Re: The "Presentation" Layer

[Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx>]

Dr. Syd Nicholson wrote:
> Yes Joe,
>
> I think the big difference between us is that I only have data in the
> response from the server. All requests are Ajax based. There is nothing in
> the response from the server that defines the data, whether or not to
> display it, or what type of field it is. The server has no idea what client
> it is talking to, it could be a browser or a web service on another system. 
>
> I rely on the "Store" objects in the JavaScript to hold the data
> definitions, and JS Widgets o handle the display.
>
> A different approach, but all equally valid.
>   
I think I misstated my position a little.  I agree 100% that the data 
messages are purely data.  The definition of the field itself (the 
metadata) is sent as part of the widget.  I do believe that ultimately 
the definition of the field should come from the server; you have to 
ensure that the data in the message and the definition in the widget 
agree.  And  that's one of the nice things about EGL.  When you define a 
field, you define the metadata.  A record can then be used either to 
build the UI from the metadata, or to build the data structure to hold 
the data.  But the relationships are always there.

No, the data message itself only contains the data.  There is also a 
separate error information structure, and the relationship between the 
two is subject to the architecture.  But you do have to have some way of 
returning to the user interface that certain fields in the message are 
in error, and what that error is.

Joe