How to handle errors on interdependent fields

This ‘How-to’ provides information on how to handle errors on two or more interdependent fields, for example a ‘Start’ and ‘End’ date range.

When in the ‘context’ of a particular field, the Supervisor will handle the ‘clean up’ of errors assigned to that field.
For example, in the context of Start date the following code checks that Start date is not greater than End date (if End date is not blank):

 $PROPERTIESCase CURPROWhen “STARTDATE” : Gosub STARTDATEEndcaseReturn$STARTDATECase ACTIONWhen “PROPAGATE”Gosub VALIDATE_STARTDATEEndcaseReturn$VALIDATE_STARTDATEIf this.ENDDATE <> AVOID.ADATE & this.STARTDATE > this.ENDDATEASTATUS = fmet this.ASETERROR(“STARTDATE”, “Start date cannot be after End date”, [V]CST_AERROR)EndifReturn

If, subsequently, a valid Start date is entered, the error is cleared by the Supervisor.

Note: Implementing the validation on the Start date’s PROPAGATE event means that the validation will not be executed again when 'Save' is clicked.

Similar validation can also be applied to the End date:

 $PROPERTIESCase CURPROWhen “STARTDATE” : Gosub STARTDATEWhen “ENDDATE” : Gosub ENDDATEEndcaseReturn$STARTDATECase ACTIONWhen “PROPAGATE”Gosub VALIDATE_STARTDATEEndcaseReturn$ENDDATECase ACTIONWhen “PROPAGATE”Gosub VALIDATE_ENDDATEEndcaseReturn$VALIDATE_STARTDATEIf this.ENDDATE <> AVOID.ADATE & this.STARTDATE > this.ENDDATE`ASTATUS = fmet this.ASETERROR(“STARTDATE”, “Start date cannot be after End date”, [V]CST_AERROR)EndifReturn$VALIDATE_ENDDATEIf this.ENDDATE <> AVOID.ADATE & this.ENDDATE < this.STARTDATEASTATUS = fmet this.ASETERROR(“ENDDATE”, “End date cannot be before Start date”, [V]CST_AERROR)EndifReturn

If, subsequently, a valid End date is entered, the error is cleared by the Supervisor.

However, instead of correcting the last error by re-entering a valid End date, what if the date range error was corrected by adjusting the Start date?

Although the date range is now valid, and no new error is displayed, the previous error (assigned to End date) is not cleared by the Supervisor because the process is now in the context of Start date.

To clear the previous error in this scenario, the method "ADELETEERROR" must be manually called to clear any errors on the alternate field (see the following code):

 $VALIDATE_DATESIf CURPRO = “STARTDATE”ASTATUS = fmet this.ADELETEERROR(“ENDDATE”)ElseASTATUS = fmet this.ADELETEERROR(“STARTDATE”)EndifIf this.ENDDATE <> AVOID.ADATE & this.STARTDATE > this.ENDDATEIf CURPRO = “STARTDATE”ASTATUS = fmet this.ASETERROR(“STARTDATE”, “Start date cannot be after End date”, [V]CST_AERROR)ElseASTATUS = fmet this.ASETERROR(“ENDDATE”, “End date cannot be before Start date”, [V]CST_AERROR)EndifEndifReturn$VALIDATE_STARTDATEASTATUS = fmet this.ADELETEERROR(“ENDDATE”)If this.ENDDATE <> AVOID.ADATE & this.STARTDATE > this.ENDDATEASTATUS = fmet this.ASETERROR(“STARTDATE”, “Start date cannot be after End date”, [V]CST_AERROR)EndifReturn$VALIDATE_ENDDATEASTATUS = fmet this.ADELETEERROR(“STARTDATE”)If this.ENDDATE <> AVOID.ADATE & this.ENDDATE < this.STARTDATEASTATUS = fmet this.ASETERROR(“ENDDATE”, “End date cannot be before Start date”, [V]CST_AERROR)EndifReturn