Re: RPG and AJAX was->RE: How do I create a web page that....

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

AJAX will be the most overused technology for the next 6-12 months, until
people realize that it's just not necessary for the majority of
applications.  In Charles' case, his initial request was to be able to enter
items and have them appear on the bottom of the page as he enters each one.
He didn't say anything about validating the entries, simply keeping track of
them using a single input field.  This could be done with a very simple fewe
lines of JavaScript.

Now, he MIGHT have wanted line by llne validation, but he didn't specify it,
and yet the immediate answer from some people was to add server-side
validation via AJAX, without a thought to performance or complexity.

When you start changing from one web hit for a page to one web hit for every
field, you're going to find that issues like latency start to become much
more pronounced.  It's perhaps less of a problem with an Intranet
application, but if this application is ever meant to go out to slower speed
connections, then AJAX may not be the idea.

I'm not against AJAX by any means.  There are applications where it makes
sense.  The problem is that there are a LOT of issues that need to be dealt
with, especially when it comes to opening up multiple persistent connections
to the host. (Oh ho, you say... we don't NEED persistence!  Well, if you're
planning on using any of the capabilities of i5/OS, like library lists and
security, then you will need persistence of some kind.)

Anyway, my two cents.  AJAX is a cool technology, but it's not the universal
panacea, and it's very "coolness" makes it highly susceptible to overuse.

Joe


> From: albartell
> 
> >Any recommendations on where to start?
> 
> If you can wait until the end of the month I have an article coming out in
> the May issue of iSeries News titled "RPG and Ajax: Together At Last"
> 
> It will guide you through the bare bones of AJAX and RPG.  The example
> used
> in the article is validating an item number and changing the appearance of
> the page based on the item entered being valid or invalid.