In order to identify a primary subject, refer to the subject with the <topicsubject> itself. Subjects can be identified by @keys (if defined in the scheme) or, if the subject definition topic exists, by @href (as with ordinary topic references).
Additional secondary subjects can be specified by nested <subjectref> elements.
See appendix for information about this element in OASIS document type shells.
+ map/topicref classify-d/topicsubject
In the following example, the map is classified as covering Linux as the primary subject; the topic "Developing web applications" also covers the secondary web and development subjects. These subjects (and their keys) are defined externally in a subject scheme map; in order to reference the subject directly without the subject scheme map, the @href attribute would be used in place of @keyref.
<map> <title>Working with Linux</title> <topicsubject keyref="linux"/> <!-- ... --> <topicref href="webapp.dita" navtitle="Developing web applications"> <topicsubject> <subjectref keyref="web"/> <subjectref keyref="development"/> </topicsubject> <!-- ... --> </topicref> <!-- ... --> </map>
The following attributes are available on this element: Universal attribute group, Link relationship attribute group (with a narrowed definition of @href, given below), @navtitle and @query from Topicref element attributes group, @outputclass, @keyref, and @keys. This element also uses narrowed definitions of @processing-role and @toc (given below) from Attributes common to many map elements.
- A pointer to the resource represented by the <topicref>. See The @href attribute for detailed information on supported values and processing implications. References to DITA content cannot be below the topic level: that is, you cannot reference individual elements inside a topic. References to content other than DITA topics should use the @format attribute to identify the kind of resource being referenced.
- For this element, the default value for @processing-role is "resource-only". Otherwise, the definition matches the one found in Attributes common to many map elements.
- Specifies whether a topic appears in the table of contents (TOC). If the value is not specified locally, but is specified on an ancestor, the value will cascade from the closest ancestor. On this element the default value for @toc is "no". See Attributes common to many map elements for a complete definition of @toc.