When Do We Need Message Conversion Plug-in

5.2.2 When Do We Need Message Conversion Plug-in

The following table lists several message conversion plug-in use cases:

Table 5-1 Message Conversion Plug-in Use Cases

-	Scenario Description	soap_in_tuxedo_CUSTBUF	soap_out_tuxedo_CUSTBUF
Oracle Tuxedo Originated Service	A SOAP message payload is transformed into a custom typed buffer	Required	N/A
	A custom typed buffer is transformed into a SOAP message payload.	N/A	Required
	An Oracle Tuxedo service input and/or output buffer is associated with a customized XML schema definition when a SOAP message payload is being transformed into this buffer.	Non XML typed buffer: Required XML typed buffer: Optional	N/A
	An Oracle Tuxedo service input and/or output buffer is associated with a customized XML schema definition when this buffer is being transformed into a SOAP message payload.	N/A	Non XML typed buffer: Required XML typed buffer:Optional
	All other general cases when a SOAP message payload is being transformed to an Oracle Tuxedo buffer.	Optional	N/A
	All other general cases when an Oracle Tuxedo buffer is being transformed into a SOAP message payload.	N/A	Optional
Web Service Originated Service	All cases when an Oracle Tuxedo buffer is transformed into a SOAP message payload.	N/A	Optional
Web Service Originated Service	All cases when a SOAP message payload is being transformed into an Oracle Tuxedo buffer.	Optional	N/A

From the table above, the following message conversion plug-ins general rules are applied.

If an Oracle Tuxedo originated service consumes custom typed buffers, the message conversion plug-in is required. The Oracle Tuxedo framework does not understand custom typed buffer detailed data structure. Therefore SALT default data type conversion rules cannot be applied.
If the input and/or output (no matter if returned with TPSUCCESS or TPFAIL) buffer of an Oracle Tuxedo originated service is associated with an external XML Schema, you should develop message conversion plug-ins to handle the transformation manually (unless you are sure that the SALT default buffer type-based conversion rules can handle it correctly).
- For example, if you associate your own XML Schema with an Oracle Tuxedo service FML32 typed buffer, you must provide a message conversion plug-in since SALT default data mapping routines may not understand the SOAP message payload structure when trying to convert into the FML typed buffer. Contrarily, the SOAP message payload structure converted from the FML typed buffer may be tremendously different from the XML shape defined via your own XML Schema.
- If you associate your own XML Schema with an Oracle Tuxedo service XML typed buffer, most of time you do not have to provide a message conversion plug-in. This is because SALT passes the XML data as is in both message conversion directions.

Parent topic: Programming Message Conversion Plug-ins