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 might need to understand ABL facilities for parsing and managing XML. This includes ABL 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 an ABL 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
Analyzing complex data.
The sections in this chapter describe how to define and use specified callback procedures (header handlers) that manage the SOAP headers for SOAP request and response messages.
