Question

I’m completely lost on what could be causing this.

I have an ASP.Net MVC 4 RC application and I have a set of Web API controllers. I’m trying to return an object that contains a set of child objects in an IList. Whenever I request the object I get a 500 error back on the browser with no noticeable exception thrown in the debugger. I’ve tried putting an Application_Error handler in the global.asax and no error is caught there either.

It doesn’t matter whether the List is an actual database relation or just a hard coded list of strings, in either case the request fails. If i set the list to null the request succeeds.

If i remove the list the request succeeds and I get an XML (or JSON) representation of the object.

I’ve also tried this line –

GlobalConfiguration.Configuration.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;

To capture the actual exception and still get nothing back.

Here’s the current object

public class Authority : IEntity
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
    public virtual string Address1 { get; set; }
    public virtual string Address2 { get; set; }
    public virtual string City { get; set; }
    public virtual string County { get; set; }
    public virtual string State { get; set; }
    public virtual string ContactPostalCode { get; set; }

    //public virtual IList<PostalCode> PostalCodes { get; set; }
    public virtual IList<string> RandomTrash { get; set; }

    public VPA()
    {
        //PostalCodes = new List<PostalCode>();
        RandomTrash = new List<string> {"foo"};
    }
}

Note the commented out PostalCodes collection – that is a real many to many database relationship. I commented it out and replaced it with the dummy “RandomTrash” collection and the failure seems to be the same.

I have a feeling this is a serialization failure somehow but I can’t figure out how to avoid it. If it helps I’m using NHibernate as the ORM.

Has anyone seen this?

Answer 1

Answering my own question in case anyone runs into this again.

It ended up being Serialization following the grid in a loop. To fix i added 2 attributes to each looping reference in one of the models.

[IgnoreDataMember] For the XML Serializer
[JsonIgnore] For JSON.Net’s Serializer.

I added those the PostalCode class on the IList property.

There may be a better solution. The downside of this one is it makes my API one sided. I can request an Authority and get all of it’s postal codes, but i can’t request a postal code and get all of it’s Authorities.