Added placeholders filter to utilize the placeholders in twig mode

Fixes #546

src/Twig/Sandbox/SandboxedLabelExtension.php

@@ -0,0 +1,51 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+
+namespace App\Twig\Sandbox;
+
+use App\Services\LabelSystem\LabelTextReplacer;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFilter;
+use Twig\TwigFunction;
+
+class SandboxedLabelExtension extends AbstractExtension
+{
+    public function __construct(private readonly LabelTextReplacer $labelTextReplacer)
+    {
+
+    }
+
+    public function getFunctions()
+    {
+        return [
+            new TwigFunction('placeholder', fn(string $text, object $label_target) => $this->labelTextReplacer->handlePlaceholderOrReturnNull($text, $label_target)),
+        ];
+    }
+
+    public function getFilters(): array
+    {
+        return [
+            new TwigFilter('placeholders', fn(string $text, object $label_target) => $this->labelTextReplacer->replace($text, $label_target)),
+        ];
+    }
+}