How to do server-side sorting with Datatables.AspNet.Mvc5

Question

I'm attempting to do server-side processing of jQuery DataTables using ASP.NET MVC with Entity Framework. I came across Datatables.AspNet Nuget package, but I'm unclear how to use it to dynamically sort columns when clicked on table headers.

In an example on Datatables.AspNet GitHub, there is this:

public ActionResult PageData(IDataTablesRequest request)
{
    var data = Models.SampleEntity.GetSampleData(); 
    var filteredData = data.Where(_item => _item.Name.Contains(request.Search.Value));

    // Paging filtered data.
    var dataPage = filteredData.Skip(request.Start).Take(request.Length);

    var response = DataTablesResponse.Create(request, data.Count(), filteredData.Count(), dataPage);

    return new DataTablesJsonResult(response, JsonRequestBehavior.AllowGet);
}

But I'm unsure how to proceed to dynamically sort based on the contents of the IDataTablesRequest object, which looks like this:

public interface IDataTablesRequest
{
    int Draw { get; }
    int Start { get; }        
    int Length { get; }
    ISearch Search { get; }
    IEnumerable<IColumn> Columns { get; }
    IDictionary<string, object> AdditionalParameters { get; }
}

public interface ISort
{
    int Order { get; }
    SortDirection Direction { get; }
}

public enum SortDirection
{
    Ascending = 0,
    Descending = 1
}

Answer 1

take a look at this answer: https://github.com/ALMMa/datatables.aspnet/issues/26

for reference:

public static IQueryable<T> OrderBy<T>(this IQueryable<T> source, IEnumerable<DataTables.AspNet.Core.IColumn> sortModels)
        {
            var expression = source.Expression;
            int count = 0;
            foreach (var item in sortModels)
            {
                var parameter = Expression.Parameter(typeof(T), "x");
                var selector = Expression.PropertyOrField(parameter, item.Field);
                var method = item.Sort.Direction == DataTables.AspNet.Core.SortDirection.Descending ?
                    (count == 0 ? "OrderByDescending" : "ThenByDescending") :
                    (count == 0 ? "OrderBy" : "ThenBy");
                expression = Expression.Call(typeof(Queryable), method,
                    new Type[] { source.ElementType, selector.Type },
                    expression, Expression.Quote(Expression.Lambda(selector, parameter)));
                count++;
            }
            return count > 0 ? source.Provider.CreateQuery<T>(expression) : source;
        }

so you can do the following:

var orderColums = request.Columns.Where(x => x.Sort != null);
 var dataPage = data.OrderBy(orderColums).Skip(request.Start).Take(request.Length);