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Message:

object or xml?

Posted by Atish Kumar on June 11, 2000 at 2:27 PM

It is an interesting question you pose here. From reading the
article, there are two issues.
- transporting "object".
- the "object" "format".

The problem of polling is always a never elagant and hence
I agree with the motivations towards event-notification via
publisher/subscriber model.

However, the fact that display
Jini services to provide notification is trivial, however,
the only differentiator is the NewsItem, which could have
an XML Document, or String.

I see the advantages of describing an object NewsItem, where
the subject is able to notify its observers, is that you receive
objects, which you could then pass through some XML generator,
which then could be passed through some XML persistence model.

If the document on the server (at moreover.com) is in XML, what benefit does it have transforming it into java objects, then
serialising, and streaming across to its subscribers, and
the subscribers in tern would de-serialise the java objects,
and perhaps make avaialable on their servers as XML as the
persistence model.

I accept that having an object described in Java does provide
a cleaner and more robust use of the object then simply using
the DOM and accessing the attributes directly, and define
tight behaviour via methods, etc.

Perhaps something else that somes to my mind for discussion
is using XQL for polling (as i noticed that you record harvest
time). Or perhaps a more legacy solution where OODBMS vendors
with XML "extentions" already provide event notification
(however, i suppose it defeats the purpose of using XML in the first place...)

Anyhow, just random thoughts....