RDF question
Dan Brickley
Daniel.Brickley at bristol.ac.uk
Sun Jun 21 19:28:26 BST 1998
On Mon, 15 Jun 1998, Roy Tennant wrote:
> I've been trying to puzzle out RDF, as we would like to use it here for
> some things we are doing. Meanwhile, it hasn't helped to see examples of
> RDF that appear to be "illegal" or at least "unconventional". But I'm
> enough of a novice that I would like to reserve judgment while awaiting
> the opinion of someone more versed in the syntax than I. Specifically, I'm
> having trouble seeing where the RDF as used by Netscape and Hotwired,
> see:
>
> Netscape RDF:
> http://home.netscape.com/netcenter.rdf
This _is_ pretty confusing syntax; mostly because it makes extensive use
of the abbreviated version of the RDF-in-XML serialisation syntax, but
also because Netscape haven't use XML namespaces or documented their
vocabulary within anything except C source code... This makes it hard to
tell which property types are 'core' RDF facilities, and which belong to
the Netscape sitemap vocabulary. As far as I can see though it is correct,
in that it can be mapped into nodes'n'arcs following the rules in the
Model and Syntax paper.
It'd be nice to see something more 'neutral' like the Dublin
Core vocabulary <http://purl.org/metadata/dublin_core> used in this
context, eg. 'DC:Title' instead of 'MOZ:name' etc. Grumble...
Anyway, here's an annotated version of the Netscape sitemap file with
comments and ASCII art. I've not looked at any of the other sitemap files
mentioned, so am assuming this one is typical. Long lines have been
wrapped.
Dan
------------------- annotated netcentre.rdf file:
<!-- Namespace PIs should go here for RDF core vocabs and
Netscape's own vocabulary. Even if we're assuming a default namespace
(arguable given current namespaces draft) we need to know it's URI... -->
<RDF:RDF>
<!-- this tells us all contained elements can be interpreted
according to the serialisation and abbrevated syntaxes
specified in the RDF Model and Syntax paper of feb'98. In this
case, extensive use it made of the facilities offered by
the abbreviated syntax. -->
<!-- Elements should have namespace prefixes tying them to URIs specified
in the namespace PI. As should attributes where these differ from
the element's namespace -->
<Topic id="root" name="Netscape Netcenter">
<!-- creates a node known as 'root' with a 'name' property
whose value is the string "Netscape Netcenter",
and tells us that root is an instance of class 'Topic'
(presumably defined in Netscape's RDF schema vocabulary
since it's not in the RDF or RDF-S core). -->
<child><Topic id="Netcenter" name="Netcenter">
<!-- the node known here as 'root' has a 'child' property whose value is
another node known as 'Netcenter', and which has
a name property with string value "Netcenter".
'Netcenter' is an instance of the class 'Topic'. -->
<child><Topic id="Commerce" name="Commerce">
<!-- the node 'Netcentre' similarly has a child property whose value
is the node 'Commerce', another instance of Netscape's 'Topic'
class with a 'name' property bearing a string value "Commerce" -->
<child href="http://home.netscape.com/netcenter/marketplace/index.html" name="Marketplace"/>
<!-- 'Commerce' has a child property whose value is the resource
identified by URI, above. That resource has a name property with
value "Marketplace"-->
</Topic></child>
An ASCII-ART version of the nodes'n'arcs graph so far...
