Re: 5250 to Web Interface / Application Modernization

On Thu, Apr 11, 2019 at 11:46 AM Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx>
wrote:

And on a slightly different tack, a software vendor said, we know how to
use system APIs, I don't think we need this. And that is maybe right for
a vendor - but vendors are not the final audience for this, users are.

I remember that comment, though I've forgotten the name of the vendor.

Vern,

When you say that users are the audience, what users are you referring to?
Legacy application developers? Wouldn't it make more sense to represent the
interests of the end-users of our applications?

For interactive web applications we've been considering "server-client" vs.
"client-server" architecture. Server-client is also referred to as the 5250
or display-file paradigm.

Under server-client, the server begins the conversation by writing records
to a workstation device, followed by waiting and reading records from that
device. In the case of web interfaces, a Javascript utility has been
downloaded, which performs services comparable to a 5250 emulator. It maps
data streams to DOM elements and visa versa, back to data streams that are
returned to the server and forwarded to a component that functions similar
to IBM i Workstation Data Management (it transforms data streams into
record formats that can be consumed by an interactive application).

Under client-server, the client requests resources from the server, and the
server responds, sometimes with static content, other times with content
that is custom-generated by an application. Local resources offer a broad
range of functionality that may be leveraged to improve and optimize the
user experience. The trend has been to use local resources more fully in
order to improve the user experience and reduce server workload.

Which architecture is more fitting for modern applications?

Back to end users. When organizations implement OA handlers, end users
notice that the application behaves essentially the same. But it feels
heavier, weighted down by extra computing and I/O overhead. Where is that
taking the IBM i platform?