Added label placeholders to add a barcode version of the IPN to a label

This fixes issue #373

src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php

@@ -76,11 +76,11 @@ final class BarcodeContentGenerator
     {
         $type = $this->classToString(self::URL_MAP, $target);
 
-        return  $this->urlGenerator->generate('scan_qr', [
-    'type' => $type,
+        return $this->urlGenerator->generate('scan_qr', [
+            'type' => $type,
             'id' => $target->getID() ?? 0,
             '_locale' => null,
-], UrlGeneratorInterface::ABSOLUTE_URL);
+        ], UrlGeneratorInterface::ABSOLUTE_URL);
     }
 
     /**

src/Services/LabelSystem/Barcodes/BarcodeHelper.php

@@ -0,0 +1,96 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2023 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\Services\LabelSystem\Barcodes;
+
+use App\Entity\LabelSystem\BarcodeType;
+use Com\Tecnick\Barcode\Barcode;
+
+/**
+ * This function is used to generate barcodes of various types using arbitrary (text) content.
+ */
+class BarcodeHelper
+{
+
+    /**
+     * Generates a barcode with the given content and type and returns it as SVG string.
+     * @param  string  $content
+     * @param  BarcodeType  $type
+     * @return string
+     */
+    public function barcodeAsSVG(string $content, BarcodeType $type): string
+    {
+        $barcode = new Barcode();
+
+        $type_str = match ($type) {
+            BarcodeType::NONE => throw new \InvalidArgumentException('Barcode type must not be NONE! This would make no sense...'),
+            BarcodeType::QR => 'QRCODE',
+            BarcodeType::DATAMATRIX => 'DATAMATRIX',
+            BarcodeType::CODE39 => 'C39',
+            BarcodeType::CODE93 => 'C93',
+            BarcodeType::CODE128 => 'C128A',
+        };
+
+        return $barcode->getBarcodeObj($type_str, $content)->getSvgCode();
+    }
+
+    /**
+     * Generates a barcode with the given content and type and returns it as HTML image tag.
+     * @param  string  $content
+     * @param  BarcodeType  $type
+     * @param  string  $width Width of the image tag
+     * @param  string|null  $alt_text The alt text of the image tag. If null, the content is used.
+     * @return string
+     */
+    public function barcodeAsHTML(string $content, BarcodeType $type, string $width = '100%', ?string $alt_text = null): string
+    {
+        $svg = $this->barcodeAsSVG($content, $type);
+        $base64 = $this->dataUri($svg, 'image/svg+xml');
+        $alt_text = $alt_text ?? $content;
+        
+        return '<img src="'.$base64.'" width="'.$width.'" style="min-height: 25px;" alt="'.$alt_text.'"/>';
+    }
+
+    /**
+     * Creates a data URI (RFC 2397).
+     * Based on the Twig implementation from HTMLExtension
+     *
+     * Length validation is not performed on purpose, validation should
+     * be done before calling this filter.
+     *
+     * @return string The generated data URI
+     */
+    private function dataUri(string $data, string $mime): string
+    {
+        $repr = 'data:';
+
+        $repr .= $mime;
+        if (str_starts_with($mime, 'text/')) {
+            $repr .= ','.rawurlencode($data);
+        } else {
+            $repr .= ';base64,'.base64_encode($data);
+        }
+
+        return $repr;
+    }
+}