Unqualified node labels are local identifiers for nodes within this graph,
ie. partial URIs. "RDF:" is an abbreviated convenience identifier
standing in for the URI of the RDF model namespace; "RDFS:" for the RDF
schema namespace and "MOZ:" for the Netscape sitemap namespace, currently
undocumented.
root--MOZ:child--> Netcenter
|--MOZ:name--> "Netcenter"
|--RDF:instanceOf--> Topic [implies Topic is a class]
| |--RDF:instanceOf->RDFS:Class
|--child--> Commerce
|--RDF:instanceOf--> Topic
|--MOZ:name--> "Commerce"
|--MOZ:child--> http://www.netscape.com/.../index.html
|--MOZ:name--> "Marketplace"
<!-- end of information about the 'Netcentre' node and its associates... -->
<!-- the rest of this document follows the same pattern as the above -->
<child><Topic id="Community" name="Community">
<child href="http://home.netscape.com/assist/is
p_select/index.html" name="ISP Select"/>
<child href="http://form.netscape.com/directory
/html/md_unreg_main.html" name="Member Directory"/>
<child href="http://www.newaol.com/aim/netscape
/adb00.html" name="Netscape AOL Instant Messenger"/>
<child href="http://form.netscape.com/directory
/community/html/pc_unreg_main.html" name="Professional Connections"/>
<child href="http://home.netscape.com/netcenter
/vo/index.html" name="Virtual Office"/>
</Topic></child>
<child><Topic id="Computing" name="Computing">
<child href="http://home.netscape.com/download/
index.html" name="Netscape Download"/>
<child href="http://merchant.netscape.com/netst
ore/store.html" name="Netscape Store"/>
<child href="http://home.netscape.com/download/
su2.html" name="Smart Update"/>
<child href="http://software-depot.netscape.com
/" name="Software Depot"/>
</Topic></child>
<child><Topic id="Content" name="Content">
<child href="http://home.netscape.com/netcenter
/businessjournal/index.html" name="Business Journal"/>
<child href="http://home.netscape.com/netcenter
/cf/index1.html" name="Channel Finder"/>
<child href="http://form.netscape.com/ibd/html/
ibd_frameset.html" name="In-Box Direct"/>
<child href="http://home.netscape.com/escapes/s
earch/" name="Net Search"/>
<child href="http://netscape.yahoo.com/guide/in
dex.html" name="Netscape Guide By Yahoo!"/>
</Topic></child>
</Topic></child>
<child><Topic id="Netscape" name="Netscape">
<child><Topic id="Columns" name="Columns">
<child href="http://home.netscape.com/comprod/c
olumns/intranet/index.html" name="Intranet Executive"/>
<child href="http://home.netscape.com/comprod/c
olumns/newsgroup/index.html" name="Newsgroup"/>
<child href="http://home.netscape.com/comprod/c
olumns/techvision/index.html" name="TechVision"/>
<child href="http://home.netscape.com/comprod/c
olumns/mainthing/index.html" name="The Main Thing"/>
</Topic></child>
<child><Topic id="Company" name="Company">
<child href="http://home.netscape.com/comprod/a
bout_netscape/hr/index.html" name="A Cool Place to Work"/>
<child href="http://home.netscape.com/company/a
bout/index.html" name="About Netscape"/>
<child href="http://home.netscape.com/company/c
ontacts/index.html" name="Contacts"/>
<child href="http://people.netscape.com/" name=
"Employee Directory"/>
<child href="http://home.netscape.com/company/i
nvestor/index.html" name="Investor Relations"/>
<child href="http://home.netscape.com/company/p
ress/index.html" name="Press Relations"/>
<child href="http://home.netscape.com/company/p
ublishers/index.html" name="Publisher Relations"/>
</Topic></child>
<child><Topic id="DevEdge Online" name="DevEdge Online"
>
<child href="http://developer.netscape.com/mark
eting/index.html" name="Co-Marketing"/>
<child href="http://developer.netscape.com/sour
ce/index.html" name="Communicator Source"/>
<child href="http://developer.netscape.com/docs
/index.html" name="Documentation"/>
<child href="http://developer.netscape.com/prog
ram/index.html" name="Membership"/>"
<child href="http://developer.netscape.com/soft
ware/index.html" name="Products & Downloads"/>
<child href="http://developer.netscape.com/supp
ort/index.html" name="Support & Newsgroups"/>
<child href="http://developer.netscape.com/tech
/index.html" name="Technologies"/>
<child href="http://developer.netscape.com/view
source/index.html" name="View Source Magazine"/>
</Topic></child>
<child><Topic id="International" name="International">
<child href="http://home.netscape.com/au/index.
