- From: Julian Reschke <julian.reschke@gmx.de>
- Date: Tue, 5 Jun 2001 20:12:27 +0200
- To: "Lisa Dusseault" <lisa@xythos.com>, <w3c-dist-auth@w3.org>
> From: w3c-dist-auth-request@w3.org > [mailto:w3c-dist-auth-request@w3.org]On Behalf Of Lisa Dusseault > Sent: Tuesday, June 05, 2001 6:29 PM > To: w3c-dist-auth@w3.org > Subject: Logic for extending text XML elements > > > I've run into a minor issue relating to XML syntax and WebDAV > extensibility. > > I'm parsing: > <D:href>http://myserver.com/</D:href> > > Since an XML element can legally contain both text and elements (e.g. > <P>Hello <em>sailor!</em></P>), it's conceivable that in the future the > <href> element could be extended to have: > > <D:href>http://myserver.com/ > <expires>123486</expires> > more-stuff > </D:href> > > RFC 2518 says: > "All DAV compliant resources MUST ignore any unknown XML element and > all its children encountered while processing a DAV method that uses > XML as its command language." > > That would indicate that I should ignore the <expires> element. I can do > that. But what does "ignore" mean? > - Do I treat it as a separator so that "http://myserver.com/" is one text > child of DAV:href and "more-stuff" is another text child? How do I know > which one to treat as the URL, particularly if they both look like urls? > - Do I conceptually remove the ignored element? That would leave > <DAV:href> with a single text child containing white space, approximately: > "http://myserver.com/ more-stuff". I think this makes the most sense. You could also define it as - remove unknown child elements, - use DOM's normalize() method (or equivalent in your API) - use the value of the resulting text node > Since all this is rather ugly, I'd most like to have a sentence > added to RFC > 2518 (section 14?) that states at a minimum that "text elements should NOT > have their syntax extended by adding XML elements because this is unlikely > to be backward-compatible." I think we already instinctively follow this > guideline, but it's hard to write solid code based on guesses and > predictions that aren't written down. I agree it's ugly, but maybe it needs to be done nevertheless. How about just describing the "correct" way to get the text value?
Received on Tuesday, 5 June 2001 14:13:05 UTC