Item13708: Foswiki::Time::parseTime()'s ISO date regex should be tightened, leads to weird table sorting

pencil
Priority: Enhancement
Current State: Confirmed
Released In: 2.2.0
Target Release: minor
Applies To: Engine
Component: FoswikiTime
Branches:
Reported By: FlorianSchlichting
Waiting For:
Last Change By: GeorgeClark
Foswiki::Time::parseTime() will identify any string containing a capital T and a four-digit number as ISO date. This leads to a peculiar sort order for a table column that contains regular text (which sometimes includes a number).

The current code at lib/Foswiki/Time.pm lines 161ff:

    # ISO date 2001-12-31T23:59:59+01:00
    # Sven is going to presume that _all_ ISO dated must have a 'T' in them.
    if (
        ( $date =~ m/T/ )
        && ( $date =~
m/(\d\d\d\d)(?:-(\d\d)(?:-(\d\d))?)?(?:T(\d\d)(?::(\d\d)(?::(\d\d(?:\.\d+)?))?)?)?(Z|[-+]\d\d(?::\d\d)?)?/
        )
      )
    {
        my ( $Y, $M, $D, $h, $m, $s, $tz ) =
          ( $1, $2 || 1, $3 || 1, $4 || 0, $5 || 0, $6 || 0, $7 || '' );

Suggested improvements:
  1. Make sure the 'T' is actually part of the parsed date expression
  2. Since the 'T' is already mandatory, month and day should also be mandatory, as should a time component - hour or even hour and minute? (ISO 8601 only uses a 'T' for concatenation of a complete date with any length time expression)
  3. Use of dashes and colons is optional in the ISO standard
  4. Anchor the pattern to the beginning of the string - who wants to sort by dates in the middle of the string? BTW some other regexes in parseTime() are anchored to the start and end of $date, but others (e.g. Foswiki date) are not.

My suggestion:
- m/(\d\d\d\d)(?:-(\d\d)(?:-(\d\d))?)?(?:T(\d\d)(?::(\d\d)(?::(\d\d(?:\.\d+)?))?)?)?(Z|[-+]\d\d(?::\d\d)?)?/
+ m/^(\d\d\d\d)-?(\d\d)-?(\d\d)T(\d\d)(?::?(\d\d)(?::?(\d\d(?:\.\d+)?))?)?(Z|[-+]\d\d(?::\d\d)?)?/

As this is very old code pre-dating the git history, and might be in use from many places, I'd prefer some positive feedback. I have checked that the TimeTests unit tests still pass, without modification.

-- FlorianSchlichting - 16 Sep 2015

 

ItemTemplate edit

Summary Foswiki::Time::parseTime()'s ISO date regex should be tightened, leads to weird table sorting
ReportedBy FlorianSchlichting
Codebase 2.1.4
SVN Range
AppliesTo Engine
Component FoswikiTime
Priority Enhancement
CurrentState Confirmed
WaitingFor
Checkins
TargetRelease minor
ReleasedIn 2.2.0
CheckinsOnBranches
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Release02x01Checkins
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Topic revision: r2 - 12 Dec 2017, GeorgeClark - This page was cached on 12 Sep 2020 - 20:52.

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