R – iPhone – calling SOAP services

One word: Don't.

OK obviously that isn't a real answer. But still SOAP should be avoided at all costs. ;-) Is it possible to add a proxy server between the iPhone and the web service? Perhaps something that converts REST into SOAP for you?

You could try CSOAP, a SOAP library that depends on libxml2 (which is included in the iPhone SDK).

I've written my own SOAP framework for OSX. However it is not actively maintained and will require some time to port to the iPhone (you'll need to replace NSXML with TouchXML for a start)

My most recent experiences with wsdl2objc is that it's on the right road, but not really there yet. It's definitely the kind of program you'd want. It just may or may not be able to handle the WSDLs you actually have.

Short answer: try it and see if it works for your WSDLs. If it does, hooray. If it doesn't, you have two options. For reasonably simple WSDLs, write the SOAP by hand. This often is actually the easiest approach. If the WSDL is complex, then use gSOAP to get to C++ and then wrap the C++ in Objective-C++ (or use the -c option to gSOAP and wrap the resulting C, whichever you're more comfortable with).