Bug 8435: DBRev 3.13.00.038

[koha.git] / C4 / Tags.pm

diff --git a/C4/Tags.pm b/C4/Tags.pm
index 85613e0..b6b319b 100644 (file)
--- a/C4/Tags.pm
+++ b/C4/Tags.pm
@@ -26,28 +26,30 @@ use Exporter;
 use C4::Context;
 use C4::Debug;
 #use Data::Dumper;
+use constant TAG_FIELDS => qw(tag_id borrowernumber biblionumber term language date_created);
+use constant TAG_SELECT => "SELECT " . join(',', TAG_FIELDS) . "\n FROM   tags_all\n";
 
 use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
-use vars qw($ext_dict $select_all @fields);
+our $ext_dict;
 
 BEGIN {
     $VERSION = 3.07.00.049;
        @ISA = qw(Exporter);
-       @EXPORT_OK = qw(
-               &get_tag &get_tags &get_tag_rows
-               &add_tags &add_tag
-               &delete_tag_row_by_id
-               &remove_tag
-               &delete_tag_rows_by_ids
-               &rectify_weights
-               &get_approval_rows
-               &blacklist
-               &whitelist
-               &is_approved
-               &approval_counts
-               &get_count_by_tag_status
-               &get_filters
-       );
+    @EXPORT_OK = qw(
+      &get_tag &get_tags &get_tag_rows
+      &add_tags &add_tag
+      &delete_tag_row_by_id
+      &remove_tag
+      &delete_tag_rows_by_ids
+      &get_approval_rows
+      &blacklist
+      &whitelist
+      &is_approved
+      &approval_counts
+      &get_count_by_tag_status
+      &get_filters
+      stratify_tags
+    );
        # %EXPORT_TAGS = ();
        $ext_dict = C4::Context->preference('TagsExternalDictionary');
        if ($debug) {
@@ -61,11 +63,15 @@ BEGIN {
        }
 }
 
+=head1 C4::Tags.pm - Support for user tagging of biblios.
+
+More verose debugging messages are sent in the presence of non-zero $ENV{"DEBUG"}.
+
+=cut
+
 INIT {
     $ext_dict and $Lingua::Ispell::path = $ext_dict;
     $debug and print STDERR "\$Lingua::Ispell::path = $Lingua::Ispell::path\n";
-       @fields = qw(tag_id borrowernumber biblionumber term language date_created);
-       $select_all = "SELECT " . join(',',@fields) . "\n FROM   tags_all\n";
 }
 
 sub get_filters {
@@ -175,7 +181,7 @@ sub delete_tag_rows_by_ids {
 
 sub get_tag_rows {
        my $hash = shift || {};
-       my @ok_fields = @fields;
+    my @ok_fields = TAG_FIELDS;
        push @ok_fields, 'limit';       # push the limit! :)
        my $wheres;
        my $limit  = "";
@@ -202,7 +208,7 @@ sub get_tag_rows {
                        push @exe_args, $hash->{$key};
                }
        }
-       my $query = $select_all . ($wheres||'') . $limit;
+    my $query = TAG_SELECT . ($wheres||'') . $limit;
        $debug and print STDERR "get_tag_rows query:\n $query\n",
                                                        "get_tag_rows query args: ", join(',', @exe_args), "\n";
        my $sth = C4::Context->dbh->prepare($query);
@@ -485,38 +491,11 @@ sub add_tag_index {
 
 sub get_tag {          # by tag_id
        (@_) or return;
-       my $sth = C4::Context->dbh->prepare("$select_all WHERE tag_id = ?");
+    my $sth = C4::Context->dbh->prepare(TAG_SELECT . "WHERE tag_id = ?");
        $sth->execute(shift);
        return $sth->fetchrow_hashref;
 }
 
-sub rectify_weights {
-       my $dbh = C4::Context->dbh;
-       my $sth;
-       my $query = "
-       SELECT term,biblionumber,count(*) as count
-       FROM   tags_all
-       ";
-       (@_) and $query .= " WHERE term =? ";
-       $query .= " GROUP BY term,biblionumber ";
-       $sth = $dbh->prepare($query);
-       if (@_) {
-               $sth->execute(shift);
-       } else {
-               $sth->execute();
-       }
-       my $results = $sth->fetchall_arrayref({}) or return;
-       my %tally = ();
-       foreach (@$results) {
-               _set_weight($_->{count},$_->{term},$_->{biblionumber});
-               $tally{$_->{term}} += $_->{count};
-       }
-       foreach (keys %tally) {
-               _set_weight_total($tally{$_},$_);
-       }
-       return ($results,\%tally);
-}
-
 sub increment_weights {
        increment_weight(@_);
        increment_weight_total(shift);
@@ -594,13 +573,46 @@ sub add_tag {     # biblionumber,term,[borrowernumber,approvernumber]
        }
 }
 
+# This takes a set of tags, as returned by C<get_approval_rows> and divides
+# them up into a number of "strata" based on their weight. This is useful
+# to display them in a number of different sizes.
+#
+# Usage:
+#   ($min, $max) = stratify_tags($strata, $tags);
+# $stratum: the number of divisions you want
+# $tags: the tags, as provided by get_approval_rows
+# $min: the minumum stratum value
+# $max: the maximum stratum value. This may be the same as $min if there
+# is only one weight. Beware of divide by zeros.
+# This will add a field to the tag called "stratum" containing the calculated
+# value.
+sub stratify_tags {
+    my ( $strata, $tags ) = @_;
+
+    my ( $min, $max );
+    foreach (@$tags) {
+        my $w = $_->{weight_total};
+        $min = $w if ( !defined($min) || $min > $w );
+        $max = $w if ( !defined($max) || $max < $w );
+    }
+
+    # normalise min to zero
+    $max = $max - $min;
+    my $orig_min = $min;
+    $min = 0;
+
+    # if min and max are the same, just make it 1
+    my $span = ( $strata - 1 ) / ( $max || 1 );
+    foreach (@$tags) {
+        my $w = $_->{weight_total};
+        $_->{stratum} = int( ( $w - $orig_min ) * $span );
+    }
+    return ( $min, $max );
+}
+
 1;
 __END__
 
-=head1 C4::Tags.pm - Support for user tagging of biblios.
-
-More verose debugging messages are sent in the presence of non-zero $ENV{"DEBUG"}.
-
 =head2 add_tag(biblionumber,term[,borrowernumber])
 
 =head3 TO DO: Add real perldoc