Simple OData Client - create OrderBy expression at runtime?

Simple OData queries are straightforward if everything is known at compile time. I have learned how to build expressions at runtime for purposes of filtering, but I have not quite figured out how to build an OrderBy expression at runtime?

Example mockup of a query (dynamic filter expression):

var empls = await client.For<MyModel>("MyTable")
                    .Top(request.PageSize)
                    .Skip((request.Page - 1) * request.PageSize)
                    .Filter(filter)
                    .FindEntriesAsync();

If I knew at compile time what order was needed I could add a .OrderBy() clause. But since the user decides the sorting at runtime, I need to build an expression for ordering.

To dynamically build the filter passed above I used ODataExpression<> object. I'm looking for equivalent capability to pass to an order clause (if that exists?).

Solution

I noticed another OrderBy() overload of the Fluent client interface:

OrderBy(IEnumerable<KeyValuePair<string, bool>> columns);

If you need dynamic multi-level ordering, you can create a List<KeyValuePair<string, bool>> and populate it with KeyValuePair<string, bool> objects where the string is the field specification and the bool is false for ASCENDING and true for DESCENDING sorts.

Just be sure that your string uses the forward slash "/" as the field path separator rather than the period.

Sorting hierarchy will be in the order that you added the KeyValuePairs to the list. So if you want to sort by:

Person.LastName ASC
Person.FirstName ASC
Person.EmployerName DESC

you just add the objects to the list in the above order, as you would expect passing false, false, true for the booleans.