<NME> WhitelistEntry.php
<BEF> ADDFILE
<MSG> Implemented new entry save form

<DFF> @@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of the Magento2 Force Login Module package.
+ *
+ * (c) bitExpert AG
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace bitExpert\ForceCustomerLogin\Validator;
+
+use \bitExpert\ForceCustomerLogin\Model\WhitelistEntry as WhitelistEntryModel;
+
+/**
+ * Class WhitelistEntry
+ * @package bitExpert\ForceCustomerLogin\Validator
+ */
+class WhitelistEntry
+{
+    /**
+     * @param WhitelistEntryModel $whitelistEntry
+     * @return bool
+     * @throw \InvalidArgumentException If validation fails
+     */
+    public function validate(
+        WhitelistEntryModel $whitelistEntry
+    ) {
+        if (0 === \strlen(\trim($whitelistEntry->getLabel()))) {
+            throw new \InvalidArgumentException('Label value is too short.');
+        }
+        if (255 < \strlen(\trim($whitelistEntry->getLabel()))) {
+            throw new \InvalidArgumentException('Label value is too long.');
+        }
+
+        if (0 === \strlen(\trim($whitelistEntry->getUrlRule()))) {
+            throw new \InvalidArgumentException('Url Rule value is too short.');
+        }
+
+        if (!\is_bool($whitelistEntry->getEditable())) {
+            throw new \InvalidArgumentException('Editable is no boolean value.');
+        }
+
+        return true;
+    }
+}

Implemented new entry save form