OpenEdge Getting Started:<br />Object-oriented Programming Comparative procedures

Comparative procedures

This is the top-level super procedure that provides common error handler and time-tracking routines:

CommonProc.p
DEFINE SHARED VARIABLE timestamp AS DATETIME NO-UNDO. PROCEDURE updateTimestamp: timestamp = NOW. END PROCEDURE. FUNCTION ErrorHandler RETURNS HANDLE (INPUT ProcType as CHARACTER). DEFINE VARIABLE hError AS HANDLE NO-UNDO. RUN ErrorProc.p PERSISTENT SET hError (INPUT ProcType). RETURN hError. END FUNCTION.

CommonProc.p

DEFINE SHARED VARIABLE timestamp AS DATETIME NO-UNDO. 
PROCEDURE updateTimestamp: 
    timestamp = NOW. 
END PROCEDURE. 
FUNCTION ErrorHandler RETURNS HANDLE (INPUT ProcType as CHARACTER). 
    DEFINE VARIABLE hError AS HANDLE NO-UNDO. 
    RUN ErrorProc.p PERSISTENT SET hError (INPUT ProcType). 
    RETURN hError. 
END FUNCTION.

This is a procedure that extends CommonProc.p to provide general functionality for handling customers and is a super procedure for the NECustomer.p procedure, that handles New England customers:

CustProc.p
/* Main Block / / 2 /* DEFINE SHARED VARIABLE iNumCusts AS INTEGER NO-UNDO. DEFINE TEMP-TABLE ttCust NO-UNDO FIELD CustNum LIKE Customer.CustNum FIELD Name LIKE Customer.Name FIELD Email AS CHARACTER. DEFINE NEW SHARED VARIABLE timestamp AS DATETIME NO-UNDO. */ 5 /* DEFINE VARIABLE hError AS HANDLE NO-UNDO. DEFINE VARIABLE hCommon AS HANDLE NO-UNDO. RUN CommonProc.p PERSISTENT SET hCommon. /* 1 / THIS-PROCEDURE:ADD-SUPER-PROCEDURE(hCommon). FUNCTION ErrorHandler RETURNS HANDLE (INPUT ProcType as CHARACTER) IN SUPER. iNumCusts = 0. / Fill temp table and get row count / FOR EACH Customer: CREATE ttCust. ASSIGN ttCust.CustNum = Customer.CustNum ttCust.Name = Customer.Name iNumCusts = iNumCusts + 1. END. hError = ErrorHandler(INPUT "CustProc"). / 3 */ PROCEDURE GetCustomerName: DEFINE INPUT PARAMETER piCustNum AS INTEGER NO-UNDO. DEFINE OUTPUT PARAMETER poName AS CHARACTER NO-UNDO. FIND ttCust WHERE ttCust.CustNum = piCustNum NO-ERROR. IF AVAILABLE ttCust THEN DO: poName = ttCust.Name. END. ELSE DO: RUN Alert IN hError(INPUT "No Customer with that number exists"). poName = ?. END. END PROCEDURE.
PROCEDURE CheckCredit: DEFINE VARIABLE hCreditProc AS HANDLE NO-UNDO. RUN CreditProc.p PERSISTENT SET hCreditProc. IF VALID-HANDLE(hCreditProc) THEN DO: FOR EACH Customer where CustNum < 15: IF Customer.CreditLimit < 15000 THEN DO: RUN Alert IN hError (INPUT "There is a problem with this Customer"). RUN CreditAlert in hCreditProc(INPUT Customer.CustNum). END. END. DELETE OBJECT hCreditProc. END. ELSE DO: RUN Alert in hError (INPUT "Unable to check credit"). END. END PROCEDURE. PROCEDURE printProc: OUTPUT TO PRINTER. DISPLAY timestamp. FOR EACH ttCust: DISPLAY ttCust. END. OUTPUT CLOSE. END PROCEDURE. PROCEDURE logProc: DEFINE INPUT PARAMETER fileName AS CHARACTER NO-UNDO. OUTPUT TO VALUE(fileName). DISPLAY timestamp. FOR EACH ttCust: DISPLAY ttCust. END. OUTPUT CLOSE. END PROCEDURE. PROCEDURE CleanUp: EMPTY TEMP-TABLE ttCust. DELETE OBJECT hError. hError = ?. END PROCEDURE.

