Sequence of Events: Saving of Changes to the Database

The following figure illustrates the sequence of events that are raised when a data record is saved.

While a user is inserting, updating, or deleting a data record, no changes are committed to the database. The system stores the modified data records in the session, and you can access them through the appropriate PXCache object. The system commits the changes to the database when the user clicks Save in the user interface, the save request is sent through the Web Service API, or Actions.PressSave() is invoked on the business logic controller (BLC) instance. In both cases, the Persist() method of the graph is invoked. The Actions.PressSave() method additionally checks that the Save action exists in the graph and is enabled. The Save action then invokes the Persist() method.

When changes are saved to the database, events are raised as follows:

1. RowPersisting is raised. At this moment, a database transaction has already been opened. If any of the handlers sets e.Cancel to true, the process will be canceled for the currently processed data record without an error being reported to the user. To cancel the process of committing changes and indicate the error to the user, you should throw the PXException exception.
2. If e.Cancel does not equal true:
   1. RowPersisted is raised. The commit operation for the current data record (available through e.Row in the handler) is completed, but the transaction is still open: e.TranStatus equals Open.
   2. RowPersisted is raised one more time, either with e.TranStatus equal to Completed (if all changes have been saved successfully) or with e.TranStatus equal to Aborted if an error has occurred and all changes have been canceled.