DKNet

Apply named filters across matching entities

Part of DKNet.EfCore.Extensions. Use IGlobalModelBuilder for model-wide changes and GlobalQueryFilter for per-entity named query filters.

Use the console-project setup in the Quick Start, then replace Program.cs with this example.

using Microsoft.EntityFrameworkCore;
using DKNet.EfCore.Extensions.Configurations;

using var connection = new Microsoft.Data.Sqlite.SqliteConnection("Data Source=:memory:");
connection.Open();
var o = new DbContextOptionsBuilder<DemoDb>();
o.UseSqlite(connection).UseAutoConfigModel<DemoDb>();
await using var db = new DemoDb(o.Options);
await db.Database.EnsureCreatedAsync();
db.Items.AddRange(new Item { Name = "visible" }, new Item { Name = "hidden" });
await db.SaveChangesAsync();
Console.WriteLine(await db.Items.CountAsync()); // 1

public sealed class DemoDb(DbContextOptions<DemoDb> options) : DbContext(options)
{
    public DbSet<Item> Items => Set<Item>();
}
public sealed class Item
{
    public int Id { get; set; }
    public string Name { get; set; } = "";
}
public sealed class VisibleItems : GlobalQueryFilter
{
    public override string FilterKey => nameof(VisibleItems);
    protected override IEnumerable<Microsoft.EntityFrameworkCore.Metadata.IMutableEntityType>
        GetEntityTypes(ModelBuilder model) => model.Model.GetEntityTypes().Where(t => t.ClrType == typeof(Item));
    protected override System.Linq.Expressions.Expression<Func<T, bool>>? HasQueryFilter<T>(DbContext context)
        => x => EF.Property<string>(x, nameof(Item.Name)) != "hidden";
}

GlobalQueryFilter.Apply selects entity types, asks HasQueryFilter<TEntity> for each expression and installs only non-null results. Exceptions from that reflected call are unwrapped.

⚙️ Configuration reference

Setting	Type	Default	Effect
FilterKey	string	abstract	EF Core named filter key.
IsIgnorable	bool	true	Includes the key in static IgnorableFilterKeys for specification bypass.
AddGlobalModelBuilder<T>()	type registration	none	Merge an extra type with scanned types, distinct by type.

Use DataAuthorization for the existing ownership filter; it sets IsIgnorable = false.

⚠️ Gotchas & limits

• Both assembly-discovered and explicitly registered builders use Activator.CreateInstance; provide a usable parameterless constructor. AddGlobalModelBuilder<T>() does not resolve constructor dependencies from DI.
• Explicit builder types live in a process-wide append-only collection; they are not scoped to a service provider or DbContext.
• IsIgnorable governs DKNet specification bypass policy. Direct EF Core filter bypass APIs remain available; this is not a database security boundary.

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