dayTimeDuration and yearMonthDuration as standard XACML DataTypes
were added fairly late in the XACML 1.0 process. One of the
primary motivating use-cases for the duration DataTypes was being
able to say things like "permit if current date minus subject
birthdate is greater than or equal to 21". These expressions
require some way to subtract dates.
We defined {dayTime|yearMonth}Duration-equal functions, but we
failed to define the other standard functions necessary to use
durations in the way required.
I believe this was an erratum due to the late date at which the
duration DataTypes and functions were added.
Date Subtraction Functions
==========================
In order to use durations in the way required, we need a way to
subtract two dates to get a duration.
[XF] defines the following function, which returns a value of
type "dayTimeDuration":
subtract-dates
The newer revision of [XF] in
http://www.w3.org/TR/2003/WD-xpath-functions-20030502/ defines
two such functions:
subtract-dateTimes-yielding-yearMonthDuration
subtract-dateTimes-yielding-dayTimeDuration
I recommend that we add the two newer functions to XACML for 1.1.
Date and Time Duration Comparison Functions
===========================================
In order to compare the results of a date subtraction function,
we need duration comparison functions.
The following functions are all defined in
http://www.w3.org/TR/2002/WD-xquery-operators-20020816/ Section
8.3 [XF].
dayTimeDuration-greater-than
dayTimeDuration-greater-than-or-equal
dayTimeDuration-less-than
dayTimeDuration-less-than-or-equal
yearMonthDuration-greater-than
yearMonthDuration-greater-than-or-equal
yearMonthDuration-less-than
yearMonthDuration-less-than-or-equal
Note that dayTime is converted to fractional seconds, and
yearMonth is converted to integer months, so all these functions
are integer comparisons, support for which is already standard.
I recommend we add all these functions to XACML for 1.1.
Detailed Schema Changes
=======================
No schema changes are required.
Detailed Spec Changes
=====================
-Section 10.2.8 Functions: add following lines
urn:oasis:names:tc:xacml:1.0:function:dayTimeDuration-greater-than
urn:oasis:names:tc:xacml:1.0:function:dayTimeDuration-greater-than-or-equal
urn:oasis:names:tc:xacml:1.0:function:dayTimeDuration-less-than
urn:oasis:names:tc:xacml:1.0:function:dayTimeDuration-less-than-or-equal
urn:oasis:names:tc:xacml:1.0:function:yearMonthDuration-greater-than
urn:oasis:names:tc:xacml:1.0:function:yearMonthDuration-greater-than-or-equal
urn:oasis:names:tc:xacml:1.0:function:yearMonthDuration-less-than
urn:oasis:names:tc:xacml:1.0:function:yearMonthDuration-less-than-or-equal
urn:oasis:names:tc:xacml:1.0:function:subtract-dateTimes-yielding-yearMonthDuration
urn:oasis:names:tc:xacml:1.0:function:subtract-dateTimes-yielding-dayTimeDuration
Each should be marked "M" for mandatory.
-Section 11. References: add following entry
[XF-03] XQuery 1.0 and XPath 2.0 Functions and Operators, W3C
Working Draft 02 May 2003. Available at
http://www.w3.org/TR/2003/WD-xpath-functions-20030502/.
-A.14.7 Date and time arithmetic functions: add following entries
o dayTimeDuration-greater-than
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#dayTimeDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the dayTimeDuration-greater-than
function in [XF Section 8.3].
o dayTimeDuration-greater-than-or-equal
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#dayTimeDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the dayTimeDuration-greater-than
function in [XF Section 8.3].
o dayTimeDuration-less-than
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#dayTimeDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the dayTimeDuration-less-than
function in [XF Section 8.3].
o dayTimeDuration-less-than-or-equal
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#dayTimeDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the
dayTimeDuration-less-than-or-equal function in [XF Section
8.3].
o yearMonthDuration-greater-than
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#yearMonthDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the yearMonthDuration-greater-than
function in [XF Section 8.3].
o yearMonthDuration-greater-than-or-equal
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#yearMonthDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the yearMonthDuration-greater-than-or-equal
function in [XF Section 8.3].
o yearMonthDuration-less-than
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#yearMonthDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the yearMonthDuration-less-than
function in [XF Section 8.3].
o yearMonthDuration-less-than-or-equal
This function SHALL take two arguments, both of data-type
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#yearMonthDuration".
It SHALL return a result of
"http://ww.w3.org/2001/XMLSchema#boolean". This function
SHALL return the value returned by comparing the value of the
first argument with the value of the second argument according
to the specification of the
yearMonthDuration-less-than-or-equal function in [XF Section
8.3].
o subtract-dateTimes-yielding-yearMonthDuration
This function SHALL take two arguments, both of data-type
"http://www.w3.org/2001/XMLSchema#dateTime". It SHALL return
a result of
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#yearMonthDuration".
This function SHALL return the value returned by subtracting
the value of the second argument from the value of the first
argument according to the specification of the
subtract-dateTimes-yielding-yearMonthDuration function in
[XF-03 Section 9.7].
o subtract-dateTimes-yielding-dayTimeDuration
This function SHALL take two arguments, both of data-type
"http://www.w3.org/2001/XMLSchema#dateTime". It SHALL return
a result of
"http://www.w3.org/TR/2002/WD-xquery-operators-2002-816#dayTimeDuration".
This function SHALL return the value returned by subtracting
the value of the second argument from the value of the first
argument according to the specification of the
subtract-dateTimes-yielding-dayTimeDuration function in
[XF-03 Section 9.7].
--
Anne H. Anderson Email: Anne.Anderson@Sun.COM
Sun Microsystems Laboratories
1 Network Drive,UBUR02-311 Tel: 781/442-0928
Burlington, MA 01803-0902 USA Fax: 781/442-1692