Using Extensible Linking Language (XLL)

According to Cover (2003):

XLL as a broad term for XML hyperlinking (linking and addressing) has two major components: Xlink and XPointer.

Xlink (proper) is currently defined in the W3C Working Draft document XML Linking Language (Xlink), WD-Xlink-19980303

This draft "specifies constructs that may be inserted into XML resources to describe links between objects"

A link is defined as "an explicit relationship between two or more data objects or portions of data objects"

Xlink uses XML syntax to create structures that can describe the simple unidirectional hyperlinks (HMTL) as well as more sophisticated multi-ended and typed links

Xlink provides a framework for creating both basic unidirectional links and more complex linking structures. It allows XML files to:

Assert linking relationships among more than two resources

Associate metadata with a link

Create link databases that reside in a location separate from the linked resources

XPointer, the companion specification, defines a language which is expected to be used with Xlink

The current draft for XPointer is also a W3C Working Draft, XML Pointer Language (XPointer), WD-xptr-19980303

This specification defines "constructs that support addressing into the internal structures of XML documents"

In particular, it provides for specific reference to elements, character strings, and other parts of XML files, whether or not they bear an explicit ID attribute

XML Pointer Language (XPointer) is the language to be used as a fragment identifier for any URI-reference that locates a resource of Internet media type text/xml or application/xml [IETF RFC 2376].

XPointer supports addressing into the internal structures of XML files

It allows for traversals of a document tree and choice of its internal parts based on various properties

These can include:

Element types

Attribute values

Character content

In particular, it provides for specific reference to elements, character strings, and other parts of XML files, whether or not they bear an explicit ID attribute.

XPointer can

Address points and ranges as well as nodes

Locate information by string matching

Use addressing expressions in URI-references as fragment identifiers

So how does it work?