html" name="Australasia"/>
<child href="http://home.netscape.com/pt/index.
html" name="Brasil"/>
<child href="http://home.netscape.com/da/index.
html" name="Danmark"/>
<child href="http://home.netscape.com/de/index.
html" name="Deutschland"/>
<child href="http://home.netscape.com/es/index.
html" name="España"/>
<child href="http://home.netscape.com/fr/index.
html" name="France"/>
<child href="http://home.netscape.com/it/index.
html" name="Italia"/>
<child href="http://home.netscape.com/ja/index.
html" name="Japan"/>
<child href="http://home.netscape.com/ko/index.
html" name="Korea"/>
<child href="http://home.netscape.com/nl/index.
html" name="Nederland & Belgie"/>
<child href="http://home.netscape.com/sv/index.
html" name="Sverige"/>
<child href="http://home.netscape.com/uk/index.
html" name="United Kingdom"/>
</Topic></child>
<child><Topic id="Partners" name="Partners">
<child href="http://home.netscape.com/partners/
programs/insight.html" name="Netscape Insight"/>
<child href="http://dev1.netscape.com/directory
/" name="Netscape ONE Directory"/>
<child href="http://home.netscape.com/comprod/n
etscape_partner_programs/opportunities/index.html" name="Opportunities"/>
<child href="http://home.netscape.com/comprod/n
etscape_partner_programs/channel_programs/index.html" name="Programs"/>
</Topic></child>
<child><Topic id="Products" name="Products">
<child href="http://home.netscape.com/products/
commapps/index.html" name="Commerce Applications"/>
<child href="http://home.netscape.com/comprod/p
roducts/communicator/index.html" name="Communicator"/>
<child href="http://home.netscape.com/navigator
/index.html" name="Navigator"/>
<child href="http://home.netscape.com/assist/se
curity/index.html" name="Security"/>
<child href="http://home.netscape.com/comprod/s
erver_central/index.html" name="Servers"/>
<child href="http://home.netscape.com/comprod/p
roducts/tools/index.html" name="Tools"/>
</Topic></child>
<child><Topic id="Solutions" name="Solutions">
<child href="http://home.netscape.com/comprod/b
usiness_solutions/education/index.html" name="Education"/>
<child href="http://home.netscape.com/comprod/a
t_work/index.html" name="Enterprise"/>
<child href="http://home.netscape.com/solutions
/govt/index.html" name="Government"/>
</Topic></child>
<child><Topic id="Support" name="Support">
<child href="http://home.netscape.com/support/c
ustomer_service/" name="Customer Service"/>
<child href="http://learning.netscape.com/" nam
e="Netscape Learning"/>
<child href="http://help.netscape.com/" name="T
ech Support"/>
</Topic></child>
</Topic></child>
<child><Topic id="Utilities" name="Utilities">
<child><Topic id="About This Site" name="About This Sit
e">
<child href="http://home.netscape.com/ads/ad_ra
te_card.html" name="Advertising"/>
<child href="http://personal.netscape.com/custo
m/index.html" name="PowerStart"/>
</Topic></child>
<child><Topic id="Feedback" name="Feedback">
<child href="http://help.netscape.com/forms/bug
-client.html" name="Bug Report"/>
<child href="http://home.netscape.com/feedback/
general.html" name="General Feedback"/>
<child href="http://home.netscape.com/feedback/
product.html" name="Product Feedback"/>
<child href="http://home.netscape.com/feedback/
site.html" name="Site Feedback"/>
</Topic></child>
<child href="http://home.netscape.com/search/index.html
" name="Search"/>
<child href="http://home.netscape.com/map/index.html" n
ame="Site Map"/>
</Topic></child>
</Topic>
</RDF:RDF>
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