I'm trying to be a purist here but it would be really nice to have a
persistent object that could move around the network. Does Java have
anything like this? Maybe Jade? Maybe just learn RPG and use the AS/400
(no objects/no worries)?
I spose I could create the empty object on the client and pass it to the
server when I want it loaded or saved. Any other manipulation is then local
to the client. Better still, if the server could return some formated data
from a method and the client can fillin attributes of the instance.
I think I'll end up with 5 tiers, 2 on the client and 2 on the server.
Client tiers will be presentation, a pure object and a data-to-object
translater. On the server I would have the opposite data-to-object
translater and the database itself.
Seems like a lot of work ? Comments?
>From: "Nic Wise" <[EMAIL PROTECTED]>
>Reply-To: [EMAIL PROTECTED]
>To: Multiple recipients of list delphi <[EMAIL PROTECTED]>
>Subject: Re: [DUG]: Marhsalling: COM vs Corba
>Date: Mon, 14 Feb 2000 18:12:53 +1300
>
> > Imageine I have a server process that creates a object and returns the
> > interface to the client. With COM, if I call methods and set properties
>on
> > this instance I get network traffic cause the object is alive on the
>server,
> > not the client. Correct ?
> >
> > With Corba (or COM), is there a way of avoiding this network traffic?
>IE,
> > can the object be magically transported to the client rather than just a
> > reference to it?
>
>Nope - what happens if you server is compiled C++ code running on an
>UltraSPARC 20?? Not gonna work on your little PIII 500, right?! (OK, bad
>example, 'cos then it would _have_ to be a CORBA object, but still....)
>
>technically could work for COM, being its WinTel only, but you can kiss
>scalability and platform neutrality goodbye.
>
>So, in general, no, you can't do this. CORBA 2.3 (Visibroker 4.0) has
>Objects By Value which is something to do with this, but I havn't used or
>looked into it much yet. Delphi only has CORBA v2.2 (Visi 3.3/3.4)
>
>I find the best way to get 'around' this is to pass records or structs, eg
>in CORBA IDL:
>
>struct EmployeeRecord {
> string name;
> string phone;
> string irdNumber;
>};
>
>interface Employee {
> attribute EmployeeRecord employee;
>};
>
>For example. Then you can get the record (one fairly big hit on the
>network), mess with it, and fire it back (another big hit on the network),
>rather than have hit-change-hit, hit-change-hit, hit-change-hit which is a
>LOT slower.
>
>HTH.
>
>N
>
>
>
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