MinimalWebAPI.md

Minimal Web API

This example demonstrates the creation of a Minimal Web API application in the pure DI paradigm using the Pure.DI code generator.

The composition setup file is Composition.cs:

using Pure.DI;
using Pure.DI.MS;
using static Pure.DI.Lifetime;

namespace MinimalWebAPI;

partial class Composition : ServiceProviderFactory<Composition>
{
    private void Setup() => DI.Setup()
        // Owned is used here to dispose of all disposable instances associated with the root.
        .Root<Owned<Program>>(nameof(Root))
        .Root<IClockViewModel>()

        .Bind().To<ClockViewModel>()
        .Bind().To<ClockModel>()
        .Bind().As(Singleton).To<Ticks>()

        // Infrastructure
        .Bind().To<MicrosoftLoggerAdapter<TT>>()
        .Bind().To<CurrentThreadDispatcher>();
}

The composition class inherits from ServiceProviderFactory<T>, where T is the composition class itself.

The web application entry point is in the Program.cs file:

using MinimalWebAPI;

using var composition = new Composition();
var builder = WebApplication.CreateBuilder(args);

// Uses Composition as an alternative IServiceProviderFactory
builder.Host.UseServiceProviderFactory(composition);

var app = builder.Build();

// Creates an application composition root of type `Owned<Program>`
using var root = composition.Root;
root.Value.Run(app);

partial class Program(
    IClockViewModel clock,
    IAppViewModel appModel)
{
    private void Run(WebApplication app)
    {
        app.MapGet("/", (
            // Dependencies can be injected here as well
            [FromServices] ILogger<Program> logger) => {
            logger.LogInformation("Start of request execution");
            return new ClockResult(appModel.Title, clock.Date, clock.Time);
        });

        app.Run();
    }
}

The project file looks like this:

<Project Sdk="Microsoft.NET.Sdk.Web">
    ...
    <ItemGroup>
        <PackageReference Include="Pure.DI" Version="2.3.6">
            <PrivateAssets>all</PrivateAssets>
            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
        </PackageReference>
        <PackageReference Include="Pure.DI.MS" Version="2.3.6" />
    </ItemGroup>

</Project>

It contains additional references to NuGet packages:

Pure.DI		DI source code generator
Pure.DI.MS		Add-ons for Pure.DI to work with Microsoft DI