Re: Variable Modules

Paul,

if your procedures are in a service program you can dynamically call with
QZRUCLSP Api that also allows you to use variable parameters and get return
values.

Example:

QZRUCLSP(SrvPgm+SrvPgmLib:%trimr(Procedure)+x'00':
         RETTYPE_NONE:PARMTYPE_PTR:1:ApiError:
         RtnVal:Parameter1);



----- Original Message ----- 
From: "Hauser, Birgitta" <Birgitta.Hauser@xxxxxxxxxxx>
To: <rpg400-l@xxxxxxxxxxxx>
Sent: Tuesday, May 24, 2005 1:25 PM
Subject: RE: Variable Modules


> Hi Paul,
>
> to call modules oder better procedures dynamically, you have to use
> prototyping and procedure pointers.
> In contrary to programs that are called dynamically, that means they
aren't
> activated before the CALL statement is executed, the procedures must exist
> at compile time. The module object that contains the procedures or the
> signature of the service program where the module is bound to are
physically
> embedded into the program object.
>
> Here an example:
> I have three procedures that convert a date into a character
representation.
>
> The first procedure converts to *EUR format, the second to *USA-Format and
> the third to *JIS-Format.
> You will see the prototypes for these functions
> D CvtDateToEur    PR            10A   extproc('CVTDATEUR')
>
> D   ParmDate                      D   const options(*NoPass)
>
> D CvtDateToUSA    PR            10A   extproc('CVTDATUSA')
>
> D   ParmDate                      D   const options(*NoPass)
>
> D CvtDateToJIS    PR            10A   extproc('CVTDATJIS)
>
> D   ParmDate                      D   const options(*NoPass)
>
> Here are the functions:
>   ************************************************************
>   * Converte Date into European Format
>   ************************************************************
>  P CvtDateToEur    B                   Export
>  D CvtDateToEur    PI            10A
>  D   ParmDate                      D   const options(*NoPass)
>   *-----------------------------------------------------------
>   /Free
>      If %Parms >= 1;
>         Return  %Char(ParmDate: *Eur);
>      else;
>         Return  %Char(%Date(): *Eur);
>      EndIf;
>   /End-Free
>  P CvtDateToEur    E
>   ************************************************************
>   * Convert Date into USA Format
>   ************************************************************
>  P CvtDateToUSA    B                   Export
> D CvtDateToUSA    PI            10A
> D   ParmDate                      D   const options(*NoPass)
>  *----------------------------------------------------------------
>  /Free
>     If %Parms >= 1;
>        Return  %Char(ParmDate: *USA);
>     else;
>        Return  %Char(%Date(): *USA);
>     EndIf;
>  /End-Free
> P CvtDateToUSA    E
>  *****************************************************************
>  * Convert Date into Japanese Format
>  *****************************************************************
> P CvtDateToJIS    B                   Export
> D CvtDateToJIS    PI            10A
> D   ParmDate                      D   const options(*NoPass)
>  *----------------------------------------------------------------
>  /Free
>     If %Parms >= 1;
>         Return  %Char(ParmDate: *JIS);
>      else;
>         Return  %Char(%Date(): *JIS);
>      EndIf;
>   /End-Free
> P CvtDateToJIS    E
>
> Depending on the language or country you want to call one of these
> functions.
> To do this you need an additional prototype. Add the Keyword EXTPROC and
> specify a procedure pointer variable instead of a procedure name.
> A procedure pointer has the data type * and the key word PROCPTR.
> The following example shows you the additional prototype and the
definition
> of the procedure pointer variable:
>
> D CvtDate         PR            10A   ExtProc(MyProcPtr)
> D   ParmDate                      D   const options(*NoPass)
>
> D MyProcPtr       S               *   ProcPtr
>
> This prototype and procedure pointer must be embedded in the source where
> you want to calle the functions "dynamically".
> The next example shows you how to call these functions.
> D ConstProcUSA    C                   const(%PAddr('CVTDATUSA'))
>
> D ConstProcJIS    S               *   ProcPtr inz(%PAddr('CVTDATJIS'))
>
>  /Free
>    Select;
>    When Country   = 'DE ';
>         MyProcPtr = %PAddr('CVTDATEUR');
>    When Country   = 'USA';
>         MyProcPtr = ConstProcUSA;
>    When Country   = 'JPN';
>         MyProcPtr = ConstProcJIS;
>    EndSL;
>
>    MyCharDate = CvtDate(MyDate);
>  /End-Free
>
> I hope this helps!
>
> Birgitta
>
> Mit freundlichen Grüßen
>
> i.A. Birgitta Hauser
>
> LUNZER + PARTNER GMBH
> Unternehmensberatung
> Carl-Zeiss-Straße 1
> 63755 Alzenau
>
> Tel:         + 49 6023 951-255
> Fax:        + 49 6023 951-111
> Internet.  www.lp-gmbh.com
>               www.rpg-schulung.de
>
>
> -- 
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