public ResultListFilter(PageCriteria paging, SortCriteria sorting)
{
Guard.Begin().IsNotNull(paging, nameof(paging)).IsNotNull(sorting, nameof(sorting)).Check();
Paging = paging;
Sorting = sorting;
}
public static IQueryable <T> PagedAndSorted <T>(this IQueryable <T> query, PageCriteria paging, SortCriteria sort, out int total)
{
return(query.OrderBy(sort).Paged(paging, out total));
}
public static IQueryable <T> PagedAndSorted <T>(this IQueryable <T> query, PageCriteria paging, SortCriteria sort)
{
//simply sort and page
return(query.OrderBy(sort).Paged(paging));
}
public static IOrderedEnumerable <T> OrderBy <T>(this IEnumerable <T> source, SortCriteria sort)
{
if (sort == null)
{
return(source.OrderBy(x => x));
}
// Reference - http://stackoverflow.com/a/233505
string[] props = sort.SortBy.Split('.');
Type type = typeof(T);
ParameterExpression arg = Expression.Parameter(type, "p");
Expression expr = arg;
foreach (string prop in props)
{
// use reflection (not ComponentModel) to mirror LINQ
PropertyInfo pi = type.GetProperty(prop);
if (pi == null)
{
throw new InvalidOperationException($"Property not found on OrderBy attempt. IEnumerable Item Type: {typeof(T).FullName} | Property Type: {type.FullName} | Property Name: '{prop}' | Full Property Reference: '{sort.SortBy}'.");
}
expr = Expression.Property(expr, pi);
type = pi.PropertyType;
}
Type delegateType = typeof(Func <,>).MakeGenericType(typeof(T), type);
LambdaExpression lambda = Expression.Lambda(delegateType, expr, arg);
object result = typeof(Enumerable).GetMethods().Single(
method => method.Name == sort.QuerySortOperation &&
method.IsGenericMethodDefinition &&
method.GetGenericArguments().Length == 2 &&
method.GetParameters().Length == 2)
.MakeGenericMethod(typeof(T), type)
.Invoke(null, new object[] { source, lambda });
return((IOrderedEnumerable <T>)result);
}
