static IOrderedQueryable <T> OrderByRulesRecursivly <T>(IOrderedQueryable <T> dataCollection, List <OrderRule> rules)
{
if (!rules.Any())
{
return(dataCollection);
}
// apply first rule
OrderRule rule = rules.First();
MethodInfo orderOperator = rule.Descending ? ThenByDescendingMethodInfo : ThenByMethodInfo;
IOrderedQueryable <T> orderedDataCollection = OrderByFieldOrPropertyName(dataCollection, orderOperator, rule.FieldOrPropertyName);
// apply next rules recursivly
return(OrderByRulesRecursivly(orderedDataCollection, rules.Skip(1).ToList()));
}
/// <summary>
/// Order <paramref name="dataCollection"/> according to <paramref name="rules"/> sequence
/// </summary>
/// <typeparam name="T">Collection item type</typeparam>
/// <param name="dataCollection">Queryable collection</param>
/// <param name="rules">Order rules to apply</param>
/// <returns>Ordered queryable collection</returns>
public static IOrderedQueryable <T> OrderByRules <T>(this IQueryable <T> dataCollection, IEnumerable <OrderRule> rules)
{
if (!rules.Any())
{
throw new ArgumentException("Rules list is empty", "rules");
}
// apply first rule (special case: use OrderBy operator and not ThenBy)
OrderRule rule = rules.First();
MethodInfo orderOperator = rule.Descending ? OrderByDescendingMethodInfo : OrderByMethodInfo;
IOrderedQueryable <T> orderedDataCollection = OrderByFieldOrPropertyName(dataCollection, orderOperator, rule.FieldOrPropertyName);
// apply next rules recursivly
return(OrderByRulesRecursivly(orderedDataCollection, rules.Skip(1).ToList()));
}