TweetFollow Us on Twitter

March 92 - Book Review - Developing Object-Oriented Software for the Mac

Book Review - Developing Object-Oriented Software for the Mac

Tom Becker

Developing Object-Oriented Software for the Macintosh
Neal Goldstein and Jeff Alger
Addison-Wesley, January, 1992
347 pages

Neal Goldstein and Jeff Alger have taken something complex and difficult-software engineering-and made it accessible and useful. Their book, Developing Object-Oriented Software for the Macintosh (DOOSM), and its methodology, Solution Based Modeling (SBM), shows a thorough understanding of the problems in developing software and the software engineering technology that can be applied to those problems.

SBM has a well designed graphic interface, called Visual Design Language (VDL). Most important, SBM is designed around the way people think. This is a real breakthrough. Of all the methodologies I've seen, SBM is the first practical one; it has a chance to improve how programmers do their work.

THE MACINTOSH AND SOFTWARE ENGINEERING

Software development methodologies tend to focus on difficult tasks like analysis and design, since there isn't much value in organizing something already straightforward, such as coding.

A methodology has a language for analysis and design concepts, and rules for ensuring the concepts are correct, or at least consistent. A good methodology is easy to use and understand, consistent, complete, flexible, and reliable. It helps diverse people work together, helps you create realistic schedules and budgets and avoid surprises, and helps you create software that meets the users' needs.

Most Macintosh software has been developed without using a formal methodology. Paradoxically, the primary reason for this is the innovation and high standards of the Macintosh. Methodologies, no matter what theories they use, are based on practical experience. The state of the art in methodology has had to catch up with graphic interfaces, event driven architectures, object-oriented programming, and application frameworks. This has meant that methodology is weakest in meeting the challenge of new technologies when it is needed the most.

In spite of the lack of methodology, Macintosh developers have managed to create a lot of excellent software. But there are also many applications that didn't make it, because of technical flaws, schedule problems, or not having the right features. The well educated, demanding users, and the intense competition in Macintosh software means that you can't just write better software. You have to continue to write ever better software, ever faster. The easiest computer to use is still hard to program.

Object programming and application frameworks such as MacApp promised to make Macintosh programming easier by making code more reusable and eliminating the need to deal directly with the Toolbox. It turns out that making code reusable, even with an OBJECT PROGRAMMING language, is harder than just hacking something out. Also, MacApp is well designed and well written, but can be hard to learn. Programming has been made easier, but only for those who manage to become MacApp experts. Making it easier to use object programming and MacApp is the challenge now.

It's interesting to see how object programming and MacApp affect the development process. MacApp frees you from writing a lot of boilerplate code such as main event loops. It separates the user interface from the rest of the program, and provides a fairly rich framework for adaptation. What's left to do is the analysis, interface design, and object design. In other words, MacApp eliminates most of the mindless parts of writing a Macintosh application, leaving only the hard parts. Meanwhile, object programming languages such as Object Pascal and C++ separate software design (class structure, object relationships and interfaces) from implementation (method code).

With object programming and MacApp, the analysis and design work that used to be mushed in with coding is forced into the open. This is good because it gets us closer to the heart of programming [1]. The next step in making programming easier is to come up with a better way to do analysis and design. In other words, a software development methodology.

ABOUT THE BOOK

The book, Developing Object-Oriented Software for the Macintosh, is divided into two parts. The first part establishes the need for SBM and goes into its theoretical background. The second part describes the details of the Visual Design Language (VDL) and SBM. The book also includes a brief appendix on a simple index card system for facilitating SBM.

Object-oriented software development

The first part of the book is written as a tutorial. It explains, in painstaking detail, the theoretical and practical considerations that went into SBM. I could tell this book was written by real engineers. It has structure. Concepts are introduced, described, and summarized. Each section depends on the previous one and leads to the next. Not a sentence was wasted.

This part of the book is well written, even entertaining. The authors present concepts with a clarity and confidence that comes from practical experience and repeated refinement. The examples are good and humor is used appropriately.

The first chapter establishes the need for improvement in how we develop software. It demolishes the standard myths of software development, then defines the characteristics of a good methodology and introduces object-oriented software development, more of which is covered in the following chapters.

The second chapter explains object programming, including inheritance, polymorphism, and class libraries.

