Create new class SubtaskPositionModel

app/Model/SubtaskPositionModel.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Kanboard\Model;
+
+use Kanboard\Core\Base;
+
+/**
+ * Class SubtaskPositionModel
+ *
+ * @package Kanboard\Model
+ * @author  Frederic Guillot
+ */
+class SubtaskPositionModel extends Base
+{
+    /**
+     * Change subtask position
+     *
+     * @access public
+     * @param  integer  $task_id
+     * @param  integer  $subtask_id
+     * @param  integer  $position
+     * @return boolean
+     */
+    public function changePosition($task_id, $subtask_id, $position)
+    {
+        if ($position < 1 || $position > $this->db->table(SubtaskModel::TABLE)->eq('task_id', $task_id)->count()) {
+            return false;
+        }
+
+        $subtask_ids = $this->db->table(SubtaskModel::TABLE)->eq('task_id', $task_id)->neq('id', $subtask_id)->asc('position')->findAllByColumn('id');
+        $offset = 1;
+        $results = array();
+
+        foreach ($subtask_ids as $current_subtask_id) {
+            if ($offset == $position) {
+                $offset++;
+            }
+
+            $results[] = $this->db->table(SubtaskModel::TABLE)->eq('id', $current_subtask_id)->update(array('position' => $offset));
+            $offset++;
+        }
+
+        $results[] = $this->db->table(SubtaskModel::TABLE)->eq('id', $subtask_id)->update(array('position' => $position));
+
+        return !in_array(false, $results, true);
+    }
+}