Background documentationUsing the ALV Grid Control in WANs Locate this document in the navigation structure

 

The protocol used for communication between the application server and the frontend ensures that the ALV Grid Control can be used in WANs. The protocol controls the data transfer from the application server to the frontend.

Initially, the control receives only the data needed to display the lines currently visible. All other data is only transferred to the control if the user scrolls there. In the WAN, packages are rather small so that each package can be transferred within a short time.

Constraints

Programmers who use the ALV Grid Control must consider one special aspect for WANs. Events DELAYED_CALLBACK and DELAYED_CHANGED_SEL_CALLBACK should be used in WANs in exceptional cases only. The reason is not to be found in the events themselves but in the fact that other controls are frequently filled with data in response to these events. Since this leads to considerable delays (> 3 seconds) in many WANs, users may feel uncomfortable with this situation.