NOTE: These slides have not been updated since 2003. They have been superseded by the book An Introduction to XML and Web Technologies Addison-Wesley, and the accompanying online material. Please see http://www.brics.dk/ixwt/ for more information. Anders Møller and Michael Schwartzbach, February 2006

THE XML REVOLUTION  -  TECHNOLOGIES FOR THE FUTURE WEB

An example

<mylink xmlns:xlink="http://www.w3.org/1999/xlink" xlink:type="extended"> <myresource xlink:type="locator" xlink:href="students.xml#Fred" xlink:label="student"/> <myresource xlink:type="locator" xlink:href="teachers.xml#Joe" xlink:label="teacher"/> <myarc xlink:type="arc" xlink:from="student" xlink:to="teacher"/> </mylink>

• the namespace http://www.w3.org/1999/xlink is used to recognize XLink information in general XML documents
  • the namespace often (but not necessarily) uses namespace prefix xlink
  • host language: elements and attributes not belonging to this namespace are ignored by XLink processors
  • all XLink information is defined in attributes (in host language elements)
• xlink:type="extended" indicates a linking element
• xlink:type="locator" locates a remote resource
• xlink:type="arc" defines traversal rules

A powerful example application of general XLinks:

Using third-party links and a smart browser, a group of people can annotate Web pages with "post-it notes" for discussion - without having write access to the pages. They simply need to agree on a set of URIs to XLink link bases defining the annotations. The smart XLink-aware browser lets them select parts of the Web pages (as XPointer ranges), comment the parts by creating XLinks to a small XHTML documents, view each other's comments, place comments on comments, and perhaps also aid in structuring the comments.

COPYRIGHT © 2000-2003 ANDERS MØLLER & MICHAEL I. SCHWARTZBACH