Re: Remote DOM access ??

At 02:05 PM 10/7/98 +0100, \"Pasqualino \\\"Titto\\\" Assini\" wrote:
>
>A question for you guys.
>
>Say that I want to access a sizable XML document (2-5 Mb for example)
>and show some parts of it.
>
>If the file is on my machine there is no problem, I parse it and access
>it through DOM.
>
>Now, what if the document is on some far distant server on the Internet
>?

There is a group of us who very much want to define a standard here for
what might be called a "Repository Object Model" based on the DOM.  It is
not on the priority list for Level 2.

>
>I would like to be able to use DOM as well but I'm not in the mood of
>downloading  the whole file so I design a CORBA DOM interface and access
>
>it through that.
>
>Do you think that it might work ?

Yes, but very slowly ... the DOM is defined on objects that are assumed to
be efficient to access one at a time; there is no way to do a "bulk load"
or "bulk save" of a DOM subtree.



>
>I suspect that it wouldn't work very well as every time that I need to
>access an element or apply some operations I have to send a CORBA
>message and wait for an answer before I can proceed.
>
>Maybe a better solution would be to have a smart XML cache, something
>that would use heuristic methods to forecast which data the user is
>going to require and forward it before the actual request take place.
[snip]
>
>What do you think ?

Seems reasonable to me.  If your architecture allows some server-side
processing to keep the full parsed document on the server and intelligently
query and selectively pull pieces down to the client, that might work better.

>
>A related question, is there any proposal for a protocol between a DOM
>implementation and an underlying datastore ?

Again, a subset of the DOM WG is very interested in this problem; with luck
we can get Level 2 out of the way quickly and address this.  Sorry if this
is not soon enough to help you much, but please keep in touch to make sure
we understand your requirements, suggestions, etc.

Mike Champion

Received on Wednesday, 7 October 1998 11:21:41 UTC