Parsed XPATH value as variable of user function

[seirerman]

Not sure if this is a bug, works-as-designed:

I'm trying to parse an xml file which includes, among other things, a string containing a ISO 8601 datetime string ("2017-12-07T07:30:00+01:00").

I can parse that with cobj_xpath just fine. But since this isn't the format I want on the website, I need to transform it into epoch format so that stdWrap can use strftime.

So I wrote a small user function that does exactly that.
But attaching the XPATH object as a variable to the user function returns only "0".
It works if I send a static date string to the user function.

I did some var_dumping in the user function ("var_dump($conf);") and saw that $conf had all the config of the xpath object, but not the parsed string.

lib.xpath {
	source = https://lawine.tirol.gv.at/rest/bulletin/latest/xml/de
	return = string
	expression = caaml:metaDataProperty//caaml:MetaData//caaml:dateTimeReport
	resultObj {
		cObjNum = 1
		1.current = 1
	}
}

lib.datetime= USER
lib.datetime{
	userFunc = user_functions->iso8601toUnixTimestamp
# Static value works
#	iso8601 = 2017-12-07T07:30:00+01:00
# XPATH doesn't work
	iso8601 < lib.xpath 
}

Any idea if this is possible, or what's wrong with my code?