One of my colleagues at Oracle, Marcie Young, has created three new excellent demonstrations of consuming web services in Application Express 4.1.
The first demonstration called "Creating and Using a Manual SOAP Web Service in Your Application" takes you step by step through creating a manual web service reference, and then using the Create Form and Report on Web Service wizard to create the page to interact with the service. The ability to use that wizard on a manual web reference was a new feature on 4.0. (This demonstration even exposed a slight branching inconvenience that I am going to file and fix in 4.1.1.)
"Creating and Using a RESTful Web Service with an XML Response" uses the Google Geocoder v3 web service and is a classic example of consuming a RESTful style web service in Application Express.
Finally, "Creating and Using a RESTful Web Service with an XML Response and a Bind Variable" is a great example of consuming a RESTful service where the parameter is passed as part of the URI path (not part of the query string), like http://someservice.com/employees/{id}, where {id} is the employee that you want to retrieve. This can be accomplished by using &ITEM_NAME. syntax when you specify the URL endpoint in the RESTful web service reference.
All of these demonstrations reinforce your need to learn to write XPath expressions to traverse an XML document. If you don't know what I am talking about, there is an excellent XPath tutorial at www.w3schools.com.
So check these demonstrations out (they are nice videos) and give your mad props to Marcie!
