Framework Design Guidelines: Conventions, Idioms, and Patterns for Reusable .NET Libraries (2nd Edition)

This book,Framework Design Guidelines,presents best practices for designing frameworks, which are reusable object-oriented libraries. The guidelines are applicable to frameworks ranging in size and in their scale of reuse: Large system frameworks, such as the .NET Framework, usually consisting of thousands of types and used by millions of developers. Medium-size reusable layers of large distributed applications or extensions to system frameworks, such as the Web Services Enhancements. Small components shared among several applications; for example, a grid control library.It is worth noting that this book focuses on design issues that directly affect the programmability of a framework (publicly accessible APIs 1 ). As a result, we generally do not cover much in terms of implementation details. Just like a user interface design book doesn't cover the details of how to implement hit testing, this book does not describe how to implement a binary sort, for example. This scope allows us to provide a definitive guide for framework designers instead of being yet another book about programming.These guidelines were created in the early days of .NET Framework development. They started as a small set of naming and design conventions but have been enhanced, scrutinized, and refined to a point where they are generally considered the canonical way to design frameworks at Microsoft. They carry the experience and cumulative wisdom of thousands of developer hours over three versions of the .NET Framework. We tried to avoid basing the text purely on some idealistic design philosophies, and we think its day-to-day use by development teams at Microsoft has made it an intensely pragmatic book.The book contains many annotations that explain trade-offs, explain history, amplify, or provide critiquing views on the guidelines. These annotations are written by experienced framework designers, industry experts, and users. They are the stories from the trenches that add color and setting for many of the guidelines presented.To make them more easily distinguished in text, namespace names, classes, interfaces, methods, properties, and types are set in monospace font.The book assumes basic familiarity with .NET Framework programming. A few guidelines assume familiarity with features introduced in version 3.5 of the Framework. If you are looking for a good introduction to Framework programming, there are some excellent suggestions in the Suggested Reading List at the end of the book. Guideline PresentationThe guidelines are organized as simple recommendations usingDo, Consider, Avoid,andDo not.Each guideline describes either a good or bad practice and all have a consistent presentation. Good practices have a check mark in front of them, and bad practices have an ex.The wording of each guideline also indicates how strong the recommendation is. For example, aDoguideline is one that should always 2 be followed. On the other hand,Considerguidelines should generally be followed, but if you fully understand the reasoning behind a guideline and have a good reason to not follow it anyway, you should not feel bad about breaking the rules. Similarly,Do notguidelines indicate something you should almost never do. Less strong,Avoidguidelines indicate that something is generally not a good idea, but there are known cases where breaking the rule makes sense.Some more complex guidelines are followed with additional background information, illustrative code samples, and rationale. Language Choice and Code ExamplesOne of the goals of the Common Language Runtime is to support a variety of programming languages: those with implementations provided by Microsoft, such as C++, VB, C#, F#, Python, and Ruby, as well as third-party languages such as Eiffel, COBOL, Fortran, and othersKrzysztof Cwalina is the author of 'Framework Design Guidelines: Conventions, Idioms, and Patterns for Reusable .NET Libraries (2nd Edition)', published 2008 under ISBN 9780321545619 and ISBN 0321545613.