RE: WebFacing: Is this really Heaven? NO, it's hell!!!!

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Simon Coulter
>
> If I have a standard RPG III display file processing loop like:
> <SNIP CODE>
> What will that look like after it has been run through your conversion
> process?  That is, what happens to the WRITE and EXFMT statements?

The mainline is very simple:

      * Display the screen until user requests exit
B1   C           EXIT      DOUEQ$YES
      *   Display the static parts of the screen
RV01dC**                   WRITEOBJHDR
RV01aC                     EXSR PSCI01
RV01dC**                   WRITEOBJOPT
RV01aC                     EXSR PSCI02
RV01dC**                   WRITEOBJFKEY
RV01aC                     EXSR PSCI03
      *   Display program messages - OS/400 does the hard work
RV01dC**                   WRITEERRCTL
RV01aC                     EXSR PSCI04
      *   If we have object list entries to display
B2   C           LSTCNT    IFGT *ZERO
      *     Display the filled SFL and wait for user action
     C                     SETON                     9192   SFLDSP
SFLDSPCTL
     C                     EXFMTOBJCTL1                     First SFL
     C                     SETOF                     9192   SFLDSP
SFLDSPCTL
      *   . . . otherwise . . .
X2   C                     ELSE
      *     Display 'no objects' message
     C                     SETON                       92   SFLDSPCTL
RV01dC**                   WRITEOBJCTL1                     First SFL
RV01aC                     EXSR PSCI05
RV01dC**                   EXFMTOBJNUN                      No objects
RV01aC                     EXSR PSCI06
     C                     SETOF                       92   SFLDSPCTL
E2   C                     END                              LSTCNT > *ZERO
      *
E1   C                     END                              EXIT U= $YES

As you can see, each I/O opcode is replaced with a subroutine.  This way,
your mainline stays pretty much intact.  I think the above code is pretty
readable, especially since the original I/O statements are left in place as
comments.  The subroutine looks something like this:

PSC aC           PSCI01    BEGSR
PSC aC           PSCTYP    IFEQ '1'
PSC aC                     WRITEOBJHDR
PSC aC                     ELSE
PSC aC                     EXSR PSCW01
PSC aC                     CALL 'PSCBAPI2'
PSC aC                     PARM PSCN01    PSCRCD 10
PSC aC                     PARM 'WRITE'   PSCOPC  5
PSC aC           *IN       PARM *IN       PSCIND
PSC aC                     PARM           PSCD01
PSC aC                     ENDIF
PSC aC                     ENDSR

If we're in interactive mode, the PSCTYP field is a '1', and the original
statement is executed.  Otherwise, a call is made to the PSC400 API program,
passing the appropriate parameters.  (Note that if the same I/O opcode
appears more than once, it's replaced by a call to the same subroutine.)

You might start wondering about a few things like "What is PSCW01"?  PSCW01
is a subroutine that moves data from screen fields into the PSCD01 data
structure.  Or "What is PSCN01"?  It's a constant containing the ID for the
OBJHDR record format.  Or "How do the command keys and the INFDS get set"?
That depends on the I/O opcode.  EXFMT will set the command keys, as will a
READ.  The INFDS is only set if there is one defined in the program.  And so
on.  Once you start getting to that level of detail, you really need to see
an assessment of the product working with your code.  I hope that this is
enough to give you a general idea of how the tool works.

Joe