Fix search criterion value lost on multiple dropdown fields

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Fixed
+
+- Fix search criterion value on multiple dropdown fields being reset after a search, which emptied the criterion when sorting or paging results
+
 ## [1.24.7] - 2026-10-28
 
 ### Fixed

inc/abstractcontainerinstance.class.php

@@ -120,14 +120,23 @@ public static function getSpecificValueToSelect($field, $name = '', $values = ''
                     $display_with = ['realname', 'firstname'];
                 }
 
-                return Dropdown::show($itemtype, ['displaywith' => $display_with, 'name' => $name, 'display' => false]);
+                return Dropdown::show($itemtype, [
+                    'displaywith' => $display_with,
+                    'name'        => $name,
+                    'value'       => $values[$field] ?? 0,
+                    'display'     => false,
+                ]);
             } elseif (
                 $field_specs->fields['type'] === 'dropdown'
                 && $field_specs->fields['multiple']
             ) {
                 $itemtype = PluginFieldsDropdown::getClassname($field_specs->fields['name']);
 
-                return Dropdown::show($itemtype, ['name' => $name, 'display' => false]);
+                return Dropdown::show($itemtype, [
+                    'name'    => $name,
+                    'value'   => $values[$field] ?? 0,
+                    'display' => false,
+                ]);
             }
         }
 

tests/Units/SearchCriteriaMultipleDropdownTest.php

@@ -0,0 +1,141 @@
+<?php
+
+/**
+ * -------------------------------------------------------------------------
+ * Fields plugin for GLPI
+ * -------------------------------------------------------------------------
+ *
+ * LICENSE
+ *
+ * This file is part of Fields.
+ *
+ * Fields is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Fields is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Fields. If not, see <http://www.gnu.org/licenses/>.
+ * -------------------------------------------------------------------------
+ * @copyright Copyright (C) 2013-2023 by Fields plugin team.
+ * @license   GPLv2 https://www.gnu.org/licenses/gpl-2.0.html
+ * @link      https://github.com/pluginsGLPI/fields
+ * -------------------------------------------------------------------------
+ */
+
+namespace GlpiPlugin\Field\Tests\Units;
+
+use Computer;
+use Glpi\Tests\DbTestCase;
+use Glpi\Tests\GLPITestCase;
+use GlpiPlugin\Field\Tests\FieldTestTrait;
+use PluginFieldsContainer;
+use PluginFieldsDropdown;
+use PluginFieldsField;
+use Search;
+use User;
+
+require_once __DIR__ . '/../FieldTestCase.php';
+
+/**
+ * The value input of a search criterion on a multiple dropdown field must keep
+ * the searched value once the search is submitted, otherwise sorting or paging
+ * the results relaunches the search with an empty criterion.
+ */
+final class SearchCriteriaMultipleDropdownTest extends DbTestCase
+{
+    use FieldTestTrait;
+
+    public function setUp(): void
+    {
+        GLPITestCase::setUp();
+    }
+
+    public function tearDown(): void
+    {
+        $this->tearDownFieldTest();
+        GLPITestCase::tearDown();
+    }
+
+    public function testCriterionKeepsValueOnMultipleDropdown(): void
+    {
+        $this->login();
+
+        $container = $this->createComputerContainer();
+        $field = $this->createField([
+            'label'                                     => 'Accessoire',
+            'type'                                      => 'dropdown',
+            'multiple'                                  => 1,
+            'default_value'                             => [],
+            PluginFieldsContainer::getForeignKeyField() => $container->getID(),
+            'ranking'                                   => 1,
+            'is_active'                                 => 1,
+            'is_readonly'                               => 0,
+        ], ['default_value']);
+
+        $dropdown_class = PluginFieldsDropdown::getClassname($field->fields['name']);
+        $value = $this->createItem($dropdown_class, ['name' => 'Searched value', 'entities_id' => 0]);
+
+        $html = $this->getCriterionValueInput($container, $field, $value->getID());
+
+        $this->assertStringContainsString(
+            sprintf('<option value="%d" selected="selected">Searched value</option>', $value->getID()),
+            $html,
+        );
+    }
+
+    public function testCriterionKeepsValueOnMultipleGlpiDropdown(): void
+    {
+        $this->login();
+
+        $container = $this->createComputerContainer();
+        $field = $this->createField([
+            'label'                                     => 'Users',
+            'type'                                      => 'dropdown-User',
+            'multiple'                                  => 1,
+            'default_value'                             => [],
+            PluginFieldsContainer::getForeignKeyField() => $container->getID(),
+            'ranking'                                   => 1,
+            'is_active'                                 => 1,
+            'is_readonly'                               => 0,
+        ], ['default_value']);
+
+        $user_id = getItemByTypeName(User::class, TU_USER, true);
+
+        $html = $this->getCriterionValueInput($container, $field, $user_id);
+
+        $this->assertStringContainsString(sprintf('<option value="%d" selected="selected">', $user_id), $html);
+    }
+
+    private function createComputerContainer(): PluginFieldsContainer
+    {
+        return $this->createFieldContainer([
+            'label'        => 'Search ' . $this->getUniqueString(),
+            'type'         => 'tab',
+            'itemtypes'    => [Computer::class],
+            'is_active'    => 1,
+            'entities_id'  => 0,
+            'is_recursive' => 1,
+        ]);
+    }
+
+    /**
+     * Render the value input of a search criterion, as done by the search query builder.
+     */
+    private function getCriterionValueInput(PluginFieldsContainer $container, PluginFieldsField $field, int $value): string
+    {
+        $so_id = PluginFieldsField::SEARCH_OPTION_STARTING_INDEX + $field->getID();
+        $searchopt = Search::getOptions(Computer::class);
+        $this->assertArrayHasKey($so_id, $searchopt);
+
+        $container_class = PluginFieldsContainer::getClassname(Computer::class, $container->fields['name']);
+        $container_item = new $container_class();
+
+        return $container_item->getValueToSelect($searchopt[$so_id], 'criteria[0][value]', $value);
+    }
+}