XML Schema choice element
Definition and Usage
The XML Schema choice element allows only one of the elements included in the <choice> declaration to appear in the containing element.
Element Information
| Occurrence | Once in group and complexType elements; unlimited otherwise. |
| Parent Element | group, choice, sequence, complexType, restriction (simpleContent), extension (simpleContent), restriction (complexContent), extension (complexContent) |
| Content | annotation, any, choice, element, group, sequence |
Syntax
<choice id=ID maxOccurs=nonNegativeInteger|unbounded minOccurs=nonNegativeInteger any attributes > (annotation?,(element|group|choice|sequence|any)*) </choice>
(The ? symbol declares that the element can appear zero or one times, and the * symbol declares that the element can appear zero or more times.)
| Attribute | Description |
|---|---|
| id | Optional. Specifies a unique ID for the element. |
| maxOccurs | Optional. Specifies the maximum number of times the choice element can appear in the parent element. This value can be any non-negative integer. To set no limit on the maximum number, use the string "unbounded". The default value is 1. |
| minOccurs | Optional. Specifies the minimum number of times the choice element can appear in the parent element. This value can be any non-negative integer. To specify that this any group is optional, set this attribute to zero. The default value is 1. |
| any attributes | Optional. Specifies any other attributes with a non-schema namespace. |
Example
<xs:element name="person">
<xs:complexType>
<xs:choice>
<xs:element name="employee" type="employee"/>
<xs:element name="member" type="member"/>
</xs:choice>
</xs:complexType>
</xs:element>
The example above defines that the "person" element must contain either an "employee" element or a "member" element.