CustProc.p

/* Main Block */ /* 2 */
DEFINE SHARED VARIABLE iNumCusts AS INTEGER NO-UNDO.
DEFINE TEMP-TABLE ttCust NO-UNDO
FIELD CustNum LIKE Customer.CustNum
FIELD Name LIKE Customer.Name
FIELD Email AS CHARACTER.
DEFINE NEW SHARED VARIABLE timestamp AS DATETIME NO-UNDO. /* 5 */
DEFINE VARIABLE hError AS HANDLE NO-UNDO.
DEFINE VARIABLE hCommon AS HANDLE NO-UNDO.
RUN CommonProc.p PERSISTENT SET hCommon. /* 1 */
THIS-PROCEDURE:ADD-SUPER-PROCEDURE(hCommon).
FUNCTION ErrorHandler RETURNS HANDLE (INPUT ProcType as CHARACTER) IN SUPER.
iNumCusts = 0.
/* Fill temp table and get row count */
FOR EACH Customer:
CREATE ttCust.
ASSIGN
ttCust.CustNum = Customer.CustNum
ttCust.Name = Customer.Name
iNumCusts = iNumCusts + 1.
END.
hError = ErrorHandler(INPUT "CustProc"). /* 3 */
PROCEDURE GetCustomerName:
DEFINE INPUT PARAMETER piCustNum AS INTEGER NO-UNDO.
DEFINE OUTPUT PARAMETER poName AS CHARACTER NO-UNDO.
FIND ttCust WHERE ttCust.CustNum = piCustNum NO-ERROR.
IF AVAILABLE ttCust THEN DO:
poName = ttCust.Name.
END.
ELSE DO:
RUN Alert IN hError(INPUT "No Customer with that number exists").
poName = ?.
END.
END PROCEDURE.

PROCEDURE CheckCredit: 
    DEFINE VARIABLE hCreditProc AS HANDLE NO-UNDO. 
    RUN CreditProc.p PERSISTENT SET hCreditProc. 
    IF VALID-HANDLE(hCreditProc) THEN DO: 
        FOR EACH Customer where CustNum < 15: 
            IF Customer.CreditLimit < 15000 THEN DO: 
                RUN Alert IN hError  
                          (INPUT "There is a problem with this Customer"). 
                RUN CreditAlert in hCreditProc(INPUT Customer.CustNum). 
            END. 
        END. 
        DELETE OBJECT hCreditProc. 
    END. 
    ELSE DO: 
        RUN Alert in hError (INPUT "Unable to check credit"). 
    END. 
END PROCEDURE. 
PROCEDURE printProc: 
    OUTPUT TO PRINTER. 
    DISPLAY timestamp. 
    FOR EACH ttCust: 
        DISPLAY ttCust. 
    END. 
    OUTPUT CLOSE. 
END PROCEDURE. 
PROCEDURE logProc: 
    DEFINE INPUT PARAMETER fileName AS CHARACTER NO-UNDO. 
    OUTPUT TO VALUE(fileName). 
    DISPLAY timestamp. 
    FOR EACH ttCust: 
        DISPLAY ttCust. 
    END. 
    OUTPUT CLOSE. 
END PROCEDURE. 
PROCEDURE CleanUp: 
    EMPTY TEMP-TABLE ttCust. 
    DELETE OBJECT hError. 
    hError = ?. 
END PROCEDURE.

This procedure extends CustProc.p to handle New England customers by overriding the GetCustomerName procedure to return the customer’s E-mail address along with their name:

NECustomer.p
DEFINE SHARED VARIABLE iNumCusts AS INTEGER NO-UNDO. DEFINE VARIABLE hCustProc AS HANDLE NO-UNDO. DEFINE NEW SHARED TEMP-TABLE ttCust NO-UNDO FIELD CustNum LIKE Customer.CustNum FIELD Name LIKE Customer.Name FIELD Email AS CHARACTER. */ 7 /* RUN CustProc.p PERSISTENT SET hCustProc. /* 8 / THIS-PROCEDURE:ADD-SUPER-PROCEDURE(hCustProc). iNumCusts = 0. / Fill temp table and get row count / FOR EACH Customer: CREATE ttCust. ASSIGN ttCust.CustNum = Customer.CustNum ttCust.Name = Customer.Name iNumCusts = iNumCusts + 1. END. PROCEDURE GetCustomerName: / 9 /* DEFINE INPUT PARAMETER piCustNum AS INTEGER NO-UNDO. DEFINE OUTPUT PARAMETER poName AS CHARACTER NO-UNDO. DEFINE VARIABLE CustName AS CHARACTER NO-UNDO. RUN SUPER(INPUT piCustNum, OUTPUT CustName). FIND FIRST ttCust WHERE CustNum = piCustNum NO-ERROR. IF AVAILABLE(ttCust) THEN RETURN ttCust.Name + ";" + ttCust.Email. END PROCEDURE.

NECustomer.p

DEFINE SHARED VARIABLE iNumCusts AS INTEGER NO-UNDO. 
DEFINE VARIABLE hCustProc AS HANDLE NO-UNDO. 
DEFINE NEW SHARED TEMP-TABLE ttCust NO-UNDO 
    FIELD CustNum LIKE Customer.CustNum 
    FIELD Name LIKE Customer.Name 
    FIELD Email AS CHARACTER. 
                                                                     /* 7 */ 
RUN CustProc.p PERSISTENT SET hCustProc.                             /* 8 */ 
THIS-PROCEDURE:ADD-SUPER-PROCEDURE(hCustProc). 
iNumCusts = 0. 
/* Fill temp table and get row count */ 
FOR EACH Customer: 
    CREATE ttCust. 
    ASSIGN 
        ttCust.CustNum = Customer.CustNum 
        ttCust.Name = Customer.Name 
        iNumCusts = iNumCusts + 1. 
    END. 
PROCEDURE GetCustomerName:                                          /* 9 */ 
    DEFINE INPUT PARAMETER piCustNum AS INTEGER NO-UNDO. 
    DEFINE OUTPUT PARAMETER poName AS CHARACTER NO-UNDO. 
    DEFINE VARIABLE CustName AS CHARACTER NO-UNDO. 
    RUN SUPER(INPUT piCustNum, OUTPUT CustName). 
    FIND FIRST ttCust WHERE CustNum = piCustNum NO-ERROR. 
    IF AVAILABLE(ttCust) THEN 
        RETURN ttCust.Name + ";" + ttCust.Email. 
END PROCEDURE.

