How to handle Ajax JQUERY POST request with WCF self-host

Ok, now there are some real MSDN gurus out there who have written solutions, but I cannot figure them out: http://blogs.msdn.com/b/carlosfigueira/archive/2012/05/15/implementing-cors-support-in-wcf.aspx

But I have come up with a simple solution. At least in WCF 4.5 you can add your own OperationContract for dealing with OPTIONS requests:

    [OperationContract]
    [WebInvoke(Method = "OPTIONS", UriTemplate = "*")]
    void GetOptions();

Note that the method signature is void, and has no arguments. This will get called first, and then the POST message will be called.

The implementation of GetOptions is:

    public partial class CatalogService : ICatalogService
{
    public void GetOptions()
    {
        mon.IsActive = true;
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-Allow-Origin", "*");
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS");
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-Allow-Headers", "Content-Type");
    }
}

and that is really all you have to do.

You might also want to add this attribute to your service class, so that you can serialize large JSON:

//This defines the base behavior of the CatalogService. All other files are partial classes that extend the service
[ServiceBehavior(MaxItemsInObjectGraph = 2147483647)]       // Allows serialization of very large json structures
public partial class CatalogService : ICatalogService
{
    PgSqlMonitor mon = new PgSqlMonitor();

    private void BypassCrossDomain()
    {
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-Allow-Origin", "*");
    }
}

Note I have a little helper method called BypassCrossDomain() which I call on all my POST and GET methods, so that I can deal with cross domain calls.

I spent a lot of research time here (in MSDN forums, stack overflow, blogs) and I hope this will help others trying to do these sorts of projects.