2002-10-24 - The Strange and Curious World of TModels - Odd Fact #2

Continuing my commentary on tModels...

Odd Fact #2 - Interestingly, tModels are self-referential. In other words, a tModel can refer to itself within itself. For example, consider the granddaddy of tModels: the uddi-org types taxonomy tModel. No UDDI instance can function without this core tModel. It is axiomatic to the functioning of UDDI, as other tModels use this tModel for typing. Take a look at the XML representation of this file:

<uddi:tModel tModelKey="uuid:C1ACF26D-9672-4404-9D70-39B756E62AB4">
	<uddi:name>uddi-org:types</uddi:name>
	<uddi:description xml:lang="en">UDDI Type Taxonomy</uddi:description>
	<uddi:overviewDoc>
		<uddi:description xml:lang="en">
			Taxonomy used to categorize Service Descriptions.
		</uddi:description>
		<uddi:overviewURL>
		http://www.uddi.org/taxonomies/Core_Taxonomy_OverviewDoc.htm#UDDItypes
		</uddi:overviewURL>
	</uddi:overviewDoc>
	<uddi:categoryBag>
		<uddi:keyedReference
			tModelKey="uuid:c1acf26d-9672-4404-9d70-39b756e62ab4"
			keyName="types"
			keyValue="categorization"/>
	</uddi:categoryBag>
</uddi:tModel>

Notice how the tModelKey is re-used as one of the keyedReference tModelKeys! Semantically, this tModel is categorized with itself. Nice.