ESM Controller and Service

When an ESM transaction is sent to the client, the initial destination is the client's Online server in which the service has been installed. The ESM Web Service initially receives the transaction as a request to the "Process Transaction" method defined in the method. At this point, each transaction is validated for proper format and required fields. If validation fails for any reason, the transaction error is included in the response sent back to ESM and the transaction has failed.

If the transaction is properly formatted and has all the mandatory fields, the transaction is passed on to the Purchasing Interface which is part of the web service and contains the methods defined in the BusinessPlus Purchasing subsystem that contains the ESM support. If the transaction validates successfully, an HTTP ComRouter request for the particular request type is sent to the Request Dispatcher as part of the BusinessPlus Data Processing Services. The request is sent on to the Purchasing Subsystem ESM Controller where it processes. If the request fails at any time, transaction is marked as "Error" in the response and the error message is included in the response.

If the request is successfully processed by the ESM Controller in the Purchasing subsystem, the response is marked as "Success." Depending on the request (insert purchase request), additional information could be included in the response (like Pre-Encumbrance). The following sections detail the individual transactions and the processing that occurs in the Purchasing ESM Controller.