How to get difference between 2 dates as duration via using xpath on BPM 11g

Question

Need to get difference between 2 dateTime payload objects as duration format for using on HT expiration value. (i.e. returned as PT2055M or P1DT10H15M) Actually checked functions on that link: http://docs.oracle.com/cd/E23943_01/dev.1111/e10224/bp_appx_functs.htm#autoId13 And i tried to solve the issue by creating duration such as

concat("P", xp20:year-from-dateTime(string(bpmn:getDataObject('myPayloadDate'))) - xp20:year-from-dateTime(xp20:current-dateTime()) ,"Y", xp20:month-from-dateTime(string(bpmn:getDataObject('myPayloadDate'))) - xp20:month-from-dateTime(xp20:current-dateTime()),"M", xp20:day-from-dateTime(string(bpmn:getDataObject('myPayloadDate'))) - xp20:day-from-dateTime(xp20:current-dateTime()),"DT", xp20:hour-from-dateTime(string(bpmn:getDataObject('myPayloadDate'))) - xp20:hour-from-dateTime(xp20:current-dateTime()),"H",xp20:minute-from-dateTime(string(bpmn:getDataObject('myPayloadDate'))) - xp20:minute-from-dateTime(xp20:current-dateTime()),"M")

But realized that this approach interests with just only seperate values not whole values as expected. I could not find the right composition of functions to solve. Could you plz guide?

Answer 1

Assuming you have an XPath 2.0 processor, just use the subtraction operator. For example

current-date() - xs:date('2001-03-04')

gives

P4744D

(You said "dates" but your examples look more like dateTime's. The subtraction operator will work with either.)