Summary

We’ve covered a lot of ground in this chapter. We started by defining SOAP and looking at the standards—the current 1.1 and the soon-to-be-ratified 1.2. We noted that 1.1 is the existing standard that current .NET SOAP implementations adhere to, and that 1.2 is just around the corner and should prove to be the final version of the standard. We then looked at the structure of a SOAP message, which is entirely contained within a root <Envelope> element and splits up broadly into a header and a body. We looked at how information is transmitted within the SOAP body and the kinds of formatting and encoding that are provided. We looked at how SOAP is bound by default to the HTTP- POST protocol and the extra information required on this layer.

We created a small application that uses ASP.NET to send and receive SOAP messages. We looked at the purpose of the SOAP header and how it can be used to convey information for other endpoints to act on. Last, we looked at how SOAP error messages are transmitted and the facilities that .NET possesses for handling them. We briefly touched on the subject of SOAP extensions, which we’ll cover in detail in later chapters.