XML in a Nutshell, 3rd Edition

Local Resources

Locators represent remote resources; that is, resources that are not part of the document that contains the extended link. Extended links can also contain local resources in which the data is contained inside the extended link element. Each such resource is represented by a resource element , which is an element of arbitrary type that has an xlink:type attribute with the value resource. For instance, in Example 10-1, the series extended link element contains an author child element. This can be made a local resource simply by giving it an xlink:type="resource" attribute:

<author xlink:type="resource">L. Frank Baum</author>

A resource element can and generally does have the same attributes as a locator element; that is, xlink:label , xlink:role , and xlink:title . These all have the same semantics as they do for locator elements. For instance, the label is a name that arcs use to connect resources. An arc can connect a resource to a resource, a resource to a locator, a locator to a resource, or a locator to a locator. Arcs really don’t care whether resources are local or remote. To link to or from this resource, an arc needs an xlink:label attribute, like this:

<author xlink:type="resource" xlink:label="baum">L. Frank Baum</author>

To establish links from this local resource to all the books, we’d simply add these three arc elements:

<book xlink:type="arc" xlink:from="baum" xlink:to="oz1" /> <book xlink:type="arc" xlink:from="baum" xlink:to="oz2" /> <book xlink:type="arc" ...