How to serialize objects into XML C# webapi

Question

I have written a simple webAPI program which returns JSON by default when running , I want the values in XML format so I tried multiple answers from this stackoverflow post but all of them returns String for me

Model class:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace JsonToXML2.Models
{
    public class Employee
    {
        public int EmployeeId
        {
            get;
            set;
        }
        public string EmployeeName
        {
            get;
            set;
        }
        public string Address
        {
            get;
            set;
        }
        public string Department
        {
            get;
            set;
        }
    }
}

Controller Class :

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Web.Http;
using System.Xml;
using System.Xml.Serialization;

namespace JsonToXML2.Controllers
{
    public class EmployeeController : ApiController
    {
        IList<Employee> employees = new List<Employee>()
        {
            new Employee()
                {
                    EmployeeId = 1, EmployeeName = "Mukesh Kumar", Address = "New Delhi", Department = "IT"
                },
                new Employee()
                {
                    EmployeeId = 2, EmployeeName = "Banky Chamber", Address = "London", Department = "HR"
                },
                new Employee()
                {
                    EmployeeId = 3, EmployeeName = "Rahul Rathor", Address = "Laxmi Nagar", Department = "IT"
                },
                new Employee()
                {
                    EmployeeId = 4, EmployeeName = "YaduVeer Singh", Address = "Goa", Department = "Sales"
                },
                new Employee()
                {
                    EmployeeId = 5, EmployeeName = "Manish Sharma", Address = "New Delhi", Department = "HR"
                },
        };
        public IList<Employee> GetAllEmployees()
        {
            //Return list of all employees  
            return employees;
        }
        public String GetEmployeeDetails(int id)
        {
            //Return a single employee detail  
            var employee = employees.FirstOrDefault(e => e.EmployeeId == id);
            if (employee == null)
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
            }
            
           
            return (GenerateXmlResponse(employee));
        }
        // override StringWriter
        public class Utf8StringWriter : StringWriter
        {
            public override Encoding Encoding => Encoding.UTF8;
        }

        private string GenerateXmlResponse(Object obj)
        {
            Type t = obj.GetType();

            var xml = "";

            using (StringWriter sww = new Utf8StringWriter())
            {
                using (XmlWriter writer = XmlWriter.Create(sww))
                {
                    var ns = new XmlSerializerNamespaces();
                    // add empty namespace
                    ns.Add("", "");
                    XmlSerializer xsSubmit = new XmlSerializer(t);
                    xsSubmit.Serialize(writer, obj, ns);
                    xml = sww.ToString(); // Your XML
                }
            }
            return xml;
        }
    }
}

To access the app I am simply hitting the URL as https://localhost:44379/api/employee/1 in postman, the problem is data is in String format within double quotes, How can I get the data in pure XML format?

Postman recognizes the response as JSON

The easiest is just to return the employee, and then the client have to decide what they want using the httpheader ("text/xml"), else they get the default (JSON). But I am unsure if you have enough control over the client to force that so I'll just leave this as a comment — Thomas Koelle, Jun 29 '21 at 13:54
Hi @ThomasKoelle, I need to pass the data to a paymentGateway which accepts XML's only. — skr, Jun 29 '21 at 13:58
Then add "Accept: text/xml" header to the request and return the plain object. ASP.NET will automatically format the response according to the header. — phuzi, Jun 29 '21 at 14:00
@ThomasKoelle "Accept: text/xml" works but it misses the xml declaration. — skr, Jun 29 '21 at 14:07
@phuzi setting "Accept: text/xml" works but it misses the xml declaration. — skr, Jun 29 '21 at 14:09
Ironically I think custom XML seriliasation is the problem here. — phuzi, Jun 29 '21 at 14:17
I mean `GenerateXmlResponse`. I would think there would be a serialisation option to include the XML declaration. — phuzi, Jun 29 '21 at 14:52

score 1 · Accepted Answer · answered Jun 30 '21 at 09:46

As I Discussed above one of the solution was to ask clients to set request header "Accept: text/xml"

Since I couldn't force the client, what I can do at my end is to set my method return type as System.Net.Http.HttpResponseMessage and use the below code to return the XML.

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") 
  };
}

Response :

How to serialize objects into XML C# webapi

1 Answers1