DI registration¶
The generated AddFiltering extension¶
The generator emits an assembly-wide services.AddFiltering() extension method that registers every [GenerateFilter<T>] class in the assembly as a singleton IFilterDefinition<T>. You call it once, and every filter class becomes injectable by interface:
builder.Services.AddDbContext<AppDbContext>(o => o.UseNpgsql(connectionString));
builder.Services.AddFiltering(); // emitted by the generator
After this, controllers and handlers resolve IFilterDefinition<User> (or any other entity type) via constructor or [FromServices] injection. The generator only emits AddFiltering() when Microsoft.Extensions.DependencyInjection.Abstractions is referenced in the project.
If your project declares no [GenerateFilter<T>] partials, the extension is not emitted — there is nothing to register. The first declaration causes it to appear; subsequent declarations are folded into the same emission.
Trim/AOT-clean variant¶
For trim or native-AOT scenarios where reflection-based JSON polymorphism is unavailable, the generator also emits an overload that accepts an IJsonTypeInfoResolver:
SampleJsonContext is a [JsonSerializable]-annotated JsonSerializerContext declared by the consumer that lists every typed FilterLeaf value type in use. The sample app under samples/UserManagement.WebApi/ includes a working SampleJsonContext.Default you can copy from.
The resolver is plumbed through to the polymorphic FilterNodeJsonConverter so leaf values deserialize without reflection.
See the AOT-clean setup guide for the full pattern.
Warning
Without the resolver overload in AOT builds, polymorphic FilterLeaf deserialization will fail at runtime when the trimmer removes the reflection metadata. Always pass an explicit JsonSerializerContext for trim / AOT builds.