ServiceStack: use attribute in DTO to set response header and response body

Question

I'm using servicestack with an AngularJS Resource module. The problem is that when I call the query() method of my service to request a paginated list, I want to send a custom response header with the total number of rows.

I would like the http response to look like this:

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Server: Microsoft-IIS/8.0
X-Total-Rows: 14
X-Powered-By: ServiceStack/3,958 Win32NT/.NET
Content-Length: 831

[{"id":11,"content":"Item 10","dueDate":"2013-10-17T00:00:00.0000000","priority":9},
{"id":13,"content":"Item 12","dueDate":"2013-06-16T00:00:00.0000000","priority":9},
{"id":20,"content":"Item 19","dueDate":"2013-04-06T00:00:00.0000000","priority":9},
{"id":32,"content":"Item 31","dueDate":"2013-01-21T00:00:00.0000000","priority":9},
{"id":42,"content":"Item 41","dueDate":"2013-05-16T00:00:00.0000000","priority":9},
{"id":19,"content":"Item 18","dueDate":"2013-07-14T00:00:00.0000000","priority":8},
{"id":15,"content":"Item 14","dueDate":"2013-03-06T00:00:00.0000000","priority":7},
{"id":12,"content":"Item 11","dueDate":"2013-02-23T00:00:00.0000000","priority":4},
{"id":18,"content":"Item 17","dueDate":"2013-10-21T00:00:00.0000000","priority":3},
{"id":14,"content":"Item 13","dueDate":"2013-01-11T00:00:00.0000000","priority":2}]

For the moment, to do that, I use the following DTOs:

[Route("/todos", Verbs = "GET")]
public class Todos : IReturn<List<Todo>> 
{
    [DataMember(Name = "q")] public string Query { get; set; }
    [DataMember(Name = "sort")] public string Sort { get; set; }
    [DataMember(Name = "desc")] public bool IsDesc { get; set; }
    [DataMember(Name = "limit")] public int? Limit { get; set; }
    [DataMember(Name = "offset")] public int Offset { get; set; }
}

[Route("/todos", Verbs = "POST")]
[Route("/todos/{Id}", Verbs = "GET,PUT,DELETE")]
public class Todo : IReturn<Todo>
{
    public int Id { get; set; }
    public string Content { get; set; }
    public DateTime? DueDate { get; set; }
    public int? Priority { get; set; }
}

And in the service:

public object Get(Todos request)
{
    long count;
    var items = _repository.GetAll(request.Query, request.Sort, request.IsDesc, request.Limit, request.Offset, out count);
    Response.AddHeader("X-Total-Rows", count.ToString(CultureInfo.InvariantCulture));
    return items.Select(Mapper.Map<TodoItem, Todo>).ToList();
}

What I'd like to do in servicestack, is to use custom attributes in a ResponseDTO to indicate that I want some properties to be serialized in the response headers and other properties serialized in the response body. The response DTO might look like this:

public class TodosResponse
{
    [Header(Name = "X-Total-Rows")] public int TotalRows { get; set; }
    [Body] public List<Todo> Todos { get; set; }
}

The service would create the response like that:

public object Get(Todos request)
{
    long count;
    var items = _repository.GetAll(request.Query, request.Sort, request.IsDesc, request.Limit, request.Offset, out count);
    return new TodosResponse
           {
               TotalRows = count,
               Todos = items.Select(Mapper.Map<TodoItem, Todo>).ToList()
           };
}

And of course, the HTTP response would look like exactly the same as above.

So my question is: Is it possible to achieve this with custom attributes ?

Dve Dve · Accepted Answer · 2013-09-03T08:44:08

A simpler/tidier way to achieve what you want would be to return a HttpResult and define the headers within.

public object Get(Todos request)
{
    long count;
    var items = _repository.GetAll(request.Query, request.Sort, request.IsDesc, request.Limit, request.Offset, out count);
    var response = items.Select(Mapper.Map<TodoItem, Todo>).ToList();

    return new HttpResult(response, HttpStatusCode.OK)
            {
                Headers =
                        {
                            {"X-Total-Rows", count}
                        }
            };
}

This avoids polluting your response object with metadata

ServiceStack: use attribute in DTO to set response header and response body

1 Answers