added annotation based exporter (#1831)

* added user exporter
* added project exporter
* added customer exporter
* added activity exporter

src/Export/Spreadsheet/CellFormatter/TimeFormatter.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Export\Spreadsheet\CellFormatter;
+
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
+
+class TimeFormatter implements CellFormatterInterface
+{
+    public const TIME_FORMAT = 'hh:mm';
+
+    public function setFormattedValue(Worksheet $sheet, int $column, int $row, $value): void
+    {
+        if (null === $value) {
+            $sheet->setCellValueByColumnAndRow($column, $row, '');
+
+            return;
+        }
+
+        if (!$value instanceof \DateTime) {
+            throw new \InvalidArgumentException('Unsupported value given, only DateTime is supported');
+        }
+
+        $sheet->setCellValueByColumnAndRow($column, $row, Date::PHPToExcel($value));
+        $sheet->getStyleByColumnAndRow($column, $row)->getNumberFormat()->setFormatCode(self::TIME_FORMAT);
+    }
+}