Pattern based model refactoring bookshelf

Behavioral refactoring, umlocl, alloy 1 introduction in model driven development mdd projects, one can expect design models. This is where refactoring and design pattern methodology can play an important and useful part in simplifying, enhancing and making code more useable and understandable to those who practice good oo design. We can achieve rigorous patternbased refactoring by developing metamodels called transformation specificationsthat characterize families of transformations. The app was centered around a beautiful map which helped users quickly orient themselves in any city. Refactoring is the process of enhancing the structure of a software artifact without changing its intended behavior. Refactoring is intended to improve the design, structure, andor implementation of the software its nonfunctional attributes, while preserving the functionality of the software. Refactoring using the module design pattern now, we are going to improve our code design a bit.

Agile modeling with uml code generation, testing, refactoring. By the end of the course, you will know how code refactoring and design patterns one coding practice and one design practice can operate together and help each other create great design. A model transformation approach to perform refactoring on. The authors demonstrate their method through the introduction of the abstract factory design pattern in a simple case study.

In this paper an approach to refactoring a software model using design patterns is described. The problem is that by evolving an aom model, the components need to be evolved as well, which generates constant rework. Then, based on the refactoring patterns, the refactoring process is performed on the pivot model. Refactoring is also widely used for producing better maintainable and reusable designs and programs. Composite is a structural design pattern that lets you compose objects into tree structures and then work with these structures as if they were individual objects.

For several years now, ive been involved with advocating agile methods in general, and extreme programming in particular. Refactoring to patterns is an interesting merger of two of the most important concepts in software engineering that have arisen in the last ten years. Model refactoring for antipattern removal can be in fact obtained by replacing an srm with the corresponding trm. Pdf antipatternbased model refactoring for software. Design patterns has been used very effectively in objectoriented design for a long time. Apr 12, 2005 but as you continue to expand this code to more complex forms, this model can quickly become unmanageable. He has more than a decade of experience with automated unit testing frameworks and is a leading expert in test automation patterns, refactoring of software and tests, and design for testability. First of all, the two methods analyze different parts of a conditional block in order to characterize it as a refactoring opportunity. In this paper, the requirements of the stakeholders are taken into account in the refactoring process by modeling them as refactoring goals. With the highly anticipated refactoring to patterns, joshua kerievsky has. Refactoring is a powerful tool to increase the chances of using patterns and improving the quality of software. Incorporating a pattern into a design to improve design quality attributes is called pattern based model refactoring. Uml models are described by class diagrams, ocl constraints, and state machine diagrams.

In most cases, excessively long methods are the root of all evil. Refactoring to p atterns is the marriage of refactoring the process of improving the design of existing code with patterns, the classic solutions to recurring design problems. In this paper we focus on metamodeling of pattern based refactoring. Automated refactoring to the strategy design pattern. Refactoring to p atterns suggests that using patterns to improve an existing design is better than using patterns early in a new design. Deciding to perform a refactoring effort from the existing code to a pattern must be weighed on the necessity and need of the code itself. Refactoring to patterns essentially attempts to merge together two types of books.

Here we see the exact adaptive object modeling uml for the strategy class pattern based on the design patterns gof95 model. Refactoring to design patterns is also treated as a series of minitransformations in the methodology proposed by cinneide and nixon. Or, you might think of metamodels as defining a transforma. Imagine that your team develops an app which works with geographic information structured as one colossal graph. In a world of cloudnative microservicesbased applications, it is. Patternbased model refactoring for the introduction. The advice id offer would depend to a degree on how you go about generating and using the parcel polymorphs. Citeseerx using roles for patternbased model refactoring. With the highly anticipated refactoring to patterns, joshua kerievsky has changed our approach to design by forever uniting patterns with the evolutionary process of refactoring. Incorporating a pattern into a source model to produce a target model is called pattern based model refactoring. Refactoring has been described as the art of safely improving the design of existing code martin fowler, see refs. This book focuses on the methodological treatment of umlp and addresses three core topics of modelbased software development. One day you decided to create a navigation app for casual travelers. Each node of the graph may represent a complex entity such as a city, but also more granular things like industries.

