* Ability to provide custom dtd to serializer

Author: mathielen

src/CXml/Serializer.php

@@ -30,9 +30,11 @@
 {
     public const DOC_TYPE_VERSION = '1.2.063';
 
-    private function __construct(private SerializerInterface $jmsSerializer)
-    {
-    }
+    private function __construct(
+        private SerializerInterface $jmsSerializer,
+        private string $dtdUri = 'http://xml.cxml.org/schemas/cXML/' . self::DOC_TYPE_VERSION . '/cXML.dtd'
+    )
+    {}
 
     public static function create(): self
     {
@@ -71,11 +73,11 @@ public function deserialize(string $xml): CXml
         return $this->jmsSerializer->deserialize($xml, CXml::class, 'xml');
     }
 
-    public function serialize(CXml $cxml, string $docTypeVersion = self::DOC_TYPE_VERSION): string
+    public function serialize(CXml $cxml): string
     {
         $xml = $this->jmsSerializer->serialize($cxml, 'xml');
 
-        $docType = '<!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/' . $docTypeVersion . '/cXML.dtd">';
+        $docType = '<!DOCTYPE cXML SYSTEM "'.$this->dtdUri.'">'."\n";
         $xmlPrefix = '<?xml version="1.0" encoding="UTF-8"?>';
 
         // add doctype, as it is mandatory in cXML