Table of contents

Appendices

4.3 Attribute Value Defaulting

Using XLink potentially involves using a large number of attributes for supplying important link information. In cases where the values of the desired XLink attributes are unchanging across individual instances in all the documents of a certain type, attribute value defaults (fixed or not) Must, May, etc. be added to a DTD so that the attributes do not have to appear physically on element start-tags. For example, if attribute defaults were provided for the xmlns:xlink, xmlns:my, type, show, and actuate attributes in the example in the introduction to [XLink Markup Design], the example would look as follows:

<my:crossReference
  xlink:href="students.xml"
  xlink:role="http://www.example.com/linkprops/studentlist"
  xlink:title="Student List">
Current List of Students
</my:crossReference>

Information sets that have been created under the control of a DTD have all attribute values filled in.