Minimal API Endpoint AutoRegistration

via Source code generators to speedup development process. Without an expensive Reflection scan at the application startup.

Usage

1. Add this nuget package
2. Rebuild solution to start the code generator.
3. Enable auto registration inside Program.cs

var registrations = app.UseEndpointAutoRegister();

This extension method returns an Registrations object that contains properties with all endpoints registrations as RouteHandlerBuilder to enable another configuration (see below).

registrations.ProductDetailEndpoint.Produces(200)

Endpoints

Create a class that implements following rules. You can skip an endpoint by using IgnoreEndpoint attribute.

Interface Handler-based endpoint

Implement one of exposed interfaces

• IApiEndpoint defaults to HTTP GET
• IApiGetEndpoint
• IApiPutEndpoint
• IApiPostEndpoint
• IApiDeleteEndpoint

All interfaces define a Handler method that handles HTTP request.

Additionally a class can implement IRoutePattern or IApiRouteEndpoint. Both add a Pattern property used for a route template.

Conventional Name Handler-based endpoints

The source code generator looks for a classes named with a suffix

• Endpoint defaults to HTTP GET
• GetEndpoint
• PostEndpoint
• PutEndpoint
• DeleteEndpoint

The class has to declare Handler method. The class could be even static with static method.

Register-based endpoint

It's the most powerful options how to declare an api endpoint. It could be either conventional or interface based:

• Implements IAutoRegisterApiEndpoint
• Name ends with one of these suffixes AutoRegisterApiEndpoint, ArApiEndpoint

The class has to declare Register method. It could be static as well.

Endpoint structure

An endpoint is a class declaring:

1. Handler-based endpoints
   1. Handler method (required) - handling HTTP requests
   2. Pattern property (optional) - a route template declaration
   3. Configure method (optional) - an additional configuration of created RouteHandlerBuilder
2. Register-based endpoints
   1. RouteHandlerBuilder Register(IEndpointRouteBuilder app) method (required) - should contain a complete endpoint declaration (Program.cs)

Conventions

Endpoint name

A classname without endpoint suffix.

DetailGetEndpoint => Detail

Applies to all endpoint types.

Route pattern

Ordered resolution:

1. Pattern property if not null
2. RouteAttribute applied on the Handler method
3. Endpoint name-based convetional
   1. Endpoint name (without the suffix) splited into words from the PascalCase
   2. Appended Handler's arguments with applied FromRouteAttribute in same order
   3. If the first argument of Handler method is of primitive type (or string) then is used it as default

Applies to the Handler-based endpoints.

Additional route configuration

If you want to configure a created RouteHandlerBuilder then declare Configure method.

You can use it to define an Action name or a 'Produces' info.

void Configure(RouteHandlerBuilder eb) => eb.WithName("Action1")

Applies to the Handler-based endpoints.

Examples

Endpoint

Static class conventional name (Handler-base)

public static class DetailGetEndpoint { public static void Configure(RouteHandlerBuilder eb) => eb.WithName("ProductDetail"); public static string Pattern => "/Detail/{id}"; public static string Handler(int id) { return $"Should return product with id: {id}"; } }

Interface (Handler-based)

public class ListApiEndpoint : IApiEndpoint { public void Configure(RouteHandlerBuilder eb) { eb .Produces(200) .Produces(404); } public string Pattern => "/list/index"; public Delegate Handler { get; } = (HttpContext c) => { return $"Hello from {nameof(ListApiEndpoint)}: {c.Request.Path}"; }; }

Registration based

public static class DetailArApiEndpoint { public static RouteHandlerBuilder Register(IEndpointRouteBuilder app) { return app .MapGet("/Detail/{id}", () => $"Should return product with id: {id}") .Produces(200); } }

Route patterns conventions

Endpoint name + FromRouteAttribute

public class DetailGetEndpoint { public Delegate Handler => (int id, object o, MyClass c, [FromRoute] int r, [FromRoute(Name = "param-s")] int s) => $"id: {id}"; }

creates app.MapGet("/detail1/{r}/{param-s}", <handler>)

Endpoint name (multiple word) + first primitive argument

public class ProductsDetailGetEndpoint { public Delegate Handler => (int id) => $"id: {id}"; }

creates app.MapGet("/products/info/{id}", <handler>)

Supported declarations

Handler method

• public Delegate Handler => (int id) => $"id: {id}";
• public string Handler(int id) => $"id: {id}";
• public static string Handler(int id) { return $"id: {id}"; }

Route Pattern property

• public string Pattern => "/detail/{id}";
• public string Pattern { get; } = "/detail/{id}";
• public string Pattern { get { return "/detail/{id}"; } }
• public string Pattern { get => "/detail/{id}"; }
• public static string Pattern => "/Detail/{id}"; same for static

Configure method

• public void Configure(RouteHandlerBuilder eb){ eb.Produces(200); }
• public string Configure(RouteHandlerBuilder eb) => eb.Produces(200);";
• public static string Configure => (RouteHandlerBuilder eb) => eb.Produces(200);