PHP Web Services: APIs for the Modern Web

Q&A with Lorna Jane Mitchell, author of "PHP Web Services"

Q. What makes this book important right now?

A. Today's web applications are beyond "making websites" and into integrating multiple data sources to present all the information and features that a user could need-- and often making that information available in turn as an API. No system is an island at this point, and APIs are the bridges between the systems.

Q. What information do you hope that readers of your book will walk away with?

A. The book will give a good understanding of the concepts; readers will learn all about HTTP theory, various different types of services, how to work with data types. It goes beyond the standard textbook though and shows examples from real projects (the code examples are also on GitHub), and gives pragmatic advice on how to apply the concepts really well.

Q. What's the most exciting thing happening in your space?

A. Seeing longstanding web developers step beyond the browser, and build systems that can work with rich AJAX frontends, mobile sites, and everything else. It's a time of great change, and it's all powered by APIs. PHP was made "to solve the web problem," so it's perfect as the backend technology for all these inspiring innovations as it's scalable and fast.

Q. Can you give us a few tips for smarter web development?

1. Get to know your tools! Your browser should have plugins to let you observe the HTTP traffic and also change it by editing cookies or sending extra headers. Mastering other tools like cURL and Wireshark can make API development much easier and faster.
2. Always consider the failure case. Most APIs work perfectly well when client are server are making expected moves. How your API responds in adverse conditions or in response to nonsense requests really defines its quality.
3. Choose your technologies for your user, not for your developer. Making websites, we deliver to the browser. Making APIs, we deliver to any number of other unknown platforms and there are many design decisions to make. The "right" choices depend much more on your target user base than on your own preferences or any consideration for what is new and shiny.
4. Have confidence. Try to avoid being overwhelmed by all the information that is out there about the "one true way" to create an API. There are lots of options and in the realm of APIs, especially RESTful ones, they are usually strong and vocal opinions. A good understanding of HTTP concepts is the only must-have; don't try to please everyone you meet on the internet-- the only way to deliver a decent API is to begin!
5. Finally, don't be afraid to break the rules. Every application is different, and while it's vital to understand why things are normally done a particular way, you may find the exception that breaks the rule. In that situation, have confidence and follow your instincts rather than the rules.