Release 10.1A: OpenEdge Development:
Web Services

Handling SOAP Message Headers in the Progress 4GL

SOAP headers are an optional part of a SOAP message and the requirement to use them depends on the Web service. Many Web services require no client handling of SOAP headers.

If the Web service requires you to handle SOAP headers, especially if you need to modify or examine the contents of a SOAP header, you often need to know XML and understand the Progress 4GL facilities for parsing and managing XML. This includes 4GL support for parsing and directly manipulating an XML document in a Document Object Model (DOM) tree or parsing and writing the elements of an XML document using the Simple API for XML (SAX). For more information on these facilities, see OpenEdge Development: Programming Interfaces .

In rare instances, you might be able to access the data in a SOAP header as a 4GL temp-table or ProDataSet, without the need to directly manage the XML. However, this is only possible if the WSDL Analyzer recognizes complex data in the header that it can map to a temp-table or ProDataSet definition. For more information, see the sections on complex data in Chapter 8, " Analyzing WSDL for Progress 4GL Access to Web Services."

This chapter describes how to define and use specified callback procedures (header handlers) that manage the SOAP headers for SOAP request and response messages:

SOAP message headers—an overview
Defining header handlers
Creating and managing SOAP message headers
Managing memory for SOAP headers
Attributes and methods for handling SOAP headers

For information on how to declare an internal procedure as a callback procedure for handling headers, see Chapter 10, " Invoking Web Service Operations from the Progress 4GL."