PreviousNextIndex

STOP statement

Signals the STOP condition in the current block. By default, the STOP condition stops processing a procedure, backs out the active transaction, and unwinds the call stack until it returns to the startup procedure or the Procedure Editor. You can change this behavior by including the ON STOP phrase on a block statement.

Syntax

STOP 

Examples

In any procedure, the outermost block that updates the database is the system transaction. In this procedure, the first iteration of the FOR EACH block starts a system transaction. The transaction ends when that iteration ends. Another transaction starts at the start of the next iteration. After you update the credit-limit field, the AVM prompts you to STOP. If you enter yes, the STOP statement stops the procedure and undoes any database modifications made in that transaction, as shown:

r-stop.p
DEFINE VARIABLE ans AS LOGICAL NO-UNDO. 
FOR EACH Customer: 
  DISPLAY Customer.CustNum Customer.Name. 
  UPDATE Customer.CreditLimit. 
  ans = FALSE. 
  MESSAGE "Stopping now undoes changes to this record.". 
  MESSAGE "Do you want to stop now?" UPDATE ans. 
  IF ans THEN STOP. 
END. 

When you add the ON STOP phrase to the block statement of the previous procedure, it changes the default behavior of the STOP statement. In this procedure, the AVM allows you to re-enter the record when you choose to stop:

r-stop2.p
DEFINE VARIABLE ans  AS LOGICAL NO-UNDO. 
FOR EACH Customer ON STOP UNDO, RETRY: 
  DISPLAY Customer.CustNum Customer.Name. 
  UPDATE Customer.CreditLimit. 
  ans = FALSE. 
  MESSAGE "Stopping now undoes changes to this record." 
    "Do you want to stop now?"  
    VIEW-AS ALERT-BOX QUESTION BUTTONS YES-NO UPDATE ans. 
  IF ans THEN STOP. 
END. 

Notes

OpenEdge Release 10.2B
Copyright © 2009 Progress Software Corporation
PreviousNextIndex