Appending to an XML document

Ingo Macherius macherius at darmstadt.gmd.de
Tue Dec 7 23:38:20 GMT 1999


Ross,

currently I'm busy designing an XML based log format myself. In 
contrast to "classic line based logging", appending indeed is 
prohibitively costly in XML. Thus I decided not to log into a 
wellformed XML document, but to stick with a sequence of <Event> type 
doc-fragments, just being well-formed per event.
Of course one can not parse the result immediately, but at the time 
of log analysis (or whatever you do with your event data), it's 
trivial to pre- and append the necessary tags to enclose the doc-
fragments.

XML was just not designed to fit the demands of concatenatiation. But 
I found the value of structuring single events in a "semi-structured" 
(read: well-formed) way valuable enough to choose XML. The "missing 
enclosing tag" is not really a serious problem if you delay its 
insertation until REALLY necessary.

	++im

Ross Bleakney <rossb at wrq.com> wrote at 7 Dec 99, 15:08:

> I know of no XML API that allows for modifying a document. They make it easy
> to create new documents out of old ones, but they don't allow you to modify
> an existing file. Doing so would mean the possibility of optimization that
> would greatly reduce disk I/O. For example, if you had XML like this:
> 
> <Events>
>    <Event>...<Event>
>    <Event>...<Event>
> </Events>
> 
> It would be really nice to write code like this:
> 
> 	ModifyXML modXML = new ModifyXML("MyDoc.XML");	
> 	Element event = modXML.createElement("Event");
> 	event.appendChild(modXML.createTextNode("A big event happened"));
> 	modXML.appendChild("Events", event);
> 	modXML.update();
> 

--
Ingo Macherius//Dolivostrasse 15//D-64293 Darmstadt//+49-6151-869-882
GMD-IPSI German National Research Center for Information Technology
mailto:macherius at gmd.de http://www.darmstadt.gmd.de/~inim/
Information!=Knowledge!=Wisdom!=Truth!=Beauty!=Love!=Music==BEST (Zappa)

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To unsubscribe, mailto:majordomo at ic.ac.uk the following message;
unsubscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)





More information about the Xml-dev mailing list