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

> From: David Gibbs
> 
> > 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.

Certainly a good place to do it.  Of course, except for the trivial things
you don't want to actually populate the whole list, you want to be able to
page it, search it and scan it.  Creating the HTML for such a thing
dynamically is certainly doable either client or server side, but I don't
think it's a simple piece of code.  Whereas creating a simple JSP to do it
really is trivial.  I suppose you could use the JSP code that generates the
web page and then insert the table portion of the HTML into the web page via
AJAX, but I don't think that's necessarily a simple exercise.


> > 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.

I don't think I was clear: the AJAX code on the client will certainly be
talking to a server.  My concern is that there will be people tempted to
start writing business logic in the JavaScript, just as they do in any other
scripting language (I'm sure you've seen JSP pages with embedded SQL, for
example).  That's what I would consider "server" work in AJAX.


> 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.

Agreed.  If AJAX is used primarily as a tool to enable either on-demand or
background retrieval of information, it will probably be benign.  However,
especially because of issues of latency, anything outside of the Intranet
should be very carefully scrutinized.

Joe