Home > Store

Object Design: Roles, Responsibilities, and Collaborations

Register your product to gain access to bonus material or receive a coupon.

Object Design: Roles, Responsibilities, and Collaborations

Book

  • Sorry, this book is no longer in print.
Not for Sale

Description

  • Copyright 2003
  • Dimensions: 7-3/8" x 9-1/8"
  • Pages: 416
  • Edition: 1st
  • Book
  • ISBN-10: 0-201-37943-0
  • ISBN-13: 978-0-201-37943-3

After more than ten years, object technology pioneer Rebecca Wirfs-Brock teams with expert Alan McKean to present a thoroughly updated, modern, and proven method for the design of software. The book is packed with practical design techniques that enable the practitioner to get the job done. Like many human endeavors, design is part art, part engineering, part guesswork, and part experimentation. Discipline, hard work, inspiration, and sound technique all play their part as well. For any given problem, there are many reasonable, but only a few very good solutions. The authors' goal is to help readers learn to make those very good design decisions on their own. The book explores challenges that software developers will face as they build their design, and shows how design patterns can be used to solve design problems. Long awaited and eagerly anticipated, this book represents the first great software design book of the century. A FUTURE CLASSIC!

Sample Content

Online Sample Chapter

Object Design: Finding Objects

Downloadable Sample Chapter

Click below for Sample Chapter(s) related to this title:
Sample Chapter 3

Table of Contents



Foreword by Ivar Jacobson.


Foreword by John Vlissides.


Preface.


1. Design Concepts.

Object Machinery.

Roles.

Object Role Stereotypes.

Roles, Responsibilities, and Collaborations.

Object Contracts.

Conditions-of-Use and Aftereffect Guarantees.

Domain Objects.

Application-Specific Objects.

Interfaces.

Classes.

Two Roles.

Composition.

Inheritance.

Object Organizations.

Components.

Patterns.

Applying Double Dispatch to a Specific Problem.

The Real Benefits of Using Patterns.

Frameworks, Inc.

Architecture.

Architectural Styles.

Centralized Control Style.

Dispersed Control: No Centers.

Delegated Control.

Examining Interactions: A Layered Architecture Example.

Locating Objects in Layers.

Design Description.

Summary.

Further Reading.



2. Responsibility-Driven Design.

A Process for Seeing, Describing, and Designing.

Launching the Production: Project Definition and Planning.

Setting the Stage: Early Description.

Staging the Production: Design.

“Seeing” from Multiple Perspectives.

Writing the Script: Analysis Descriptions.

Usage Descriptions.

Other Specifications.

Glossaries.

Conceptual Objects.

Casting the Characters: Exploratory Design.

CRC Cards.

Inventions: Using Patterns.

Pursuing a Solution.

Bouncing Between Ideas and Details.

Tuning the Production: Design Refinement.

Designing for Flexibility and Extension.

Designing for Reliability.

Making Our Design Predictable, Consistent, and Comprehensible.

Summary.

Further Reading.



3. Finding Objects.

A Discovery Strategy.

Looking for Objects and Roles, and Then Classes.

Why Tell a Design Story?

Search Strategies.

What's in a Name?

Describing Candidates.

Characterizing Candidates.

Connecting Candidates.

Looking for Common Ground.

Defend Candidates and Look for Others.

Summary.

Further Reading.



4. Responsibilities.

What Are Responsibilities?

Where Do Responsibilities Come From?

Strategies for Assigning Responsibilities.

Recording Responsibilities.

Making Initial Assignments.

Getting Unstuck.

Implementing Objects and Responsibilities.

Testing Your Candidates' Quality.

Summary.

Further Reading.



5. Collaborations.

What Is Object Collaboration?

Preparing for Collaboration.

Recording Candidate Collaborations.

The Design Story for the Speak for Me Software.

Collaboration Options.

Who's In Control?

How Much Should Objects Trust One Another?

Strategies for Identifying Collaborations.

Looking at an Individual Object's Role: Stereotypes Imply Collaborations.