The primary purpose of chapter 3, the Folklore of Object-Oriented Software Development, is the debunking of objectivism, the belief that objects in a computer program work the same way as real objects in the real world (and vice versa). The attractiveness of objectivism is easy to understand when you consider that a major early use of object-oriented programming was for simulation, where the purpose is to model real world objects. Real-time control is another application where there is a strong resemblance between the objects inside and the ones outside the computer. For most applications, however, objectivism really doesn't work. Real world objects have identity and structure, and may be similar to other objects in different ways, but real world objects are too complicated to be organized into hierarchies, even with multiple inheritance. Computer objects are an organization of code and data for the convenience of the programmer. Objects allow you to write software that has minimal side effects when it runs. Objects make it easier to modify the software because interfaces between objects are well defined and dependencies can be minimized. Class hierarchies are simply another convenience that allow code and data definitions for similar objects to be consolidated.

Chapter 4, Sample Applications (Why Aren't They Easy), is one of the best parts of the book. It shows how the classic object-oriented design approaches fall apart for non-trivial examples. It describes the messes you can get into. Object programmers will recognize them. It looks at how an expert might approach the problem, the principles behind that approach, and the characteristics of a good object-oriented design.

Chapter 5 is a short primer on cognitive science. It describes how people think in terms of cognitive categories, and the difference between overlapping categories (how people think), and hierarchical classes (how people think they think). This is a little subtle, but important because it is the primary justification for using planes, scenarios, and calibration in SBM, instead of using a top-down or linear approach.

Solution based modeling

The second part of the book is written as a reference. It gets down to brass tacks and describes how to use SBM.

Chapter 6 describes the Visual Design Language, which is used to communicate design information throughout the rest of the book. This is human interface design at its best. The authors worked with a graphic design firm to create VDL, and it shows. VDL simply looks better than the symbols for other methodologies. Perspective is used to make symbols easier to recognize, while packing more meaningful information into diagrams. The symbols are not hard to draw. This lets non-programmers participate more fully in analysis and design.

Chapter 7 is an overview of SBM. Chapters 8 through 11 describe the Business, Technology, Execution, and Program planes in a Solution Based Model.

The fundamental unit in a Solution Based Model is the scenario, a description in VDL of a single topic or concept. Scenarios are supposed to be simple-something that can be easily drawn on an index card. There is no fixed structure that the scenarios have to fit into. Instead, a calibration process is used to find inconsistencies among overlapping scenarios.

This is another great thing about SBM. It's hard for people to be simultaneously creative and critical; it always works better if you can separate the two dynamics. The different levels of abstraction in a project, such as requirements, specification, design, and implementation, are handled in SBM as planes. The relationships between planes are described using scenarios, just like everything else. The calibration process ensures that the model is valid from top to bottom. The same methodology is used for the whole software life cycle.

The Business plane is where you do requirements analysis. You describe how things are done now (the reference model), and how they will be done with the new system (the solution model). SBM can do an impact analysis by looking at the differences between the reference and solution models. This has enormous value for justifying a system proposal, marketing, planning, and training.

The Technology plane is where you do the system specification, in the form of a user interface model, content model, and environment model. The separation between the Business and Technology planes is a key factor. The Business plane focuses on people and how they do their work. The Technology plane focuses on the computer system and how it appears to the user.

The Execution plane contains the user interface, content, and environment architectures. This is where you design the objects and interfaces and figure out how library building blocks will be used in the system. The Business and Technology planes describe real-world objects (such as people, forms, reports, screens and keyboards) while the Execution plane describes software objects (such as views, documents, and commands). This is where you apply the theory on the failures of the classic object-oriented design approaches. If objectivism were true, the contents of the Execution plane would look just like the Business and Technology planes, when actually it takes real work to design the run-time objects. In practice, the principles of good object design are the same as those for good software design: well defined modules with minimal interdependencies.

The Program plane is where you design the types and classes for implementing the system. There is an important distinction between the Execution plane, which describes how the run-time objects are organized, and the Program plane, which describes how the source code is organized. This helps you avoid a common pitfall: confusing objects and classes.

The second part of the book is not as easy to understand as the first part. Because it's written as a reference, there isn't as much continuity between sections. I needed to read through it twice to fit everything together. For example, I got confused because I couldn't tell the difference between the "reference frame" and the "reference model" in the business plane. That was cleared up in the last chapter, which talks about looping around to the next iteration in the software life-cycle.

