Home >
Online Product Documentation >
Table of Contents >
Attribute and Attribute Reference Properties in XML Schemas
Attribute and Attribute Reference Properties in XML Schemas
Both global and local attributes have the properties described in the
Table 44. References to attributes have the same properties, except where noted.
Property
|
Description
|
Type
|
For attributes, the type is always
Attribute . For attribute references, the type is always
Ref. to Attribute .
|
Name
|
The attribute name you use in an instance document. Specify the name you want the attribute to have.
|
Data Type
|
The type of the data that is the value of the attribute. Select from all simpleTypes defined in an XML Schema, and all simpleTypes that you already defined in the same schema. References to attributes do not have this property.
|
Default
|
Specifies the default value for this attribute. Specification of this property makes sense only for optional attributes. If you specified
optional for the
Restrictions property, you can specify a default value.
If this attribute is in an instance document, the attribute has whatever value you specify. If you do not specify this attribute, the schema processor behaves as though you had specified it with the default value. When you specify a default value for an attribute, that attribute must be optional in an instance document. An attribute can have a value for the
Default property or a value for the
Fixed Value property. The two properties are mutually exclusive.
|
Fixed Value
|
When you specify a value for
Fixed Value , it is optional for the attribute to appear in an instance document. However, if the attribute does appear, it must have the value specified by
Fixed Value . Whether or not you specify this attribute in an instance document, the schema processor behaves as though you had specified this attribute with the fixed value. An attribute can have a value for the
Fixed Value property or a value for the
Default property. The two properties are mutually exclusive.
|
Restrictions
|
Specify
prohibited ,
optional , or
required .
|
Form
|
An attribute's form is either
qualified or
unqualified . A form of
qualified means that each time the attribute is referenced in a schema document, you must specify the prefix of its namespace. Every attribute has a
form attribute. If it is not explicitly defined, the schema processor checks the default attribute form specified for the
Schema node.
|
Table 44. Attribute and Attribute Reference Properties