The first thing I noticed as soon as I received the printed copy is that it's substantially longer than the previous version. A whole 72 pages longer, to be exact! In a mind-blowing 560 pages, the authors James Kennard and Chuck Lanham set on to provide us with the missing developer's documentation for the Joomla! Framework API in a concise and easy to understand format, involving both discussion and code examples. Having the previous edition on the side, I sat down and did a comparison between the two books.
The old edition was more of a reference than a guide. It walked you through the available API functions, but some parts of it left the code speak for itself. Well, not any more. For example, when introducing the database layer the author no longer speaks of the CRUD lifetime of a record, tossing in a bunch of code. Instead, the new version discusses the lifetime of a record step-by-step, introducing the necessary code to perform that after the short discussion.
In my opinion, the way the new edition is organized is more developer-friendly and doubles as a guide and an in-depth reference of the Joomla! Framework API. It methodically discusses all the aspects of the API, from the basic to the arcane. It covers everything: from the database layer and MVC design basics to the only full coverage of the installation XML manifest and invaluable tips on security best practices. After all those years of developing software for Joomla! I couldn't find something wrong or anything missing from this book. It's an absolutely excellent work.
Overall, if you are looking for one and only one book to use while developing Joomla! components, modules and plug-ins, this is it. Lest you delve on Joomla!'s source code, this book is the most complete reference you'll find in the market. If you are a beginner or intermediate developer who wants to leverage the full power of the Joomla! Framework you need this book. If you ask me, I swear by it.
Originally published at http://dionysopoulos.me/blog/the-joomla-developers-bible