We show how this new design is able to permit a smooth incremental transition from programs with algebraic datatypes and pattern matching, to ones with proper encapsulation, while maintaining simple and sound reasoning. What i mean is, we cant see what criteria are used to determine whether something is express or special and whether those criteria have to do with the properties of the parcel itself or some external factor. How can i practice design patterns and refactoring in a. In this paper, we propose a new approach of model refactoring based on the combined use of uml, b and csp. We treat a design pattern as a characterization of a family of solutions, where the solutions are expressed as uml unied modeling language design models. Precise pattern speci cations can help one determine the transformations needed to incorporate a pattern into a design. Software quality improvement via patternbased model. Refactoring for software design smells presents 25 structural design smells, their role in identifying design issues, and potential refactoring solutions. Authors propose a model refactoring browser within the model transformation. During refactoring, many design patterns will fit into place almost without effort. Deciding to perform a refactoring effort from existing code to a pattern or enhanced design model must be weighed on the necessity and the need of the code itself. We detail a refactoring pattern that allows for the. State is a behavioral design pattern that lets an object alter its behavior when its internal state changes. The strategy deals with actual business rule and operational rule implementations.

In this paper, we propose a fullyautomated search based approach to refactor model transformations based on a multiobjective algorithm that recommends the best refactoring sequence e. Design patterns are typical solutions to commonly occurring problems in software design. The customer is very interested in a particular brand of product say, its a new model of the. Software quality improvement via patternbased model refactoring. Another work on model refactoring is proposed in zhang05, based on the constraintspecification aspect weaver csaw1, a model transformation engine which describes the binding and parameterization of strategies to specific entities in a model. Numerous approaches to model refactoring, problem detection, consistency management, and tool support to automate and verify refactoring are discussed and distributed across numerous research literatures. Description with the highly anticipated refactoring to p atterns, joshua kerievsky has changed our approach to design by forever uniting patterns with the evolutionary process of refactoring intended for the more experienced student, this book introduces the theory and practice of pattern directed refactorings. For example, imagine that you have two types of objects. Im refactoring a set of classes as below which does some price calculations. Refactoring and design patterns university of texas at.

Martin fowler born 1963 is a british software developer, author and international public speaker on software development, specialising in objectoriented analysis and design, uml, patterns, and agile software development methodologies, including extreme programming his 1999 book refactoring popularised the practice of code refactoring. Leverage industry bestpractices, patterns and tools to close the model to implementation round trip loop. Oo object oriented programming refactoring design patterns. The process of transforming a model using a design pattern is called patternbased refac toring. A visual based framework for the model refactoring techniques m. They also provide some case studies on model transformation using different types of design patterns. We present a new notation that we call role models to characterize pattern solutions, and describe how they can be used to support systematic patternbased model refactoring. Gerard meszaros is chief scientist and senior consultant at clearstream consulting, a calgary based consultancy specializing in agile development.

In this approach, we define a design pattern as a set of three components, a problem specification characterizing problem models, a solution specification characterizing solution models and a transformation specification describing how a problem model should be. Most of the time, the projects design and architecture isnt controlled by me, i can only follow. Support for refactoring an application towards an adaptive. Refactoring is an important software development process involving the restructuring of a model to improve its internal qualities without changing its external behavior. Design patterns and refactoring articles and guides. Filter pattern or criteria pattern is a design pattern that enables developers to filter a set of objects, using different criteria, chaining them in a decoupled way through logical operations.

