Matt Zandstra - PHP 8 Objects, Patterns, and Practice: Mastering OO Enhancements, Design Patterns, and Essential Development Tools

Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the books product page, located at www.apress.com/9781484267905 . For more detailed information, please visit http://www.apress.com/source-code .

When I first conceived of this book, object-oriented design in PHP was an esoteric topic. The intervening years have not only seen the inexorable rise of PHP as an object-oriented language but also the march of the framework. Frameworks are incredibly useful, of course. They manage the guts and the glue of many (perhaps, these days, most) web applications. Whats more, they often exemplify precisely the principles of design that this book explores.

There is, though, a danger for developers here, as there is in all useful APIs. This is the fear that one might find oneself relegated to userland, forced to wait for remote gurus to fix bugs or add features at their whim. Its a short step from this standpoint to a kind of exile in which one is left regarding the innards of a framework as advanced magic and ones own work as not much more than a minor adornment stuck up on top of a mighty unknowable infrastructure.

Although Im an inveterate reinventor of wheels, the thrust of my argument is not that we should all throw away our frameworks and build MVC applications from scratch (at least not always). It is rather that, as developers, we should understand the problems that frameworks solve and the strategies they use to solve them. We should be able to evaluate frameworks not only functionally but in terms of the design decisions their creators have made and to judge the quality of their implementations. And yes, when the conditions are right, we should go ahead and build our own spare and focused applications and, over time, compile our own libraries of reusable code.

I hope this book goes some way toward helping PHP developers apply design-oriented insights to their platforms and libraries and provides some of the conceptual tools needed when its time to go it alone.

As always, I have benefited from the support of many people while working on this edition. But as always, I must also look back to the books origins. I tried out some of this books underlying concepts in a talk in Brighton, back when we were all first marveling at the shiny possibilities of PHP 5. Thanks to Andy Budd, who hosted the talk, and to the vibrant Brighton developer community. Thanks also to Jessey White-Cinis, who was at that meeting and who put me in touch with Martin Streicher at Apress.

Once again, this time around, the Apress team has provided enormous support, feedback, and encouragement. I am lucky to have benefited from such professionalism.

Im very lucky to have had my friend and colleague, Paul Tregoing, working on this edition as Technical Reviewer. The fact that PHP itself was under active development throughout the writing of this book demanded extra vigilance. Code examples that were perfectly valid in early drafts were rendered incorrect by the languages fast evolution. Once again, this edition has greatly benefited from Pauls knowledge, insight, and attention to detailmany thanks Paul!

Thanks and love to my wife, Louise. The production of this book has coincided with three pandemic lockdowns, so thanks are also due to our children, Holly and Jake, for many much-needed distractionsoften provided during Zoom meetings conducted in my office space (the corner of the kitchen table).

Thanks to Steven Metsker for his kind permission to reimplement in PHP a simplified version of the parser API he presented in his book, Building Parsers with Java (Addison-Wesley Professional, 2001).

I write to music, and, in previous editions of this book, I remembered the great DJ, John Peel, champion of the underground and the eclectic. The soundtrack for this edition was largely provided by BBC Radio 3s contemporary music show, Late Junction, played on a loop. Thanks to them for keeping things weird.