Re: Green-screen versus browser

On 4/25/05, Scott Klement <midrange-l@xxxxxxxxxxxxxxxx> wrote:
> > A simple example:  PC user is signed onto the iSeries thru Client
> > Access/5250.  User selects option 5=display details from a subfile
> > display.  Instead of the RPG program sending another 5250 display
> > screen down to the user, you want to establish a socket connection to
> > that PC, send the data to the PC program on the other end of the
> > socket, and have that program put a WinForm window up to display the
> > option 5=display data.
> 
> Personally, I'd rather see the entire application be GUI or the entire
> application be green screen. I don't like it when someone mixes the two
> like this. (Just my opinion, of course.)

If it is all GUI, I have problems with the basic security of the
application. How does the user signon to the iSeries?  If I am
starting from an interactive job I know I have a secure connection and
the iSeries can be the party that initiates the socket session.    If
the PC is starting the GUI session, right away there are security
concerns.  What user profile does the iSeries partner program run as?

> > How would you go about doing that?  It is not easy, if not impossible.
> > The 5250 interactive job cannot start a thread to handle the socket
> > link because interactive jobs on the as400 cant multi thread.
> 
> Shrug...

just answering your post stating that IBM provides everything needed
for great applications.

>  The spawn() API could be used so that you have multiple jobs
> instead of multiple threads. You could have one job that reads the socket
> and write's the data to a data queue.  Another that reads a data queue and
> puts the results onto the socket.

that is a lot of work.  difficult to debug such a setup.  also there
are problems with the primary job ending and the spawned, service job
continuing.

>  Then the interactive job could work
> purely with data queues, which can be attached to the display file to
> allow multiplexing.

I am not sure if once that display is input inhibited there is
anything that can be done to interupt it.   A practical problem with
data queues and display files is that they dont work with the DSM set
of APIs.

> Like I said, I don't like this type of coding. I'd rather see all 5250 or
> all GUI. And that's my recommendations to programmers who are trying to
> implement this. But if you MUST mix them for some reason, it's not
> impossible.

I have never seen an all GUI windows to iSeries application in action
or even a discussion of its technical workings.

-Steve