How to better organize the minimum web api code structure

Preface

We are 《.NET 6 Try out new features 》 In the said , As project requirements and complexity increase , Minimum size of a single file WEB API Will become very bloated .

and ,Program.cs You should only put the startup and initialization code . It should not contain too much MapXXX Method .

that , How to better organize the smallest WEB API What about the code structure ？

1. Static help class

You can move them into separate classes .

for example , You can create one called MinimalApiHelper And add static methods to it ：

public static class MinimalApiHelper
{
    public static void RegisterWeatherForecastAPIs(WebApplication app)
    {
        var summaries = new[]
        {
            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
        };

        app.MapGet("/weatherforecast", () =>
        {
            ......
        })
        .WithName("GetWeatherForecast");
    }
}

Program.cs Revised as follows :

......

app.UseHttpsRedirection();

MinimalApiHelper.RegisterWeatherForecastAPIs(app);

app.Run();

2. Extension method

Further more , You can create these static methods as WebApplication Class extension methods ：

public static void RegisterWeatherForecastAPIs(this WebApplication app)
{
    ......
}

You can simplify the calling code like this :

......

app.RegisterWeatherForecastAPIs();

app.Run();

3. Dependency injection

however , When there are a large number of services , You need to execute the registration code multiple times ：

app.RegisterService1APIs();
app.RegisterService2APIs();
......

We can use dependency injection to simplify registration code .

The implementation code is as follows :

public  static class MinimalApiExtentions
{
    public static void AddMinimalApiRegisters(this IServiceCollection services, params Type[] types)
    {
        var registers = new List<IMinimalApiRegister>();
        foreach (var type in types)
        {
            registers.AddRange(type.Assembly.GetTypes()
                .Where(x => typeof(IMinimalApiRegister).IsAssignableFrom(x) && !x.IsInterface && !x.IsAbstract)
                .Select(Activator.CreateInstance).Cast<IMinimalApiRegister>());
        }

        services.AddSingleton<IEnumerable<IMinimalApiRegister>>(registers);
    }

    public static void UseMinimalApiRegisters(this WebApplication app)
    {
        var registers = app.Services.GetRequiredService<IEnumerable<IMinimalApiRegister>>();

        foreach (var register in registers)
        {
            register.RegisterAPIs(app);
        }
    }
}

Program.cs Revised as follows :

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddMinimalApiRegisters(typeof(Program));

var app = builder.Build();
app.UseMinimalApiRegisters();
app.Run();

Traverse all of the in the assembly IMinimalApiRegister Implementation class , Then iterate through the calling implementation class RegisterAPIs Method .

The example implementation classes are as follows ：

public class Service1Register : IMinimalApiRegister
{ 
    public void RegisterAPIs(WebApplication app)
    {
        app.MapGet("/", () => "Hello My IO");
    }
}

Conclusion

today , We introduced how to organize the smallest WEB API The code structure .

If you have a better plan , Welcome to my official account. “My IO” Message discussion