EclipseLink/DesignDocs/217508

Support for Root Elements representing Simple Types

ER 217508

Document History

Date	Author	Version Description & Notes
2008-02-01	Rick Barkhouse	Initial Draft

Project overview

This project will add the ability for EclipseLink OX to unmarshal XML documents that have simple types as their root element. Instead of a "rich" top-level element representing a domain object (e.g. Employee, PurchaseOrder), the root element may be a simple primitive value.

Goals:

• Allow the user to unmarshal XML documents that contain simple type root elements.

Concepts

The following concepts are used in this document:

• Simple Type - one of the basic, "built-in" types available in XML Schema. These may represent basic Java primitives (such as xsd:boolean and xsd:float), or more robust types (xsd:hexBinary, xsd:dateTime, xsd:QName). XML Schema has two categories of simple types; Primitive Types (the most basic of data type), and Derived Types (other simple types that are defined in terms of primitive types).
  
  

XML Schema Primitive Data Types
string	boolean	decimal	float	double	duration	dateTime
time	date	gYearMonth	gYear	gMonthDay	gDay	gMonth
hexBinary	base64Binary	anyURI	QName	NOTATION
XML Schema Derived Data Types
normalizedString	token	language	NMTOKEN	NMTOKENS	Name	NCName
ID	IDREF	IDREFS	ENTITY	ENTITIES	integer	nonPositiveInteger
negativeInteger	long	int	short	byte	nonNegativeInteger	unsignedLong
unsignedInt	unsignedShort	unsignedByte	positiveInteger

For more information see: http://www.w3.org/TR/xmlschema-2/#built-in-datatypes

Requirements

The requirements for this project are as follows:

• Support unmarshalling of XML instance documents that contain Simple Type (both primitive and derived) root elements.
• Support marshalling "primitive" Java objects to XML.
• Ensure that the proper ConversionManager is used when converting XML to Java.
• Ensure that the proper ClassLoader is used when converting values.

For example, the JAXB TCK uses the following types of test documents:

XML Schema - The schema contains a single element, a restriction (extension) of the base64Binary simple type:

<schema ...>
...
   <element name="NISTSchema-base64Binary-enumeration" type="nist:NISTSchema-base64Binary-enumeration-Type"/>
 
   <simpleType name="NISTSchema-base64Binary-enumeration-Type">
      <restriction base="base64Binary">
         <enumeration value="bHlsY2JmaXFjaW9ubmg="/>
      </restriction>
   </simpleType>
</schema>

XML Instance Document - The document contains a single element with value zGk=:

<NISTSchema-base64Binary-enumeration
    xmlns="NISTSchema-base64Binary-enumeration-NS"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="NISTSchema-base64Binary-enumeration-NS enumeration.xsd">zGk=</NISTSchema-base64Binary-enumeration>

Open Issues

This section lists the open issues that are still pending that must be decided prior to fully implementing this project's requirements.

Decisions

This section lists decisions made. These are intended to document the resolution of open issues or constraints added to the project that are important.

Issue #	Owner	Description / Notes

Future Considerations

Issue #	Description / Notes	Decision