added tags for timesheets (#604)

src/Form/DataTransformer/TagArrayToStringTransformer.php

@@ -0,0 +1,82 @@
+<?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\Form\DataTransformer;
+
+use App\Entity\Tag;
+use App\Repository\TagRepository;
+use Symfony\Component\Form\DataTransformerInterface;
+use Symfony\Component\Form\Exception\TransformationFailedException;
+
+class TagArrayToStringTransformer implements DataTransformerInterface
+{
+    /**
+     * @var TagRepository
+     */
+    private $tagRepository;
+
+    /**
+     * @param TagRepository $tagRepository
+     */
+    public function __construct(TagRepository $tagRepository)
+    {
+        $this->tagRepository = $tagRepository;
+    }
+
+    /**
+     * Transforms an array of tags to a string.
+     *
+     * @param Tag[]|null $tags
+     *
+     * @return string
+     */
+    public function transform($tags): string
+    {
+        if (empty($tags)) {
+            return '';
+        }
+
+        return implode(', ', $tags);
+    }
+
+    /**
+     * Transforms a string to an array of tags.
+     *
+     * @param string $stringOfTags
+     *
+     * @return Tag[]
+     * @throws TransformationFailedException if object (issue) is not found
+     */
+    public function reverseTransform($stringOfTags): array
+    {
+        // check for empty tag list
+        if (empty($stringOfTags)) {
+            return [];
+        }
+
+        $names = array_filter(array_unique(array_map('trim', explode(',', $stringOfTags))));
+
+        // Get the current tags and find the new ones that should be created
+        $tags = $this->tagRepository->findBy(['name' => $names]);
+
+        $newNames = array_diff($names, $tags);
+        foreach ($newNames as $name) {
+            $tag = new Tag();
+            $tag->setName($name);
+            $tags[] = $tag;
+
+            // There's no need to persist these new tags because Doctrine does that automatically
+            // thanks to the cascade={"persist"} option in the App\Entity\Timesheet::$tags property.
+        }
+
+        // Return an array of tags to transform them back into a Doctrine Collection.
+        // See Symfony\Bridge\Doctrine\Form\DataTransformer\CollectionToArrayTransformer::reverseTransform()
+        return $tags;
+    }
+}