Externalizing I/O was RPG read loops

[rob@xxxxxxxxx]

Paul,

I think you're the first person that I heard of, that wasn't the person in 
charge of writing the access programs, that actually liked this scenario. 
Why an end developer would like to replace

chain(e) myfile;
// now actually do some real work with the fields

with
getFilename();
MyWorkField1=GetField(field1);
MyWorkField2=GetField(field2);
...
// now actually do some real work with the fields

rather escapes me.

Rob Berendt
-- 
Group Dekko Services, LLC
Dept 01.073
PO Box 2000
Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com





"Paul Morgan" <pmorgan@xxxxxxxxxxxxxx> 
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
02/02/2005 10:18 AM
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RPG programming on the AS400 / iSeries <rpg400-l@xxxxxxxxxxxx>


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Re: RPG read loops






Richard,

Great setup.  I once contracted at a shop that did this with OPM programs
even before ILE.  You never put a file into production without it's access
program.  Applications programs never referred to a file directly but did
all access through the IO program.  Even all the file logicals were in 
that
same program so you could select which logical to use with a parameter on
the call.

Paul

-- 
Paul Morgan
Senior Programmer Analyst - Retail
J. Jill Group
100 Birch Pond Drive, PO Box 2009
Tilton, NH 03276-2009
Phone: (603) 266-2117
Fax:   (603) 266-2333

"Richard ECUYER" wrote

> I did it.
>
> For each file (physical, logical, with ot without key), i build one 
source
> with some procedures :
>     Get_Filename          (CHAIN)
>     Set_filename            (SET, LL, GT)
>     Exists_filename        (SETLL without read)
>     Read_filename         (READ, readp, readE, READPE)
>     Insert_filename        (write)
>     Delete_filename       (delete)
>     Unlock_filename      (unlock)
>     Update_filename     (update)
>     dft_filename            (populate the exported datastructure with
defaul
> values)
> All "READ" procedures include a parm (*on/*off) to lock or not the 
record)
>
> Create a module and one service pgm by file
> a ds (io_filename) is exported.
>
> It is not done by hand, i create a little pgm that get file decription 
and
> create all sources needed (procedure interface, module...)
>
> When i use suche a procedure, i include 3 lines :
>
>     /copy of the bnddir (it is one with only IO service pgm)
>     /copy of procedure interface
>     an external DS (linked with the file) if i use data from the file.
>
> the only think (for me) to watch is in a loop that call a program that
read
> the same file i must make a setgt before the next read.
> all procedure return *off if request fald or *on if not.
>
> My loop are like this :
>
> Dow    Read_filename (*off : '*NEXT' : '*EQ' : Key1 : Key2 ...)
> do staff
> Enddo
>
> One cool thing is that i can change the file (add new fields at the end)
> without getting level error (new field will not be usable until i
recompile)
> I have a performance gain, and all IO for a file are in ONE source.
> It is new for us, but all find it easy and pretty to use.
>
> My little piece of 0,1 euro.



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