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.
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
defaultandfixedattributes are mutually exclusive.-
fixed When specified, the value of the attribute is fixed and must be equal to the value specified here. The
defaultandfixedattributes 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
attributeFormDefaultattribute of thexs:schemadocument 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 Possible usage of the attribute. Marking an attribute “prohibited” is useful to exclude attributes during derivations by restriction.