From 55013bb699002972144fda996ef626164040c07e Mon Sep 17 00:00:00 2001
From: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Date: Wed, 6 Jan 2021 16:34:23 +0100
Subject: [PATCH] Bug 27353: Set X-Base-Total-Count header for REST API

We already set X-Total-Count to the total number of filtered rows,
but we don't have the total number of non-filtered rows.

Test plan:
This is easy to test on top of bug 27352 or bug 27251, apply them if not
pushed yet.
1. Create 40 items with public notes = "xxx" for biblionumber=4
then, using Postman (or whatever you prefer):
http://kohadev-intra.mydnsname.org:8081/api/v1/biblios/4/items?_page=1&_per_page=20&q=[{"me.public_notes"%3A{"like"%3A"%25x%25"}}]&_match=contains
Check the headers and confirm you see X-Total-Count=40 and
X-Base-Total-Count=44

2. go to /cgi-bin/koha/tools/quotes.pl
You see "Showing 1 to 20 of 28 entries"
Search "he"
Showing 1 to 20 of 22 entries (filtered from 28 total entries)
---
 Koha/REST/Plugin/Objects.pm                   | 23 ++++++++++++-------
 Koha/REST/Plugin/Pagination.pm                |  4 +++-
 koha-tmpl/intranet-tmpl/prog/js/datatables.js |  3 +++
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/Koha/REST/Plugin/Objects.pm b/Koha/REST/Plugin/Objects.pm
index fec1fe794a..35742dc1ff 100644
--- a/Koha/REST/Plugin/Objects.pm
+++ b/Koha/REST/Plugin/Objects.pm
@@ -114,18 +114,25 @@ sub register {
             }
             # Perform search
             my $objects = $result_set->search( $filtered_params, $attributes );
+            my $total   = $result_set->search->count;
 
             if ($objects->is_paged) {
-                $c->add_pagination_headers({
-                    total => $objects->pager->total_entries,
-                    params => $args,
-                });
+                $c->add_pagination_headers(
+                    {
+                        total      => $objects->pager->total_entries,
+                        base_total => $total,
+                        params     => $args,
+                    }
+                );
             }
             else {
-                $c->add_pagination_headers({
-                    total => $objects->count,
-                    params => $args,
-                });
+                $c->add_pagination_headers(
+                    {
+                        total      => $objects->count,
+                        base_total => $total,
+                        params     => $args,
+                    }
+                );
             }
 
             return $objects->to_api({ embed => $embed });
diff --git a/Koha/REST/Plugin/Pagination.pm b/Koha/REST/Plugin/Pagination.pm
index 911aa43aaf..90d220c1cf 100644
--- a/Koha/REST/Plugin/Pagination.pm
+++ b/Koha/REST/Plugin/Pagination.pm
@@ -50,7 +50,7 @@ sub register {
 
 Adds a Link header to the response message $c carries, following RFC5988, including
 the following relation types: 'prev', 'next', 'first' and 'last'.
-It also adds X-Total-Count, containing the total results count.
+It also adds X-Total-Count containing the total results count, and X-Base-Total-Count containing the total of the non-filtered results count.
 
 If page size is omitted, it defaults to the value of the RESTdefaultPageSize syspref.
 
@@ -61,6 +61,7 @@ If page size is omitted, it defaults to the value of the RESTdefaultPageSize sys
             my ( $c, $args ) = @_;
 
             my $total    = $args->{total};
+            my $base_total = $args->{base_total};
             my $req_page = $args->{params}->{_page} // 1;
             my $per_page = $args->{params}->{_per_page} //
                             C4::Context->preference('RESTdefaultPageSize') // 20;
@@ -114,6 +115,7 @@ If page size is omitted, it defaults to the value of the RESTdefaultPageSize sys
 
             # Add X-Total-Count header
             $c->res->headers->add( 'X-Total-Count' => $total );
+            $c->res->headers->add( 'X-Base-Total-Count' => $base_total );
             return $c;
         }
     );
diff --git a/koha-tmpl/intranet-tmpl/prog/js/datatables.js b/koha-tmpl/intranet-tmpl/prog/js/datatables.js
index 13db0e495c..69fc5a998f 100644
--- a/koha-tmpl/intranet-tmpl/prog/js/datatables.js
+++ b/koha-tmpl/intranet-tmpl/prog/js/datatables.js
@@ -544,6 +544,9 @@ jQuery.fn.dataTable.ext.errMode = function(settings, note, message) {
                                     json.recordsTotal = total;
                                     json.recordsFiltered = total;
                                 }
+                                if(total = this._xhr.getResponseHeader('x-base-total-count')) {
+                                    json.recordsTotal = total;
+                                }
                                 return JSON.stringify(json);
                             },
                             'data': function( data, settings ) {
-- 
2.20.1