Re: EGL RichUI Was:Re: From RGP to ¿Java?

[Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx>]

Nope, you didn't miss anything, Pete.  The fundamental difference 
between rich clients and thin clients is that with a thin client, all 
logic is on the host, including generating the user interface.  That's 
why simple scripting languages like PHP and RPG-CGI can handle thin 
client.  With rich client, the UI logic resides on the client in the 
browser.  You in effect send down a program that builds widgets (this is 
actually fairly close to what Aaron Bartell is pushing for), and then 
that logic requests data in chunks from the host.

It is those requests for data that require AJAX and thus a web services 
approach.  Now technically you could write those services however you 
wanted and parse the data yourself, but with EGL you simply specify the 
record layout - using the SAME syntax at both the rich client and the 
host level - and EGL does all the plumbing for you, formatting the data 
into either XML or JSON on the host, sending it down the wire, 
disassembling it on the client and populating the records for use in the 
widgets.

You have to see it to believe it.

Joe

> One follow up question Joe.
>
> It seems to me that EGL RUI requires a web services interface layer.  Is 
> that correct?  Most of my "hand tooled" RUI apps use AJAX/JSON to talk 
> to Java servlets.  Would I be writing RPG service programs wrapped by 
> web services for my EGL RUI apps or can I write directly to the DB?  My 
> question stems primarily from the ease with which you can create a CRUD 
> app that goes "direct" to the DB in EGL vs using a RUI to access the 
> data.  RUI seemed to unnecessarily require a web service to handle the 
> DB access where the non-RUI EGL method basically allowed you to point to 
> the DB tables and it created all the I/O infrastructure quickly and 
> easily.  I was looking for the same "point to the table and go" ease of 
> development in EGL RUI. Did I miss something?
>