JSON to MVC Api Controller via AJAX - asp.net-mvc

Question

So I'm trying to add a "like" function to some blog posts by POSTing some JSON through ajax to the MVC api controller.
Models:
public class Blog{
public int ID{get;set;}
public string Title{get;set;}
//Some more stuff
public virtual ICollection<Likes> Likes {get;set;}
}
public class Likes{
public int ID{get;set;}
public string UserName{get;set;}
//Some more stuff
public virtual Blog Blog{get;set;}
}
Controller:
public void Post(Likes like){
if(ModelState.IsValid){
db.Likes.Add(like)
db.SaveChanges();
}
}
The below return is passed into the JSON.stringify() in the ajax call:
var UserName = "Dave";
//More stuff
var Blog = "????";
return {UserName:UserName, More Stuff, Blog:Blog}
So that last line is my problem I think, what do I pass in for "Blog"? I have tried using the ID of the Blog but it's still null in the controller. It seems the controller wants a full Blog model instead of just the ID, is there a way around this or am I doing something bad?
TLDR I guess is: What to pass to a field that's a public virtual Blog Blog{get;set;} in the model when sending JSON to the controller?
P.S. My code works when I don't include the "Blog" as part of the JSON.

Answer 1

if you are posting a like then this would probably do the thing
{
ID : 789 //ID of the Like
UserName : "Username",
Blog : {
ID : 789 //id of the blog
}
}
This way you will have the id of the blog and would be mapped correctly.
But i would advise you make a separate view model of the following structure
public LikeAjax
{
public string UserName{get; set;}
public int BlogId {get; set;}
}
then send json like below
{
UserName : "User Name",
BlogId : 789
}