Adding array title to Linq-to-SQL-to-JSON in Web API - asp.net

Question

I am using Linq to SQL in a Web API web service to retrieve data from a database and return a JSON file.
My question is actually pretty simple, but I have been through the forums and couldn't find an answer. Please find below the description of my issue, as well as my (simplified) sourcecode.
The objects I return have two levels of data. To make you understand, here is how my classes look like :
public class X
{
public int ID { get; set; }
public DateTime date { get; set; }
public virtual ICollection<Y> Ys
public virtual ApplicationUser User { get; set; }
}
public class Y
{
public int ID { get; set; }
public int XID { get; set; }
public decimal Price { get; set; }
public int Quantity { get; set; }
public virtual X x { get; set; }
}
You can see that for each X1 object, I can have several X2 objects nested.
To retrieve that, I use the following Linq to SQL in my WebAPI Controller :
public IHttpActionResult GetXsByUser(string userID)
{
var xs = (from x in db.Xs
where x.User.Id == userID
orderby x.date
select new
{
x_id = x.ID,
date = x.date,
Ys = (from y in db.Ys
where x.User.Id == userID && x1.ID == y.XID
select new
{
unit_price = y.Price,
quantity = y.Quantity
})
});
if (xs == null)
{
return NotFound();
}
return Ok(xs);
}
My web service works fine and returns the following JSON :
[
{
"$id": "1",
"x_id": 1,
"date": "2014-01-24T00:00:00",
"Ys": [
{
"$id": "2",
"unit_price": 2.47,
"quantity": 2
},
{
"$id": "3",
"unit_price": 1.25,
"quantity": 3
},
{
"$id": "4",
"unit_price": 1.99,
"quantity": 2
}
]
},
{
"$id": "5",
"x_id": 2,
"date": "2014-01-28T00:00:00",
"Ys": [
{
"$id": "6",
"unit_price": 6.22,
"quantity": 1
},
{
"$id": "7",
"unit_price": 1.2,
"quantity": 3
}
]
}
]
The problem is, to then deserialize this in my mobile app, I have to use classes as follows :
public class Y
{
public string _$id { get; set; }
public double unit_price { get; set; }
public int quantity { get; set; }
}
public class RootObject
{
public string _$id { get; set; }
public int x_id { get; set; }
public string date { get; set; }
public List<Y> Ys { get; set; }
}
But i would like to be able to use classes as follow :
public class Y
{
public string _$id { get; set; }
public double unit_price { get; set; }
public int quantity { get; set; }
}
public class OnlineX
{
public string _$id { get; set; }
public int x_id { get; set; }
public string date { get; set; }
public List<Y> Ys { get; set; }
}
public class RootObject
{
public List<OnlineX> OnlineXs { get; set; }
}
I have worked with a JSON editor and know that the solution to get this is to have the following JSON file instead of the previous one :
{
"OnlineXs": [
{
"$id": "1",
"x_id": 1,
"date": "2014-01-24T00:00:00",
"Ys": [
{
"$id": "2",
"unit_price": 2.47,
"quantity": 2
},
{
"$id": "3",
"unit_price": 1.25,
"quantity": 3
},
{
"$id": "4",
"unit_price": 1.99,
"quantity": 2
}
]
},
{
"$id": "5",
"x_id": 2,
"date": "2014-01-28T00:00:00",
"Ys": [
{
"$id": "6",
"unit_price": 6.22,
"quantity": 1
},
{
"$id": "7",
"unit_price": 1.2,
"quantity": 3
}
]
}
]
}
Notice that the only thing that changes is that I add a title to my array of Xs ("Online Xs"). That is why I said that my question is simple. But the thing is, I have no idea how to do that in Web API. Is it just a small change in my Linq to SQL request? Should i build a custom JSON serializer?
I hope that my question is clear enough, and if you want some more information, I'll be happy to provide them.
Thanks a lot in advance
EDIT :
Ok, I've found the solution, it was simple indeed. Here it is :
I had to replace :
return Ok(xs);
by
return Ok(new { OnlineXs = xs });

Answer 1

Just to rephrase your answer, when you return the IHttpActionResult, just assign the query result to a named property and return it like:
return Ok(new { OnlineXs = xs});