Add class SubtaskListFormatter

app/Formatter/SubtaskListFormatter.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Kanboard\Formatter;
+
+use Kanboard\Core\Filter\FormatterInterface;
+
+/**
+ * Class SubtaskListFormatter
+ *
+ * @package Kanboard\Formatter
+ * @author  Frederic Guillot
+ */
+class SubtaskListFormatter extends BaseFormatter implements FormatterInterface
+{
+    /**
+     * Apply formatter
+     *
+     * @access public
+     * @return mixed
+     */
+    public function format()
+    {
+        $status = $this->subtaskModel->getStatusList();
+        $subtasks = $this->query->findAll();
+
+        foreach ($subtasks as &$subtask) {
+            $subtask['status_name'] = $status[$subtask['status']];
+            $subtask['timer_start_date'] = isset($subtask['timer_start_date']) ? $subtask['timer_start_date'] : 0;
+            $subtask['is_timer_started'] = ! empty($subtask['timer_start_date']);
+        }
+
+        return $subtasks;
+    }
+}