API - XML doesn't get correct format (WebAPI Controller)

Question

I'm struggling with my XML output.

I have a method that takes in a PersonalID and shall return address, as well as some additional information from it.

Execute a API request and put separate values in string variables

public string ReturnRegistered(String personalID)
{
                string apiurl = apiadress + personalID;
                WebRequest request = WebRequest.Create(apiurl);

                //TILLÄGG FÖR AUTHENTICATION
                request.PreAuthenticate = true;
                request.Credentials = new NetworkCredential(user, pass);
                //TILLÄGG FÖR AUTHENTICATION

                WebResponse respons = request.GetResponse();
                Stream dataStream = respons.GetResponseStream();

                //OBJEKT
                XmlSerializer serializer = new XmlSerializer(typeof(List<PrimaryContact>), new XmlRootAttribute("QueueSlot"));
                var input = (List<PrimaryContact>)serializer.Deserialize(dataStream);

             
                string firstname = input[0].firstname;
                string lastname = input[0].lastname;
                string postalAddress = input[0].postalAddress;
                string zipCode = input[0].zipCode;
                string address = input[0].address;   

     //FÖR ATT KUNNA TA FRAM ENDAST ETT ATTRIBUT BEHÖVER MAN GÖRA OM HELA WEBREQUESTEN OCH NERÅT
                WebRequest request2 = WebRequest.Create(apiurl);

                //TILLÄGG FÖR AUTHENTICATION
                request2.PreAuthenticate = true;
                request2.Credentials = new NetworkCredential(user, pass);
                //TILLÄGG FÖR AUTHENTICATION

                WebResponse respons2 = request2.GetResponse();
                Stream dataStream2 = respons2.GetResponseStream();

                //ENVÄRDE
                XmlDocument doc = new XmlDocument();
                doc.Load(dataStream2);
                XmlNodeList elemList2 = doc.GetElementsByTagName("lastPaymentDate");
                string lastPaymentDate = elemList2[0].InnerText;            


String returnvalue = "<Fields><Field><Name>lastPaymentDate</Name><Value>" + lastPaymentDate + "</Value></Field><Field><Name>Firstname</Name><Value>"+ firstname + "</Value></Field><Field><Name>Lastname</Name><Value>"+ lastname + "</Value></Field><Field><Name>Adress</Name><Value>"+ address + "</Value></Field><Field><Name>ZipCode</Name><Value>"+ zipCode + "</Value></Field><Field><Name>PostalAdress</Name><Value>"+ postalAddress + "</Value></Field></Fields>";
*//I have tryed start with <?xml version="1.0" encoding="UTF-8"?> but no different.*

return returnvalue;
}

Then my API uses that method and shall return a XmlElement. "I have read on this site that I don't need to specify which element is Root and child and so on when using LoadXml"

Controller:

public XmlElement Get(string id)
        {
            Models.TomtkoRegistered tomtko = new Models.TomtkoRegistered();
            String returnvalue = tomtko.ReturnRegistered(id);     
                XmlDocument doc = new XmlDocument();
                doc.LoadXml(returnvalue);
                XmlElement root = doc.DocumentElement;
            return root;
        }

If I print it to file I get it to work, but I don't know how to make the XML in the correct format for a webAPI so the format is usable by the receiver of my webAPI.

But when I use the API in Firefox or Chrome

It "looks" fine but when I look at the page source and try to use it, or add it to Notepad++ then everything is just on one line and not formatted or structured.

What is wrong??

Can I force the Content-Type to be "text/xml" in some way? Did I use the wrong return type? Is it missing some other code?

When a friend used it in Postman some action value was default set to anyvalue (*) in some way not 100% what it was but when he put it in XML it works. But how to I make the receiver understand from the beginning that it shall be XML if XmlElement doesn't do the trick?

