Whether you're sharing data between two internal systems or building an API so that users can access their data, this practical guide has everything you need to build APIs with PHP. Author Lorna Jane Mitchell provides lots of hands-on code samples, real-world examples, and advice based on her extensive experience to guide you through the process-from the underlying theory to methods for making your service robust.You'll learn how to use this language to work with JSON, XML, and other web service technologies. This updated second edition includes new tools and features that reflect PHP updates and changes on the Web.Explore HTTP, from the request/response cycle to its verbs, headers, and cookiesWork with and publish webhooks-user-defined HTTP callbacksDetermine whether JSON or XML is the best data format for your applicationGet advice for working with RPC, SOAP, and RESTful servicesUse several tools and techniques for debugging HTTP web servicesChoose the service that works best for your application, and learn how to make it robustDocument your API-and learn how to design it to handle errors