RUN SUPER statement

The RUN SUPER statement must appear only within an internal procedure, but can appear anywhere within the internal procedure. If the RUN SUPER statement appears outside an internal procedure, the compiler reports an error.

RUN SUPER [ ( `parameter` [ , `parameter` ] ... ) ] [ NO-ERROR ]

A parameter of the super procedure. The parameters of the super procedure must have the same signature (number of parameters, and type and mode of each) as the parameters of the current internal procedure. You can, however, adjust a parameter’s value.

For the parameter syntax, see the Parameter passing syntax reference entry.

Suppresses ABL errors or error messages that would otherwise occur and diverts them to the ERROR-STATUS system handle. If an error occurs, the action of the statement is not done and execution continues with the next statement. If the statement fails, any persistent side-effects of the statement are backed out. If the statement includes an expression that contains other executable elements, like methods, the work performed by these elements may or may not be done, depending on the order the AVM resolves the expression elements and the occurrence of the error.

Note: Specifying NO-ERROR does not shorten the search in any way.

If you do not specify the NO-ERROR option and the super procedure version of the internal procedure does not exist, the AVM generates an error message:


Procedure `prog`.p `name` has no SUPER procedure with internal procedure `name`

To check for errors after a statement that uses the NO-ERROR option:

Check the ERROR-STATUS:ERROR attribute to see if the AVM raised the ERROR condition.

Check if the ERROR-STATUS:NUM-MESSAGES attribute is greater than zero to see if the AVM generated error messages. ABL handle methods used in a block without a CATCH end block treat errors as warnings and do not raise ERROR, do not set the ERROR-STATUS:ERROR attribute, but do add messages to the ERROR-STATUS system handle. Therefore, this test is the better test for code using handle methods without CATCH end blocks. ABL handle methods used in a block with a CATCH end block raise ERROR and add messages to the error object generated by the AVM. In this case, the AVM does not update the ERROR-STATUS system handle.

Use ERROR-STATUS:GET-MESSAGE( message-num ) to retrieve a particular message, where message-num is 1 for the first message.

If the statement does not include the NO-ERROR option, you can use a CATCH end block to handle errors raised by the statement.

Some other important usage notes on the NO-ERROR option:

NO-ERROR does not suppress errors that raise the STOP or QUIT condition.

A CATCH statement, which introduces a CATCH end block, is analogous to a NO-ERROR option in that it also suppresses errors, but it does so for an entire block of code. It is different in that the error messages are contained in a class-based error object (generated by the AVM or explicitly thrown), as opposed to the ERROR-STATUS system handle. Also, if errors raised in the block are not handled by a compatible CATCH block, ON ERROR phrase, or UNDO statement, then the error is not suppressed, but handled with the default error processing for that block type.

When a statement contains the NO-ERROR option and resides in a block with a CATCH end block, the NO-ERROR option takes precedence over the CATCH block. That is, an error raised on the statement with the NO-ERROR option will not be handled by a compatible CATCH end block. The error is redirected to the ERROR-STATUS system handle as normal.

If an error object is thrown to a statement that includes the NO-ERROR option, then the information and messages in the error object will be used to set the ERROR-STATUS system handle. This interoperability feature is important for those integrating code that uses the traditional NO-ERROR technique with the newer, structured error handling that features error objects and CATCH end blocks.

The following example consists of three procedure files: a main routine, a driver, and a third procedure file that becomes a super procedure of the driver.

The following main routine, procedure file r-pomain.p, runs the driver procedure persistently:

r-pomain.p
DEFINE VARIABLE h AS HANDLE NO-UNDO. DEFINE VARIABLE a AS CHARACTER NO-UNDO. FUNCTION sample2 RETURNS CHARACTER (INPUT-OUTPUT a AS CHARACTER) IN h. RUN r-podrvr.p PERSISTENT SET h. RUN sample1 IN h (INPUT-OUTPUT a). MESSAGE a VIEW-AS ALERT-BOX. a = "". MESSAGE sample2(a) VIEW-AS ALERT-BOX.

The following driver, procedure file r-podrvr.p, runs the third procedure file persistently, makes it a super procedure of itself, defines the internal procedure sample1, and defines the user-defined functions sample2, GetPartName, and SetPartName:

r-podrvr.p
DEFINE VARIABLE h AS HANDLE.DEFINE VARIABLE localPartName AS CHARACTER. FUNCTION SetPartName RETURNS INTEGER (INPUT a AS CHARACTER) FORWARD. /* Add a super procedure / RUN r-posupr.p PERSISTENT SET h. THIS-PROCEDURE:ADD-SUPER-PROCEDURE (h). SetPartName("1998 Calendar"). PROCEDURE sample1: DEFINE INPUT-OUTPUT PARAMETER a AS CHARACTER NO-UNDO. a = a + "proc: Part name is: ". / Invoke procedure sample1 in the super procedure. / RUN SUPER (INPUT-OUTPUT a). END PROCEDURE. FUNCTION sample2 RETURNS CHARACTER (INPUT-OUTPUT a AS CHARACTER). a = a + "func: Part name is: ". / Invoke function sample2 in the super procedure. */ SUPER (INPUT-OUTPUT a). RETURN a. END FUNCTION. FUNCTION GetPartName RETURNS CHARACTER (): RETURN localPartName. END FUNCTION. FUNCTION SetPartName RETURNS INTEGER (INPUT partname AS CHARACTER): localPartName = partname. END FUNCTION.

r-podrvr.p

DEFINE VARIABLE h AS HANDLE.DEFINE VARIABLE localPartName AS CHARACTER. 
FUNCTION SetPartName RETURNS INTEGER (INPUT a AS CHARACTER) FORWARD. 
/* Add a super procedure */ 
RUN r-posupr.p PERSISTENT SET h. 
THIS-PROCEDURE:ADD-SUPER-PROCEDURE (h). 
SetPartName("1998 Calendar"). 
PROCEDURE sample1: 
  DEFINE INPUT-OUTPUT PARAMETER a AS CHARACTER NO-UNDO. 
  a = a + "proc: Part name is: ". 
  /* Invoke procedure sample1 in the super procedure. */ 
  RUN SUPER (INPUT-OUTPUT a). 
END PROCEDURE. 
FUNCTION sample2 RETURNS CHARACTER (INPUT-OUTPUT a AS CHARACTER). 
  a = a + "func: Part name is: ". 
  /* Invoke function sample2 in the super procedure. */ 
  SUPER (INPUT-OUTPUT a). 
  RETURN a. 
END FUNCTION. 
FUNCTION GetPartName RETURNS CHARACTER (): 
  RETURN localPartName. 
END FUNCTION. 
FUNCTION SetPartName RETURNS INTEGER (INPUT partname AS CHARACTER): 
  localPartName = partname. 
END FUNCTION.

The following third procedure file, r-posupr.p, defines a new version of the internal procedure sample1 and a new version of the user-defined function sample2: