XML Pocket Reference, 3rd Edition

Name

rng:parentRef — References a named pattern in a parent grammar

XML syntax example

<grammar xmlns="http://relaxng.org/ns/structure/1.0">

<start>
 <choice>
  <ref name="type" />
  <ref name="alt" />
 </choice>
</start>

<define name="type">
 <element name="type">
  <list>
   <choice>
    <value>html</value>
    <value>xhtml</value>
    <value>xml</value>
   </choice>
  </list>
 </element>
</define>

<define name="alt">
 <grammar>
  <start>
  <choice>
   <element name="method">
    <list>
     <choice>
      <value>text</value>
      <value>other</value>
     </choice>
    </list>
   </element>
   <parentRef name="type"/>
  </choice>
  </start>
 </grammar>
</define>

</grammar>

Compact syntax example

start = type | alt
type = element type { list { "html" | "xhtml" | "xml" } }
alt = grammar { start =
 element method { list { "text" | "other" } } | parent
 type }

Parents

attribute, choice (( ) and |), define (name of pattern followed by =), element, except (-), group (( ) and ,), interleave (&), list, mixed, oneOrMore (+), optional (?), start (start followed by =), zeroOrMore (*)

Description

The parentRef pattern references a named pattern in a parent grammar—that is, a grammar that directly or indirectly contains the current grammar. parentRef extends the scope of the current grammar to definitions in the parent grammar.

See also

§13, externalRef, ref