Re: [WEB400] Re: Re: Modify the IE Browser

["Nathan M. Andelin" <nandelin@xxxxxxxxxxxxxxxxxxx>]

> From: "Buck" <buck.calabro@xxxxxxxxxxxx>
> The problem for us iSeries developers is that browsers
> are stateless, and 5250 applications are stateful.

Let's keep in mind that robust Web applications are stateful too.  The
difference generally is in how state is retained.

With the 5250 interface, one instance of a program supports one user, so the
program automatically retains state for the user.

With most other Web interfaces, one instance of a program (or servlet)
supports multiple users, so the programmer uses a session component or some
other mechananism to retrieve state associated with each request, then save
state after each request is processed.

The 5250 interface is simpler from a programming point of view.  The state
of the program IS the state of the user.  I think a one to one relationship
is still valid for many applications.  Consider that some programs are used
only occasionally by a few users.  In those situations, it makes sense to
launch a new instance of the program when needed, and unload that instance
when the task is completed.

The other paradigm, where one program or servlet instance supports multiple
concurrent users, is better suited for applications that get continuous use
from many users.

My point is that both types of interfaces serve a useful purpose.  An
instance of a servlet is generally loaded when initially requested, but
remains active thereafter.  If only used occasionally by one user, then
retaining the servlet in an active state is a waste of resources, including
active connections to database resources.

The 5250 paradigm still makes sense.

Nathan M. Andelin
www.relational-data.com