Name
xsd:IDREFS — Definition of lists of references to unique identifiers
Synopsis
<xsd:simpleType name="IDREFS” id="IDREFS"> <xsd:restriction> <xsd:simpleType> <xsd:list> <xsd:simpleType> <xsd:restriction base="xsd:IDREF"/> </xsd:simpleType> </xsd:list> </xsd:simpleType> <xsd:minLength value="1"/> </xsd:restriction> </xsd:simpleType>
Description
xsd:IDREFS is derived as a list from
xsd:IDREF. It represents whitespace-separated
lists of references to identifiers that are defined using the ID
datatype.
The lexical space of xsd:IDREFS is the lexical
space of a list of xsd:NCName values with a
minimum length of one element (xsd:IDREFS
can’t be empty lists).
For RELAX NG implementations that support the DTD compatibility
library, xsd:IDREFS emulates the
IDREFS attribute type of the XML DTDs, even though
it can define simple content elements as well as attributes.
Restrictions
Applications that need to maintain compatibility with DTDs shouldn’t use this datatype for elements, but instead should reserve it for attributes.
The lexical domain (lists of xsd:NCName) of this
datatype doesn’t allow the definition of lists of
numerical key references or references containing whitespace.
Example
<element name="book">
<element name="isbn">
<data type="xsd:int"/>
</element>
<element name="title">
<data type="xsd:string"/>
</element>
<element name="author-ref">
<attribute name="ref">
<data type="xsd:IDREF"/>
</attribute>
</element>
<element name="character-refs">
<data type="xsd:IDREFS"/>
</element>
<attribute name="identifier">
<data type="xsd:ID"/>
</attribute>
</element>