Question

MVC newbie here:

I’ve more or less worked out the page navigation aspect of MVC. But let’s say I don’t want to navigate to a View, but rather I want to get a response out of the web site, e.g. by sending a request to http://mysite.com/Services/GetFoo/123 I want to make a database request to select a Foo object with ID 123 and return it serialized as XML.

How do you do that?

Answer 1

I would write a custom action result:

public class XmlResult : ActionResult
{
    private readonly object _data;
    public XmlResult(object data)
    {
        if (data == null)
        {
            throw new ArgumentNullException("data");
        }
        _data = data;
    }

    public override void ExecuteResult(ControllerContext context)
    {
        // You could use any XML serializer that fits your needs
        // In this example I use XmlSerializer
        var serializer = new XmlSerializer(_data.GetType());
        var response = context.HttpContext.Response;
        response.ContentType = "text/xml";
        serializer.Serialize(response.OutputStream, _data);
    }
}

and then in my controller:

public ActionResult GetFoo(int id)
{
    FooModel foo = _repository.GetFoo(id);
    return new XmlResult(foo);
}

And if this return new XmlResult(foo); feels ugly to your eyes, you could have an extension method:

public static class ControllersExtension
{
    public static ActionResult Xml(this ControllerBase controller, object data)
    {
        return new XmlResult(data);
    }
}

and then:

public ActionResult GetFoo(int id)
{
    FooModel foo = _repository.GetFoo(id);
    return this.Xml(foo);
}