Answer 1

Im not sure why you are creating your XML that way. Typically i create an object and then just return it, you can set that in your configure services it might be worth checking you have an xml formatter added if you want to do that. Or you could use a ContentResult to just send the string as xml see Return "application/xml" instead of "text/plain" ASP.NET Core Web API. Im also not sure I understand the question so apologies if this answer does not help. Im not sure what the problem you are getting when you 'try to use it' is so i dont know if this will help but if you just want it to look good in notepad++ you could just format it before it comes out. This isnt very efficent because you are taking a string that is already usable xml to turn xml and then back into xml String but it would make it look good(this is me assuming the question is how do you format xml). Feel free to use spaces instead of tab if thats your preference. Note: I would not recommend doing this if your xml is gigantic.

XmlDocument doc = new XmlDocument();
doc.LoadXml(xml);//put your xml string here
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.IndentChars = "\t";//set your inten
using (var stringWriter = new StringWriter())
using (var xmlTextWriter = XmlWriter.Create(stringWriter, settings))
{
    doc.WriteTo(xmlTextWriter);
    xmlTextWriter.Flush();
    returnvalue = stringWriter.GetStringBuilder().ToString();
}

Answer 2

It seems that the system you are designing has many opportunities for improvement. Any code that processes XML ought to be able to handle what you are producing but after reading the question and the comments I think that the following changes may get you what you need.

[Produces("application/xml")]
public XmlElement Get(string id)
{
   Models.TomtkoRegistered tomtko = new Models.TomtkoRegistered();
   String returnvalue = tomtko.ReturnRegistered(id);
   var returnXml = XElement.Parse(returnValue);
   return returnXml.ToString();  
}

This should work because the Produces attribute will tell the api consumer what type of data to expect through the Content-Type in the response header.

The XElement.ToString prints a formatted string. If you need more control over the formatting you can look into other options.

Answer 3

The problem was that it souldent be a XmlElement the type should be a HttpResponseMessage insted and in the <> tags it sould have

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

public HttpResponseMessage Authenticate()
{
  //process the request 
  .........

  string XML="<note><body>Message content</body></note>";
  return new HttpResponseMessage() 
  { 
    Content = new StringContent(XML, Encoding.UTF8, "application/xml") 
  };
}

WebAPI to Return XML

Answer 4

If the problem is really about indenting that XML you construct then you could use an XmlWriter with the proper XmlWriterSettings and later on load the constructed string with PreserveWhitespace on the XmlDocument set to true e.g.

       string returnValue;

        using (StringWriter sw = new StringWriter())
        {
            using (XmlWriter xw = XmlWriter.Create(sw, new XmlWriterSettings() { Indent = true }))
            {
                xw.WriteStartElement("Fields");

                xw.WriteStartElement("Field");
                xw.WriteElementString("Name", "lastPaymentDate");
                xw.WriteElementString("Value", lastPaymentDate);
                xw.WriteEndElement();

                xw.WriteStartElement("Field");
                xw.WriteElementString("Name", "FirstName");
                xw.WriteElementString("Value", firstName);
                xw.WriteEndElement();

                xw.WriteStartElement("Field");
                xw.WriteElementString("Name", "LastName");
                xw.WriteElementString("Value", lastName);
                xw.WriteEndElement();

                xw.WriteStartElement("Field");
                xw.WriteElementString("Name", "Adress");
                xw.WriteElementString("Value", address);
                xw.WriteEndElement();

                xw.WriteStartElement("Field");
                xw.WriteElementString("Name", "ZipCode");
                xw.WriteElementString("Value", zipCode);
                xw.WriteEndElement();

                xw.WriteStartElement("Field");
                xw.WriteElementString("Name", "Adress");
                xw.WriteElementString("Value", postalAddress);
                xw.WriteEndElement();

                xw.WriteEndElement();
            }

            returnValue = sw.ToString();
        }

plus

        XmlDocument doc = new XmlDocument();
        doc.PreserveWhitespace = true;
        doc.LoadXml(returnValue);

        XmlElement root = doc.DocumentElement;

Answer 5

Have you tried this? https://community.postman.com/t/sending-a-request-with-xml-data/8053

const options = {
 'method': 'POST',
 'url': 'httpbin.org/post',
 'header': {
   'Content-Type': 'application/xml'
 },
 body: xmlBody

It sounds like you are trying to define the MIME type? am I correct?