From 88e539f51daaf8d443409cd09a3d2025a1b99bec Mon Sep 17 00:00:00 2001
From: nathan <nathangray.bsc+github@gmail.com>
Date: Thu, 28 Oct 2021 16:07:25 -0600
Subject: [PATCH] Calendar: Enable filtering by customfield in list view

---
 calendar/inc/class.calendar_so.inc.php     | 38 +++++++++++++++++++---
 calendar/inc/class.calendar_uilist.inc.php |  8 +++--
 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/calendar/inc/class.calendar_so.inc.php b/calendar/inc/class.calendar_so.inc.php
index 386c64cd21..c97bc7573a 100644
--- a/calendar/inc/class.calendar_so.inc.php
+++ b/calendar/inc/class.calendar_so.inc.php
@@ -785,7 +785,7 @@ class calendar_so
 		}
 		if (!empty($params['sql_filter']))
 		{
-			if (is_string($params['sql_filter']))
+			if(is_string($params['sql_filter']))
 			{
 				$where[] = $params['sql_filter'];
 			}
@@ -794,15 +794,45 @@ class calendar_so
 				$where = array_merge($where, $params['sql_filter']);
 			}
 		}
+		if(array_filter($where, fn($key) => str_contains($key, '#'), ARRAY_FILTER_USE_KEY))
+		{
+			$custom_fields = Api\Storage\Customfields::get('calendar');
+			foreach($where as $col => $data)
+			{
+				if($col[0] == '#' && $data)
+				{
+					unset($where[$col]);
+					$filtermethod = " $this->cal_table.cal_id IN (SELECT DISTINCT cal_id FROM $this->extra_table WHERE ";
+					if($custom_fields[substr($col, 1)]['type'] == 'select' && $custom_fields[substr($col, 1)]['rows'] > 1)
+					{
+						// Multi-select - any entry with the filter value selected matches
+						$filtermethod .= $this->db->expression($this->extra_table, array(
+								'cal_extra_name' => substr($col, 1),
+								$this->db->concat("','", 'cal_extra_value', "','") . ' ' . $this->db->capabilities[Api\Db::CAPABILITY_CASE_INSENSITIV_LIKE] . ' ' . $this->db->quote('%,' . $data . ',%'),
+							)) . ')';
+					}
+					else
+					{
+						$filtermethod .= $this->db->expression($this->extra_table, array(
+								'cal_extra_name'  => substr($col, 1),
+								'cal_extra_value' => $data,
+							)) . ')';
+					}
+					$where[] = $filtermethod;
+				}
+			}
+		}
+
 		$useUnionQuery = $this->db->capabilities['distinct_on_text'] && $this->db->capabilities['union'];
-		if ($users)
+
+		if($users)
 		{
 			$users_by_type = array();
 			foreach((array)$users as $user)
 			{
-				if (is_numeric($user))
+				if(is_numeric($user))
 				{
-					$users_by_type['u'][] = (int) $user;
+					$users_by_type['u'][] = (int)$user;
 				}
 				else
 				{
diff --git a/calendar/inc/class.calendar_uilist.inc.php b/calendar/inc/class.calendar_uilist.inc.php
index 2379c1c7c8..a7788c1914 100644
--- a/calendar/inc/class.calendar_uilist.inc.php
+++ b/calendar/inc/class.calendar_uilist.inc.php
@@ -408,14 +408,18 @@ class calendar_uilist extends calendar_ui
 			$col_filter = array();
 			foreach($params['col_filter'] as $name => $val)
 			{
-				if (!in_array($name, array('participant','row_id')) && (string)$val !== '')
+				if(!in_array($name, array('participant', 'row_id')) && (string)$val !== '')
 				{
 					$col_filter[$name] = $val;
 				}
-				else if ( $name == 'row_id' && (string)$val !== '')
+				elseif($name == 'row_id' && (string)$val !== '')
 				{
 					$col_filter['cal_id'] = $val;
 				}
+				if($name[0] == '#')
+				{
+					$search_params['cfs'][] = $name;
+				}
 			}
 			// Videocalls
 			if(array_key_exists('include_videocalls',$params['col_filter']))