Handling Errors › Error Handling During Panel Definition › Restoring Prior Edits: CHECKPOINT and ROLLBACK

Restoring Prior Edits: CHECKPOINT and ROLLBACK

When you create or edit a panel definition, CA Ideal creates a temporary copy of the panel definition as shown in the following illustration.

The changes you make are written to the original copy of the panel definition. When you finish the editing session by entering a command that invokes another CA Ideal function, such as EDIT PANEL or DISPLAY PROGRAM, the temporary (E) copy is deleted.

If you decide that you do not want to keep the changes you made so far during the editing session, you can restore the panel definition to its original condition by entering the ROLLBACK command

The original copy, which contains the changes you made during the editing session, is overwritten by the rollback (E) copy, as shown below. Any changes made since the beginning of the editing session are lost when the panel definition is refreshed from the rollback copy as shown in the following illustration.

If you are working on a panel definition and reach a point where you know that you want to keep the changes you made so far, but you are unsure of the next few changes you intend to make, you can update the rollback copy of the panel definition with the edited original copy by entering the CHECKPOINT command.

Since the CHECKPOINT command saves the current changes to the rollback (E) copy, as shown below, you can restore the panel definition to the checkpointed state if you decide not to keep any changes made after the CHECKPOINT was issued as shown in the following illustration.

If a system failure interrupts an editing session, both copies of the panel definition remain in the library. You must indicate which copy you want to work with after you enter the EDIT command for that panel. To continue working with the edited original copy, enter the CHECKPOINT command. To continue from the last checkpointed changes, enter the ROLLBACK command.

If you are not sure which changes were checkpointed, you can enter the command DISPLAY ROLLBACK to display the rollback copy of the panel definition. You then have to enter the EDIT command, followed by either CHECKPOINT or ROLLBACK, to continue editing the copy of the panel definition.