Immediate.Apis

Immediate.Apis is a source generator for minimal APIs, for Immediate.Handlers handlers. Simply add a [MapGet] to the [Handler] class and an endpoint will automatically be added.

Examples

• Immediate.Apis.FunctionalTests

Installing Immediate.Apis

You can install Immediate.Apis with NuGet:

Install-Package Immediate.Apis

Or via the .NET Core command line interface:

dotnet add package Immediate.Apis

Either commands, from Package Manager Console or .NET Core CLI, will download and install Immediate.Handlers.

Using Immediate.Apis

Creating an Endpoint

Create a Handler and an endpoint by adding the following code:

[Handler]
[MapGet("/users")]
public static partial class GetUsersQuery
{
    public record Query;

    private static ValueTask<IEnumerable<User>> HandleAsync(
        Query _,
        UsersService usersService,
        CancellationToken token)
    {
        return usersService.GetUsers();
    }
}

Registering the endpoints

In your Program.cs, add a call to app.MapXxxEndpoints(), where Xxx is the shortened form of the project name.

• For a project named Web, it will be app.MapWebEndpoints()
• For a project named Application.Web, it will be app.MapApplicationWebEndpoints()

Customizing the endpoints

AsParameters

By default on POST and PUT requests Immediate.Apis will assume that your request class should be treated as a [FromBody]. Sometimes, however, this is not desired. For example imagine a PUT request that sits at a route /api/todos/{id} and updates a TODO with a given ID. We would want to get the id from the route and the properties to update from the body. To do so, we need to create the following request command class:

public sealed record Command
{
    public sealed record CommandBody
    {
        // props here;
    }
    
    [FromRoute]
    public required int Id { get; init; }
    
    [FromBody]
    public required CommandBody Body { get; init; }
}

...and modify the HandleAsync method to let Immediate.Apis know we want to treat the outer Command class as [AsParameters], like so:

private static async ValueTask<Results<NoContent, NotFound>> HandleAsync(
    [AsParameters] Command command,
    ExampleDbContext dbContext,
    CancellationToken ct
) 
{
    // ...
}

Authorization

The [AllowAnonymous] and [Authorized("Policy")] attributes are supported and will be applied to the endpoint.

[Handler]
[MapGet("/users")]
[AllowAnonymous]
public static partial class GetUsersQuery
{
    public record Query;

    private static ValueTask<IEnumerable<User>> HandleAsync(
        Query _,
        UsersService usersService,
        CancellationToken token)
    {
        return usersService.GetUsers();
    }
}

Additional Customization of Endpoint Registration

Additional customization of the endpoint registration can be done by adding a CustomizeEndpoint method.

[Handler]
[MapGet("/users")]
[Authorize(Policies.UserManagement)]
public static partial class GetUsersQuery
{
    internal static void CustomizeGetFeaturesEndpoint(IEndpointConventionBuilder endpoint)
        => endpoint
            .Produces<IEnumerable<User>>(StatusCodes.Status200OK)
            .ProducesValidationProblem()
            .ProducesProblem(StatusCodes.Status500InternalServerError)
            .WithTags(nameof(User));

    public record Query;

    private static ValueTask<IEnumerable<User>> HandleAsync(
        Query _,
        UsersService usersService,
        CancellationToken token)
    {
        return usersService.GetUsers();
    }
}

Transforming the handler result into a different type

In some cases, you may wish to transform the result of the handler into a different type; for example, you may wish to return a Results<> type which will work with asp.net core to return various status codes.

You can transform the result of your handler into a different type by adding a TransformResult method, like so:

[Handler]
[MapGet("/users")]
[Authorize(Policies.UserManagement)]
public static partial class GetUsersQuery
{
    internal static Results<Ok<IEnumerable<User>>, NotFound> TransformResult(IEnumerable<User> result)
    {
        return TypedResults.Ok(result);
    }

    public record Query;

    private static ValueTask<IEnumerable<User>> HandleAsync(
        Query _,
        UsersService usersService,
        CancellationToken token
    )
    {
        return usersService.GetUsers();
    }
}