.2.7 Facade.............................................. 53 1.2.8 Fluent Interface......................................... 56 1.2.9 Flyweight............................................ 59 1.2.10 Proxy.............................................. 62 1.2.11 Registry............................................. 66 1.3 Behavioral................................................ 69 1.3.1 Chain Of Responsibilities................................... -
Design Patterns in Ocaml
Design Patterns in OCaml Antonio Vicente [email protected] Earl Wagner [email protected] Abstract The GOF Design Patterns book is an important piece of any professional programmer's library. These patterns are generally considered to be an indication of good design and development practices. By giving an implementation of these patterns in OCaml we expected to better understand the importance of OCaml's advanced language features and provide other developers with an implementation of these familiar concepts in order to reduce the effort required to learn this language. As in the case of Smalltalk and Scheme+GLOS, OCaml's higher order features allows for simple elegant implementation of some of the patterns while others were much harder due to the OCaml's restrictive type system. 1 Contents 1 Background and Motivation 3 2 Results and Evaluation 3 3 Lessons Learned and Conclusions 4 4 Creational Patterns 5 4.1 Abstract Factory . 5 4.2 Builder . 6 4.3 Factory Method . 6 4.4 Prototype . 7 4.5 Singleton . 8 5 Structural Patterns 8 5.1 Adapter . 8 5.2 Bridge . 8 5.3 Composite . 8 5.4 Decorator . 9 5.5 Facade . 10 5.6 Flyweight . 10 5.7 Proxy . 10 6 Behavior Patterns 11 6.1 Chain of Responsibility . 11 6.2 Command . 12 6.3 Interpreter . 13 6.4 Iterator . 13 6.5 Mediator . 13 6.6 Memento . 13 6.7 Observer . 13 6.8 State . 14 6.9 Strategy . 15 6.10 Template Method . 15 6.11 Visitor . 15 7 References 18 2 1 Background and Motivation Throughout this course we have seen many examples of methodologies and tools that can be used to reduce the burden of working in a software project.