Knockout and MVC2: sending model to controller - asp.net-mvc-2

Question

I'm having problem with sending json from knockout to mvc2 controller action.
Here is what I have in my View:
var ViewModel = {
FirstName: ko.observable("FirstName"),
LastName: ko.observable("LastName"),
Save: function () {
ko.utils.postJson(location.href, this);
}
}
ko.applyBindings(ViewModel);
I have an action in controller:
public virtual ActionResult SomeAction(MyModel model) {
//do smth
return View(registrationModel);
}
public class MyModel {
public string FirstName {get;set;}
public string LastName {get;set;}
}
The problem is that i'm getting string values quoted, like "\"FirstName\"", and I know that there is some way to avoid that(work with JSON.stringify in MVC3).
I've tried the following:
ko.utils.postJson(location.href, JSON.stringify({model: this});
also
var json = JSON.stringify({
FirstName: this.FirstName(),
LastName: this.LastName()
});
ko.utils.postJson(location.href, JSON.stringify({model: json});
or
ko.utils.postJson(location.href, json);
In all these 3 options I get model = null, or all the values null in Controller.
Maybe someone has done this before?

Answer 1

I've found that in order for the MVC object mapping to work you need to set the content type of the POST to be "application/json; charset=utf-8". I've never done this using ko.utils.postJson() before but here's a working example using jQuery:
$.ajax({
url: url,
type: "POST",
data: ko.toJSON(ViewModel),
dataType: "json",
contentType: "application/json; charset=utf-8",
success: function (response) {
},
error: function (response, errorText) {
}
});
Note I'm using ko.toJSON to serialize the model as JSON.