188.8.131.52 XML Schema: Coding requirements for structural modules
An XSD structural module declares a top-level map or topic type. It is implemented as a pair of XSD documents, one that defines groups used to integrate and override the type and one that defines the element types specific to the type.
All vocabulary and constraint modules must document their
@domains attribute contribution. The OASIS grammar files use a
<dita:domainsModule> element to document the contribution; this
element is used consistently to make it easy to find values when creating a document type
shell. An XML comment or
<xs:appinfo> element can also be used.
A structural vocabulary module has two files:
- A module schema document.
- A module group definition schema document.
Required topic and map element attributes
The root element for a structural type must reference the
attribute and the
@domains attribute. These attributes give processors a
reliable way to check the architecture version and look up the list of domains available in
the document type. The attributes are referenced as in the following example:
<xs:attributeGroup name="concept.attributes"> <!-- Various other attributes --> <xs:attribute ref="ditaarch:DITAArchVersion"/> <xs:attributeGroup ref="domains-att"/> <xs:attributeGroup ref="global-atts"/> </xs:attributeGroup>
Controlling nesting in topic types
For topic modules, the last position in the content model is typically a reference to the
topictype-info-types group. Document types shells
can control how topics are allowed to nest by redefining the group. If topic nesting is hard
coded in the structural module, and cannot be modified from the document-type shell, the
topictype-info-types group is not needed.
<concept>structural type uses the group
concept-info-types; this group is given a default value, and then referenced from the content model for the
<xs:group name="concept-info-types"> <xs:choice> <xs:group ref="concept"/> <xs:group ref="info-types"/> </xs:choice> </xs:group> <xs:group name="concept.content"> <xs:sequence> <xs:group ref="title"/> <!-- ...other elements, such as shortdesc and body, and then... --> <xs:group ref="related-links" minOccurs="0"/> <xs:group ref="concept-info-types" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> </xs:group>