Sortable properties¶

What this does¶

Sortable = true on [Map] opts the property into the sort array of an incoming FilterRequest. The generator emits a typed OrderBy / ThenBy chain dispatch for that property. DefaultSortDirection = SortDir.Desc flips the default direction for SortItem entries that omit Direction.

When to use¶

Any property your UI exposes as a sortable column. The sort field of a request is an ordered array, so a multi-key sort like "by department, then by created-at descending" requires marking each contributing column sortable.

Minimal code¶

[GenerateFilter<User>]
public partial class UserFilter
{
    [Map(nameof(User.Id), Sortable = true)]
    private static partial void MapId();

    // DefaultSortDirection.Desc — a SortItem with no Direction lands newest-first.
    [Map(nameof(User.CreatedAt), Sortable = true, DefaultSortDirection = SortDir.Desc)]
    private static partial void MapCreatedAt();

    [Map(nameof(User.Age), Sortable = true, DefaultSortDirection = SortDir.Desc)]
    private static partial void MapAge();
}

A consumer requesting { "sort": [{ "field": "createdAt" }, { "field": "id", "direction": "asc" }] } gets OrderByDescending(u => u.CreatedAt).ThenBy(u => u.Id).

Variations¶

Multiple sortable properties — every [Map] with Sortable = true becomes a tie-breaker option in the sort array.
Explicit per-SortItem direction — { "field": "age", "direction": "asc" } overrides the property's DefaultSortDirection.
Combine with Alias = "..." — the sort[].field matches the alias, not the underlying property name.

Pitfalls¶

Only one [Map] per property is allowed to set Sortable = true. Repeating it on multiple methods triggers FN0002.
Properties with sortable-looking CLR types (numbers, dates) that are not marked Sortable = true raise FN1002 as a friendly nudge.