Entity object fails when converting to JSON - json

Question

I have been trying to get an Entity Framework model to convert to JSON to display in a web page. The Entity object is created fine but something fails when it is returned. Below is the code from my ASP.NET Web API project. By setting a breakpoint I can see the object collection is created just fine.
public class ClientsController : ApiController
{
public IEnumerable<Client> GetAllClients()
{
using (var context = new MyClientModel.MyEntities())
{
var query = context.Clients.Where(c => c.State == "CA");
var customers = query.ToList();
return customers;
}
}
}
Here is the HTML/Javascript code I use to call the ASP.NET Web API
<script>
var uri = 'api/clients';
$(document).ready(function () {
// Send an AJAX request
$.getJSON(uri)
.done(function (data) {
// On success, 'data' contains a list of products.
alert('Made it!'); // ** Never reaches here **
$.each(data, function (key, item) {
// Add a list item for the product.
$('<li>', { text: item }).appendTo($('#clients'));
});
});
});
</script>
I use Fiddler to view the response and it returns a .NET error that says ...
The 'ObjectContent' type failed to serialize the response body for content type 'application/json; charset=utf-8'."
and the inner exception message is ...
Error getting value from 'Patients' on 'System.Data.Entity.DynamicProxies.Client
Patients is a related entity in my model but I am confused why it would be an issue as I am only returning Client objects.

Answer 1

I found a solution that works, though I admit I am not sure exactly how it works. I added the line context.Configuration.ProxyCreationEnabled = false; to my method that returns the object collection and all my objects were returned. I got the code from the following SO Question - WebApi with EF Code First generates error when having parent child relation.
public class ClientsController : ApiController
{
public IEnumerable<Client> GetAllClients()
{
using (var context = new MyClientModel.MyEntities())
{
context.Configuration.ProxyCreationEnabled = false; // ** New code here **
var query = context.Clients.Where(c => c.State == "CA");
var customers = query.ToList();
return customers;
}
}
}