[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Function converting RFC 2822 date to xsd:dateTime

Subject: Re: Function converting RFC 2822 date to xsd:dateTime
From: "Michael Kay mike@xxxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Mon, 8 Apr 2019 23:03:57 -0000
Re:  Function converting RFC 2822 date to xsd:dateTime
The main question about error handling here is how liberal you want to be,
e.g. do you want to fail on "Wed 9 Apr 2019" on the grounds that 9 April isn't
a Wednesday? Similarly, do you want to validate leap years etc? As far as I
can see, you're allowing 31 Apr but not 32 Apr, and that seems a bit pointless
to me.

The secondary point is what you do when invalid input is detected. If you want
to do a hard fail then xsl:message terminate="yes" is as good as anything.

Also, I can't work out what you're trying to do with timezones.

Michael Kay

> On 8 Apr 2019, at 23:32, Martynas JuseviD
ius martynas@xxxxxxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
> Thanks Michael, I will have parse-ietf-date() in mind.
> As for invalid values, the template invoking the function should
> handle the error with some kind of conditional and skip creating
> content with such values.
> How would such error handling look like? Preferably in XSLT 2.0, but
> I'm also interested in how it would compare to XSLT 3.0.
> I was reading about the error() function in relation to this, but
> couldn't figure out how exactly it could be used here.
> On Tue, Apr 9, 2019 at 12:16 AM Michael Kay mike@xxxxxxxxxxxx
> <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>> Are you aware that XPath 3.0 has the function parse-ietf-date() for this?
>> https://www.w3.org/TR/xpath-functions-31/#func-parse-ietf-date
>> The Saxon implementation is in Java; I haven't attempted an XPath
implementation. But you might find the spec (and the associated notes) is
useful in itself; and of course the QT3 test suite has test cases.
>> I don't know how date/times in RFC 2822 relate to all the other
miscellaneous RFCs referenced in the spec. Liam Quin did most of the research
for this.
>> What are your requirements for handling invalid values?
>> Michael Kay
>> Saxonica
>>> On 8 Apr 2019, at 22:58, Martynas JuseviD
ius martynas@xxxxxxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>>> Hi,
>>> I have an XSLT 2.0 task where I'm parsing email Date headers defined
>>> in RFC 2822 and converting them to xsd:dateTime.
>>> Below is a function that converts between the two. I wanted to hear if
>>> there are improvements that could be made?
>>>   <xsl:function name="aex:rfc2822dateTime-to-dateTime" as="xs:dateTime">
>>>       <xsl:param name="date-time" as="xs:string"/> <!-- Tue, 9 Apr
>>> 2019 00:07:24 +1200 (NZST) -->
>>>       <xsl:variable name="months" select="'Jan', 'Feb', 'Mar',
>>> 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'"
>>> as="xs:string*"/>
>>>       <xsl:analyze-string select="$date-time"
>>>           <xsl:matching-substring>
>>>               <xsl:sequence
>>> select="xs:dateTime(concat(format-number(xs:integer(regex-group(4)),
>>> '0001'), '-', format-number(index-of($months, regex-group(3)), '01'),
>>> '-', format-number(xs:integer(regex-group(2)), '01'), 'T',
>>> format-number(xs:integer(regex-group(5)), '01'), ':',
>>> format-number(xs:integer(regex-group(6)), '01'), ':',
>>> format-number(xs:integer(regex-group(7)), '01'),
>>> substring(regex-group(8), 1, 3), ':', substring(regex-group(8), 4,
>>> 2)))"/>
>>>           </xsl:matching-substring>
>>>           <xsl:non-matching-substring>
>>>               <xsl:message>Invalid RFC 2822 datetime: <xsl:value-of
>>> select="$date-time"/></xsl:message>
>>>           </xsl:non-matching-substring>
>>>       </xsl:analyze-string>
>>>   </xsl:function>
>>> The regex pattern is taken from
>>> https://stackoverflow.com/questions/9352003/rfc-2822-date-regex
>>> Martynas
>>> atomgraph.com

Current Thread


Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
First Name
Last Name
Subscribe in XML format
RSS 2.0
Atom 0.3
Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.