This version: January 3, 2001
Latest Version: January 3, 2001
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This document defines Resource Directory Description Language (RDDL). A Resource Directory provides a text description of some class of resources and of other resources related to that class. It also contains a directory of links to these related resources. An example of a class of resources is that defined by an XML Namespace. Examples of such related resources include schemas, stylesheets, and executable code. A Resource Directory Description is designed to be suitable for service as the body of a resource returned by deferencing a URI serving as an XML Namespace name.
The Resource Directory Description Language is an extension of XHTML Basic
1.0 with a new element named resource.
This element serves as an
XLink to the referenced resource.
This document defines the syntax and semantics of the Resource Directory Description Language, and also serves as a Resource Directory Description for the namespace http://www.openhealth.org/RDDL/.
The Resource Directory Description 1.0 DTD has been produced as an extension of XHTML Basic 1.0 [5]. The definition uses the method described in Modularization for XHTML, based on the use of internal-subset parsed entities.
The Resource Directory Description Language was initially proposed and specified after discussion on the XML-DEV mailing list.
This document has no official standing and has not been considered nor approved by any organization.
rddl:resource ElementThe resource element is in a namespace whose name
is http://www.openhealth.org/RDDL/.
In this discussion, we assume the use of the namespace prefix
rddl for this name, and refer to this element as rddl:resource.
The rddl:resource element represents a simple xlink (using the
attributes defined in the XLink namespace), and an
additional attribute content-type
which
provides for an optional content type specifier.
The content-type attribute is not in any namespace.
The rddl:resource element is placed within the html
body. The XHTML %Flow.mix entity has been
redefined to contain rddl:resource so it roughly may be placed anywhere a p tag may be placed.
The rddl:resource element itself uses the %Flow.mix content model, and should have content
which describes the associated resource.
<!ELEMENT rddl:resource (#PCDATA | %Flow.mix;)*> <!ATTLIST rddl:resource %Common.attrib; xmlns:rddl CDATA #FIXED 'http://www.openhealth.org/RDDL/' xlink:type (simple) #FIXED "simple" xlink:role CDATA 'http://www.openhealth.org/RDDL/' xlink:arcrole CDATA #REQUIRED xlink:title CDATA #IMPLIED xlink:href CDATA #IMPLIED content-type CDATA #IMPLIED > |
The definition above has been edited for clarity.
The value of this attribute must be supplied and must a URI reference. It provides a machine-readable identifier for the type of the related resource. Software perfoming resource resolution may dispatch on the this value.
It is anticipated that many related-resource types will be well known. A list of well-known resource types may be found at http://www.openhealth.org/RDDL/arcrole.htm (which itself is an RDDL directory).
The value of this attribute must be a URI reference.
In this version of RDDL, its value must be
the RDDL namespace name:
http://www.openhealth.org/RDDL/.
This XLink locator attribute's value is a URI reference to the target related resource
A human readable short descriptive title. This should be specified but not be seen as a replacement for descriptive content.
Not used. The only legal value is "none".
An optional attribute whose value provides the related resource's media type. This attribute is not in any namespace.
A CSS stylesheet used to provide the "look-and-feel" of this document, suitable in general for RDDL documents.
A DTD for RDDL, defined using Modularization for XHTML