XML Encoding Reference
This section describes the format for exchanging instances of the Open Information Model (OIM) through the use of Extensible Markup Language (XML). The XML encoding format works for any information model that is based on the Meta Data Coalition (MDC) OIM framework. A set of rules governs the encoding of meta data objects by OIM in XML. The XML encoding of OIM types enables the interchange of meta data between heterogeneous repositories. The encoding format defined in this specification is completely driven by the abstract model. The names of the element and attribute tags used in the representation are derived from the model. Documents can be generated and parsed automatically by any implementation of OIM, regardless of technology.
Accompanying this section is a set of XML Document Type Definitions (DTDs) that together form a grammar to express the structure of XML instances. DTDs are currently the only approved mechanism for describing the structure of XML documents. In its current form, DTDs are not expressive enough to cover the semantics of OIM completely. A correct interpretation of an XML document is only possible based on the OIM specification. However, DTDs have been supplied to make understanding the XML documents easier and to help with the development of XML import/export functionality based on this encoding format.
The following topics are discussed in this section.
|XML Encoding Definition||Explains the XML encoding format rules for OIM|
|OIM-to-XML Mapping||Shows the mapping of the core concepts, which include diagrams and example code|
|Sample Encoding||Provides an example code of an XML OIM transfer|
|EBNF Representation||Shows an example of an OIM XML encoding in Extended Backus-Naur Form (EBNF)|
|Namespaces in OIM||Shows a table of unique namespaces of each OIM information model|
|DTD for the OIM Namespace||Shows an example of OIM Namespace Definition|
|XML Import Export||Describes the import and export interfaces for XML in the OIM|
|XML Encoding Errors||Lists the XML encoding error messages|
It is assumed that the reader is familiar with the concepts represented by the OIM. A basic knowledge of XML, COM, and Microsoft® SQL Server™ 2000 Meta Data Services is also assumed throughout this section. This section is based on XML standards as defined by the World Wide Web Consortium (W3C), and XML Namespaces provide a simple method for qualifying names in XML documents. The implementation of namespaces in this section is based on the W3C recommendation Namespaces in XML.
For more information about XML standards, see the W3C Web site http://www.w3.org/.