This procedure provides a notification of customers who have exceeded their credit limit:

CreditProc.p
PROCEDURE CreditAlert: DEFINE INPUT PARAMETER iCustNum AS INTEGER NO-UNDO. FIND FIRST Customer WHERE Customer.CustNum = iCustNum NO-ERROR. IF AVAILABLE(Customer) THEN MESSAGE Customer.Name " is on Credit Hold" SKIP "with a credit limit of " Customer.CreditLimit VIEW-AS ALERT-BOX. END PROCEDURE.

CreditProc.p

PROCEDURE CreditAlert: 
    DEFINE INPUT PARAMETER iCustNum AS INTEGER NO-UNDO. 
    FIND FIRST Customer WHERE Customer.CustNum = iCustNum NO-ERROR. 
    IF AVAILABLE(Customer) THEN 
        MESSAGE Customer.Name " is on Credit Hold" SKIP 
                              "with a credit limit of " Customer.CreditLimit 
                              VIEW-AS ALERT-BOX. 
END PROCEDURE.

This procedure provides a common error handler for other procedures to report error information:

ErrorProc.p
DEFINE INPUT PARAMETER ProcType AS CHARACTER NO-UNDO. PROCEDURE Alert: DEFINE INPUT PARAMETER ErrorString AS CHARACTER NO-UNDO. MESSAGE "Error in " ProcType "!" SKIP ErrorString VIEW-AS ALERT-BOX. END PROCEDURE.

ErrorProc.p

DEFINE INPUT PARAMETER ProcType AS CHARACTER NO-UNDO. 
PROCEDURE Alert: 
    DEFINE INPUT PARAMETER ErrorString AS CHARACTER NO-UNDO. 
    MESSAGE "Error in " ProcType "!" SKIP 
             ErrorString  
             VIEW-AS ALERT-BOX. 
END PROCEDURE.

This procedure is the main driver for running all the other comparative procedures:

Main.p
DEFINE VARIABLE hCustProc AS HANDLE NO-UNDO. DEFINE VARIABLE oCustName AS CHARACTER NO-UNDO. DEFINE NEW SHARED VARIABLE iNumCusts AS INTEGER NO-UNDO. DEFINE TEMP-TABLE ttCustNames NO-UNDO FIELD CustNum AS INTEGER FIELD CustName AS CHARACTER FIELD Email AS CHARACTER. DEFINE VARIABLE i AS INTEGER NO-UNDO. RUN CustProc.p PERSISTENT SET hCustProc. RUN updateTimestamp IN hCustProc. /* 4 / DO i = 1 to iNumCusts: CREATE ttCustNames. RUN GetCustomerName IN hCustProc(INPUT i, OUTPUT oCustName). ASSIGN ttCustNames.CustName = oCustName ttCustNames.CustNum = i. END. RUN CheckCredit IN hCustProc. RUN logProc IN hCustProc (INPUT "CustomerProc.out"). RUN CleanUp IN hCustProc. / 6 */ DELETE OBJECT hCustProc. hCustProc = ?.

Main.p

DEFINE VARIABLE hCustProc AS HANDLE NO-UNDO. 
DEFINE VARIABLE oCustName AS CHARACTER NO-UNDO. 
DEFINE NEW SHARED VARIABLE iNumCusts AS INTEGER NO-UNDO. 
DEFINE TEMP-TABLE ttCustNames NO-UNDO 
    FIELD CustNum AS INTEGER 
    FIELD CustName AS CHARACTER 
    FIELD Email AS CHARACTER. 
DEFINE VARIABLE i AS INTEGER NO-UNDO. 
RUN CustProc.p PERSISTENT SET hCustProc. 
RUN updateTimestamp IN hCustProc.                                    /* 4 */ 
DO i = 1 to iNumCusts: 
    CREATE ttCustNames. 
    RUN GetCustomerName IN hCustProc(INPUT i, OUTPUT oCustName). 
    ASSIGN 
        ttCustNames.CustName = oCustName 
        ttCustNames.CustNum  = i. 
END. 
RUN CheckCredit IN hCustProc. 
RUN logProc IN hCustProc (INPUT "CustomerProc.out"). 
RUN CleanUp IN hCustProc.                                            /* 6 */ 
DELETE OBJECT hCustProc. 
hCustProc = ?.