Name

xs:attribute

Synopsis

<xs:attribute

  default = "string"
  fixed = "string"
  form = "( qualified | unqualified )
  id = "ID"
  name = "NCName"
  ref = "QName"
  type = "QName"
  use = "( optional | prohibited | required )">
  <!-- ( xs:annotation?, xs:simpleType? ) -->
</xs:attribute>

The xs:attribute element declares an attribute. Inside an xs:complexType element it indicates that elements of that type can have an attribute with the specified name and type.

Attributes

default, optional

The default value of the attribute reported for those elements in the instance document that do not contain an explicit specification of this attribute.

fixed, optional

A default value for this attribute that may not be overridden in the instance document. An xs:attribute element cannot have both fixed and default attributes.

form, optional

If this has the value qualified, then the attribute must be in the schema's target namespace. If this has the value unqualified, then the attribute must not be in any namespace. The default value for this is set by the attributeFormDefault attribute on the root xs:schema element.

id, optional

An XML name unique among all of the ID-type attributes in this schema document.

name, optional

The local name of the attribute.

ref, optional

The qualified name of an attribute declared by a top-level xs:attribute element elsewhere in the schema. Either the name or ref attribute should be provided, but not both.

type, optional

The qualified name of the type of the attribute, either a built-in simple type such as xs:integer or a user-defined simple type.

use, optional

One of the three keywords—optional, prohibited, or required—which have the following meanings:

optional

Authors of instance documents may or may not include this attribute as they choose. This is the default.

prohibited

Authors of instance documents must not include this attribute. This is typically used to remove legal attribute values when defining a subtype that would otherwise inherit an attribute declaration from its base type.

required

Authors of instance documents must include this attribute on all elements of the requisite type.

Contents

The xs:attribute element may contain a single xs:annotation element to describe itself. This has no effect on the attribute type.

In place of a type attribute, the xs:attribute element may contain a single xs:simpleType element that provides an anonymous type for the attribute derived from a base simple type.