- From: Henri Sivonen <hsivonen@iki.fi>
- Date: Tue, 22 Jul 2008 11:53:10 +0300
- To: Jirka Kosek <jirka@kosek.cz>
- Cc: Karl Dubost <karl@w3.org>, Lachlan Hunt <lachlan.hunt@lachy.id.au>, public-html WG <public-html@w3.org>
On Jul 22, 2008, at 11:39, Jirka Kosek wrote: > Henri Sivonen wrote: >> On Jul 22, 2008, at 03:45, Karl Dubost wrote: >>>> Without an official DTD, no other references can be reliably used >>>> in XHTML 5. Even if you provide your own custom DTD and DOCTYPE, >>>> most browsers don't use validating parsers and so won't be able >>>> to dereference the entity references. >>> >>> That is a false assumption. Browsers *can*, if they implement it, >>> deference the *named* entity references. >> Implementing it is not feasible. >> * It would cause a massive DDoS attack on www.w3.org. >> * It would make www.w3.org a single point of failure for the Web. >> * It would be bad for XML parsing performance. >> * It would break compatibility with existing content (IIRC MIT >> courseware, for example) that refers to a DTD that is not namespace- >> well-formed (i.e. has colons in PI targets). >> * New documents authored with the assumption that DTDs get fetched >> would break very ungracefully in existing Gecko and WebKit instances. > > Not that I'm fan of DTDs, but you can solve those problems by using > XML catalogs: > > http://www.oasis-open.org/committees/download.php/14809/xml-catalogs.html > > Each browser then will have local copies of well known DTDs and will > fetch only custom created ones. How do catalogs address: * older browsers performing a DDoS on www.w3.org when a new DTD that isn't in the catalog is published * www.w3.org as a single point of failure when a DTD isn't in the catalog * parsing performance other than network * colons in PI targets * ungraceful behavior in existing Gecko and WebKit instances * the fact that the very reason why the XML spec doesn't require XML processors to process the DTD is to cater for browsers (see http://www.xml.com/axml/testaxml.htm) , so failing to exercise the opportunity not to process DTDs would be defeat the intent of the XML spec ? -- Henri Sivonen hsivonen@iki.fi http://hsivonen.iki.fi/
Received on Tuesday, 22 July 2008 08:53:55 UTC