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From: bvs@light.uucp (Bakul Shah)
Newsgroups: news.software.b
Subject: Splitting news access from its presentation
Summary: Define an object oriented interface to access news
Message-ID: <1990Mar14.233441.28554@light.uucp>
Date: 14 Mar 90 23:34:39 GMT
Reply-To: bvs@light.UUCP (Bakul Shah)
Organization: Newsreaders Anonymous
Lines: 65
Keywords:

Reading all these news reader reviews makes me think we need to
separate the issue of *presentation* of news from its *access*
(roughly speaking.  I can't think of a better way of expressing
what i have in mind).

While all the readers reviewed here so far and even Notes and
readnews (remember?) let me access the news system (i.e. let me
read/discard articles, tell me if there is something not read by
me in a group, subscribe/unsubscribe groups etc.) they don't
present this information in the way _I_ like.

If the access layer is separated out, people can concentrate on
building better presentation software or even embedding news
access in other software.  Similarly, people can experiment with
other ways of organizing the news database as long as they provide
the same access interface.

Here is the basic idea to get the ball rollling.

- *Model* the news system as a set of objects and relationships
  between them.  Define operations to add/delete/change these
  objects and relationships.  Then relaynews, expire, news-readers
  all become specialized applications that will access the news
  objects via a clean interface.

  Group Operations:
	create, delete
	moderate, un-moderate   // and other attribute changing ops
	add-article, delete-article
	add-sub-group, delete-sub-group

  Article Operations:
	create, delete
	send-to-system, receive-from-system
	attach-property, detach-property

  User operations:
	add-user, delete-user           // these may be implicit
	subscribe-to-group, unsubscribe-from-group
	read-article, write-article
	cancel-article, reply-to-article
	filter-group    // to filter out unwanted stuff

- Maintain important relationships such as articles-read-by-user,
  articles-not-yet-sent-to-system, articles-ready-for-expiry,
  group-expiration-schedule, groups-we-are-interested-in, groups-
  our-neighbor-wants and so forth.

This is just to give a flavor of what can be done.  A real design
would involve specifying lots of details.

I suspect most of the code to implement these objects can be
cribbed from existing tools.  The important thing is to a) come up
with a model that accurately (and simply) reflects how a news
system is accessed in real life and b) replace built-in
dependencies on various specific files/directories with an object
interface.  I might fer'nstance want to suck-up all the news in a
news-server with 4Gig virtual address space and simply dole out
articles as requested.

So.  WhaddayaThink?

-- Bakul Shah
   bvs@BitBlocks.COM
   ..!{ames,sun,ucbvax,uunet}!amdcad!light!bvs