Proper way to return JSON list in Web API with MVC and partial model - json

Question

I am trying to use Web API to grab certain fields from my MVC controller. I can't seem to match the right type with the right list. I am fine with converting everything to string.
I either get an error in code (can not convert types), or if I get it to compile, I get this error:
"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'."
From other similar posts, people responded with how to create a list, but not with the declaration of the return value of the Get. Please include both.
Also I would prefer not to add additional controllers as I need to do this on a number of my models.
Here is my code--note you can see I tried a number of different ways:
public class APICLIENTsController : ApiController
{
private ApplicationDbContext db = new ApplicationDbContext();
// GET api/<controller>
public IEnumerable<string> Get()
//public IEnumerable<CLIENT> Get()
{
//return db.CLIENTs.OrderBy(x => x.CLIENTNAME).ToList();
string[] listOfUsers = db.CLIENTs.OrderBy(x => x.CLIENTNAME).Select(r => new
{
ID = r.CLIENTID.ToString(),
NAME = r.CLIENTNAME
});
return listOfUsers.ToList();
//return db.CLIENTs.Select(x => new { x.CLIENTNAME }).ToArray();
}

Answer 1

If you want to return JSON use the
JsonResult
type.
public JsonResult Get()
{
//return db.CLIENTs.OrderBy(x => x.CLIENTNAME).ToList();
string[] listOfUsers = db.CLIENTs.OrderBy(x => x.CLIENTNAME).Select(r => new
{
ID = r.CLIENTID.ToString(),
NAME = r.CLIENTNAME
});
return Json(listOfUsers.ToList(), JsonRequestBehavior.AllowGet);
}

Answer 2

Your query is returning a collection of anonymous objects, not string[] so it will throw an exception. Even if you were to generate string[] by concatenating the CLIENTID and CLIENTNAME properties, it would be a little use to the client.
Create a model to represent what you need to return to the view
public class ClientVM
{
public int ID { get; set; }
public string Name { get; set; }
}
and modify your method to
public IEnumerable<ClientVM> Get()
{
IEnumerable<ClientVM> model = db.CLIENTs.OrderBy(x => x.CLIENTNAME).Select(r => new ClientVM
{
ID = r.CLIENTID,
Name = r.CLIENTNAME
});
return model;
}
Side note: depending on how your calling and consuming this in the client, you may need to change the Content-Type to specifically return json (refer these answers for more detail)