public static List <PropertyInfo> GetOrderBysFromQueryable <T>(IQueryable <T> queryable)
{
var vistor = new OrderByCollectionVisitor();
vistor.Visit(queryable.Expression);
return(vistor.OrderedProperties);
}
public IQueryable <T> ApplyOrder(IQueryable <T> items, GridSortDirection direction)
{
var existingOrders = OrderByCollectionVisitor.GetOrderBysFromQueryable(items);
var orderToApply = OrderByCollectionVisitor.GetOrderByFromExpression(_expression);
if (existingOrders.Any(prop => prop == orderToApply))
{
// order was already applied, so skip applying it
return(items);
}
switch (direction)
{
case GridSortDirection.Ascending:
return(items.OrderBy(_expression));
case GridSortDirection.Descending:
return(items.OrderByDescending(_expression));
default:
throw new ArgumentOutOfRangeException("direction");
}
}
