From 3e8bc6b15b5431105010dae45b270d2f780a8923 Mon Sep 17 00:00:00 2001
From: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Date: Mon, 5 Oct 2015 15:29:52 +0100
Subject: [PATCH] Bug 12478: Display facet terms ordered by number of
 occurrences

By default ES returns the facet terms ordered by most used, which makes
sense.

This patch removes resort done in the scripts (catalogue/search.pl and
opac/opac-search.pl) and moves it to the module.

For Zebra it's now done in C4::Search::getRecords, and there is no
change to expect (still alphabetically).

On the Elastic search side, we could imagine to let the library define
the order of the facets. The facet terms are now sorted by most used.

To test easily this change, turn on the displayFacetCount pref.
---
 C4/Search.pm                              |  8 ++++++++
 Koha/SearchEngine/Elasticsearch/Search.pm | 26 +++++++++++++++-----------
 catalogue/search.pl                       |  6 ------
 opac/opac-search.pl                       |  8 --------
 4 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/C4/Search.pm b/C4/Search.pm
index b3d5554..d755ff0 100644
--- a/C4/Search.pm
+++ b/C4/Search.pm
@@ -643,6 +643,14 @@ sub GetFacets {
         $facets = _get_facets_from_records( $rs );
     }
 
+    # This sorts the facets into alphabetical order
+    if ($facets && @$facets) {
+        foreach my $f (@$facets) {
+            $f->{facets} = [ sort { uc($a->{facet_label_value}) cmp uc($b->{facet_label_value}) } @{ $f->{facets} } ];
+        }
+        @$facets = sort {$a->{expand} cmp $b->{expand}} @$facets;
+    }
+
     return $facets;
 }
 
diff --git a/Koha/SearchEngine/Elasticsearch/Search.pm b/Koha/SearchEngine/Elasticsearch/Search.pm
index 0b4e16f..d7ce445 100644
--- a/Koha/SearchEngine/Elasticsearch/Search.pm
+++ b/Koha/SearchEngine/Elasticsearch/Search.pm
@@ -390,13 +390,14 @@ sub _convert_facets {
 
     # These should correspond to the ES field names, as opposed to the CCL
     # things that zebra uses.
+    # TODO let the library define the order using the interface.
     my %type_to_label = (
-        author   => 'Authors',
-        location => 'Location',
-        itype    => 'ItemTypes',
-        se       => 'Series',
-        subject  => 'Topics',
-        'su-geo' => 'Places',
+        author   => { order => 1, label => 'Authors', },
+        itype    => { order => 2, label => 'ItemTypes', },
+        location => { order => 3, label => 'Location', },
+        'su-geo' => { order => 4, label => 'Places', },
+        se       => { order => 5, label => 'Series', },
+        subject  => { order => 6, label => 'Topics', },
     );
 
     # We also have some special cases, e.g. itypes that need to show the
@@ -408,20 +409,21 @@ sub _convert_facets {
         itype    => { map { $_->itemtype         => $_->description } @itypes },
         location => { map { $_->authorised_value => ( $opac ? ( $_->lib_opac || $_->lib ) : $_->lib ) } @locations },
     );
-    my @res;
+    my @facets;
     $exp_facet //= '';
     while ( ( $type, $data ) = each %$es ) {
         next if !exists( $type_to_label{$type} );
 
-        # We restrict to the most popular $limit results
+        # We restrict to the most popular $limit !results
         my $limit = ( $type eq $exp_facet ) ? 10 : 5;
         my $facet = {
             type_id    => $type . '_id',
             expand     => $type,
             expandable => ( $type ne $exp_facet )
               && ( @{ $data->{terms} } > $limit ),
-            "type_label_$type_to_label{$type}" => 1,
+            "type_label_$type_to_label{$type}{label}" => 1,
             type_link_value                    => $type,
+            order      => $type_to_label{$type}{order},
         };
         $limit = @{ $data->{terms} } if ( $limit > @{ $data->{terms} } );
         foreach my $term ( @{ $data->{terms} }[ 0 .. $limit - 1 ] ) {
@@ -442,9 +444,11 @@ sub _convert_facets {
                 type_link_value => $type,
             };
         }
-        push @res, $facet if exists $facet->{facets};
+        push @facets, $facet if exists $facet->{facets};
     }
-    return \@res;
+
+    @facets = sort { $a->{order} cmp $b->{order} } @facets;
+    return \@facets;
 }
 
 
diff --git a/catalogue/search.pl b/catalogue/search.pl
index a43f970..0b9de4c 100755
--- a/catalogue/search.pl
+++ b/catalogue/search.pl
@@ -484,12 +484,6 @@ eval {
     );
 };
 
-# This sorts the facets into alphabetical order
-if ($facets) {
-    foreach my $f (@$facets) {
-        $f->{facets} = [ sort { uc($a->{facet_label_value}) cmp uc($b->{facet_label_value}) } @{ $f->{facets} } ];
-    }
-}
 if ($@ || $error) {
     $template->param(query_error => $error.$@);
     output_html_with_http_headers $cgi, $cookie, $template->output;
diff --git a/opac/opac-search.pl b/opac/opac-search.pl
index a9a0a73..13fbcab 100755
--- a/opac/opac-search.pl
+++ b/opac/opac-search.pl
@@ -589,14 +589,6 @@ if ($tag) {
     };
 }
 
-# This sorts the facets into alphabetical order
-if ($facets && @$facets) {
-    foreach my $f (@$facets) {
-        $f->{facets} = [ sort { uc($a->{facet_label_value}) cmp uc($b->{facet_label_value}) } @{ $f->{facets} } ];
-    }
-    @$facets = sort {$a->{expand} cmp $b->{expand}} @$facets;
-}
-
 # use Data::Dumper; print STDERR "-" x 25, "\n", Dumper($results_hashref);
 if ($@ || $error) {
     $template->param(query_error => $error.$@);
-- 
2.1.0