You cant just find a pattern and copy it into your program, the way you can with offthe shelf functions or libraries. Much of refactoring is devoted to correctly composing methods. Code refactoring is the process of restructuring existing computer codechanging the factoringwithout changing its external behavior. Refactoring cleans up codes and help a target design pattern fit in the program better. Model refactoring should preserve the behavior of the model. A visual based framework for the model refactoring techniques. The book contains a lot of bitesized chapters, so it is okay to grab it for 15 minutes, read a bit and get back to it some time later. Refactoring to p atterns essentially attempts to merge together two types of books. This type of design pattern comes under structural pattern as this pattern is combining multiple criteria to obtain single criteria. Aug, 2014 use case modeling is a popular technique for documenting functional requirements of software systems. Today refactoring requires considerable design knowhow, but once tools become available, all programmers should be able to improve their code using refactoring techniques. The refactoring course teaches you about 21 smells of bad code and 66 refactoring techniques to fix them. The proposed refactoring patterns support the improvement of the software qualities, including extensibility, reusability, and efficiency, and allow model designers to introduce concepts such as inheritance relationship, polymorphism, abstract and.

In this paper, we investigate how design patterns and refactoring rules are used in a formal method by formulating and showing them as refinement laws in the calculus of. A design pattern is described as a set of three components. The book identifies eight fundamental design principles and also includes a set of approximately fifty refactoring rules that illustrate the principles. Design patterns capture some of the best software development experiences in forms that are intended to facilitate reuse. Change propagation in context of consistency, completeness, and human guidance. Refactoring is thus a process of software source code transformation. Refactoring, which was first introduced for source code, has been extended for use case models. Polasek faculty of informatics and information technologies, stu bratislava, slovakia gratex international, a. Classification of patterns design patterns differ by their complexity, level of detail and scale of applicability to the entire system being designed. Refactoring to patterns is on a subject that has tremendous potential.

The state pattern is closely related to the concept of a finitestate machine. Antipattern based model refactoring for software performance improvement. The method proposed in this work, for automated refactoring to the strategy design pattern, is differentiated from the approach of or jdeodorant for brevity in a series of aspects. Oct 06, 2016 in our last article of the series, we refactor a single object using the module design pattern. Iparcel implementation of inteface properties these properties set. We can put it on our bookshelf and go through it every time we feel it is necessary. The design models we discuss, both source and target, are expressed in the unified modeling language. Patterns and adaptive models are only design templates, helpers to accommodate better overall design. A refactoring example involving the abstract factory design pattern is used in the paper to illustrate the approach.

Sign up a list of 31 javascript refactoring patterns, based on the 31 days of refactoring book by sean chambers and simone chiaretta, with the applied solutions. With the highly anticipated refactoring to p atterns, joshua kerievsky has changed our approach to design by forever uniting patterns. Organized across common areas of software design, each smell is presented with diagrams and examples illustrating the poor design practices and the problems that result, creating a catalog of. A strategy pattern would be the logic to decide which calculator to use based on other criteria date, coupon number, etc. We treat a design pattern as a characterization of a family of solutions, where the solutions are expressed as uml unified modeling language design models. I was reading the book refactoring to patterns and was wondering how i can get chance to practice the skills, because without deliberate practice on new ways to refactor and use patterns, my skills wont improve but office work requires me to finish each task as quickly as possible. Incorporating a pattern into a design to improve design quality attributes is called patternbased model refactoring. Model for any physical components that are rackcabinet shelf based or standalone in a data center or telco environment see slide notes. Design patterns, model refactoring, reuse, objectoriented models, role models, uml. Pdf experimenting the influence of numerical thresholds. The examples given are templates only, and the designer must keep in mind that they are the ones who must decide where different patterns, if any, may be best used in their code.

A metamodeling approach to patternbased model refactoring. We propose model refactoring by example morex, an approach to automate model refactoring using heuristic based search. Each refactoring contains a theoretical part explaining the symptoms of said smell and a suggested refactoring, a mechanics part how to perform the refactoring and a practical example. Model refactoring may be done for various reasons, such as 1 to meet design goals, 2 to address deficiencies uncovered by design analyses, and 3 to explore alternative designs.

