Attachment 63471 Details for Bug 18356 – Bug 18356: Fix date calculations for yearly frequencies in Serials

[patch] Bug 18356: Fix date calculations for yearly frequencies in Serials

Bug-18356-Fix-date-calculations-for-yearly-frequen.patch (text/plain), 4.96 KB, created by Marcel de Rooy on 2017-05-15 13:12:08 UTC

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Creator: Marcel de Rooy

Created: 2017-05-15 13:12:08 UTC

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patch

obsolete

>From 854a56193d32246fcfd67e28ba0fe4caa62cbdfd Mon Sep 17 00:00:00 2001
>From: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
>Date: Tue, 9 May 2017 17:01:46 +0200
>Subject: [PATCH] Bug 18356: Fix date calculations for yearly frequencies in
> Serials
>Content-Type: text/plain; charset=utf-8
>
>The problem as described on BZ 18356 is a combination of an error in
>GetFictiveIssueNumber and GetNextDate for unit==year.
>
>In GetFictiveIssueNumber the year should be decreased by one if you have
>more units per year and you did not yet reach firstacqui day and month.
>This affects calculations in GetNextDate with irregularities.
>
>In GetNextDate the Add_Delta_YM calculation should be applied only to
>frequencies based on years per unit.
>In the case of multiple units per year we calculate the number of days to
>add. And if we have reached the end of a year cycle, we 'round' up to
>firstacqui day and month as long as we are close enough. Otherwise we just
>add the number of calculated days, since we can safely assume that the
>publish dates have been adjusted manually.
>
>Test plan:
>[1] Verify that both GetNextDate.t as well as GetFictiveIssueNumber.t pass.
>[2] Look at the prediction pattern for a few frequencies.
>    For example: 1 iss/y, 1 iss/2y, 5 iss/y.
>
>Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
>---
> C4/Serials.pm | 50 ++++++++++++++++++++++++++++++++++++--------------
> 1 file changed, 36 insertions(+), 14 deletions(-)
>
>diff --git a/C4/Serials.pm b/C4/Serials.pm
>index c1316f2..bbb4802 100644
>--- a/C4/Serials.pm
>+++ b/C4/Serials.pm
>@@ -2270,6 +2270,9 @@ depending on how many rows are in serial table.
> The issue number calculation is based on subscription frequency, first acquisition
> date, and $publisheddate.
> 
>+The routine is used to skip irregularities when calculating the next issue
>+date (in GetNextDate) or the next issue number (in GetNextSeq).
>+
> =cut
> 
> sub GetFictiveIssueNumber {
>@@ -2297,6 +2300,10 @@ sub GetFictiveIssueNumber {
>                    : ( ($year-$fa_year-1)*12 + (12-$fa_month+$month) );
>         } elsif($unit eq 'year') {
>             $delta = $year - $fa_year;
>+            if( $frequency->{issuesperunit} > 1 ) {
>+                $delta-- if $month < $fa_month ||
>+                    ( $month == $fa_month && $day < $fa_day );
>+            }
>         }
>         if($frequency->{'unitsperissue'} == 1) {
>             $issueno = $delta * $frequency->{'issuesperunit'} + $subscription->{'countissuesperunit'};
>@@ -2372,23 +2379,38 @@ sub _get_next_date_month {
> sub _get_next_date_year {
>     my ($subscription, $freqdata, $year, $month, $day) = @_;
> 
>-    my ($fa_year, $fa_month, $fa_day) = split /-/, $subscription->{firstacquidate};
>+    my (undef, $fa_month, $fa_day) = split /-/, $subscription->{firstacquidate};
> 
>-    if ($subscription->{countissuesperunit} + 1 > $freqdata->{issuesperunit}){
>-        $subscription->{countissuesperunit} = 1;
>-        ($year) = Add_Delta_YM($year,$month,$day, $freqdata->{"unitsperissue"},0);
>-        $month = $fa_month;
>-        my $days_in_month = Days_in_Month($year, $month);
>-        $day = $fa_day <= $days_in_month ? $fa_day : $days_in_month;
>+    my @newissue; # ( yy, mm, dd )
>+    if( $freqdata->{issuesperunit} == 1 ) { # adding years
>+        @newissue = Add_Delta_YM(
>+            $year, $month, $day, $freqdata->{"unitsperissue"}, 0 );
>     } else {
>-        # Try to guess the next day in year
>-        my $days_in_year = Days_in_Year($year,12); #Sum the days of all the months of this year
>-        my $delta_days = int(($days_in_year - ($fa_day - 1)) / $freqdata->{issuesperunit});
>-        ($year,$month,$day) = Add_Delta_Days($year, $month, $day, $delta_days);
>-        $subscription->{countissuesperunit}++;
>-    }
>+        # Add rounded number of days based on frequency.
>+        # We always use the same number of days (calculated with 365.25).
>+        my $delta_days = int( 365.25 / $freqdata->{issuesperunit} );
>+        @newissue = Add_Delta_Days( $year, $month, $day, $delta_days );
> 
>-    return ($year, $month, $day);
>+        # Did we finish a cycle of issues within a unit? Correct rounding.
>+        if( $subscription->{countissuesperunit} >= $freqdata->{issuesperunit} )
>+        {
>+            $subscription->{countissuesperunit} = 1;
>+            my $newyr = $newissue[0];
>+            $newyr++ if $fa_month < $newissue[1];
>+            my $days_in_month = Days_in_Month($newyr, $fa_month);
>+            $fa_day = $days_in_month if $fa_day > $days_in_month;
>+            # If newissue is older than the firstacqui based date, and
>+            # difference <= number of issues per unit, we accept
>+            # the firstacqui based date.
>+            # Note: We use <= because of leap years!
>+            $delta_days = Delta_Days( @newissue, $newyr, $fa_month, $fa_day );
>+            @newissue = ( $newyr, $fa_month, $fa_day )
>+                if $delta_days > 0 && $delta_days <= $freqdata->{issuesperunit};
>+        } else {
>+            $subscription->{countissuesperunit}++;
>+        }
>+    }
>+    return @newissue;
> }
> 
> =head2 GetNextDate
>-- 
>2.1.4

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