Content not allowed in prolog - XML Document Post-CodePudding

I am trying to create an xml document to send via a POST request. However, I am getting this error on the server side :

[org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.]

I think it may be because I am missing

 <?xml version="1.0" encoding="UTF-8"?>

However I am unsure on the correct way to implement it. If anyone has any ideas that would great !

export function jsToXML(film, crudOp) {
  //Creating Document and elements

  var xmlDoc = document.implementation.createDocument(null, "film");
  const xmlVersion = '<?xml version="1.0"?>';

  var title = xmlDoc.createElement("title");
  var year = xmlDoc.createElement("year");
  var director = xmlDoc.createElement("director");
  var stars = xmlDoc.createElement("stars");
  var review = xmlDoc.createElement("review");

  //Edit & Delete CRUD Operations need ID
  if (crudOp === "edit" || crudOp === "delete") {
    var id = xmlDoc.createElement("id");
    id.append(film.id);
    xmlDoc.documentElement.appendChild(id);
  }

  //Assign form data to elements
  title.append(film.title);
  year.append(film.year);
  director.append(film.director);
  stars.append(film.stars);
  review.append(film.review);

  //Append the elements to the xml doc
  xmlDoc.documentElement.appendChild(title);
  xmlDoc.documentElement.appendChild(year);
  xmlDoc.documentElement.appendChild(director);
  xmlDoc.documentElement.appendChild(stars);
  xmlDoc.documentElement.appendChild(review);

  return xmlDoc;
}

CodePudding user response：

There's a very wide variety of possible causes: see org.xml.sax.SAXParseException: Content is not allowed in prolog for some of them. Omitting the XML declaration isn't one of those causes.

This is generally a message from the Java XML parser, so I'm not sure where your Javascript code (for constructing an XML tree) fits in.

CodePudding user response：

To fix this I added a serializer as .createElement(Item), creates a HTML Node.

  //Serialize xml dom
  var serializer = new XMLSerializer();
  var xmlString = serializer.serializeToString(xmlDoc);

  return xmlString;

This is what I added to solve the problem