This paper provides a systematic overview of existing research in the. They are like premade blueprints that you can customize to solve a recurring design problem in your code. In principle based refactoring, halladay explains a set of software refactoring rules and links the refactoring rules back to the basic principles that drive robust software design. A flexible domain model, usually implemented with using the adaptive object model aom architectural style, required custommade components to handle the current implementation of the domain entities.

In international conference on theory and practice of model transformations icmt, pages 114, 2011. Observer is a behavioral design pattern that lets you define a subscription mechanism to notify multiple objects about any events that happen to the object theyre observing. Art of improving the design of existing code a process of changing a software system in such a way that it does not alter the external behavior of the code yet improves its internal structuremartin fowler in his refactoring book 12. Experimenting the influence of numerical thresholds on model based detection and refactoring of performance antipatterns. Formal use of design patterns and refactoring springerlink. Model refactoring is the process of transformation of model, which changes its internal structure for improving the qualitative features. Refactoring to patterns is the marriage of refactoring the process of improving the design of existing code with patterns, the classic solutions to recurring design problems. Refactoring to patterns is an interesting merger of two of the most important concepts in.

Strategy is a behavioral design pattern that lets you define a family of algorithms, put each of them into a separate class, and make their objects interchangeable. Patternbased model refactoring the process of transforming a model using a design pattern is called patternbased refactoring. The refactoring techniques are illustrated with live examples. In this approach, we define a design pattern as a set of three components, a problem specification characterizing problem models, a solution specification characterizing solution models and a transformation specification describing how a problem model. Notice that the entity object accepts and has specific operations or strategies associated with it. The main idea is that, at any given moment, theres a finite number of states which a. Visitor is a behavioral design pattern that lets you separate algorithms from the objects on which they operate.

Morex relies on a set of refactoring examples to propose sequences of refactorings that can be applied on a given objectoriented model. Pdf using roles for patternbased model refactoring. In 1999, refactoring revolutionized design by introducing an effective process for improving code. Refactoring for software design smells sciencedirect. Using the composite pattern makes sense only when the core model of your app can be represented as a tree. Oct 15, 20 model driven engineering, an emerging trend in software engineering, has enabled the use of refactoring to uml models. The vagaries of code inside these methods conceal the execution logic and make the method extremely hard to understand and even harder to change. And finally, the pivot model is converted back to the original source model.

In this approach, we define a design pattern as a set of three components, a problem specification characterizing problem models, a. Using design patterns for refactoring realworld models. In 1994, design patterns changed the landscape of objectoriented development by introducing classic solutions to recurring design problems. Refactoring to patterns suggests that using patterns to improve an existing design is better than using patterns early in a new design. A small change will deal with some of the issues created by the module design pattern while keeping our enclosure protected from global scope and able to use public and private variables and methods. Refactoring and design patterns this lab will introduce two of the most important skillsets that software engineers must wield effectively. Deciding to perform a refactoring effort from existing code to a pattern or enhanced design model must be weighed on the necessity and need of the code itself. Model refactoring occurs when a design model is transformed to improvespeci c qualities e. A common pattern to follow is to initialize the client in a module so you can easily reference. This book introduces the theory and practice of pattern directed refactorings. Pdf an automated refactoring approach to design patternbased. Refactoring reduces your riskcan lead to lightweight pragmatic design 11 whats refactoring again. Noted as one of the ten must sees at toronto international design show 2008, and awarded for best design at montreals international design show, sidim, 2008.

Apr 12, 2011 most influential books on oo, refactoring, design patterns, architecture. Improving the design of existing code shows how refactoring can make objectoriented code simpler and easier to maintain. Using roles for patternbased model refactoring baylor university. Antipatterns are low quality solutions to commonly occurring design problems. Move code base to src code is now compiled into lib via babel.