Looking at Individual Responsibilities: They Imply Collaborations.

Designing the Details of a Complex Responsibility.

Designing Collaborations for a Specific Task.

Identifying Applicable Patterns.

Identifying How Architecture Influences Collaborations.

Solving Problems in Collaborations.

Simulating Collaborations.

Planning a Simulation.

Running a Simulation.

Designing Good Collaborations.

The Law of Demeter: A Case Study.

Making Collaborations Possible.

Guidelines for Making Connections.

Designing Reliable Collaborations.

When Are We Finished?

Summary.

Further Reading.



6. Control Style.

What Is Control Style?

Control Style Options.

Making Trade-offs.

Centralizing Control.

Delegating Control.

The Limits of Control Decisions.

Developing Control Centers.

A Case Study: Control Style for External User Events.

Centralizing Control in the MessageBuilder.

Refactoring Decision Making into State Methods within the MessageBuilder.

Abstracting Away Decisions.

Delegating More Responsibility.

Designing the Control Style for the Guessing Neighborhood.

Designing a Similar Control Center: Can We Be Consistent?

Summary.



7. Describing Collaborations.

Telling Collaboration Stories.

A Strategy for Developing a Collaboration Story.

Establishing Scope, Depth, and Tone.

Listing What You Will Cover.

Deciding on the Level of Detail.

Showing a Bird's-Eye View.

Showing Collaborators Only.

Showing a Sequence of Interactions Among Collaborators.

Showing an In-Depth View.

Showing a Focused Interaction.

Showing an Implementation View.

Showing How to Adapt a Collaboration.

Where UML Diagrams Fall Short.

Choosing the Appropriate Form.

Tell It, Draw It, Describe It: Guidelines.

Organizing Your Work.

Adding Emphasis.

Unfolding Your Story.

Understanding What's Fundamental.

Putting It All Together.

Preserving Stories.

Summary.

Further Reading.



8. Reliable Collaborations.

Understanding the Consequences of Failure.

Increasing Your System's Reliability.

Determining Where Collaborations Can Be Trusted.

Trusted Versus Untrusted Collaborations.

Implications of Trust.

Identifying Collaborations to Be Made Reliable.

What Use Cases Tell Us.

Distinguish Between Exceptions and Errors.

Object Exceptions Versus Use Case Exceptions.

Object Exception Basics.

Exception- and Error-Handling Strategies.

Determining Who Should Take Action.

Designing a Solution.

Brainstorm Exception Conditions.

Limit Your Scope.

Record Exception-Handling Policies.

Documenting Your Exception-Handling Designs.

Specifying Formal Contracts.

Reviewing Your Design.

Summary.

Further Reading.



9. Flexibility.

What Does It Mean to Be Flexible?

Degrees of Flexibility.

The Consequences of a Flexible Solution.

Nailing Down Flexibility Requirements.

Recording Variations.

Variations and Realizations.

Identifying the Impact of a Variation.

Exploring Strategies for Realizing Flexibility.

Using Templates and Hooks to Support Variations.

The Role of Patterns in Flexible Designs.

Varying an Object's Behavior with the Strategy Pattern.

Hiding Interacting Objects with Mediator.

Making a Predefined Object or System Fit Using Adapter.

How Do Patterns Increase Flexibility?

How to Document a Flexible Design.

Consider Your Audience.

Describing How to Make a Variation.

Changing a Working System's Design.

Summary.

Further Reading.



10. On Design.

The Nature of Software Design.

Tackling Core Design Problems.

Frame the Problem.

Dealing with Revealing Design Problems.

A Story About Managing Shared Information.

A Story About Connection Problem Complexity.

A Story About a Design Problem That Never Got Easier.

Can Revealing Problems Be Wicked, Too?

Strategies for Solving Revealing Problems.

Redefining the Problem.

Synthesizing a Solution.

Working on the Rest.

Designing Responsibly.

Further Reading.



Bibliography.


