Public comment on XML Schemas

If would be helpful to allow for an attribute type in the same way that an 
element type is supported.



Currently, if an attribute is defined, as if it were a type, then the 
actual attribute element cannot use within the type attribute the defined 
attribute type.



As an example, suppose I have a type of attribute that supports a certain 
set of values that extend the Boolean type to include any humanly accepted 
value:



             <xs:attribute name="yesnoType" default="true">

                         <xs:simpleType>

                                     <xs:restriction base="xs:NMTOKEN">

                                                 <xs:enumeration value="true"/>

                                                 <xs:enumeration 
value="false"/>

                                                 <xs:enumeration value="yes"/>

                                                 <xs:enumeration value="no"/>

                                                 <xs:enumeration value="ok"/>

                                                 <xs:enumeration 
value="never"/>

                                                 <xs:enumeration value="1"/>

                                                 <xs:enumeration value="0"/>

                                     </xs:restriction>

                         </xs:simpleType>

             </xs:attribute>



This type of attribute may be used for any number of attributes within the 
set of defined elements.  An example, that is not supported, is this:



             <xs:complexType name="statusType">

                         <xs:attribute name="id" type="xs:IDREF" 
use="required"/>

                         <xs:attribute name="popup" type="xs:IDREF"/>

                         <xs:attribute name= visible type="b:yesnoType"/>

                         <xs:attribute name= enabled type="b:yesnoType"/>

             </xs:complexType>





This would greatly reduce the size of a schema that uses these attributes.