Selecting unique records in XSLT/XPath

Question

I have to select only unique records from an XML document, in the context of an loop. I am limited by Visual Studio to usi

Answer 1

I. As a single XPath expression:

/*/item[normalize-space() and not(. = preceding-sibling::item)]

II. More efficient (XSLT) implementation, using keys:

Both I and II, when applied on the provided XML document correctly select/copy the following nodes:

2010-06-2410:00:0013:00:00
2010-06-2510:00:0012:00:00
2010-06-2613:00:0014:00:00
2010-06-2610:00:0012:00:00

Update: In case has other children, then this transformation:

produces the wanted result.