Understanding Message Filtering

You use filtering to suppress an input message based on its content. For example, you can suppress all inbound purchase order messages that specify order quantities less than the minimum number required for a discount.

Place filtering steps early in your Application Engine transform program; each message suppressed by the filter is one less message for subsequent steps to process.

You must use PeopleCode for filtering, so it'll probably be a distinct step. Because you must use the XmlDoc and XmlNode classes in your PeopleCode transform steps, you can analyze messages in any way that those classes support.

Filtering requires the following actions in your PeopleCode program:

1. Retrieve the message content from the %TransformData system variable.

2. Examine your filtering criteria.

3. If the message meets your criteria, do nothing further. It remains intact in the %TransformData system variable for the next transform program step to process.

4. If the message fails to meet your criteria, replace the entire message content with a single node called Filter, containing the reason it failed.

   <?xml version="1.0"?>
   <Filter>reason_for_failure</Filter>

5. Set the TransformData Status property to 1 to indicate failure.

PeopleSoft Integration Broker examines the Status property after each step, and terminates the transform program if its value is 1. You can then view the message in Integration Broker Monitor and see the reason for the failure.