Topic Constraint Module Step 4: Integrate the Constraint Module in a Document Type Shell

For testing purposes, copy the standard topic.dtd file to a convenient location, either in the same directory as the constraint module file or in a nearby directory. To make its purpose clear, you can name it something like topic-with-highlight-constraint.dtd if you want.

Edit the copied topic DTD file, search for the comment "DOMAINS ATTRIBUTE OVERRIDE," and update the declaration of the &included-domains; text entity to include a reference to the &topic-constraints; text entity:

<!-- ============================================================= -->
<!--                    DOMAINS ATTRIBUTE OVERRIDE                 -->
<!-- ============================================================= -->
<!--                    Must be declared ahead of the DTDs, which
                        puts @domains first in order               -->

<!ENTITY included-domains 
                          "&hi-d-att; 
                           &ut-d-att; 
                           &indexing-d-att;
                           &hazard-d-att;
                           &abbrev-d-att;
                           &pr-d-att; 
                           &sw-d-att;
                           &ui-d-att; 
                           &topic-constraints;
  "
>

This adds the declaration of the topic-element-type constraint module to the @domains attribute for the <topic> element as configured in this document type shell.

Now search for the comment "TOPIC ELEMENT INTEGRATION" and add this parameter entity declaration and reference:

...

<!-- ============================================================= -->
<!--                    CONTENT CONSTRAINT INTEGRATION             -->
<!-- ============================================================= -->

<!ENTITY % hiOnlyTopic-c-def  
  SYSTEM "highlightOnlyTopicConstraint.mod">
%hiOnlyTopic-c-def;

<!-- ============================================================= -->
<!--                    TOPIC ELEMENT INTEGRATION                  -->
<!-- ============================================================= -->

...

The topic.dtd file you started with may or may not have the "CONTENT CONSTRAINT INTEGRATION" comment. If it's not there, add it.