How to use Nancy in ASP.NET Core

Nancy favors conventions over configuration and supports HTTP operations such as GET, HEAD, POST, PUT, DELETE, and PATCH.

Nancy is a web framework that operates independently of System.Web and other .NET libraries, and doesn't require adherence to the MVC pattern. It serves as a service endpoint responding to HTTP verbs, making it suitable for websites, APIs, and web services.

Nancy is host-agnostic, capable of running in various environments such as IIS, WCF, or as a self-hosted application. It is easy to set up, customize, and includes built-in support for dependency injection and a testing library for the request-response cycle.

To install Nancy, right-click your project in Solution Explorer, select "Manage NuGet packages...", search for Nancy, and install it.

Alternatively, use the NuGet Package Manager console with the command Install-Package Nancy.

After installation, configure Nancy by calling the UseNancy method in the Configure method of the Startup class.

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
     app.UseMvc();
     app.UseOwin(x => x.UseNancy());
}

Creating a Nancy module in ASP.NET Core

Now let's create a Nancy module and add some functionality. A Nancy module is a regular C# class that extends the NancyModule class from the Nancy framework.

public class HomeModule : NancyModule
{
}

Remember, the module must be marked as public for the Nancy framework to detect it.

In ASP.Net Core, routes are defined within the constructor of the module.

To define a route, you need to specify the HTTP verb, the route pattern, the action, and optionally, a condition.

public class HomeModule : NancyModule
{
    public HomeModule()
    {
       Get("/", args => "Welcome to the Home page.");
       Get("/{id:int}", args => GetItemById(args.id));
    }
}

A Nancy module serves as a place to define HTTP endpoints.

public class HomeModule : NancyModule
{
    public HomeModule()
    {
        Get("/", args => "Welcome to Nancy.");
        Get("/Test", args => "Test Message.");
        Get("/Hello", args => $"Hello {this.Request.Query["name"]}");
    }
}

Nancy is not only lightweight, modular, and fast, but it also makes installation and configuration simple.