public override PagedResult <TKey, TAggregateRoot> FindAll(Expression <Func <TAggregateRoot, bool> > specification, SortSpecification <TKey, TAggregateRoot> sortSpecification, int pageNumber, int pageSize)
{
if (specification == null)
{
specification = _ => true;
}
if (sortSpecification?.Count == 0)
{
throw new ArgumentNullException(nameof(sortSpecification), "The sort specification has not been specified.");
}
if (pageNumber <= 0)
{
throw new ArgumentOutOfRangeException(nameof(pageNumber), "The page number should be greater than 0.");
}
if (pageSize <= 0)
{
throw new ArgumentOutOfRangeException(nameof(pageSize), "The page size should be greater than 0.");
}
var sorts = sortSpecification.Specifications.ToList();
if (sorts.Any(s => s.Item2 == SortOrder.Unspecified))
{
throw new InvalidOperationException("The SortOrder of the items in the sort specification should be either Ascending or Descending.");
}
var query = this.dbContext.Set <TAggregateRoot>().Where(specification);
var total = query.Count();
if (total == 0)
{
return(PagedResult <TKey, TAggregateRoot> .CreateDefault(pageNumber, pageSize));
}
var skip = (pageNumber - 1) * pageSize;
var take = pageSize;
IOrderedQueryable <TAggregateRoot> orderedQuery = null;
foreach (var sort in sorts)
{
switch (sort.Item2)
{
case SortOrder.Ascending:
orderedQuery = orderedQuery == null?query.OrderBy(sort.Item1) : orderedQuery.OrderBy(sort.Item1);
break;
case SortOrder.Descending:
orderedQuery = orderedQuery == null?query.OrderByDescending(sort.Item1) : orderedQuery.OrderByDescending(sort.Item1);
break;
}
}
//var pagedQuery = orderedQuery.Skip(skip).Take(take).GroupBy(p => new { Total = total }).FirstOrDefault();
//return pagedQuery == null ? null :
// new PagedResult<TKey, TAggregateRoot>(pagedQuery.Select(_ => _), pageNumber, pageSize, pagedQuery.Key.Total, (pagedQuery.Key.Total + pageSize - 1) / pageSize);
var pagedQuery = orderedQuery.Skip(skip).Take(take);
return(pagedQuery == null ? null :
new PagedResult <TKey, TAggregateRoot>(pagedQuery, pageNumber, pageSize, total, (total + pageSize - 1) / pageSize));
}
