RELAX NG: Coding requirements for attribute-domain modules

An attribute-domain vocabulary module declares a new attribute specialized from either the @props or @base attribute.

The name of an attribute domain is the name of the attribute plus Att. For example, for the attribute named @deliveryTarget, the attribute-domain name is "deliveryTargetAtt". The attribute-domain name is used to construct pattern names for the domain.

An attribute-domain module consists of a single file, which has three sections:

Specializations attribute contribution

The contribution to the @specializations attribute is documented in the module. The value is constructed according to the rules found in The specializations attribute rules and syntax.

The OASIS grammar files use a <domainsContribution> element to document the contribution; this element is used to help enable generation of DTD and XSD grammar files. An XML comment or <a:documentation> element also can be used.

Attribute declaration pattern

The specialized attribute is declared in a pattern named domainName-d-attribute. The attribute is defined as optional.

For example, the following code samples shows the the @audience specialization of @props:

<define name="audienceAtt-d-attribute">
  <optional>
    <attribute name="audience" dita:since="2.0">
      <a:documentation>Specifies the audience to which an element applies.</a:documentation>
    </attribute>
  </optional>    
</define>

Attribute extension pattern

The attribute extension pattern extends either the @props or @base attribute-list pattern to include the attribute specialization.

Specializations of @props

The pattern is named props-attribute-extensions. The pattern specifies a @combine value of interleave, and the content of the pattern is a reference to the specialized-attribute declaration pattern.

For example:

<define name="props-attribute-extensions" combine="interleave">
  <ref name="audienceAtt-d-attribute"/>
</define>

Specializations of @base

The pattern is named base-attribute-extensions. The pattern specifies a @combine value of interleave, and the content of the pattern is a reference to the specialized-attribute declaration pattern.

For example:

<define name="base-attribute-extensions" combine="interleave">
    <ref name="myBaseSpecializationAtt-d-attribute"/>
</define>