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Netscape Says No RSS 0.91 For You
beat.bolli asks: "As of today, Netscape has 'updated' its my.netscape.com personalized portal to version 2. It seems that they decided to drop all external RDF channels. What gives?" Well, Will Sargent writes: "Netscape removed the RSS 0.91 DTD from their website. This means that all RSS feeds which depend on the RSS 0.91 (many, MANY news sites) cannot be used with a validating parser. Rael Dornfest has more details."
I hate to say it, but this is YA example of why forking over petty differences can be A Bad Thing. If one stubborn contingent hadn't steadfastly clung onto the deprecated RSS 0.91 spec instead of moving to RSS 1.0 (which returns to RSS's more dynamic roots), said contingent wouldn't be locked out because *a single document was removed from a web site*. Yeah, Netscape did the wrong thing. But the proponents of the outdated and outmoded spec should have seen this coming a mile away.
OK:
$ g-request http://slashdot.org/slashdot.rdfx -ns#"
...
<?xml version="1.0" encoding="ISO-8859-1"?><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-synta
xmlns="http://my.netscape.com/rdf/simple/0.9/">
Sorry, no cigar. This does not contain a DOCTYPE declaration. Try an RSS 0.91 file, e.g. from xmlhack.com:
$ g-request http://xmlhack.com/rsscat.phpd td">
...
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE rss PUBLIC "-//Netscape Communications//DTD RSS 0.91//EN"
"http://my.netscape.com/publish/formats/rss-0.91.
<rss version="0.91">
You can not run a validating parser solely on this. Because the URIs given above are in fact (what you appearently do not want to understand) only Namespace, and not a reference to the DTD.
No, you cannot run a validating parser solely on the first one because it uses XML namespaces! Try the RSS 0.91 file format. That's what we're talking about here.
There is no defined way to automatically determine where to get the DTD. You need to get it yourself and supply it to your validating Parser.
I, and the XML spec, beg to differ. I quote:
[Definition: The SystemLiteral is called the entity's system identifier. It is a URI reference (as defined in [IETF RFC 2396], updated by [IETF RFC 2732]), meant to be dereferenced to obtain input for the XML processor to construct the entity's replacement text.]
How do you dereference HTTP URI's? Well shock horror you use the HTTP protocol! ;-)
I've given the XSL(T)-Example. The XSL(T)-Declaration contains a URI as well.
No, it does NOT. There is no Declaration, only a start element. The reason being that XSLT uses XML namespaces, and namespaces aren't compatible with DTDs (well, they *mostly* aren't compatible - but I'll leave it to a book like XML in a Nutshell to explain the finer details).
But the DTD is not there, only a information by the W3C, that this is the XSL(T)-Namespace. After all you may imagine that the W3C knows what it does.Correct, the W3C does know what it does. The document pointed at by the namespace (which as you correctly, but confusingly point out, doesn't actually need to exist) at the W3C site is in RDDL. Go to XML.com to find out what RDDL is. (actually it might not yet be in RDDL, because the W3C is only slowly moving over to RDDL. But the Schema namespace *does* point to a RDDL document, and this is a sign of things to come).
A valid XSL(T)-Document does not contain any reference about where to get the DTD.
That's because XSLT can't use DTDs, because it uses XML namespaces.
This was specifically intended so, as the Locations of DTD can change, as the example here shows us.
Actually the reason namespaces chose not to have anything at the URI is because they didn't have a namespace compatible schema system in place at the time, and so nobody could agree what to put there. Now the people on the XML-Dev mailing list have agreed on putting RDDL documents there.
So you are still wrong. Having the DTD disappeared from Netscapes site DOES NOT make problems to validating parsers by default. Just obtain the DTD elsewhere and feed it into your parser.
That's possible if you implement a custom URI resolver, but barely anybody does that because it's not the right way to go about fixing the problem (which is to use a catalog system based on the PUBLIC identifier instead).
But this IS NOT A PROBLEM BY CONCEPT. The W3C recognized that it can be virtually impossible to maintain a ever lasting repository for a DTD, and therefore does not urge you to make any links to your DTD. The URI in the Declaration is only Namespace, and you don't even need to put a Webpage there. The W3C itself had not webpages at there URIs at the beginning. Only after having too much people who do not understand (like you) complaing the added this short text. You can use mailto:bla@fasel or gopher:.. or telnet: or anyother unique URI you might imagine. Just make it unique for a given DTD.
You're talking about namespaces again, not DTD's. Please go and buy a good book on XML (such as XML in a Nutshell, which I was one of two tech editors for) that will help clear up your confusion.
Matt. Want XML + Apache + Stylesheets? Get AxKit.
Dave has also put the DTD back up on one of Userland's site, available at:
http://www.scripting.com/dtd/rss-0_91.dtd
---
When in danger or in doubt, run in circles, scream and shout. --Robert A. Heinlein
From Dave's Scripting News on Friday, 27 Apr 01:
From the If-It-Weren't-So-Sad-It-Would-Be-Funny Department, yesterday when Netscape (apparently) deprecated RSS and broke all the links to their RSS stuff, they also broke people whose XML parsers require a DTD. The old URL for the RSS 0.91 DTD is totally 404 not found. John Munsch has a report from the field. I put a copy of the DTD into a folder here on scripting.com, and it will stay there, Murphy-willing, for perpetuity.
You can find his copy of the DTD here.
J.J.
The new My Netscape looks great in IE, but it's bad wrong with Mozilla. What gives?
The last sentecne says it all:
RSS partisanship aside, this episode strikes yet another blow against the use of centralized (specifically copyright) DTDs in an increasingly distributed computing environment.
Publicly used DTDs need to be somewhere where the public can count on them long term.
Or else we need a DTD caching mechanism with an inifinite TTL - and this *still* doesn't address the copyright issue.
--
"that's not encryption - it's a new perl script that I'm working on..." - from some Matrix parody
If you're looking for the already implemented RSS 0.92 look here There's also a reference to RSS 0.93 on which development started on April 01,2001.
When set to "Opera" or "Mozilla 3.0", the My Netscape page doesn't load at all, displaying an "invalid browser" page, saying you must use NS 4.x or IE 5.x. (Apparently they think NS 6 sucks too). Setting the User Agent to "Mozilla 5.0" or "Mozilla 4.76" (strange, since the real NS 4.76 works) result in the same one-columned-stretched layout as Mozilla. However, when Opera is emulating MSIE 5.0, it works perfectly!
So apparently, it's not that the page couldn't display in Mozilla, it's that My Netscape intentionally screws up the page for Mozilla!!
"It's better to keep your mouth shut and be thought a fool than to open it and remove all doubt."
The article is about RSS files, which are files used mostly by news sites and blogs. They contain a summary of the most recent topics on a site. RSS files were used by my.netscape.com to monitor multiple sites on your MyNetscape page, also they are used in Evolution and the Nautilus has the ability in CVS (under a "News" sidebar IIRC).
The problem here is that the RSS format was written in XML and used a DTD (document type definition) that was stored on the Netscape servers. Whenever *someone* *somewhere* tries to parse a RSS file the Netscape server is queried for the file and the RSS file is validated against it. So now that Netscape removed the file people don't get to see the RSS summary but get an error instead.
What could be done is putting a copy of the file on an alternate location and changing all RSS files to match the new URI... well, this could be done if it weren't for the fact that Netscape copyrighted the RSS DTD... the only sollution left is to change to the updated RSS format which doesn't depend on Netscape.
Monkey sense
What about those of us who use Perl?
"My mother works for Microsoft now. A whole other cult."