Designing Near Real Time NDS Messages
As described above, near real time NDS messages require you to define:
- A download staging receiver to process records on the NDS table.
- A download staging sender to process "responses" to the download staging receiver.
The following sections identify other control table design issues.
Consider the following integration scenario. A change to a certain type of record in your product should trigger a message to an external system to inform that system of the change. This will be a near real time message and we expect an asynchronous response.
Designing the XML Request and Inbound Service
You should work with the external system to determine the information they require for this message. If a system service already exists to extract all the required information, you may use that service. However, it's possible that you would need to create a new service to extract the information you need.
Your implementers must create an appropriate service and then use the schema editor to create request and response schemas based on this service.
Message ID. If you expect an asynchronous response to this message, the request and response schemas must include a private attribute to hold the MessageID.
Create an XAI inbound service for extracting the appropriate information and building the XML request.
Designing the Near Real Time NDS Type
Define an appropriate NDS type. The information defined here is required to successfully build the XML request.
- Indicate the XAI Inbound Service created above.
- Indicate an appropriate notification download condition. This allows the mechanism that creates the NDS to refer to this condition rather than hard-coding the NDS type.
- Use the notification download type context to identify the data required to build the request to invoke the XAI Inbound Service for this download type. In our case, context types must be defined for the business object id and the message id. Use the XPATH to indicate the relative page for this element in the request schema.
|
Context Type |
XPATH |
|
Maintenance Object ID |
//ExtractInfoService/ExtractInfoHeader@MaintenanceObjectID |
|
Message ID |
//ExtractInfoService/ExtractInfoHeader/MessageID |
Designing the Response
If you expect a response to the message sent, you must also design the XAI inbound service to be used to process the response.
- The XSL transformation scripts that are referenced by the inbound service should populate the appropriate XML elements to allow XAI to recognize that the inbound message is a response.
- Otherwise, the inbound service should be designed to process this message as appropriate. For example, if the response should update the status of the record that initiated the outgoing request, the inbound service should reference the appropriate schema to update the appropriate record.