Add helper class with service URIs as constants

src/main/php/JsonSerializer.php

@@ -191,19 +191,19 @@ class JsonSerializer implements Visitor
         $data = array();
         $serviceId = $availability->getService();
         switch ((string)$serviceId) {
-        case 'http://purl.org/ontology/dso#Presentation':
+        case Service::PRESENTATION:
             $data['service'] = 'presentation';
             break;
-        case 'http://purl.org/ontology/dso#Loan':
+        case Service::LOAN:
             $data['service'] = 'loan';
             break;
-        case 'http://purl.org/ontology/dso#Interloan':
+        case Service::INTERLOAN:
             $data['service'] = 'interloan';
             break;
-        case 'http://purl.org/ontology/dso#Remote':
+        case Service::REMOTE:
             $data['service'] = 'remote';
             break;
-        case 'http://purl.org/ontology/dso#Openaccess':
+        case Service::OPENACCESS:
             $data['service'] = 'openaccess';
             break;
         default:

src/main/php/Service.php

+<?php
+
+/*
+ * This file is part of DAIA Model.
+ *
+ * DAIA Model is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * DAIA Model 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 General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with DAIA Model. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <david.maus@sub.uni-hamburg.de>
+ * @copyright (c) 2023 by Staats- und Universitätsbibliothek Hamburg
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+declare(strict_types=1);
+
+namespace SUBHH\DAIA\Model;
+
+final class Service
+{
+    const PRESENTATION = "http://purl.org/ontology/dso#Presentation";
+    const OPENACCESS = "http://purl.org/ontology/dso#Openaccess";
+    const INTERLOAN = "http://purl.org/ontology/dso#Interloan";
+    const REMOTE = "http://purl.org/ontology/dso#Remote";
+    const LOAN = "http://purl.org/ontology/dso#Loan";
+
+    private function __construct ()
+    {}
+}