How to force ASP.NET Web API to return JSON or XML data based on my input?

Question

I try to get the output XML or JSON data based on my input. I used the below WEB API code but not able to exact output.

public string Get(int id)
{
    if (G         


        

Answer 1

QueryStringMapping` is nice solution but I need a default value for type.

for xml : localhost:49533/api/?type=xml

for json: localhost:49533/api/

I solve that situation like that:

GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
var jSettings = new JsonSerializerSettings();

GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings = jSettings;
GlobalConfiguration.Configuration.Formatters.XmlFormatter.MediaTypeMappings.Add(new QueryStringMapping("xml", "true", new MediaTypeHeaderValue("application/xml")));

Answer 2

Looked into this a bit more, and found your answer in another post:

public HttpResponseMessage Get(int id)
{
    string content = "value";

    if (id == 1)
    {
        return Request.CreateResponse<string>(HttpStatusCode.OK, content, Configuration.Formatters.JsonFormatter);
    }

    return Request.CreateResponse<string>(HttpStatusCode.OK, content, Configuration.Formatters.XmlFormatter);
}

Answer 3

Add the below code app_start event in global.asax file. In API Url add the query string:

GlobalConfiguration.Configuration.Formatters.JsonFormatter.MediaTypeMappings.Add(
    new QueryStringMapping("type", "json", new MediaTypeHeaderValue("application/json")));

GlobalConfiguration.Configuration.Formatters.XmlFormatter.MediaTypeMappings.Add(
    new QueryStringMapping("type", "xml", new MediaTypeHeaderValue("application/xml")));

e.g.:

for xml : http://localhost:49533/api/?type=xml

for json: http://localhost:49533/api/?type=json

Answer 4

It also works to force the accept headers. Great option if you aren't always returning HttpResponseMessage's. I.e

Request.Headers.Add("Accept", "text/json");
return Request.CreateResponse(HttpStatusCode.OK, yourobject);

or

Request.Headers.Add("Accept", "application/xml");
return new Rss20FeedFormatter(feed);

Answer 5

If your request specifies the mime type, for example application/json, then web api will format the response appropriately.

If you are attempting to debug your web api manually, use a tool like Fiddler 2 to specify the type.

This article describes the concept.

Answer 6

What you are trying to do will not work in a multi-threaded environment. You cannot add to and remove from the formatters collection on a per-request basis. Here is a better way of accomplishing what you want.

public HttpResponseMessage Get(int id)
{
    Foo foo = new Foo();
    var content = new ObjectContent<Foo>(foo,
                    ((id == 1) ? Configuration.Formatters.XmlFormatter :
                                Configuration.Formatters.JsonFormatter));
    return new HttpResponseMessage()
    {
         Content = content
    };
}