Index. 0201379430T10212002

Preface

This is a book about designing object software. Like many human endeavors, design is part art, part engineering, part guesswork and experimentation. Discipline, hard work, inspiration, and sound technique all play their parts. Although a highly creative activity, software design fundamentals can be easily learned. There are fundamental strategies and techniques for developing a design solution. This book is packed with many practical design techniques that help you get the job done. We hope you become adept at thinking in objects and excited about devising solutions that exploit object technology.

Design choices can only be considered in light of what you know to be relevant and important. To achieve good results, however, you need to learn to discriminate important choices from mundane ones, and to acquire a good set of techniques that you intelligently practice. In this book, we present informal tools and techniques that don't require much more than a white board, a stack of index cards, a big sheet of paper and chairs around a table. Oh yeah, be sure to bring your brain, too!

But more important than a grab bag of techniques are the fundamental ways you view a design. Although the techniques we present in this book are independent of any particular implementation technology or modeling language or design method; our approach to object design requires a specific perspective:

Objects are not just simple bundles of logic and data... they are responsible members of an object community.

This approach, called Responsibility-Driven Design, forms the basis of how to reason about objects.

Most novice designers are searching for the right set of techniques to rigidly follow in order to produce the correct design. In practice, things are never that straightforward. For any given problem there are many reasonable, and a few very good solutions. People don't produce identical designs, even if they follow similar practices or apply identical design heuristics. For each problem you approach, you make a different set of tactical decisions. The effects of each small decision accumulate. Your current design as well as your current lines of reasoning shape and limit subsequent possibilities. Given the potential impact of seemingly inconsequential decisions, designers need to thoughtfully exercise good judgment.

Your primary tool as a designer is your power of abstraction--forming objects that represent the essence of a working application. In a design, objects play specific roles and occupy well-known positions in an application's architecture. Each object is accountable for a specific portion of the work. Each has specific responsibilities. Objects collaborate in clearly-defined ways, contracting with each other to fulfill the larger goals of the application.

Design is both a collaborative and a solo effort. To work effectively you not only need a rich vocabulary for describing your design, but strategies for finding objects, recipes for developing a collaborative model, and a framework for discussing design trade-offs. You will find these tools in this book. We also explore how design patterns can be used to solve a particular design problem and demonstrate their effects on a design. We present you with strategies for increasing your software's reliability and flexibility. We discuss different types of design problems and effective ways to approach them. This book presents many tools and techniques for reasoning about a design's qualities and effectively communicating design ideas. Whether a student or a seasoned programmer, a senior developer or a newcomer to objects, there are many practical things you can take away from this book.

How to Read This Book

This book is organized into two major parts. The first six chapters--Design Concepts, Responsibility-Driven Design, Finding Objects, Responsibilities, Collaborations, and Control Style--form the core of Responsibility-Driven Design principles and techniques.You should get a good grounding by reading these chapters.

Design Concepts introduces fundamental views of object technology and explains how each element contributes to a coherent way of designing an application. Even if you are a veteran designer, a quick read will set the stage for thinking about object design in terms of their roles and responsibilities. Responsibility-Driven Design provides a brief tour of Responsibility-Driven Design in practice. Finding Objects presents strategies for selecting and, equally important, rejecting candidate objects in an emerging design model. Responsibilities presents many techniques for coming up with responsibilities and intelligently allocating them to objects. Collaborations gives many practical tips and examples of how to develop a collaboration model. Control Style describes strategies for developing your application's control centers and options for allocating decision-making and control responsibilities.

The last four chapters explore challenges you may encounter as you develop your design. Each chapter covers a specific topic that builds on the design concepts and techniques presented in the first part of the book. Describing Collaborations explores options for documenting and describing your design. Reliable Collaborations presents strategies for handling exceptions, recovering from errors and collaborating within and across a "trusted region." Flexibility discusses how to characterize software variations and design to support them. On Design discusses how to sort design problems into one of three buckets--the core, the revealing and the rest--and treat each accordingly.



0201379430P07242002

Index

Click below to download the Index file related to this title:
Index

Updates

Submit Errata

More Information

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020