Integration Platform Technologies: Siebel eBusiness Application Integration Volume ll > Web Services > About Custom SOAP Filters >

About Handling Custom Headers Using Filters

SOAP headers provide the option of providing optional or mandatory processing information. To process optional custom headers that are provided by external applications, a special business service known as a filter may be defined. Filters can process both request and response headers. A special attribute, mustUnderstand, is used to indicate whether or not the custom header is to be processed:

• If 'mustUnderstand' = 1, the custom header is interpreted as being mandatory and the custom header is processed by the filter defined for this purpose.
• If 'mustUnderstand' = 1 and a filter is not specified, the custom header is not read and a SOAP:MustUnderstand fault is generated.
• If 'mustUnderstand' = 0, no processing of the custom header is attempted.

You want to keep SOAP body and header processing isolated. The inbound dispatcher and outbound proxy know how to process the SOAP body but have no idea on how to set or consume headers. Headers are application-specific. Some customization is needed to set and consume custom headers. To process optional custom headers that are provided by external applications, a special business service, a filter, is defined. The Web Service outbound proxy and the Web Service inbound dispatcher can be configured to call specific filters for the processing of individual (custom) headers.

NOTE:  Headers that are consumed by the filter service have to be removed from the SOAP message.