PHP Web Services

Chapter 9. Debugging Web Services

Anyone with extensive development experience has, by default, extensive debugging experience. Many of the skills learned as a PHP developer on more traditional web applications are very useful when working with APIs. Understanding how the pieces go together is probably the most important part of the puzzle. When you see a problem, you must answer several questions to determine the solution. Is that something that happened in the server? During transfer? Did the client not understand the response it received? And, if you have an application consuming an API, is it the application or the remote API with the problem? Narrowing down where exactly to look when things go wrong will save time and sanity.

Particularly with complex projects, it’s easy for the problem of “it’s not working” to be blamed on an API, especially if different teams take responsibility for different system components. In one such situation, the team providing the API created a requirement that all bug reports be provided with a replication case using only Curl. This caused grumbling from the developers of the consuming application, but at the end of the project, it emerged that half of the “bugs” in the API were in fact bugs in the consuming application code, and the developers had been able to track down and squash the bugs in their own system without interrupting the work of the API team. To this day I recommend Curl or other very simple replication cases, excluding as many other ...