This version: January 3, 2001
Latest Version: January 3, 2001
Previous Version: January 2, 2001
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
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
The Resource Directory Description 1.0 DTD has been produced as an extension of XHTML Basic 1.0 . 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.
resource element is in a namespace whose name
In this discussion, we assume the use of the namespace prefix
rddl for this name, and refer to this element as
rddl:resource element represents a simple xlink (using the
attributes defined in the XLink namespace), and an
provides for an optional content type specifier.
content-type attribute is not in any namespace.
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.
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:
This XLink locator attribute's value is a URI reference to the target related resource
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