private IQueryable <TModel> FormFetchQuery <TModel>(FetchParameters <TModel> fetchParameters) where TModel : class
{
Check.NotNull(fetchParameters, "fetchParameters");
// !IMPORTANT! Call order DOES matter!
// 1 Build Query
var queriedItems = Query(fetchParameters);
if (fetchParameters.NoTracking)
{
queriedItems = queriedItems.AsNoTracking();
}
// 2 Sorting
if (fetchParameters.HasSorting())
{
queriedItems = fetchParameters.PerformSorting(queriedItems);
}
else
{
// HACK: https://stackoverflow.com/a/14524571/3469518
// this hack required for paging
queriedItems = queriedItems.OrderBy(x => 0);
}
// 3 Filtering
return(fetchParameters.PerformFiltering(queriedItems));
}
internal static IQueryable <TModel> PerformSorting <TModel>(this FetchParameters <TModel> target, IQueryable <TModel> queriedItems) where TModel : class
{
if (target.HasSorting())
{
var rules = target.SortingRules.Where(x => x != null);
if (!rules.Any())
{
return(queriedItems); // sanity check
}
foreach (var sortingRule in rules)
{
queriedItems = queriedItems.OrderBy(sortingRule);
}
}
return(queriedItems);
}