Question

I use ScriptServices to return IPaged<> result:

[WebService]
public IPaged<int> DoSomething() {
    ....
    ....
}

IPaged<> is:

public interface IPaged<T> : IEnumerable where T : class
{
    int PageNumber { get; }
    int PageSize { get; }
    IEnumerable<T> Items { get; }
    int PagesCount { get; }
    int TotalItemsCount { get; }
}

The Paged<> class that returned from DoSomething implements IPaged<> and therefore implements the IEnumerator GetEnumerator():

  public IEnumerator GetEnumerator()
    {
        return ((IEnumerable)Items).GetEnumerator();
    }

Whenever I call DoSomething from Javascript ajax, the script service engine returns IEnumerable instance and not IPaged so I get an array (the Items member from GetEnumerator() method).

How can I return IPaged<> and not IEnumerable<> from the script service?

Answer 1

A bit of a guess, but it is very common for IEnumerable[<T>] (and also sometimes IList[<T>] to take priority over anything else, and jump into the “colllection of” branch (ignoring any properties defined on the “container”).

As such, I expect your best bet is to not have IPaged<T> implement IEnumerable<T>.
This may mean having to change a few places to add .Items.

Another approach would to add a ForJson() extension method that returns something similar to IPaged<T>, but without implementing IEnumerable[<T>].