Improve create and start permission handling (#613)

src/Security/CurrentUser.php

@@ -0,0 +1,55 @@
+<?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\Security;
+
+use App\Entity\User;
+use App\Repository\UserRepository;
+use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
+
+class CurrentUser
+{
+    /**
+     * @var TokenStorageInterface
+     */
+    protected $storage;
+    /**
+     * @var UserRepository
+     */
+    protected $repository;
+
+    /**
+     * @param TokenStorageInterface $storage
+     * @param UserRepository $repository
+     */
+    public function __construct(TokenStorageInterface $storage, UserRepository $repository)
+    {
+        $this->storage = $storage;
+        $this->repository = $repository;
+    }
+
+    /**
+     * @return User|null
+     */
+    public function getUser()
+    {
+        if (null === $this->storage->getToken()) {
+            return null;
+        }
+
+        /** @var User $user */
+        $user = $this->storage->getToken()->getUser();
+
+        if (!($user instanceof User)) {
+            return null;
+        }
+
+        return $this->repository->getById($user->getId());
+    }
+}