Optimization of Message Handling

This section covers the following topics:

Screen Output Handling

Natural provides an extensive message optimization capability. Prior to sending an output screen, Natural determines which portion of the screen has been modified; only data which have actually been modified are sent.

This is to be considered when, between two successive terminal outputs, portions or the entire terminal contents are changed

  • by using the CLEAR key or

  • by intervening dialog steps at system level (K2 interruption or similar interruption).

This is particularly true if a subprogram called from Natural by an external CALL interface produces dialog output.

Restoring the Screen Content

In the above-mentioned cases, you can use one of the following methods to cause Natural to restore the most recent terminal screen contents.

  • Issue the terminal command %R.

  • Use the statement SET CONTROL 'R'