You are here: Popular FormatsXML (Extensible Markup Language) Reader/WriterxfMapMore Expression Elementsdefnval Expressions

defnval Expressions

The defnval expression allows access to the value of a let variable in an expression sequence. The expr attribute of a <defnval> element must be equal to the name of a let variable defined under the mapping rule’s <define> element.

The following feature mapping rule shows how to access the value of a let variable in an expression sequence:

<mapping match="...">
	... 		
	<define>
		<let name="theFeatureType">
			<!-- some expression sequence -->	
		</let>
	</define>
	...
	<feature-type>
		<defnval expr="theFeatureType"/>		
	<feature-type>
	...
</mapping>