Re: RPG and AJAX was->RE: How do I create a webpagethat....

Joe Pluta wrote:
> It's just that some programmers will be looking really hard for places to
> use it where it doesn't really belong.

No question.

> As to application in a "large number" of situations, I'm taking a wait and
> see approach on that.  There are definitely a few classes of use (my
> favorite is "history lists", like on Mapquest clicking a button to bring up
> your list of recent addresses, and replacing information stored in cookies).

Using the iSeries, green screen experience, convention ... I think that
ajax could be useful just about anytime you would normally use a F4 to
prompt a list.  Click a button to get the most current list of values
available, select the one you want, and the value with it's description
are populated on the page.

> But I think that there is a lot of danger in over-AJAXing something.  Having
> the screen change every time I hit a key or exit a field can be overkill.
> There's a reason that the block-mode 5250 interface has been so successful.

Everything can be misused.  I should tell you about the guy in my high
school programming class that learned about the BLINK command in
applesoft basic :)

> I think from a purely semantic standpoint you're correct, David.  If your
> only two options are "client" and "server", then the bulk of the work done
> by AJAX routines will be client.  

Ajax exclusively on the client doesn't really accomplish anything, does
it?  The whole point is to query a server to get some information for
display.

> These days, though, I break applications
> up into at least three tiers: UI, application controller and business logic.

As always, a good approach.

> The application controller logic which is traditionally the bailiwick of the
> server in block-mode applications is moved more into the browser with AJAX.
> Especially when people are talking about rearranging the screen in response
> to keyboard events, you run the risk of losing control of your application;
> you could conceivably go to a completely different application without ever
> returning to the controlling application.  That to me would be a bad thing.

Well, I guess it depends on the application ... to my mind, ajax would
be used to service the main application ... not change the application flow.

>> Oh man ... but using cool stuff is so FUN! <grin>.
> Especially when you're not paying for it <g>.

Well of course.

david