xs:attribute(reference or local definition)

Name

xs:attribute(reference or local definition) — Reference to a global attribute definition or local definition (local definitions cannot be referenced).

Synopsis

<xs:attribute
           default        = xs:string
           fixed          = xs:string
           form           = ( “qualified” | “unqualified” )
           id             = xs:ID
           name           = xs:NCName
           ref            = xs:QName
           type           = xs:QName
           use            = ( “prohibited” | “optional” | “required” ) : “optional”
           {any attributes with non-schema namespace}
           >
           Content: ((xs:annotation?), (xs:simpleType?))
</xs:attribute>

May be included in: xs:attributeGroup (global definition), xs:complexType (local definition), xs:complexType (global definition), xs:extension (complex content), xs:extension (simple content), xs:restriction (complex content), xs:restriction (simple content)

Description

This element serves two different purposes and has two different content models for these two purposes: it can either be a reference to a globally defined attribute or it can be a local attribute definition. These options are mutually exclusive.

When used as a reference to an attribute, the ref attribute must contain the qualified name of the attribute (with its namespace prefix).

When used as a local definition, the definition is done by assigning a simple datatype to the attribute. This assignment can be done either by reference, using the type attribute to refer to a simple datatype by its qualified name, or inline, by embedding the definition of the simple type (xs:simpleType element) within the xs:attribute element.

Restrictions

Locally defined attributes cannot be referenced.

Example

<xs:complexType>
  <xs:simpleContent>
    <xs:extension base="xs:string">
      <xs:attribute ref="lang"/>
    </xs:extension>
  </xs:simpleContent>
</xs:complexType>
              .../...
       

<xs:simpleContent>
  <xs:extension base="xs:string">
    <xs:attribute name="lang" type="xs:language"/>
  </xs:extension>
</xs:simpleContent>

Attributes

default: Default value. When specified, an attribute is added by the schema processor, if missing from the instance document, and is given this value. The default and fixed attributes are mutually exclusive.
fixed: When specified, the value of the attribute is fixed and must be equal to the value specified here. The default and fixed attributes are mutually exclusive.
form: Specifies if the attribute is qualified (i.e., must have a namespace prefix in the instance document) or not. The default value for this attribute is specified by the attributeFormDefault attribute of the xs:schema document element—local definition only.
id: W3C XML Schema’s element ID.
name: Local name (without namespace prefix)—local definition only.
ref: Qualified name of a globally defined attribute—reference only.
type: Qualified name of a simple datatype—definition only.
use