XmlValue for root node

Question

Hello,
I have inserted the following documents into a container:
<root><value>bob</value></root>
<anotherRoot><value>bob</value></anotherRoot>
<anotherRoot><value>bill</value></anotherRoot>
<anotherRoot><value>fred</value></anotherRoot>I am then attempting to construct a query that extracts the right documents based on the root node name in a variable:
qc.setVariableValue('container', XmlValue('test.dbxml'))
qc.setVariableValue('root', XmlValue('anotherRoot'))
collection($container)/$rootHowever, the results I get are rather strange (XmlResult.asString()):
anotherRoot
anotherRoot
anotherRoot
anotherRootAny ideas?

Answer 1

Hi,
Not sure what you mean by "works as expected", but I guess it does something different that you think. If you predicate consists of a string variable (and in your case $nodeName is a string), then this predicate will return true if a string has non-zero length.
A quite from the XPath spec:
If its operand is a singleton value of type xs:string, xs:anyURI, xs:untypedAtomic, or a type derived from one of these,
  fn:boolean returns false if the operand value has zero length; otherwise it returns true.That's how a boolean value of the predicate is constructed for strings.
So the query:
collection($container)/anotherRoot[$nodeName]just will return all anotherRoot elements given that $nodeName is not an empty string, whereas
collection($container)/anotherRoot[""]
OR
collection($container)/anotherRoot[()]will return zero results
To sum up, a query:
$nodes["string"]will behave exactly as just:
$nodesHope this helps,
Vyacheslav