The concepts that I had the most difficulty with were how dangling threads are managed and how calibration is performed. The theory is clear, but the details are skimpy. It would help to have a worked out example-such as for the Payroll sample application-that goes through the whole SBM process, showing overlapping scenarios, dangling threads, calibration, and scenario revision. Of course, that might double the size of the book.

EVALUATION

SBM could clearly use a CASE (Computer Aided Software Engineering) tool. The tool would have a VDL drawing module for creating and editing scenarios that would be stored in a database. The database would make it easy to navigate through overlapping scenarios, and calibration could be automated. If a CASE tool came out soon enough and weren't too expensive, it could become a useful standard for communicating design information.

It would help to have more worked out examples and diagrams; they would be even more useful on-line. The ultimate test would be a diagram of SBM, done using its own Visual Design Language.

DOOSM is the result of two years of work by Neal Goldstein and Jeff Alger. In some respects the book has the feel of a version 1.0.0, but the authors' experience and hard work shows through. To quote James Plamondon, "MacApp is not just a bunch of user interface code, it is a library of accumulated wisdom on Macintosh programming." The real value of SBM is its accumulated wisdom. Get a copy, and study it carefully. And have your manager and any non-programmers on your team read the first part, at least. Any one of the many insights in the book will make it worthwhile.

 
AAPL
$97.67
Apple Inc.
+0.64
MSFT
$44.50
Microsoft Corpora
+0.10
GOOG
$589.02
Google Inc.
-4.33

MacTech Search:
Community Search:

Software Updates via MacUpdate

TinkerTool 5.3 - Expanded preference set...
TinkerTool is an application that gives you access to additional preference settings Apple has built into Mac OS X. This allows to activate hidden features in the operating system and in some of the... Read more
Audio Hijack Pro 2.11.0 - Record and enh...
Audio Hijack Pro drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio with Audio Hijack... Read more
Intermission 1.1.1 - Pause and rewind li...
Intermission allows you to pause and rewind live audio from any application on your Mac. Intermission will buffer up to 3 hours of audio, allowing users to skip through any assortment of audio... Read more
Autopano Giga 3.6 - Stitch multiple imag...
Autopano Giga allows you to stitch 2, 20, or 2,000 images. Version 3.0 integrates impressive new features that will definitely make you adopt Autopano Pro or Autopano Giga: Choose between 9... Read more
Airfoil 4.8.7 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
Microsoft Remote Desktop 8.0.8 - Connect...
With Microsoft Remote Desktop, you can connect to a remote PC and your work resources from almost anywhere. Experience the power of Windows with RemoteFX in a Remote Desktop client designed to help... Read more
xACT 2.30 - Audio compression toolkit. (...
xACT stands for X Aaudio Compression Toolkit, an application that encodes and decodes FLAC, SHN, Monkey’s Audio, TTA, Wavpack, and Apple Lossless files. It also can encode these formats to MP3, AAC... Read more
Firefox 31.0 - Fast, safe Web browser. (...
Firefox for Mac offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals... Read more
Little Snitch 3.3.3 - Alerts you to outg...
Little Snitch gives you control over your private outgoing data. Track background activityAs soon as your computer connects to the Internet, applications often have permission to send any... Read more
Thunderbird 31.0 - Email client from Moz...
As of July 2012, Thunderbird has transitioned to a new governance model, with new features being developed by the broader free software and open source community, and security fixes and improvements... Read more

