In this example, a procedure FMTADDR has been changed several times to allow for a change in the address information for the employees of a company. FMTADDR is called by three different procedures. The procedures differ only in the number of parameters they use to process the employee information. That is, new requirements for the FMTADDR have arisen, and to support them, new parameters have been added. However, old procedures calling FMTADDR are still supported and do not have to be changed or recompiled.
The changes to the employee address can be summarized as follows:
The procedure processes the information based on the number of parameters passed. The number may vary from 3 to 5. The number tells the program whether to provide default city or province values or both. Figure 70 shows the source for this procedure. Figure 71 shows the source for /COPY member containing the prototype.
The main logic of FMTADDR is as follows:
*=================================================================*
* FMTADDR - format an address
*
* Interface parameters
* 1. Address character(70)
* 2. Street number packed(5,0)
* 3. Street name character(20)
* 4. City character(15) (some callers do not pass)
* 5. Province character(15) (some callers do not pass)
*=================================================================*
* Pull in the prototype from the /COPY member
/COPY FMTADDRP
DFmtAddr PI
D Address 70
D Street# 5 0 CONST
D Street 20 CONST
D P_City 15 OPTIONS(*NOPASS) CONST
D P_Province 15 OPTIONS(*NOPASS) CONST
*-----------------------------------------------------------------*
* Default values for parameters that might not be passed.
*-----------------------------------------------------------------*
D City S 15 INZ('Toronto')
D Province S 15 INZ('Ontario')
*-----------------------------------------------------------------*
* Check whether the province parameter was passed. If it was,
* replace the default with the parameter value.
*-----------------------------------------------------------------*
C IF %PARMS > 4
C EVAL Province = P_Province
C ENDIF
*-----------------------------------------------------------------*
* Check whether the city parameter was passed. If it was, *
* replace the default with the parameter value. *
*-----------------------------------------------------------------*
C IF %PARMS > 3
C EVAL City = P_City
C ENDIF
*-----------------------------------------------------------------*
* Set 'CStreet#' to be character form of 'Street#' *
*-----------------------------------------------------------------*
C EXSR GetStreet#
*-----------------------------------------------------------------*
* Format the address as Number Street, City, Province *
*-----------------------------------------------------------------*
C EVAL ADDRESS = %TRIMR(CSTREET#) + ' ' +
C %TRIMR(CITY) + ' ,' +
C %TRIMR(PROVINCE)
C RETURN
*=================================================================*
* SUBROUTINE: GetStreet#
* Get the character form of the street number, left-adjusted *
* and padded on the right with blanks. *
*=================================================================*
C GetStreet# BEGSR
C MOVEL Street# CStreet# 10
*-----------------------------------------------------------------*
* Find the first non-zero. *
*-----------------------------------------------------------------*
C '0' CHECK CStreet# Non0 5 0
*-----------------------------------------------------------------*
* If there was a non-zero, substring the number starting at *
* non-zero. *
*-----------------------------------------------------------------*
C IF Non0 > 0
C SUBST(P) CStreet#:Non0 CStreet#
*-----------------------------------------------------------------*
* If there was no non-zero, just use '0' as the street number. *
*-----------------------------------------------------------------*
C ELSE
C MOVEL(P) '0' CStreet#
C ENDIF
C ENDSR *=================================================================*
* Prototype for FMTADDR - format an address
*=================================================================*
DFmtAddr PR
D addr 70
D strno 5 0 CONST
D st 20 CONST
D cty 15 OPTIONS(*NOPASS) CONST
D prov 15 OPTIONS(*NOPASS) CONSTFigure 72 shows the source for the procedure PRTADDR. This procedure serves to illustrate the use of FMTADDR. For convenience, the three procedures which would each call FMTADDR are combined into this single procedure. Also, for the purposes of the example, the data is program-described.
Since PRTADDR is 'three procedures-in-one', it must define three different address data structures. Similarly, there are three parts in the calculation specifications, each one corresponding to programs at each stage. After printing the address, the procedure PRTADDR ends.
*=================================================================*
* PRTADDR - Print an address
* Calls FmtAddr to format the address
*=================================================================*
FQSYSPRT O F 80 PRINTER
*-----------------------------------------------------------------*
* Prototype for FmtAddr
*-----------------------------------------------------------------*
DFmtAddr PR
D addr 70
D strno 5 0
D st 20
D cty 15 OPTIONS(*NOPASS)
D prov 15 OPTIONS(*NOPASS)
DAddress S 70
*-----------------------------------------------------------------*
* Stage1: Original address data structure.
* Only street and number are variable information.
*-----------------------------------------------------------------*
D Stage1 DS
D Street#1 5P 0 DIM(2) CTDATA
D StreetNam1 20 DIM(2) ALT(Street#1)
*-----------------------------------------------------------------*
* Stage2: Revised address data structure as city information
* now variable.
*-----------------------------------------------------------------*
D Stage2 DS
D Street#2 5P 0 DIM(2) CTDATA
D Addr2 35 DIM(2) ALT(Street#2)
D StreetNam2 20 OVERLAY(Addr2:1)
D City2 15 OVERLAY(Addr2:21)
*-----------------------------------------------------------------*
* Stage3: Revised address data structure as provincial
* information now variable.
*-----------------------------------------------------------------*
D Stage3 DS
D Street#3 5P 0 DIM(2) CTDATA
D Addr3 50 DIM(2) ALT(Street#3)
D StreetNam3 20 OVERLAY(Addr3:1)
D City3 15 OVERLAY(Addr3:21)
D Province3 15 OVERLAY(Addr3:36)
*-----------------------------------------------------------------*
* 'Program 1'- Use of FMTADDR before city parameter was added.
*-----------------------------------------------------------------*
C DO 2 X 5 0
C CALLP FMTADDR (Address:Street#1(X):StreetNam1(X))
C EXCEPT
C ENDDO
*-----------------------------------------------------------------*
* 'Program 2'- Use of FMTADDR before province parameter was added.*
*-----------------------------------------------------------------*
C DO 2 X 5 0
C CALLP FMTADDR (Address:Street#2(X):
C StreetNam2(X):City2(X))
C EXCEPT
C ENDDO
*-----------------------------------------------------------------*
* 'Program 3' - Use of FMTADDR after province parameter was added.*
*-----------------------------------------------------------------*
C DO 2 X 5 0
C CALLP FMTADDR (Address:Street#3(X):
C StreetNam3(X):City3(X):Province3(X))
C EXCEPT
C ENDDO
C SETON LR
*-----------------------------------------------------------------*
* Print the address. *
*-----------------------------------------------------------------*
OQSYSPRT E
O Address
**
00123Bumble Bee Drive
01243Hummingbird Lane
**
00003Cowslip Street Toronto
01150Eglinton Avenue North York
**
00012Jasper Avenue Edmonton Alberta
00027Avenue Road Sudbury OntarioTo create these programs, follow these steps:
CRTRPGMOD MODULE(MYLIB/FMTADDR)
CRTRPGMOD MODULE(MYLIB/PRTADDR)
CRTPGM PGM(MYLIB/PRTADDR) MODULE(PRTADDR FMTADDR)
123 Bumble Bee Drive, Toronto, Ontario 1243 Hummingbird Lane, Toronto, Ontario 3 Cowslip Street, Toronto, Ontario 1150 Eglinton Avenue, North York, Ontario 12 Jasper Avenue, Edmonton, Alberta 27 Avenue Road, Sudbury, Ontario