Integrating business logic into ProDataSets using events

One of the most basic advantages of OpenEdge as a development environment is the tight integration between the data access layer of an application and the business logic that operates on that data. This is something that set-oriented data access languages like SQL, combined with programming languages that were generally not designed specifically for data navigation, have never been able to match.

The ProDataSet extends this integration by allowing developers to associate business logic procedures with ProDataSets, to be executed when specific events occur, such as beginning a ProDataSet FILL operation, loading a record into one of its member buffers, making a change to a row, and so forth. This event logic can be written in separate procedures from the procedure where the ProDataSet is defined and used, so that it can be coded independent of the ProDataSet and attached to the ProDataSet in any procedure where it is used. Generally speaking, these event procedures receive the ProDataSet as an INPUT parameter so that they can examine and modify any records in the ProDataSet, depending on the nature of the logic and the event. This provides developers with a standard way to associate business logic with a ProDataSet to extend or replace the default behavior the ProDataSet provides, or to provide behavior where no default support is possible. This logic is executed consistently wherever the ProDataSet is used so that the developer can write business logic in one place and know that it will be applied uniformly.