xselement

Xselement is an informal term used in documentation to refer to the element declaration construct in the XML Schema Definition Language (XSD), typically represented in documents as xs:element. In XML Schema, an element declaration defines a named element that can appear in an XML instance, and can be declared globally (top-level) or locally inside a complex type or group.

A declaration specifies the element’s name (or a reference), its type (either a built-in simple type, a user-defined simpleType or complexType, or an inline anonymous type), and how many times it may occur in its parent content model (minOccurs and maxOccurs). Global elements have global scope and can be referenced by other schemas via ref or substitutionGroup; local elements are scoped within their containing type or group. Additional properties include nillable, form, abstract, final, and block. A declaration may also supply a default or fixed value for the element’s content when present.

Common usage:

<xs:element name="customer" type="xs:string"/>

<xs:element name="price" type="xs:decimal" minOccurs="0" maxOccurs="unbounded"/>

These define elements that appear in XML documents constrained by the surrounding schema.

Impact: Xselements influence validation, document structure, and namespace handling. They are essential for defining and reusing component names within XML schemas, and they support features such as substitution groups and scoped declarations.

See also: XML Schema, xs:element, XSD.

References: W3C XML Schema Definition Language (XSD) 1.0 and 1.1 specifications.