Repositories for B2B

Repositories for B2B

David Webber's ( XML/EDI Group) second presentation focused on XML/EDI Repositories for e-Business and their importance to Enterprise Application Integration (EAI). Repositories (or Registries) provide an idea of who is doing what.

Repositories provide a standard reference point for understanding data and processes. In the context of XML and EDI repositories provide the means to implement strategic business systems. Repositories also provide the link between business process designs (UML) and their physical implementation (XML).... An XML repository contains one or more XML glossaries, each of which is designed for use in a single business domain or industry. The XML repository provides a single point of reference that XML/EDI based applications can use to ensure consistency and maintainability of shared definitions and processes.

Webber postulated that if your interest in EDI is to send data outside your own organization, your definitely need a DTD or schema. He expressed major concern that XLink -- something of utmost importance to the EDI community in his view -- hasn't been completed by the W3C Linking Working Group. He has introduced the notion of BizCodes, a numeric representation of an XML/EDI element that is stored in an (out-of-line, in XLink terminology) repository. For example, given this definition of UnitPrice:

<!ELEMENT UnitPrice (#PCDATA)>
<!ATTLIST UnitPrice 
	href CDATA #FIXED
	'handle://&root-URI;#id(PO304)' %XLink-Syntax;>

we can imagine an XML transaction containing this fragment:

<UnitPrice>6.05</UnitPrice>

compared to this less-human readable form:

<PO304>6.05</PO304>

By defining the href attribute of UnitPrice to be a fixed value, and by specifying that value to use XLink syntax, namely mapping via id to the unique BizCode PO304, we have effectively established the UnitPrice element to be a symbolic name (alias) for the more cryptic BizCode. Besides being more human-readable, this permits different companies to use different element names that all map to the same PO304 BizCode. Another advantage is keeping the semantic meaning of an element in a central repository so all EDI applications can share what may be a complex definition, perhaps based on Architectural Forms.

Eventually, applications will be able to query repositories to validate documents against their corresponding schema and to map from one schema to another. Webber cites the Repository White Paper. He listed several repositories:

• BizTalk Repository
• OASIS Repository and Organizations producing XML specifications
• Other Registers/repositories

Astronomical Instrument Control
What Happened at XML World?
BizTalk and SOAP