XPointer &schemename;() Scheme
&doctype;-xptr-&shortname;-&isodate;
W3C Recommendation
&day;
&month;
&year;
&dirname;
XML
&trpath;xptr-&shortname;/
http://www.w3.org/TR/2002/PR-xptr-element-20021113/
Paul Grosso
Arbortext, Inc.
paul@arbortext.com
Eve Maler
Sun Microsystems
eve.maler@sun.com
Jonathan Marsh
Microsoft
jmarsh@microsoft.com
Norman Walsh
Sun Microsystems
Norman.Walsh@Sun.COM
&abstract;
This section describes the status of this document at the time of its publication. Other documents may supersede this document. The latest status of this document series is maintained at the W3C.
This document is a Recommendation (REC) of the W3C. It has been reviewed by W3C Members and other interested parties and has been endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited as a normative reference from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web.
This document has been produced by the W3C XML Linking Working Group as part of the XML Activity. It is intended to address a subset of the original XPointer requirements, and to serve, along with the accompanying XPointer Framework and XPointer xmlns() Scheme specifications, as a part of a fragment identifier syntax for the XML Media types.
Public comments on this Recommendation are welcome. Please send them to
the public mailing list www-xml-linking-comments@w3.org (archive).
Information about implementations relevant to this
specification and the accompanying XPointer element() Scheme and XPointer xmlns() Scheme can be found in the Implementation Report.
There are patent disclosures and license commitments associated with
this Recommendation, which may be found on the XPointer IPR Statement page in conformance with W3C policy.
A list of current W3C Recommendations and other technical documents can
be found at http://www.w3.org/TR/. W3C publications may be updated, replaced, or obsoleted by other documents at any time.
English
Extended Backus-Naur Form (formal grammar)
So out of date it's been dropped
Introduction
&abstract;
The key words must, must not, required, shall, shall not, should, should not, recommended, may, and optional in this specification are to be interpreted as described in .
The terms pointer part, scheme, XPointer processor, error, and namespace binding context are used in this specification as defined in the XPointer Framework specification.
The formal grammar for the &scheme-phrase; is given using simple Extended Backus-Naur Form (EBNF) notation, as described in the XML Recommendation .
Language and Processing
This section describes the syntax and semantics of the &scheme-phrase; and the behavior of XPointer processors with respect to this scheme.
The scheme name is &schemename;
. The scheme data syntax is as follows; if scheme data in a pointer part with the &scheme-phrase; does not conform to the syntax defined in this section the pointer part does not identify a subresource.
element() Scheme Syntax
ElementSchemeData
(NCName ChildSequence?) | ChildSequence
ChildSequence
('/' [1-9] [0-9]*)+
The scheme data consists of either a NCName (as defined in the XML namespaces specification ) or a child sequence, or both.
A NCName appearing alone identifies a single element exactly as it would in a shorthand pointer, as defined in the XPointer Framework specification, except that failure to identify an element results simply in no subresource being identified by this pointer part rather than an XPointer Framework error.
For example, the following pointer part identifies the element with an ID (as defined in XPointer Framework) of intro
:
element(intro)
A child sequence appearing alone identifies an element by means of stepwise navigation, which is directed by a sequence of integers separated by slashes (/); each integer n locates the nth child element of the previously located element. The integer n following the first slash locates the nth top-level element: either the unique document element (the [document element] property, if the resource is an XML document, in which case the integer is always 1) or one of potentially several root elements (the entity root element(s), if the resource is an external parsed entity). For example, assuming that the XML resource is a whole XML document, the following pointer part identifies the second child element inside the root element of the document:
element(/1/2)
A child sequence appearing after an NCName identifies an element by means of stepwise navigation, starting from the element located by the given name. For example, the following pointer part identifies an element by first locating the element identified by the value intro, then locating that element's third child element, then finally identifying that element's first child element:
element(intro/3/1)
If either the NCName or the child sequence does not locate an element, no element is identified by the pointer part as a whole.
The &scheme-phrase; does not use the namespace binding context because it does not support qualified names.