design

Head First Object-Oriented Analysis and Design

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Head First Object-Oriented Analysis and Design by Brett D. McLaughlin, Gary Pollice and David West. Published by O’Reilly.

I found it hard to write a review about this book. Why? Because apart from a few, very minor typos it is simply superb! In my opinion, it is one of the best and sure to be one of the most influential books in this subject area. The O’Reilly Head First series of books are fast becoming the de facto standard, and I recommend that anyone who wants to get a deep understanding of how you should approach designing and developing software, read this book, no matter what your background or current skill set is. To date, I’ve read this book twice, cover to cover. It is not a particularly thin book, but it is very easy to read.
A colleague once told me that he picked up “Head First: Design Patterns” in a bookshop and flicked through it. He didn’t buy it because he wasn’t sure about the format, which if you’ve never seen a Head First book before, might at first seem a little different and perhaps off putting. As one reviewer put it:

“Hidden behind the funny pictures and crazy fonts is a serious, intelligent,
extremely well-crafted presentation of OO Analysis and Design. As I read the
book, I felt like I was looking over the shoulder of an expert designer who was
explaining to me what issues were important at each step and why.” — Edward Sciore

The book’s primary focus is “How to write great software”; this is summarised in 3 steps:
  1. Make sure your software does what the customer wants
  2. Apply basic OO principles to add flexibility
  3. Strive for a maintainable, reusable design.
It is a practical, readable and refreshing step-by-step walkthrough of the development process. It covers how to incorporate flexibility into all aspects of the software development life cycle. This book leads you through simple and then more advanced concepts by allowing you, the reader, to make the connections. In addition, it gives an easy to understand introduction to UML class diagrams.
Kathy Sierra talks about “Creating passionate users” over at the blog of the same name (highly recommended reading, as it is a gold mine of ideas and advice on creating great software). One of the beliefs espoused there is that it is better to get passionate responses from users at either end of the spectrum (i.e. love or hate it), rather than a mediocre “Yeah, it’s OK”. Judging by the polarised reviews over at Amazon, this book certainly creates passionate users/readers.
It is always hard to do justice to a great book in a short review, and this book is no exception. It is more readable and accessible than most other OO design books (excluding the other Head First design titles, of course!). I agree with Steve Bailey’s comments:

”I’d recommend this book to even the most veteran OO programmers. I put it up
there along with Code Complete …”

I would love to hear your thoughts on this book, so please leave a comment.

.NET Framework Design Guidelines (Book Review)

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I believe that good technical books fall roughly into 3 categories:

  1. Required reading now but throwaway later: these books go out of date quickly (for instance, that thick copy of plain ASP 3.0, which is now almost completely useless!)
  2. Essential, technology agnostic, lifespan of more than 10 years: containing advice which applies across the board regardless of technology, language or version. These are often process related books. Examples of books in this category are “Code Complete”, and the excellent, recently released “Head First OO A & D” (review to follow shortly).
  3. Essential, technology specific, lifespan hard to measure due to possibility of rapid technology shifts: vital books targeted at some specific technology or language.

The Framework Design Guidelines by Brad Abrams and Krzysztof Cwalina falls mainly into the last category, but also overlaps somewhat with the second.


Who should read this book?

Architects, API and Framework designers, lead developers, junior developers who want to be senior developers(!). Basically, anyone who is designing frameworks or writing code targeting the .NET framework.

The book is divided into 9 chapters and 3 appendices. The guidelines are presented in 4 major forms: Do, Consider, Avoid and Do Not. The authors choose a single language for the examples (which are in C#), which rather being a snub to VB.NET developers is rather more of a complement, as they mention they wanted the book to appeal to the widest audience. A DVD is also included containing several hours of video presentations.

This book represents the condensed wisdom and best practices of literally hundreds of developers, and a number of well known and respected, industry heavyweights have annotated the book, providing discussion and reasoning behind the guidelines.

1. Introduction
This chapter is a brief introduction and discusses the qualities of a well designed framework and the philosophy behind the design. In summary, frameworks are: simple, expensive, full of trade-offs, borrow from previous designs, are designed to evolve, are integrated and last but not least, are consistent.

2. Framework Design Fundamentals
Offers principles and guidelines central to framework design. Talks about scenario-driven design (very similar to TDD), having a low barrier to entry, self documenting wherever possible, the principle of layered architecture, API usability studies.

3. Naming Guidelines
Consistent and accurate naming is an essential principle of designing and writing all code. Krzysztof writes: “The team that develops the .NET Framework Base Class Library spends an enormous amount of time on naming, and considers it to be a crucial part of framework development.” As a consultant, poor method naming is something I see often. As Steven Clarke notes, methods should be named according to what they do, not according to some implementation detail.

4. Type Design Guidelines
This chapter provides general guidelines for the design of types and covers some of the associated subtleties and tradeoffs. This is a heavily annotated chapter, brimming with excellent advice.

5. Member Design
This is one of the slightly longer chapters (57 pages), and follows on from chapter 4, covering basic guidelines that should be followed when designing members of any type. It covers the design of properties, constructors, events, fields, operator overloads, and parameters. I seem to learn something new each time I re-read this and the preceding chapter.

6. Designing for Extensibility
How do you ensure that your framework will be extensible and stand the test of time? This chapter covers unsealed classes, protected members, events and callbacks, virtual members and abstractions. The annotations in this chapter contain several gems of advice, including determining the trade off of extensibility versus performance and some of the subtleties of creating types with virtual members.

7. Exceptions
This chapter is surely the definitive reference for exception handling. It covers the reasoning and benefits behind using exceptions and the best practices in creating and using them within frameworks. Required reading for all developers. [David M Kean posted excellent advice on which exceptions to raise here.]

8. Usage Guidelines
This chapter covers guidelines for the use of common types in publicly accessible APIs, implementing common interfaces and extending common base classes.

9. Common Design Patterns
Chapter 9 does not cover the subject of design patterns in general; rather it discusses a limited set of patterns that are frequently used in the .NET framework.

Conclusion
There is little doubt that a few paragraphs can adequately capture what is contained in the Framework Design Guidelines, or the amount of cumulative effort that has gone into producing this distilled wisdom. If you are a serious .NET developer then you should definitely have access to a copy of this must-read book.

My favourite quotes from the book:
“I have always felt that a key characteristic of a framework must be consistency”, Anders Hejlsberg in the foreword.

“Frameworks must be designed starting from a set of usage scenarios and code samples implementing these scenarios.”

Great CSS Techniques

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I recently purchased “The Zen of CSS Design” by Dave Shea and Molly Holzschlag and I would highly recommend it to any web designers or graphic artists working in the area of web design. You can visit the accompanying site CSS Zen Garden which is “A demonstration of what can be accomplished visually through CSS-based design”, and tries to address “the need for CSS to be taken sereiously by graphic artists.”

I also came across this link to a collection of excellent CSS techniques to solve common design tasks. Well worth book-marking: 53 CSS-Techniques You Couldn’t Live Without

If you are interested in this topic you should check out the recently released CSS Control Adaptor Toolkit from Microsoft, which basically enables ASP.NET 2.0 controls, which normally render as HTML markup, to be emitted as pure CSS based output. Scott Guthrie has a quick introduction to what they are and how they work here.

UPDATED: I also came across the CSS Handbook site. Also, check out this CSS cheat sheet.

For discussion on the pros and cons of Table versus CSS layout see Bill Merikallio and Adam Pratt’s Why tables for layout is stupid. There’s a more balanced look at the two approaches at Tables vs. CSS: PROS and CONS. (saw this via Scott Mitchell over at 4GuysFromRolla)