Latest Forum Discussions

See All

Reddme for iPhone - The Reddit Client (...
Reddme for iPhone - The Reddit Client 1.0 Device: iOS iPhone Category: News Price: $.99, Version: 1.0 (iTunes) Description: Reddme for iPhone is an iOS 7-optimized Reddit client that offers a refreshing new way to experience Reddit... | Read more »
Jacob Jones and the Bigfoot Mystery : Ep...
Jacob Jones and the Bigfoot Mystery : Episode 2 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Jacob Jones is back in Episode 2 of one of Apples 'Best of 2013' games and an App Store... | Read more »
New Trailer For Outcast Odyssey, A New K...
New Trailer For Outcast Odyssey, A New Kind of Card Battler Posted by Jennifer Allen on July 25th, 2014 [ permalink ] Out this Fall is a new kind of card battle game: Outcast Odyssey. | Read more »
Garfield: Survival of the Fattest Coming...
Garfield: Survival of the Fattest Coming to iOS this Fall Posted by Jennifer Allen on July 25th, 2014 [ permalink ] Who loves lasagna? Me. Also everyone’s favorite grumpy fat cat, Garfield. | Read more »
Happy Flock Review
Happy Flock Review By Andrew Fisher on July 25th, 2014 Our Rating: :: HERD IT ALL BEFOREUniversal App - Designed for iPhone and iPad Underneath the gloss of Happy Flock’s visuals is a game of very little substance. It’s cute, but... | Read more »
Square Register Updates Adds Offline Pay...
Square Register Updates Adds Offline Payments Posted by Ellis Spice on July 25th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Looking For Group – Hearthstone’s Curse...
For the first time since its release (which has thankfully been a much shorter window for iPad players than their PC counterparts), Blizzard’s wildly successful Hearthstone: Heroes of Warcraft CCG is sporting some brand new content: the single... | Read more »
Poptile Review
Poptile Review By Jennifer Allen on July 25th, 2014 Our Rating: :: SIMPLY FUNUniversal App - Designed for iPhone and iPad Simple yet a little bit glorious, Poptile is a satisfying entertaining puzzle game with oodles of the ‘one... | Read more »
Modern Combat 5: Blackout Review
Modern Combat 5: Blackout Review By Brittany Vincent on July 25th, 2014 Our Rating: :: LESS QQ, MORE PEW PEWUniversal App - Designed for iPhone and iPad The fifth entry into the blockbuster Modern Combat series is what mobile... | Read more »
Watch and Share Mobile Gameplay Videos W...
Watch and Share Mobile Gameplay Videos With Kamcord Posted by Jennifer Allen on July 25th, 2014 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »

Price Scanner via MacPrices.net

iMacs on sale for $150 off MSRP, $250 off for...
Best Buy has iMacs on sale for up to $160 off MSRP for a limited time. Choose free home shipping or free instant local store pickup (if available). Prices are valid for online orders only, in-store... Read more
Mac minis on sale for $100 off MSRP, starting...
Best Buy has Mac minis on sale for $100 off MSRP. Choose free shipping or free instant local store pickup. Prices are for online orders only, in-store prices may vary: 2.5GHz Mac mini: $499.99 2.3GHz... Read more
Global Tablet Market Grows 11% in Q2/14 Notwi...
Worldwide tablet sales grew 11.0 percent year over year in the second quarter of 2014, with shipments reaching 49.3 million units according to preliminary data from the International Data Corporation... Read more
New iPhone 6 Models to Have Staggered Release...
Digitimes’ Cage Chao and Steve Shen report that according to unnamed sources in Apple’s upstream iPhone supply chain, the new 5.5-inch iPhone will be released several months later than the new 4.7-... Read more
New iOS App Helps People Feel Good About thei...
Mobile shoppers looking for big savings at their favorite stores can turn to the Goodshop app, a new iOS app with the latest coupons and deals at more than 5,000 online stores. In addition to being a... Read more
Save on 5th generation refurbished iPod touch...
The Apple Store has Apple Certified Refurbished 5th generation iPod touches available starting at $149. Apple’s one-year warranty is included with each model, and shipping is free. Many, but not all... Read more
What Should Apple’s Next MacBook Priority Be;...
Stabley Times’ Phil Moore says that after expanding its iMac lineup with a new low end model, Apple’s next Mac hardware decision will be how it wants to approach expanding its MacBook lineup as well... Read more
ArtRage For iPhone Painting App Free During C...
ArtRage for iPhone is currently being offered for free (regularly $1.99) during Comic-Con San Diego #SDCC, July 24-27, in celebration of the upcoming ArtRage 4.5 and other 64-bit versions of the... Read more
With The Apple/IBM Alliance, Is The iPad Now...
Almost since the iPad was rolled out in 2010, and especially after Apple made a 128 GB storage configuration available in 2012, there’s been debate over whether the iPad is a serious tool for... Read more
MacBook Airs on sale starting at $799, free s...
B&H Photo has the new 2014 MacBook Airs on sale for up to $100 off MSRP for a limited time. Shipping is free, and B&H charges NY sales tax only. They also include free copies of Parallels... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.